Baisc Geological Mapping

8/13/2019 Baisc Geological Mapping

1/111

FIELD MEASUREMENTS AND TECHNIQUES

360

Figure 5.8 Plotting a bearing with a Silva type compass

as where the trace of bedd !" ca! be see! o! a c#ea$a"e %#a!e& These # !'eat o!s ca! ofte! be (eas)red (ore eas #* b* the r pitch +ra,e-. that s. thea!"#e the # !eat o! (a,es w th the str ,e of the s)rface o! wh ch t occ)rs+F ")re /& +a--& 1ro$ ded the str ,e a!d d % of the s)rface ha$e bee! (ea's)red. tre!d a!d %#)!"e ca! the! be ca#c)#ated o! a stereo"ra%h c !et& Lo"the a!"#e of % tch ! *o)r !oteboo, b* the c#oc,w se a!"#e so that there s!o a(b ") t* o$er ts d rect o! o! the s)rface +F ")re /& +b--& 1 tch ca! be(eas)red w th a co((o! tra!s%are!t %rotractor. the b ""er the better&

/&2& Meas)r !" # !eat o!sA#tho)"h so(e # !eat o!s ca! be (eas)red b* the r % tch o! a s)rface. (a!*()st be (eas)red d rect#* w th a co(%ass& So(et (es th s s s (%#e. as

46


Figure 5.9 The right-hand rule method for measuring and recording dip and strike

N

Tre!d

1#)!"e

Figure 5.10 The geometry of trend and plunge

44


2/111


3056/

3622

+b-

+a-

Figure 5.11 (a) Geometry of pitch on a lineated dip slope. (b) ecord pitchin your notebook by a diagram! record its angle together with the strike and dip of the surface it lies on

Figure 5.12 Stretched conglomerate pebbles in S" #ganda! trend and plungecan be measured directly

! the case of the stretched co!"#o(erate %ebb#es show! ! F ")re /& &A## that !eeds to be do!e s to sta!d abo$e the e7%os)re a!d (eas)re thetre!d $ert ca##* be#ow& 1#)!"e ca! the! be (eas)red b* co!tact or b* e!d'o! (ethods& D rect (eas)re(e!ts of tre!d a!d %#)!"e ca! a#so be (ade for # !eat o!s o! (oderate#* d %% !" s)rfaces b)t. as s)rfaces beco(e stee%er. ts !creas !"#* (ore d ff c)#t to (eas)re tre!d acc)rate#*& F ")re /& 3 showso!e wa* t ca! be do!e f *o)r co(%ass s s) tab#e& La* the ed"e of the

48


3/111


Figure 5.13 $easuring lineation on a steep surface using a compass with ahinged lid

co(%ass # d a#o!" the # !eat o!9 #e$e# the co(%ass case b* !ot !" whether the

co(%ass card or !eed#e oats hor :o!ta##* +so(e !str)(e!ts ha$e a c rc)#ar #e$e# b)bb#e-& If the co(%ass case s tr)#* hor :o!ta# the ed"e of the co(%ass()st. "eo(etr ca##*. # e ! the tre!d %#a!e& Read the bear !" for tre!d& 1#)!"es (eas)red b* d rect co!tact ! the tre!d %#a!e& ;er* ser o)s errors ! tre!d(a* ar se fro( (eas)re(e!ts (ere#*


4/111


5/111


Figure 5.15 & minor fold in Precambrian ('aragwe-&nkolean) sedimentaryrocks in S" #ganda. The ma or antiform closes to the * (to the right of the

photograph)

There s a! e7te!s $e ter( !o#o"* for the descr %t o! of fo#ds a!d before

"o !" !to the f e#d *o) are we## ad$ sed to read F#e)t*=s %a%er


6/111


Figure 5.16 &+ial-plane cleavage in ,evonikan slates at ombe $artin orth ,evon. orth is to the left of the photo

a! or e!tat o! a%%ro7 (ate#* %ara##e# to the a7 a# %#a!e of the fo#d a!d th s sa )sef)# too# whe! (a%% !" fo#d str)ct)res9 t )ses the re#at $e or e!tat o!sof bedd !" a!d c#ea$a"e +F ")re /& 6-& At o)tcro%s where both bedd !" a!dc#ea$a"e ca! be see!. (a,e a f e#d !oteboo, s,etch of the r d %s +F ")re /& 4-&Ho#d the !oteboo, )% to the o)tcro% a!d rotate t )!t # the c#ea$a"e a%%ears to

be $ert ca#& Bhe! th s s do!e. the d % d rect o! of the bedd !" ! the rotateddraw !" !d cates the d rect o! ! wh ch the !earest s*!for( s to be fo)!d&For e7a(%#e. f the rotated bedd !" d %s to the east. the !earest s*!for( s#ocated to the east of the e7%os)re& If s)ch obser$at o!s are (ade re%eated#*across a! area a!d recorded o! the (a%. #ar"e'sca#e a!t for(s a!d s*!for(sca! be (a%%ed o)t&

5.6 FaultsMost s(a##er fa)#ts !e$er "et (a%%ed beca)se the* are !e$er see!& Ma!*ha$e s)ch s(a## d s%#ace(e!ts that t (atters # tt#e f the* are !d $ d)a##*( ssed. b)t record those *o) do see ! *o)r !oteboo, to he#% *o) to estab# sha fract)re %atter!& Ma@or fa)#ts are (ore # ,e#* to be fo)!d. b)t e$e! thosew th d s%#ace(e!ts of te!s of (etres (a* be ( ssed where e7%os)res are

%oor& Co(%are the ()#t %# c t* of fa)#ts o! a coa#f e#d "eo#o" ca# (a% w th a(a% fro( a !o!'coa#bear !" area& The "ro)!d s %robab#* @)st as fa)#ted o!

8


7/111


Best East

edd !"

edd !" d %s E9s*!for( # es to Eof o)tcro%

Figure 5.17 $apping out fold structures from cleavage and bedding! makea notebook sketch of the dip hold it up to the outcrop and rotate until thecleavage appears to be vertical! the dip direction of the bedding now indicatesthe direction of the nearest synform

both (a%s. b)t ! the coa#f e#d the fa)#ts ha$e bee! detected )!der"ro)!d a!d %ro@ected to the s)rface& Ma!* fa)#ts ha$e to be (a%%ed b* !fere!ce& S)s%ecta fa)#t where there are )!acco)!tab#e cha!"es ! # tho#o"*9 where se?)e!cesare re%eated9 where str ,es of s%ec f c beds ca!!ot be %ro@ected to the !e7te7%os)re9 or where roc,s s)dde!#* beco(e a""* w th @o !t s%ac !" s)dde!#*decreas !" to a few ce!t (etres& To%o"ra%h* s ofte! a "ood ") de& Fa)#ts(a* res)#t ! s%r !" # !es. bo""* ho##ows. see%a"es. or ! se( 'ar d co)!tr esa # !e of ta##er "ree!er trees. a!,ed b* #ower at'to%%ed acac a& Howe$er.

beware9 a#tho)"h (ost fa)#t :o!es erode a # tt#e faster tha! the ad@ace!t roc,s.to for( #o!" t)d !a# de%ress o!s. so(e fa)#ts ! # (esto!es (a* for( #owr d"es ow !" to s# "ht s # c f cat o! wh ch he#%s to res st eros o!& Fa)#ts are(ost eas #* traced o! aer a# %hoto"ra%hs. where the $ert ca# e7a""erat o! of

83


8/111


to%o"ra%h* see! )!der a stereosco%e acce!t)ates those ( !or # !ear feat)resca##ed lineaments . feat)res ofte! d ff c)#t to f !d o! the "ro)!d9 (a!* of the(are %robab#* fa)#ts&

The se!se of d s%#ace(e!t of a fa)#t. that s. d st !") sh !" the dow!throw!s de. (a* beco(e e$ de!t o!#* b* !ot !" the d ffere!t strat "ra%h* o! each

s de of a fa)#t& I! te7tboo,s ()ch s (ade of s# c,e!s des. a!d f the* aresee! the* sho)#d be !oted. b)t do !ot %)t too ()ch fa th ! the(. the* (ere#*re ect the #ast %hase of (o$e(e!t& Most fa)#ts ha$e (o$ed se$era# t (es.a#tho)"h !ot a#wa*s ! the sa(e d rect o!& Note a#so that fa)#ts (a* ha$e ath c,!ess w de e!o)"h to show o! *o)r (a%& Fa)#ts (a* a#so be brecc a or "o)"e f ##ed. or e$e! ( !era# sed. %erha%s w th ca#c te or e$e! )or te& Notes)ch facts ! *o)r !oteboo,&

5.7 Thrusts and UnconformitiesThr)sts a!d )!co!for( t es are treated here to"ether beca)se o!e ca! eas'#* be ( sta,e! for the other& Lar"e thr)sts are )s)a##* ob$ o)s. w th o#der roc,s o$er#* !" *o)!"er o!es9 b)t !ot a## thr)sts show s)ch a c#ear re#at o!'sh %& So(et (es thr)st !" (a* be d sco$ered o!#* b* )!e7%ected cha!"es !strat "ra%h*& If the thr)st s)rface s !ot %ro%er#* e7%osed. the )%%er a!d the#ower


9/111


10/111


)% we## o! aer a# %hoto"ra%hs. es%ec a##* ! # (esto!e re" o!s where the*(a* be !d cated b* karst %atter!s a!d # !es of s !,ho#es + dolines -& >o !t

%atter!s o! %hoto"ra%hs ca! so(et (es be )sed to d st !") sh o!e for(at o!fro( a!other&

5.9 Map SymbolsThere are !ter!at o!a##* acce%ted "eo#o" ca# (a% s*(bo#s9 )!fort)!ate#*e$er* !at o!a# or"a! sat o! has ts ow! !ter%retat o! of the(& A short # st of the (a ! s*(bo#s s %r !ted o! the !s de bac, co$er of th s boo,& er,(a!+ 00 - " $es a co(%rehe!s $e # st s%read o$er (a!* %a"es wh ch ()st co$er

%ract ca##* e$er* "eo#o" ca# %oss b # t*& Note. a str ,e # !e s draw! o! a (a% w th ts centre at the %o !t where the

read !" was ta,e!& The %o !t of a # !eat o! arrow head s the %o !t wherethat read !" was (ade& The e7ce%t o! s where se$era# read !"s are (ade at

o!e %o !t ! that case the s*(bo#s rad ate fro( the obser$at o! %o !t&

5. ! Specimen "ollectin#Co##ect re%rese!tat $e s%ec (e!s of e$er* for(at o! a!d roc, t*%e *o) showo! *o)r (a%& fte!. se$era# s%ec (e!s of the sa(e for(at o! are !eededf t $ar es ! co(%os t o! o$er the re" o!& E$e! f t does !ot $ar*. *o)(a* !eed s%ec (e!s fro( d ffere!t %arts to %ro$e that t does !ot& So(e$ar at o!s ! co(%os t o! (a* !ot. of co)rse. be ob$ o)s ! a ha!d s%ec (e!so e7tra s%ec (e!s are !eeded as a safe")ard& The s :e of s%ec (e! *o)co##ect ()st de%e!d o! the %)r%ose *o) w sh to %)t t to. !ot o! what *o)th !, *o) ca! carr*& See *o)r roc, c)tter before *o) "o !to the f e#d to f !do)t what he !eeds for th !'sect o! !"& Bhe!e$er %oss b#e. choose s%ec (e!sshow !" both weathered a!d )!weathered s)rfaces a!d f !ecessar* co##ecttwo s%ec (e!s to show both as%ects& Do !ot co##ect @)st a!* % ece of roc, *o) ca! ,!oc, off a! e7%os)re w th *o)r ha((er& The eas est % ece to brea, off (a* !ot be re%rese!tat $e of the e7%os)re as a who#e& o) (a* ha$eto s%e!d co!s derab#e t (e ! brea, !" o)t a "ood s%ec (e! w th ha((er a!d ch se#&

Ha$ !" bro,e! off a s%ec (e!. tr ( t& Mar, sed (e!tar* roc, s%ec (e!sto show wh ch s the r to%& Meta(or%h c s%ec (e!s (a* !eed to be or e!tedso that d rect o!a# th !'sect o!s ca! be c)t9 e ther (ar, the str ,e a!d d %d rect o!s o! the roc, w th a (ar,er %e! before *o) brea, t off. or f t t

bac, !to %#ace a!d (ar, t after brea, !" t off a!d record whether to% or botto( s)rface& M)ch de%e!ds o! the o)tcro% tse#f&

/& 0& Mar, !" s%ec (e!sS%ec (e!s are best (ar,ed w th a water%roof fe#t't %%ed %e!. or for dar, roc,s w th e ther a *e##ow t (ber cra*o! or a !)(bered % ece of s)r" ca#

86


11/111


st c, !" %#aster& Bra% each s%ec (e! ! !ews%a%er to %rotect t fro( br) s !"! *o)r r)c,sac,. a!d !c de!ta##* to %rotect *o)r r)c,sac, too& I! ca(%.scr)b *o)r s%ec (e!s a!d dr* the(. add a s%ot of wh te %a !t. a!d whe! thats dr* !)(ber t w th b#ac, %a !t. or w th a f !e b#ac, (ar,er9 do !ot )seI!d a! !, as t r)bs off too eas #*& Re'wra% the s%ec (e!s ! !ews%a%er a!d

!)(ber each %ac,et o! the o)ts de w th a fe#t't %%ed (ar,er so that *o) ca!eas #* #ocate a!* s%ec (e! *o) ( "ht w sh to #oo, at a"a !. w tho)t ha$ !"to )!wra% ha#f a do:e! others to f !d t&

/& 0& Foss #sSo(e foss #s are eas* to re(o$e fro( the r %are!t roc,. others are !ot& Ma!*are dee%#* e(bedded w th o!#* a s(a## %ort o! show !"9 scra%e awa* e!o)"hroc, w th a ,! fe to see whether the s%ec (e! s worth co##ect !". a!d f sothe! brea, o)t the roc, co!ta ! !" t& Ma!* foss #s are casts or (%ress o!s !

the roc,9 a"a ! co##ect the % ece of roc, co!ta ! !" the(& Bhere$er %oss b#eco##ect both e7ter!a# a!d !ter!a# casts both are (%orta!t& So(et (es *o)(a* ha$e to co##ect se$era# , #o"ra(s of foss # fero)s roc, so that !d $ d')a# foss #s ca! be e7tracted ! the #aborator*& Th s s %art c)#ar#* so where( cro'foss #s are !eeded& Mar, a## s%ec (e!s w th the wa* )% ! wh ch the*were fo)!d&

1ac, de# cate s%ec (e!s ! bo7es or t !s a!d %ad the( w th cotto! woo#.t ss)e %a%er or !ews%a%er. or )se e7%a!ded %o#*st*re!e ce # !" t #es c)t tof t the bo7es& Use "rass f there s !oth !" e#se& Carr* a se#ect o! of bo7es.fro( (atchbo7 )%wards ! s :e& Bra% !o!'fra" #e s%ec (e!s ! !ews%a%er a!d treat the( ! the sa(e wa* as roc, s%ec (e!s&

As w th roc, s%ec (e!s. do !ot co##ect (ore tha! *o) !eed9 do !ot c#ea!o)t a "ood #oca# t* to se## to dea#ers a!d re%ort a!*bod* *o) see do !" so.a!d th s a%%# es e?)a##* for ( !era# #oca# t es&

/& 0&3 oo, !" s%ec (e!sLo" s%ec (e!s ! *o)r !oteboo, ((ed ate#* after *o) ha$e co##ected the(&1referab#*. wr te the s%ec (e! !)(bers ! the #eft'ha!d (ar" ! of the %a"eso that the r deta #s ca! be re#ocated eas #*& If the r !)(bers are wr tte! w thred %e!c #. the* ca! be e$e! (ore eas #* d st !") shed fro( f e#d obser$a't o! !)(bers # sted ! the sa(e co#)(!& A#ter!at $e#*. f *o) are co##ect !"#ar"e !)(bers of s%ec (e!s. add a co#)(! to *o)r !oteboo, s%ec f ca##* for s%ec (e! !)(bers& I! add t o! to #o"" !" s%ec (e!s o! the wor, !" %a"esof *o)r !oteboo,. re" ster the( w th a br ef descr %t o! ! a s%ec f c !de7 atthe bac, of *o)r !oteboo, too& Th s a$o ds f !d !" *o)rse#f w th two a#(ostde!t ca# s%ec (e!s fro( d ffere!t %#aces w th the sa(e !)(ber. a!d !o wa*to te## wh ch s wh ch& A re" ster a#so he#%s *o) to e!s)re that *o) ha$eco##ected s%ec (e!s of e$er*th !" *o) sho)#d ha$e co##ected. a!d f *o) " $e

84


12/111


Figure 5.19 & specimen register in a field notebook

the !oteboo, %a"e !)(bers where the* are (ore f)##* descr bed. t acts as aha!d* read*'refere!ce +F ")re /& -&

/& 0&2 Sh %% !" s%ec (e!sGeo#o" ca# s%ec (e!s are hea$* a!d f sh %%ed ! a bo7 wh ch s too #ar"eca! o!#* be acce%ted as fre "ht& S(a##er bo7es. wh ch o!e (a! ca! # ft

88


13/111


eas #*. ca! "o ()ch (ore ?) c,#* b* %asse!"er tra!s%ort& A bo7 abo)t / 30 / c( (ade of t (ber abo)t c( th c,. batte!ed a!d stee# ba!ded.s acce%tab#e b* TIR. ra #wa* %asse!"er ser$ ces a!d a r# !es& Stee# s(a##'ar(s a(()! t o! bo7es (a,e dea# co!ta !ers too. f *o) ca! f !d the( !a @)!, sho%& Mar, *o)r !a(e a!d address o! to% a!d o! at #east o!e s de.

a!d add R C S1ECIMENS F R SCIENTIFIC RESEARCH& Ne$er wr te


14/111


otherw se *o) (a* e!d scratch !" *o)r head a!d wo!der !" wh* o! earth*o) e$er too, so(e %hoto"ra%hs&

/& & D " ta# ca(erasD " ta# ca(eras are beco( !" %o%)#ar for "eo#o" ca# )se a!d ha$e se$era#

ad$a!ta"es o$er f #( ca(eras ! the f e#d& F rst a!d fore(ost. beca)se the(a"e s stored e#ectro! ca##*. the % ct)re ca! be (a! %)#ated ! ter(s of ts

%ro%ert es. s)ch as s :e. br "ht!ess. co!trast. etc& !ce (od f ed to e!ha!cethe feat)re be !" recorded. the (a"e ca! be %asted d rect#* !to the co(%)ter f #e co!ta ! !" *o)r re%ort or d ssertat o!& So(e ca(eras ca! ! add t o!co!str)ct a (osa c a)to(at ca##* fro( a ser es of o$er#a%% !" % ct)res& Th s s)sef)# for record !" %a!ora(as& A#so (%orta!t s that a! ((ed ate %re$ ewof the shot s " $e!. a##ow !" a chec, to be (ade o! ts s)ccess. before(o$ !" o! to the !e7t #oca# t*&

Tech!o#o" ca# de$e#o%(e!ts (ea! that so(e of the d sad$a!ta"es of d "'ta# %hoto"ra%h* are ra% d#* be !" o$erco(e& For a " $e! s%ec f cat o! thecost of b)* !" a d " ta# ca(era s fa## !". a!d a#tho)"h st ## (ore e7%e!'s $e tha! a trad t o!a# f #( ca(era. th s s offset ! that !o de$e#o% !"costs are !$o#$ed& The (ore e7%e!s $e ca(eras ta,e h "h'reso#)t o! (a"eswh ch s)r$ $e e!#ar"e(e!t w tho)t beco( !" b#oc,* +% 7e#*- ! te7t)re& For f e#dwor, the st)rd !ess of d " ta# ca(eras re(a !s a co!s derat o!9 # ,e a##e#ectro! c !str)(e!ts the* do !ot # ,e (o st)re. a!d sea water s fata#&

The stora"e of (a"es ca! a#so %ose a %rob#e( for f e#dwor,& De%e!d !"o! the (e(or* ca%ab # t es of the ca(era. a!d the reso#)t o! chose! for the(a"es. there s a # ( t to the !)(ber of % ct)res that the ca(era ca! store&Howe$er f *o) ha$e access to a #a%to% co(%)ter at base ca(%. *o) w ## beab#e to dow!#oad the (a"es a!d free the ca(era=s (e(or* for f)rther wor,&F !a##*. re(e(ber that d " ta# ca(eras are hea$* o! batter es9 d s%osab#e

batter es for a f e#d seaso! wo)#d be a s "! f ca!t cost. so co!s der whether rechar"eab#e batter es co)#d be )sed&

5. % $annin#To be ab#e to )se a "o#d %a! s a )sef)# acco(%# sh(e!t for a "eo#o" st&It !eeds # tt#e %ract ce& Go#d a!d cass ter te ca! be %a!!ed fro( strea(s.

b)t (a!* roc, ( !era#s wh ch s)r$ $e eros o! ca! be co!ce!trated b* %a!'! !" too& These !c#)de "ar!et. r)t #e. : rco!. e% dote. (o!a: te. (a"!et te.hae(at te a!d #(e! te& D ffere!ces ! the


15/111


Bater s)rface

To% of f !er r $er A##)$ )(Sa!ds

Gra$e#sCobb#es

o)#ders

Hea$*'( !era# sa!ds

edroc, w th hea$*sa!ds ! crac,s

Figure 5.20 & simplified profile through stream gravels! the heavy-mineral sands accumulate at the base of the coarser material and may even penetratecracks in the bed rock. ote that the sands and gravels of the stream are in con-

stant movement which allows the 1heavies2 to pass downwards through them

# tt#e de!ser tha! sa!d a!d roc, debr s +SG &4- a!d (ore s, ## s !eeded toco!ce!trate the(& A 30 c( d a(eter %a! s s)ff c e!t for %)re#* "eo#o" ca#

%)r%oses& ee% t s%ot#ess a!d free fro( r)st a!d "rease. so do !ot )se tas a ca(% fr* !" %a!& Co##ect stream gravel fro( the coarsest (ater a# *o)ca! f !d. for that s where the hea$ er ( !era#s co!ce!trate +F ")re /& 0-&D " for t w th a trowe# or e!tre!ch !" too# a!d "et dow! to bedroc, f

%oss b#e& Co##ect soils fro( be#ow the h)()s& Hea% the %a! f)## of (ater a#.the! sha,e t $ "oro)s#* )!derwater ! a strea(. or e$e! ! a t ! bath& Thef !er hea$ es w ## %ass dow! thro)"h the coarser # "ht (ater a#. a %rocess,!ow! to the ( !era# dresser as igging +a!d th s s what. w th the co!sta!t(o$e(e!t of strea( "ra$e#s. he#%s to co!ce!trate the


16/111


Figure 5.21 & geologist panning in the *uphrates valley

)!der a co$er of a # tt#e water. de!t f* a!* ( !era#s *o) ca!. )s !" *o)r ha!d #e!s& Bash the co!ce!trates !to a %h a# for f)t)re e7a( !at o!. )s !"a %#ast c f)!!e# a!d a ca(e#'ha r br)sh& Labe# t& Deca!t the s)r%#)s water

bac, ! ca(%& 1a!! !" s # ,e f sh !" *o) do !ot ha$e to f !d a!*th !" toe!@o* t&


17/111

6R C S. F SSILS AND RES

Th s cha%ter ass)(es that readers are a#read* fa( # ar w th s*ste(at c (eth'ods of roc, !a( !" ! the #aborator*. ,!ow bas c %a#aeo!to#o"* a!d ca!reco"! se the ( !era# (ater a#s (e!t o!ed& Here *o) are to#d how to a%%#*that ,!ow#ed"e ! the f e#d&

6. &oc' (escriptionsBhe! *o) ha$e (a%%ed a roc, )! t for #o!" e!o)"h to be fa( # ar w tht a!d ts $ar at o!s. descr be t f)##* a!d s*ste(at ca##* ! *o)r !oteboo,&

Roc, descr %t o!s are esse!t a# whe! *o) co(e to wr te *o)r re%ort #ater&A roc, descr %t o! (ade fro( (e(or*. %erha%s wee,s #ater. s )!# ,e#* to

be acc)rate or co(%#ete& !e (ade ! the f e#d descr bes the roc, as see!.w th (eas)re(e!ts of s%ec f c feat)res. a!d fact)a# co((e!ts o! those s)bt#echaracter st cs that are (%oss b#e to re(e(ber %ro%er#* #ater& It a#so e!s)resthat *o) record all the deta #s !eeded&

S*ste(at ca##* descr be each roc, )! t show! o! *o)r (a% ! t)r!& 1refer'ab#* wor, fro( the "e!era# to the %art c)#ar& Descr be f rst the a%%eara!ce of the "ro)!d t co$ers ts to%o"ra%h*. ts $e"etat o!. #a!d )se. a!d a!* eco'

!o( c act $ t* assoc ated w th t& If the so #s are d st !ct $e. descr be the(too& Ne7t descr be the roc, e7%os)res the(se#$es the r s :e fre?)e!c* a!dsha%e9 whether the* are t)rt#ebac,s. %a$e(e!ts. or tors9 or ro)!ded or @a""edr d"es. "e!t#e scar%s or c# ffs& Co((e!t o! @o !t s%ac !". bedd !" a!d #a( !a't o!s +see A%%e!d 7 ;-. str)ct)res. te7t)res. c#ea$a"e a!d fo# at o!& S)%%ort*o)r obser$at o!s w th measurements & Descr be the co#o)r of the roc, o!

both weathered a!d fresh#* bro,e! s)rfaces& Beather !" ofte! e(%has seste7t)res9 !ote ts effect. s)ch as the ho!e*co(b of ?)art: #eft o! the s)rfaceof "ra! tes after fe#ds%ars ha$e bee! #eached awa*. wh ch ((ed ate#* d s't !") shes s # c c fro( #ess s # c c $ar et es& F !a##* descr be the feat)res see!! a ha!d s%ec (e!. both w th a!d w tho)t a ha!d #e!s& Note te7t)re. "ra !'s :e a!d the re#at o!sh % betwee! "ra !s& Ide!t f* the ( !era#s a!d est (atethe r re#at $e ?)a!t t es +A%%e!d 7 ;. F ")re A;& -. bear !" ! ( !d the te!'de!c* to o$er'est (ate the %ro%ort o! of dar, ( !era#s o$er %a#er $ar et es&

Na(e the roc,& Bhere a%%ro%r ate. %re%are a sed (e!tar* sect o! a!d5or #o"+Sect o!s 6&3& a!d 6&3&3-& A formation letter(s) w ## e$e!t)a##* be ass "!ed to

3asic Geological $apping 4ourth *dition & >oh! B& ar!es w th R chard >& L s#e002 >oh! B #e* K So!s. Ltd IS N 0'240'82 86'

3


18/111

R C S. F SSILS AND RES

e$er* (a%%ab#e roc, )! t. b)t that s so(eth !" to be do!e #ater& Re(e(ber.*o) ca! ta,e a s%ec (e! ho(e w th *o). b)t !ot a! e7%os)re& E!s)re that*o) do ha$e a## the !for(at o! *o) !eed before *o) #ea$e the f e#d&

6.% )dentifyin# and *amin# &oc's in the FieldThere are two %rob#e(s here& The f rst s to f !d o)t what the roc, s !

%etro"ra%h c ter(s. the seco!d to " $e t a! de!t f* !" !a(e to )se o! *o)r fa r co%* (a% a!d ! *o)r re%ort& The f rst s the field name . the seco!d the

formation name &

6& & F e#d !a(esA f e#d !a(e sho)#d be descr %t $e& It sho)#d sa* s)cc !ct#* what the roc, s. b)t *o) ca!!ot !a(e a roc, )!t # *o) ha$e de!t f ed t& A f e#d "eo#o" stsho)#d be ab#e to deter( !e the te7t)re. the re#at o!sh % betwee! ( !era#s. a!dest (ate the r re#at $e ab)!da!ces ! (ost roc,s )!der a ha!d #e!s& He sho)#d

be ab#e to d st !") sh %#a" oc#ase fro( orthoc#ase. a!d a)" te fro( hor!b#e!de! a## b)t the f !er'"ra !ed roc,s& He sho)#d be ab#e to " $e so(e sort of f e#d!a(e to a!* roc,& D etr ch a!d S, !!er=s ocks and ock $inerals + 4 -s a! e7ce##e!t ") de to de!t f* !" roc,s w tho)t a ( crosco%e&

A f e#d !a(e sho)#d !d cate str)ct)re. te7t)re. "ra !'s :e. co#o)r. ( !era#co!te!t a!d the "e!era# c#ass f cat o! the roc, fa##s !to. e&"& thin-bedded

fine-grained buff sandstone a!d porphyritic medium-grained red muscovite granite & These are the f)## f e#d !a(es b)t shorte!ed $ers o!s. or e$e! ! t a#s.ca! be )sed o! *o)r f e#d (a%& A$o d at a## costs ca## !" *o)r roc,s. A. .C. etc&. o! the ass)(%t o! that *o) ca! !a(e the( %ro%er#* ! the #aborator*#ater th s s the coward=s wa* o)t& If *o) are rea##* st)c, for a !a(e. a!dw th the f !er'"ra !ed roc,s t does ha%%e!. the! ca## t spotted green rock .or e$e! red-spotted green rock to d st !") sh t fro( white-spotted green rock .f !eed be& E!s)re. howe$er. that *o) ha$e a t*%e s%ec (e! of e$er* roc, !a(ed& So(et (es *o) (a* f !d t he#%s to carr* s(a## ch %s aro)!d w th*o) ! the f e#d. for co(%ar so!&

6.+ ,itho-strati#raphy and Sedimentary &oc's

I! the %re$ o)s sect o! the word for(at o! has bee! )sed ! a $er* "e!era#se!se for a (a%%ab#e roc, )! t as a (atter of co!$e! e!ce. a!d for the #ac, of a better word& Howe$er. for for(a# )se there s a! acce%ted co!$e!t o!a## tho'strat "ra%h ca# h erarch* of ter(s to descr be the "ro)% !" of roc, )! ts+Ho##a!d et al & 48. %& 8-& These are descr bed as

s)%er"ro)%"ro)%

for(at o!(e(ber

bed

2


19/111


6&3& Sed (e!tar* for(at o!sA sed (e!tar* formation has !ter!a# # tho#o" ca# ho(o"e!e t*. or d st !ct $e# tho#o" ca# feat)res that co!st t)te a for( of )! t* ! co(%ar so! w th ad@a'ce!t strata& It s the bas c #oca# (a%%ab#e )! t& It cro%s o)t a!d ca! be traceds)b's)rface to other e7%os)res9 *o) show t o! *o)r (a% w th a d st !ct $e

co#o)r& It s the %r (ar* #oca# )! t +Ho##a!d et al & 48-& 4or convenience it may be sub-divided into members & If a for(at o! has !ot a#read* bee! for'(a##* !a(ed. !a(e t *o)rse#f ! the a%%ro$ed (a!!er. attach !" a %#ace!a(e to the roc, !a(e. e&"& asterbridge 0imestone 4ormation .orforwor,'!" %)r%oses @)st ca## t the asterbridge 0imestone & A$o d ter(s. s)ch as"hite 0imestone or 3rachiopod 3ed & Estab# sh a t*%e sect o! for e$er* !a(edfor(at o! for refere!ce or co(%ar so! ! case %rob#e(s ar se& See the Geo'#o" ca# Soc et* of Lo!do! ") de + 4 - o! the s)b@ect& The US Geo#o" ca#S)r$e* offers s ( #ar ad$ ce +Cohee 6 -&

& formation (a* co!s st of se$era# members . wh ch (a* !ot be co!t !)o)s b)t ha$e a d st !ct # tho#o" ca# character& The s(a##est d $ s o! of a for(at o!

s a bed . wh ch s a )! t w th a we##'(ar,ed d ffere!ce fro( the strata bothabo$e a!d be#ow t&

A group co!s sts of two or (ore !at)ra##* re#ated for(at o!s& A super- group co!s sts of two or (ore assoc ated "ro)%s& Gro)%s do !ot ha$e to beco##ected !to s)%er"ro)%s&

6&3& Strat "ra%h c sect o!sStrat "ra%h c sect o!s show the se?)e!ce of roc,s ! a (a%%ed re" o!. d s't !") sh !" a!d !a( !" the for(at o!s a!d (e(bers that co(%r se the(&The* show the th c,!ess of the )! ts. the re#at o!sh %s betwee! the(. a!*)!co!for( t es or brea,s ! s)ccess o!. a!d the foss #s fo)!d& It s (%oss '

b#e to f !d o!e co!t !)o)s e7%os)re that w ## e7h b t the co(%#ete s)ccess o!of a re" o! +e$e! ! the Gra!d Ca!*o!- a!d a co(%#ete s)ccess o! s b) #t)% fro( a !)(ber of o$er#a%% !" %art a# sect o!s& There (a* e$e! be "a%swhere for(at o!s are !co(%#ete#* e7%osed&

Sect o!s ca! be (eas)red ! a !)(ber of d ffere!t wa*s a!d so(e ") de'# !es are " $e! here& The f rst tas, s to f !d a s) tab#e %#ace w th "oode7%os)re& Ma,e (eas)re(e!ts of the tr)e th c,!esses of the beds. start !" atthe base of the se?)e!ce. a!d #o" the( ! *o)r !oteboo, as a $ert ca# co#)(!&I! (eas)r !" th c,!ess. correct o!s ()st be (ade for the d % of the beds a!dthe s#o%e of the s)rface o! wh ch the* cro% o)t& Th s ca! be do!e "ra%h ca##*or tr "!o(etr ca##* +F ")re 6& -& Co(%to! + 66- ##)strates se$era# (ethodsof (eas)r !" tr)e th c,!ess d rect#*&

I!d cate o! the strat "ra%h ca# sect o! the !a(e a!d e7te!t of e$er* # tho'#o" ca# )! t. to"ether w th the roc, t*%es w th ! t& Ta,e s%ec (e!s of e$er*'th !" #o""ed& Mar, a!d !ote the !a(es of a!* foss #s fo)!d9 co##ect s%ec (e!s

/


20/111


C A

a b 0

Figure 6.1 orrecting for the true thickness of a bed. The stratigraphic thick-ness &3 & s ! (a 5)

for #ater de!t f cat o! where !ecessar*& Note the %os t o! of e$er* sect o!o! *o)r f e#d (a%& Redraw to sca#e ! ca(% the sect o!s fro( *o)r !oteboo, o! s?)ared %a%er& Later the sect o! (a* be s (%# f ed a!d co(b !ed w thsect o!s fro( other %arts of *o)r (a%% !" area as a co#)(!ar sect o! or a fe!ce d a"ra( +Sect o!s & &6 a!d &3&2-& Strat "ra%h c sect o!s (a* a#so!c#)de "!eo)s a!d (eta(or%h c roc,s&

6&3&3 Sed (e!tar* +"ra%h c- #o"sA#tho)"h there are s ( #ar t es. sed (e!tar* #o"s a!d strat "ra%h c sect o!sd ffer ! the r %)r%oses& Sed (e!tar* #o"s are deta #ed "ra%h c d s%#a*s of the # tho#o" es. sed (e!tar* str)ct)res. a!d the fa)!a of a s)ccess o!& Thes)ccess o! s bro,e! dow! !to ho(o"e!eo)s )! ts ter(ed sedimentary facieswh ch co!ta ! d st !ct $e co(b !at o!s of feat)res& The (a!!er of de%os t o!of a )! t ca! be !ferred fro( ts fac es. a!d the o$era## e!$ ro!(e!t of de%os t o! fro( ts $ert ca# a!d #atera# $ar at o!s& There are a !)(ber of co!$e!t o!s ! record !" #o"s& As w th strat "ra%h c sect o!s. the th c,!ess

of beds s show! to sca#e ! a $ert ca# co#)(!& Howe$er. ! a sed (e!tar*#o" there s a#so a hor :o!ta# sca#e the w dth of the co#)(! s a (eas)reof the "ra ! s :e of each roc, )! t %ortra*ed +F ")re 6& -& S*(bo#s are )sedto !d cate a w de $ar et* of sed (e!tar* feat)res. s)ch as d ffere!t for(s

Figure 6.2 & graphic sedimentary log. The hori6ontal scale is a measure of grain-si6e. ,ivisions are une7ual because the f -scale range for silt is only four fifths that for sand (see &ppendi+ 8). The vertical triangles to the right indicate coarsening and fining in the se7uence (from orth "ales courtesy of

&. . Gardiner) (facing page)

6


21/111


4


22/111


of r %%#es. cross'bedd !". root#ets a!d ()d' a,es& So far !o co!$e!t o! of s*(bo#s has bee! )! $ersa##* acce%ted& De$ se *o)r ow! ! a for( wh ch(a,es the( eas* to )!dersta!d&

Choose a s te for a sed (e!tar* #o" as for a strat "ra%h c sect o!& Meas)rethe th c,!ess of each # tho#o" ca# )! t a!d record ts sed (e!to#o" ca# feat)res

! *o)r !oteboo,& Ta,e s%ec a# !ote of the bo)!dar es betwee! )! ts. &e&whether the* are eros $e. shar% or "radat o!a#. a!d see whether there area!* #atera# $ar at o!s& Draw #o"s before #ea$ !" the f e#d so that a!* "a%s! *o)r !oteboo, !for(at o! ca! be de!t f ed a!d rect f ed& T)c,er + 6-" $es f)## deta #s&

6&3&2 Ba*')% of beds

S*(bo#s !d cat !" wh ch wa* beds


23/111


too !d)rated. the c#a* ( !era#s w ## ha$e bee! a#tered to !ew ( !era#s& ther roc,s. !a(e#* those wh ch o!ce had a h "h or"a! c co!te!t. e( t a s)#%h)ro)ss(e## whe! h t w th a ha((er& Iro! sta ! !" !d cates a! ro! ce(e!t&

6&3&4 Hard!ess

A#wa*s test a $er* f !e'"ra !ed or a%%are!t#* "ra !#ess roc, b* scra% !" the %o !t of *o)r ha((er across t& If t scratches. t s %robab#* a sed (e!tar*roc,. f !ot t (a* be a chert or hor!fe#s. or a! "!eo)s or %*roc#ast c roc,&So(e wh te. crea( or "re* roc,s. ca! be scratched w th *o)r f !"er!a #& The*are %robab#* "*%s)( or a!h*dr te9 %oss b#* e$e! roc, sa#t. b)t o!e # c, ca!sett#e thatO

6&3&8 Ac dE$er* "eo#o" st sho)#d carr* a s(a## bott#e of 0P h*droch#or c ac d ! the

f e#d& To )se t. brea, off a fresh % ece of roc,. blow off any rock dust .a!dadd one dro% of ac d& If the react o! s $ "oro)s. the roc, s limestone &If tdoes !ot f ::. scra%e )% a s(a## hea% of roc, %owder w th *o)r ,! fe a!d adda!other dro% of ac d to t& Ge!t#e react o! !d cates dolomite & Ma!* carbo!ateroc,s co!ta ! both ca#c te a!d do#o( te. so co##ect s%ec (e!s for sta ! !"whe! *o) ret)r! to base& Re(e(ber. howe$er. that so(e rarer carbo!atesreact to ac d too& Do !ote that o!e dro% of ac d s e!o)"h to test for react o!s&Do !ot ood the s)rface w th t. a## *o) !eed s a $er* s(a## %#ast c bott#e.the t*%e )sed for e*e'dro%s&

6. FossilsFoss #s ca!!ot be co!s dered ! so#at o! fro( the r e!$ ro!(e!t& A## thefeat)res fo)!d ! a foss # fero)s roc, ()st be recorded f *o) are to "a ! thef)## be!ef t fro( the foss # tse#f& Note the r ab)!da!ce ! each foss # fero)shor :o! of the #oca# t*& Are the* w des%read or c#)stered ! "ro)%s D d thefoss #s d e where fo)!d or were the* tra!s%orted there after death Do the*show a# "!(e!ts d)e to c)rre!ts D ffere!t foss #s (a* occ)r ! d ffere!t %artsof the sa(e hor :o! a!d there (a* be #atera# cha!"es that ca! be traced o$er co!s derab#e d sta!ces. !d cat !" a cha!" !" e!$ ro!(e!t& There (a* a#so bea $ert ca# cha!"e as the de%th of water the roc,s were de%os ted ! cha!"ed&A## th s ()st be recorded ! *o)r !oteboo,. e ther o! a (eas)red sect o! or.f the occ)rre!ce s s) tab#e. o! a strat "ra%h c sect o! or "ra%h c #o"&

Do !ot be o$er'a!7 o)s to co##ect a foss # whe! *o) f !d t& F rst st)d* t ! %#ace. !ot !" ts att t)de a!d s)rro)!d !"s (a,e !otes a!d s,etches& 1robab#**o) w ## see o!#* a s(a## %art of the foss #. %erha%s beca)se o!#* a s(a## %artof t s e7%osed. or beca)se o!#* s(a## fra"(e!ts occ)r& Dec de how best tore(o$e t fro( the roc,. the! re(o$e the s%ec (e! caref)##*. tr* !" to ,ee%t !tact& Use a ch se# or e$e! scra%e aro)!d t w th *o)r ,! fe& So(et (es


24/111


t s better to re(o$e a #ar"e % ece of roc, a!d carr* t aro)!d a## da*. tha!to be too a(b t o)s ! tr* !" to e7tract a s%ec (e! ! the f e#d& If *o) f !d awho#e foss #. o!e s%ec (e! of that s%ec es w ## %robab#* be e!o)"h9 #ea$e therest for others& Us)a##*. howe$er. *o) w ## o!#* be ab#e to co##ect !co(%#etes%ec (e!s& So(e (a* show e7ter!a# feat)res. so(e !ter!a# casts& Co##ect

both& As w th roc,s. !a(e foss #s ! the f e#d b)t before "o !" !to the f e#d.refer to the t*%es *o) (a* e7%ect to see ! the roc,s *o) w ## be #oo, !" at&Do !ot be d sco)ra"ed f *o) ca!!ot !a(e ! deta # e$er* foss # *o) f !d&E7%ert he#% s ofte! !eeded&

!ce *o) ha$e d sco$ered a se?)e!ce co!ta ! !" s%ec f c foss #s ! o!e %art of *o)r (a%% !" area. *o) (a* the! f !d that *o) ca! )se t for (a%% !"o! a w der bas s. es%ec a##* where *o) ha$e a ser es of re%eated se?)e!ces or c*c#othe(s& The foss #s w ## te## *o) wh ch %art of the ser es *o) are !& A"a !.where *o) ha$e beds of "reat th c,!ess. *o)r foss # fero)s hor :o! w ## te##

*o) where ! that bed *o) are& It ca! e$e! te## *o) the d s%#ace(e!t. where both s des of a fa)#t are ! the sa(e roc, t*%e& Mar, r ch. or (%orta!t. foss ##oca# t es o! *o)r (a% w th a s*(bo#. so that others ca! f !d the( a"a ! #ater&

6.5 $haneritic )#neous &oc's1ha!er t c "!eo)s roc,s are eas #* reco"! sed a!d the ac d to !ter(ed ate+#e)cocrat c- $ar et es ca! )s)a##* be read #* !a(ed& Dar,'co#o)red +(e#a!o'crat c- %ha!er tes are %erha%s a # tt#e (ore d ff c)#t to de!t f*. b)t *o) ca!)s)a##* %)t so(e f e#d !a(e to the( wh ch s !ear#* correct& efore *o) "o!to the f e#d. tr* to #oo, at s%ec (e!s of the t*%es of roc, *o) e7%ect toe!co)!ter9 f %oss b#e. those fro( the area *o) are "o !" to&

6&/& Gra !'s :e ! %ha!er t c roc,sGra !'s :e ter( !o#o"* ! "!eo)s roc,s d ffers fro( that )sed for sed '(e!ts. !a(e#*

Coarse'"ra !ed 9 /((Med )('"ra !ed J/ ((F !e'"ra !ed : ((

Use the ter(s coarse. (ed )( a!d f !e whe! d sc)ss !" a roc,. b)t ! for(a#descr %t o!s state "ra ! s :es ! ( ## (etres& If a roc, s %or%h*r t c or %or'

%h*rob#ast c. re(e(ber to ?)ote the s :e of the %he!ocr*sts or %or%h*rob#aststoo9 a %he!ocr*st or %or%h*rob#ast 0 (( #o!" (a* a%%ear to be


25/111


a#(ost certa !#* o$erest (ate the ?)a!t t* of the dar, ( !era#s b* a factor of )% to two& Loo, at a selection of the "ra !s of e$er* ( !era# %rese!t. !ot

@)st o!e or two of the(& Ide!t f* each ( !era# ! t)r!. )s !" *o)r ha!d#e!s& Note the re#at o!sh %s betwee! d ffere!t ( !era#s& Rotate the s%ec (e! ! the# "ht to catch re ect o!s fro( %o#*'s*!thet c tw !! !" ! %#a" oc#ase9 t s

re(ar,ab#e how (a!* "eo#o" sts ha$e !e$er reco"! sed th s e7ce%t )!der a( crosco%e& Dar, ( !era#s are the (ost d ff c)#t to de!t f* ! a ha!d s%ec '(e!. a!d %*ro7e!e. a(%h bo#e. e% dote a!d to)r(a# !e are eas #* co!f)sed&The d ffere!t cross'sect o!s a!d c#ea$a"es ! %*ro7e!e a!d a(%h bo#e sho)#d

be ,!ow! to a## "eo#o" sts& Note a#so that the c#ea$a"e ! a(%h bo#e s ()ch better tha! ! %*ro7e!e9 e% dote has o!#* o!e c#ea$a"e9 a!d to)r(a# !e has$ rt)a##* !o!e& Refer to D etr ch a!d S, !!er + 4 - to !a(e the dar,er roc,s&

6.6 /phanitic )#neous &oc's

A%ha! t c "!eo)s roc,s ca! be d ff c)#t to !a(e ! the f e#d& Hard a!d co(' %act. at f rst s "ht the* a%%ear to " $e # tt#e !d cat o! of the r de!t t*& D $ dethe( !to # "ht'co#o)red a%ha! tes. ra!" !" )% to (ed )( red. brow!. "ree!a!d %)r%#e9 a!d dar,er a%ha! tes co$er !" co#o)rs )% to b#ac,& Use the o#dter( felsite for the f rst "ro)% a!d (af te for the seco!d& Tab#e 6& shows howthe two "ro)%s d $ de& Caref)# e7a( !at o! of a%ha! tes )!der a ha!d#e!s)s)a##* " $es so(e %o !ters to the r de!t t*. a!d (a!* co!ta ! %he!ocr*sts.wh ch a#so he#%s& asa#t s b* far the co((o!est of a## b#ac, a%ha! tes& I!the f e#d. refer to the


26/111


co!ta ! bar te a!d )ors%ar a!d e$e! s)#%h des& If %*r te s %rese!t. chec, for ore ( !era#s +b)t see F ")re 6&3-& Howe$er. !ot a## $e !s are ?)art: $e !s&So(e co!ta ! ca#c te. do#o( te. a!,er te or s der te. or ( 7t)res of the(. a!dthe* (a* be ( !era# sed too& Note. howe$er. that $e !s do !ot !ecessar #*ha$e "!eo)s assoc at o!s&

1e"(at tes a#wa*s ha$e "!eo)s assoc at o!s& The* are )s)a##*. b)t !ote7c#)s $e#*. of "ra! to d co(%os t o!&Gra ! s :e (a* be fro( 0 (( )%wardsto o$er (etre s :e +F ")re 6&3-&


27/111


28/111


or ashy andesite tuff . b)t (a!* f !e'"ra !ed $ar et es are d ff c)#t to de!t f*! the f e#d a!d (ore !o!'co(( tta# !a(es are @)st f ab#e& So(e t)ffs are so"#ass*. or e$e! a%%are!t#* ow'ba!ded. that the* ca! be ( sta,e! for #a$as! the f e#d& T)ffs te!d to de$ tr f* to " $e s%her)# t c a!d %er# t c te7t)res&Ma!* weather eas #* to !d)str a##* )sef)# %rod)cts. s)ch as bentonite a!d

perlite & Thor%e a!d row! + - " $e (ore deta #ed acco)!ts of how to (a%"!eo)s roc,s&

6. ! Metamorphic &oc'sCo!tact (eta(or%h s( has bee! dea#t w th )!der "!eo)s roc,s& Here weare co!cer!ed o!#* w th roc,s res)#t !" fro( regional (eta(or%h s(& Twofactors !eed to be co!s dered whe! (a%% !" the( the or " !a# # tho#o"*5strat "ra%h*. a!d %rese!t # tho#o"*& Bhe!e$er %oss b#e. (a% the( se%arate#*&

6& 0& Na( !" (eta(or%h c roc,sSed (e!tar* roc,s cha!"e w th !creas !" (eta(or%h s(. f rst to s#ates. the!to %h*## tes. sch sts a!d "!e sses& I"!eo)s roc,s defor( a!d recr*sta## seto "e! sses or sch sts a!d (a!* bas c "!eo)s roc,s. !c#)d !" $o#ca! cs.

beco(e amphibolites & Na(e slates for the r co#o)r. s)ch as brow!. "ree!. "re*. b#)e or %)r%#e

a!d for the r reco"! sab#e ( !era#s. e&"& pyritic black slate or green chiastolite slate . a!d do re(e(ber that (ost s#ates are !ot hard roof !"'?)a# t* s#ates& Phyllites c#ea$e (ore read #* tha! s#ates. #ea$ !" #)stro)s faces sh ! !" w thser c te sca#es&

Geo#o" sts se#do( a"ree where to %)t the r bo)!dar* betwee! %h*## tesa!d sch sts ! the f e#d the d $ s o! te!ds to be s)b@ect $e& I! "e!era#. f individual ( ca or ch#or te a,es ca! be c#ear#* see!. ca## t a sch st. f !ot. t s a %h*## te& $ica schist s a co((o!


29/111


roc,. %erha%s re%#ac !" for(er a)"e!& o) %robab#* ca!!ot te## wh ch )!t #see! ! th ! sect o!. b)t augen gneiss s a co!$e! e!t f e#d !a(e ! e ther case. e$e! f !ot a#wa*s str ct#* correct&

$igmatites are. # tera##*. ( 7ed roc,s& The* co!ta ! ( 7t)res of sch stose."!e ssose a!d "!eo)s'#oo, !" (ater a#& Treat the( ! the sa(e wa* as other

"!e sses !a(e the( for co(%os t o!. te7t)re a!d str)ct)re& For a## theseroc,s. (eas)re the d %s a!d str ,es of fo# at o! a!d the d rect o! a!d a(o)!tof %#)!"e of a!* ( !or fo#ds +see F ")re /& 2-& I! (a!* !sta!ces. so(estr)ct)re ca! be obta !ed b* draw !" for('# !es as descr bed ! Sect o! 2&3&a!d show! ! F ")re 2& a!d a#so see Marsha, a!d M tra + 88-&

6& 0& Co!tactsCo!tacts betwee! (a!* (eta(or%h c roc,s are @)st as shar% as those betwee!(ost sed (e!tar* roc,s or "!eo)s roc,s& So(e. howe$er. (a* be "rada'

t o!a#. es%ec a##* w th ! sch sts a!d "!e sses& Ide!t f* e$er* e7%os)re co(%o's t o!a##* whe! (a%% !" the( so that "rad at o!a# bo)!dar es ca! be !ferredwhere !ecessar* +Sect o! 2&3& -&

6& 0&3 Fo# at o!Bhere str)ct)re s fa r#* re")#ar. (a% the c#ea$a"e. sch stos t* a!d other fo# at o!s at ()ch the sa(e de!s t* as for sed (e!tar* roc,s& If str)ct)re

beco(es so co(%#e7 that t s (%oss b#e to show t ade?)ate#* o! *o)r (a%. (a% t at a #ar"er sca#e. or (a,e !)(ero)s s,etch (a%s a!d !oteboo, d a"ra(s& A (a% c#)ttered w th t "ht#* crowded c#)sters of s*(bo#s s d ff c)#tto !ter%ret b* ts a)thor. #et a#o!e b* those who (a* ha$e to refer to t#ater o!&

I! add t o! to fo# at o!. there are (a!* other str)ct)res wh ch !eed to be(a%%ed ! (eta(or%h c roc,s& These !c#)de the %#)!"e a!d tre!d of a!*( !or fo#ds. whether ! bedd !". c#ea$a"e or other fo# at o!s. or e$e! ! %t*"'(at c $e !s& The se!se of fo#d !" sho)#d be !oted too. to !d cate where the(a@or fo#d c#os)res # e& St*#e of fo#d !" s a#so (%orta!t& Loo, for # !eat o!s.!c#)d !" !tersect o!s of %#a!ar feat)res. s)ch as bedd !"5c#ea$a"e. c#ea$'a"e5c#ea$a"e. etc&9 or ( !era# a# "!(e!ts. rodd !". ()## o!s a!d stretchedco!"#o(erate %ebb#es +F ")re /& -& I! fact. (a% a!* str)ct)re. e$e! f *o)do !ot ,!ow ts s "! f ca!ce at the t (e& Its (ea! !" (a* beco(e c#earer #ater. or t (a* !ot. b)t at #east *o) ha$e t o! record f t does& For f)rther !for(at o! refer to Fr* + 82- a!d L s#e + 003-&

6. 2conomic 1eolo#yA!* "eo#o" sts worth the r sa#t sho)#d be ab#e to reco"! se the %r !c %a#eco!o( c ( !era#s a!d roc,s. for t s the r d)t* to co!s der the eco!o( c. aswe## as the %)re#* sc e!t f c. as%ects of a!* area the* (a%& To "!ore the(.

0/


30/111


or to co!s der the( be!eath the r sc e!t f c d "! t*. as so(e do a!d free#*ad( t. s !te##ect)a# s!obber*&

efore "o !" !to the f e#d. re$ ew a!* # terat)re co!cer! !" the ( !era#s! the re" o! *o) are abo)t to (a%. both (eta## fero)s a!d !d)str a#& Noterecords of ?)arr es a!d ( !es& F !d o)t what ores ha$e bee! ( !ed. a!d

%art c)#ar#*. whether the* were assoc ated w th s)#%h des. for these ores ha$ed st !ct $e o)tcro%s& A#so !ote the roc,s the ores were assoc ated w th a!d,ee% the( ! ( !d whe! (a%% !"&

6& & T*%es of bod*re bod es do !ot !ecessar #* cro% o)t at the s)rface ! eas #* reco"! sab#efor(& So(e are @)st roc, ! wh ch (eta## c ( !era#s are d sse( !ated a!dofte! s%arse#* d sse( !ated at that& So(e stratiform : !c'#ead ores are (ere#*sha#es w th f !e#* d s%ersed : !c a!d #ead s)#%h des. s ( #ar ! "ra !'s :e to

the roc, ( !era#s the(se#$es& Porphyry copper de%os ts. those #ar"e stoc,'# ,e "ra! to d !tr)s o!s wh ch s)%%#* (ore tha! ha#f the wor#d=s co%%er.ofte! co!ta ! #ess tha! o!e %er ce!t (eta#. a!d #oo, ()ch # ,e a!* other !tr)s o!& Ta,e !oth !" for "ra!ted&

6& & 7 dat o!re bod es do !ot sta!d )% o)t of the "ro)!d w th fresh sh ! !" cr*sta#s of ore( !era#s "# !t !" ! the s)!& S)#%h des. ! %art c)#ar. are )s)a##* e7te!s $e#*a#tered abo$e the water'tab#e b* o7 dat o!& So(e o7 d se to a h "h#* so#)b#estate +co%%er. : !c a!d s #$er ores are e7a(%#es- a!d the (eta#s are #eacheddow!wards to be re'de%os ted !ear the water'tab#e as a :o!e of secondary(supergene) enrichment . #ea$ !" the )%%er %art of the ore bod* de%#eted !these (eta#s& Those rede%os ted ! the o7 d sed e!$ ro!(e!t @)st abo$e thewater'tab#e for( a! e!r ched :o!e of o7 de a!d carbo!ate ores. those rede'

%os ted be#ow t are red)ced a"a ! b* react o! w th the other s)#%h des %rese!tto for( a :o!e of secondary sulphide enrichment & Nat $e (eta#s. s)ch as s #'$er a!d co%%er. (a* a#so res)#t fro( seco!dar* e!r ch(e!t. de%e!d !" o!co!d t o!s +F ")re 6&2-& The ro! s)#%h des. !$ar ab#* assoc ated w th s)#'

%h de ores. for( !so#)b#e o7 des wh ch re(a ! at. a!d c#ose to. the s)rfaceto acc)()#ate d)r !" eros o! res)#t !" ! a (ass of ce##)#ar # (o! te ca##ed

gossan & Gossa!s. a!d the redd sh'brow! so #s assoc ated w th the(. for( d s't !ct $e !d cat o!s of s)#%h de ( !era# sat o!. b)t that does !ot !ecessar #*(ea! that a!* )sef)# ores are assoc ated w th the(9 o!#* too fre?)e!t#* *o)f !d o!#* %*r te be#ow&

Bhere s(a## "ro)!dwater s%r !"s !ear ( !era# sat o! ha$e #ea,ed o)t.roc,s (a* be sta !ed b* the br "ht#* co#o)red co%%er carbo!ates a:)r te a!d(a#ach te. or coated w th t !* "ree! cr*sta#s of the #ead ch#oro'%hos%hate

pyromorphite . so eas #* ( sta,e! for (oss&

06


31/111

04


32/111


6& &3 Str)ct)ra# co!tro#1a* %art c)#ar atte!t o! to the fract)re %atter! ! a!* ( !era# sed d str ct. for ore de%os t o! (a* ha$e bee! co!tro##ed b* fa)#ts or @o !ts& Howe$er. ore(a* a#so be co!tro##ed b* fo#ds. bedd !" %#a!es. )!co!for( t es. # tho#o" ca#cha!"es. a!d b* co!tacts where "ra! tes a!d d or tes ha$e !tr)ded # (esto!es

or do#o( tes& re bod es ca! be a!* sha%e& So(e are $e !'# ,e. so(e arerre")#ar (asses "rad !" !to the r host'roc,s. so(e are ( !era# sed roc,

brecc as ! co##a%sed carbo!ate roc, ca$er!s9 others are (ere#* a! ore'bear !" %art of a! otherw se barre! roc,. sed (e!tar*. (eta(or%h c or "!eo)s. a!dthese are the (ost eas #* ( ssed&

6& &2 I!d)str a# ( !era#s a!d roc,sMa!* of the (ater a#s *o) (a% ha$e a! eco!o( c )se& The ra!"e s e7te!s $ea!d co$ers roc,s the(se#$es. s)ch as # (esto!e +b) #d !". ce(e!t. che( ca#

!e)tra# ser-9 (arb#e +b) #d !". (o!)(e!ts. etc&-9 "ra! te +(o!)(e!ts. b) #d'!" fac !". ba##ast-9 s#ate9 a!d s)%erf c a# de%os ts s)ch as "ra$e#s a!d sa!ds+co!crete a""re"ate. (o)#d !" sa!ds-9 c#a*s +br c,s. cera( cs. f ##ers-& The # sts e7te!s $e& Note the "ra$e# % ts. so(e of the( %oss b#* !ow #a,es. a!d a#sothe ?)arr es ! *o)r area& ) #d )% *o)r bac,"ro)!d of !d)str a# ( !era#sa!d refer to ! ## + 48- a!d Harb ! a!d ates + 82-. a!d #oo, aro)!d *o)a!d !ote the ( !era# %rod)cts ! e$er*da* # fe. fro( "#ass ! *o)r w !dowsto the b) #d !"s ! *o)r streets& I! o!e 300 ( stretch of Swa!sea H "h Streetthere were ! !e d ffere!t t*%es of %o# shed fac !" sto!e& I! ce(eter es. !ote

wh ch t*%e of "ra$esto!e has weathered best9 @)st #oo, at the dates o! the(&

6& &/ F)e#sCoa# s the (ost # ,e#* f)e# to be e!co)!tered whe! (a%% !" ! Carbo! fer'o)s areas of the U! ted !"do( a!d the coa# f e#ds are we##'doc)(e!ted&$erseas. !ot a## coa#s are Carbo! fero)s. a!d ! so(e co)!tr es brow! coa#sa!d # "! tes are (%orta!t& # sha#es are a! ofte! for"otte! %ote!t a# e!er"*so)rce. for whe! %etro#e)( so)rces are de%#eted a!d5or the %r ce of # ?) d a!d"aseo)s f)e#s r ses too h "h to be eco!o( c9 ro! ca##* the* are #ar"e#* co!'

f !ed to the !o!' 1EC co)!tr es Ch !a. the USSR a!d Esto! a e7%#o t the(&r ta ! has #ar"e %ote!t a# reso)rces assoc ated w th the >)rass c ((er d"eC#a* a!d. ! fact. sha#e o # was %rod)ced fro( a s(a## Carbo! fero)s f e#d! the M d#a!d ;a##e* of Scot#a!d fro( 8/0 )!t # 62 + ar!es 88-& #sha#es ca! be a!* a"e fro( 1a#aeo:o c )%wards& Howe$er. # ?) d o # a!d"as are )!# ,e#* reso)rces to be e!co)!tered whe! f e#d (a%% !" )!#ess !1EC areas&

6& &6 Bater Bater has bee! descr bed as the


33/111


34/111


Figure 6.6 "ells; well no. < penetrates to an a7uifer and the water must be pumped. =ver-pumping will draw down the rest-level and locally depletethe water-table until it is re-charged. "ell no. > has penetrated through thea7uiclude which confines the water within the a7uifer and because the well-head is below the pie6ometric surface (the level of the water-table in thea7uifer where it crops out) the well is artesian and water ows without pump-ing. "ell-head no. ? however is above the pie6ometric surface and needs tobe pumped. ote that the pie6ometric surface slopes downwards towards the

centre of the artesian basin

!o!'%er(eab#e a7uiclude +F ")re 6&6-& Dee% we##s are cased. &e& # !ed b* % %es to %re$e!t co!ta( !at o! fro( sha##ow "ro)!dwater&

Carbo!ate roc,s (a,e e7ce##e!t a?) fers. #ar"e#* beca)se of the r @o !t'!". ofte! e!#ar"ed b* so#)t o!& Howe$er. a!* we##'@o !ted roc, ca! be a!a?) fer. a!d ! so)ther! Afr ca arroo do#er tes are a! (%orta!t water so)rce.wh #st ! East Afr ca ?)art: tes co!f !ed b* %h*## tes ser$e as a?) fers too9a!d *et a"a ! ! the a%%are!t#* )!%ro( s !" Afr ca! base(e!t. "ra! to droc,s s)%%#* water where o%e!'@o !ted water'bear !" :o!es are sa!dw ched

betwee! t "hter'@o !ted )!a#tered roc, be#ow a!d dee%#* weathered a!d %art#*,ao# ! sed "ra! te abo$e + ar!es 88-& Do !ot be too h debo)!d o$er *o)r dea of what a! a?) fer sho)#d be& Howe$er. we##s ! a! )!co!f !ed a?) fer ca! soo! be de%#eted b* o$er'%)(% !" a!d. des% te the r )s)a##* far #ar"er reser$e. artes a! we##s ca! be de%#eted too so that the* are !o #o!"er artes a!a!d ()st be %)(%ed to (a !ta ! s)%%#*& The Lo!do! as ! s a! e7a(%#e&

Reser$o rs de%e!d o! be !" s ted ! a $a##e* w th catch(e!t wh ch w ##ha$e a s)ff c e!t a(o)!t of water to f ## t reser$o rs wh ch d d !ot f ## are!ot )!,!ow!O Geo#o" ca##*. the da( wa## ()st be s ted so that t !e ther

0


35/111


#ea,s aro)!d the wa##s !or be!eath t& Ca$er!o)s # (esto!es are !ot "oodfo)!dat o! roc,s a"a !. th s has bee! do!e& There are two t*%es of da(wa## gravity dams . he#d ! %#ace b* earth' or roc,'f ## s)%%ort !" a c#a* corewh ch %re$e!ts the #ea,a"e of water thro)"h the da( wa##. or be!eath or aro)!d ts s des9 a!d co!crete arch dams & oth are (atters of e!" !eer !"

"eo#o"*. be*o!d o)r re( t here&


36/111


37/111

4FIELD MA1S AND FIELD N TE S

F e#d (a%s a!d !oteboo,s are $a#)ab#e doc)(e!ts wh ch co!st t)te %art of the record of f e#d e$ de!ce o! wh ch the !ter%retat o! of "eo#o"* de%e!ds&oth are the %ro%ert* of *o)r e(%#o*ers a!d w ## be reta !ed b* the( as

%art of the r %er(a!e!t records whe! *o) #ea$e the(& The reaso! s ob$ o)sf *o)r erstwh #e e(%#o*ers w sh to re !$est "ate a! area *o) (a%%ed. the!t w ## be !ecessar* to refer bac, to the or " !a# records& If *o) ha$e ta,e!the( awa* w th *o). the* (a* be )!ab#e to retr e$e the(& o) (a* be !a!other co)!tr*. or otherw se )!traceab#e& Re(e(ber. *o)r e(%#o*ers are

the o!es who %a d for the wor, to be do!e& St)de!ts are ob$ o)s#* !ot !the sa(e %os t o! as e(%#o*ees b)t the* are ofte! ta,e! abac, whe! ! the r f rst @ob the r e(%#o*ers de(a!d the r f e#d (a%s a!d !oteboo,s for their

%er(a!e!t records&

7. Field Maps4& & Data !eededA f e#d (a% s a! a d to the s*ste(at c co##ect o! of "eo#o" ca# data ! thef e#d a!d shows the e$ de!ce o! wh ch the !ter%retat o! of the "eo#o"* was

(ade& It shows the "eo#o" ca# feat)res *o) act)a##* saw ! the f e#d9 t a#soshows "eo#o"* *o) ha$e inferred fro( !d rect e$ de!ce. s)ch as cha!"es! to%o"ra%h* or $e"etat o!. s%r !" # !es or oat& A f e#d (a% s !ot a!!ter%retat $e (a% as s)ch a!d. f %oss b#e. a## co!tacts sho)#d be %#ottedo! t whe! *o) are ! the f e#d. tho)"h so(e (a* be !ferred fro( ( !or !d rect e$ de!ce or so(et (es (ere#* b* *o)r @)d"e(e!t of where the*(ost %robab#* occ)r. he#%ed b* !ter%retat o! fro( aer a# %hoto"ra%hs a!d

b* !ter%o#at !" strat)( co!to)rs bac, ! ca(%& Howe$er. fact ()st a#wa*s be c#ear#* d st !") shed fro( !fere!ce& A f e#d (a% s !ot (ere#* a ro)"hwor,sheet o! wh ch to te(%orar #* %#ot !for(at o! before tra!sferr !" t o!to a oh! B& ar!es w th R chard >& L s#e002 >oh! B #e* K So!s. Ltd IS N 0'240'82 86'

3


38/111

FIELD MA1S AND FIELD N TE S

& the #ocat o! of a## roc, e7%os)res e7a( !ed9& br ef !otes o! the roc,s see!93& str)ct)ra# s*(bo#s a!d (eas)re(e!ts. s)ch as those for d % a!d str ,e92& #ocat o!s to wh ch (ore deta #ed !otes ! *o)r !oteboo,s refer9/& the #ocat o! fro( wh ch each roc, or foss # s%ec (e! was co##ected9

6& the #ocat o! at wh ch e$er* %hoto"ra%h was ta,e! or f e#d s,etch (ade94& to%o"ra%h c feat)res fro( wh ch "eo#o"* (a* be !d rect#* !ferred b)t

wh ch are !ot a#read* %r !ted o! the (a%9 cha!"es of s#o%e or $e"etat o!a!d the %os t o! of see%s a!d s%r !"'# !es are e7a(%#es9

8& a## co!tacts. !c#)d !" fa)#ts. both certa ! a!d !ferred9& r $er terraces. beach terraces. a!d other s ( #ar feat)res9

0& a##)$ )(. scree. bo)#der c#a* a!d a!* other s)%erf c a# (ater a#s. !c#)d'!" #a!ds# de debr s9

& c)tt !"s. ?)arr es a!d other (a!'(ade e7ca$at o!s e7%os !" "eo#o"*.

e&"& % ts a!d boreho#es9 e$e! ( !e s%o # hea%s ca! !d cate "eo#o"* be!eath the s)rface9

& co((e!ts o! the de"ree of e7%os)re or #ac, of e7%os)re. a!d o! so #co$er&

eca)se the* are $a#)ab#e. f e#d (a%s sho)#d. as far as %oss b#e. be ,e%t c#ea!a!d %rotected fro( ra ! a!d da(%& Th s s !ot a#wa*s %oss b#e a!d (%orta!t!for(at o! ()st !ot re(a ! )!%#otted for fear that the (a% (a* "et wet or d rt* f the (a% case s o%e!ed ! the ra !&

I!,' ! *o)r da*=s wor, ! the e$e! !" the wor, was do!e. !c#)d !" *o)r (a% !otes wr tte! ! s(a## b)t #e" b#e %r !t !". )s !" a f !e %e! a!d water-

proof !,&

4& & 1re%arat o!efore )s !" a !ew (a% sheet. c)t t !to a !)(ber of sect o!s or


39/111


Figure 7.1 everse side of a field slip with the information it should carry. ote the inde+ showing how this slip relates to those that make up the whole field sheet

th s sho)#d be tr)e !orth& I! add t o!. the s# % sho)#d show ts a)thor=s !a(e.the dates co$er !" ts %rod)ct o!. a!d the !oteboo, !)(bers re#at !" to t&

Do !ot st c, *o)r f e#d s# %s to"ether w th tra!s%are!t adhes $e ta%e whe!f e#dwor, s co(%#ete& It (a,es the (a% aw,ward to )se a"a ! ! the f e#df !ew !for(at o! s to be added. a!d a#so (ost adhes $e ta%es shr !, a!ddr* o)t w th t (e at a d ffere!t rate to the %a%er of the (a%& Th s d stortsthe (a%. or the ta%e co(es adr ft. #ea$ !" a d rt* sta ! wh ch (a* %e!etratefro( the bac, to the fro!t of the (a%&

4& &3 How a!d what to %#otA f e#d (a% s a record of f e#d obser$at o!s of the t*%e # sted ! Sect o! 4& & &1#ot the %os t o! of e7%os)res see! a!d !d cate roc,'t*%e b* for(at o! #et'ters. #etter s*(bo#s. or b* co#o)r !". s)%%orted where !ecessar* b* !oteso! the roc, co!d t o!& ee% !otes short a!d )se abbre$ at o!s s)ch as f"+f !e'"ra !ed-. #a( +#a( !ated-. shd +sheared-& Refer to Sect o! 2&3& & Ma!*e7%os)res !eed !o (ore tha! a! o)t# !e to show the r # ( ts. shaded w ththe a%%ro%r ate co#o)red %e!c #& E7%os)res wh ch are so s(a## that the* ca!

be show! o!#* b* a dot sho)#d. howe$er. a#wa*s be s)%%orted b* a #etter s*(bo#. otherw se the* te!d to be o$er#oo,ed whe! !, !" ! the (a% #ater&If !oteboo, !otes are (ade at a! e7%os)re. the! ts #ocat o! o! the (a% ()st

be # !,ed to the !oteboo, record +see Sect o! 4& &/-& Str)ct)ra# obser$at o!s

/


40/111


/8 4/ 38 20 2/

220/8

3/

40

+a- +b-

Figure 7.2 Symbols for field (a) and fair copy (b) maps compared. Strike and trend dip and plunge are shown on the field map but only dip and plungeon the fair copy

are show! b* the a%%ro%r ate s*(bo#s. draw! #ar"e e!o)"h to e!ab#e the( to be traced off acc)rate#* o!to the fa r co%* (a% o! a # "ht'tab#e 6J4 (( sa s) tab#e #e!"th for str ,e s*(bo#s o! a f e#d (a%& 1r !t the !)(er ca# $a#)e

of d % or %#)!"e #e" b#* ! s)ch a %os t o! that there s !o a(b ") t* o$er wh ch s*(bo# the f ")res refer to& E$e! better. record both str ,e a!d d %to"ether b* )s !" the


41/111


A#tho)"h a f e#d (a% s esse!t a##* a fact)a# data (a%. th s does !ot %re$e!t*o) fro( %#ott !" the !ferred %os t o!s of co!tacts ded)ced fro( !d recte$ de!ce s)ch as $e"etat o!. s%r !"'# !es a!d brea,s of s#o%e& I! fact. thef e#d s the %ro%er %#ace to !fer co!tacts. for there s )s)a##* so(e e$ de!ce.howe$er s# (. of the r %os t o!s& The draw !" of co!tacts ! the off ce. or bac,

! ca(%. s o!#* @)st f ed f *o) ha$e to resort to "eo(etr ca# co!str)ct o!s.s)ch as strat)( co!to)rs. where there s a co(%#ete #ac, of e$ de!ce o!the "ro)!d. or whe! *o) ha$e "eo%h*s ca# or %hoto"eo#o" ca# !for(at o! tohe#% *o)&

A!* to%o"ra%h c feat)res wh ch (a* re ect co!cea#ed "eo#o"* b)t are !ota#read* %r !ted o! *o)r base (a% sho)#d be added to t& These !c#)de brea, of s#o%e. $e"etat o!a# cha!"es. d st !ct $e so #s. s%r !"s a!d swa(%* %atches&Show a#so #a!ds# des. scree a!d a##)$ a# terraces& )t# !e ( !e t %s beca)sethe* ca! ofte! %ro$ de fresh s%ec (e!s of (ater a#s wh ch are otherw se see!

at s)rface o!#* ! a hea$ #* weathered state +th s s %art c)#ar#* so ! h)( dtro% ca# c# (ates- or e$e! %ro$e that certa ! roc,s wh ch are !ot e7%osed. or are ?) te )!s)s%ected ! the area. do occ)r at de%th&

The a(o)!t of deta # that ca! be show! o! a (a% ob$ o)s#* de%e!ds o!the sca#e *o) are wor, !" o!& A f e#d s# % sho)#d !ot be so c#)ttered w th!for(at o! that the


42/111


bac, of the (a%. f !ot a#read* wr tte! o!. b)t do !ot (a,e a "e!era# %ract ceof t& If *o) !eed (ore s%ace. )se a #ar"er sca#e. or (a,e a deta #ed (a% of a # ( ted area as descr bed ! Sect o! 2&8&

4& &2 Neat!ess

I!for(at o! wr tte! o! the (a% ! the f e#d ()st be wr tte! as #e" b#* asc rc)(sta!ces a##ow& ee% o!e %e!c #. a!d a reaso!ab#* hard o!e at that. for

%#ott !" o! *o)r (a%. a!d a!other for *o)r !oteboo,& ee% *o)r %#ott !" %e!c # !eed#e shar%. otherw se *o) ca!!ot wr te #e" b#* o! *o)r (a%& If *o))se the sa(e %e!c # for (a% a!d !oteboo,. *o) w ## be co!sta!t#* shar%e! !"t betwee! !oteta, !" a!d %#ott !"& Br te o! *o)r (a% ! a f !e. c#ear printed scr %t& Do !ot )se ( ! at)re c)rs $e


43/111


how the #etter s*(bo#s re#ate to (a% s?)ares& The drawbac, s that f *o) do#ose the f e#d (a%. the !oteboo, beco(es $ rt)a##* )se#ess&

Ma% #oca# t es ca! a#so be de!t f ed b* !oteboo, %a"e !)(bers& If se$era#!otes are (ade o! the sa(e %a"e. des "!ate the( a. b. c& Bhe! (ore tha!o!e !oteboo, s )sed for a %ro@ect. %ref 7 the %a"e !)(ber w th the boo,

!)(ber #oca# t* /5 3b. for e7a(%#e. (ea!s !ote b o! %a"e 3 of !oteboo, !)(ber /& M)ch de%e!ds o! whether *o) are (a%% !" %)re#* for *o)r ow!

%)r%oses. s)ch as o! a tra ! !" co)rse or for *o)r ow! research %ro@ect. or whether *o) are wor, !" for a! or"a! sat o!& r"a! sat o!s )s)a##* ha$e the r ow! r)#es so that #ater wor,ers ca! )se *o)r f e#d (a%s a!d !otes for #ater re'assess(e!t of a re" o!&

4& &6 I!, !" a!d co#o)r !" f e#d s# %sbser$at o!s (ade o! f e#d s# %s d)r !" the da* sho)#d be !,ed' ! that ! "ht&

E$e! o! the best %rotected (a%s. f !e %e!c # # !es beco(e b#)rred or #ost w tht (e& Bhe! "ree! # !e (a%% !". e7%os)re (ar" !s sho)#d be o)t# !ed w th"ree! waterproof !, or. ! s)!! er c# (ates. w th a f !e c#ose#* dotted +!otdashed- # !e ! b#ac, water%roof !,& After !, !". reco#o)r each e7%os)rew th the a%%ro%r ate co#o)red %e!c #& I!, tra$erse # !es w th a co!t !)o)s# !e where "eo#o"* s e7%osed or certa !. a!d a bro,e! # !e where !ferred.the! o$er#a* the tra$erse # !e. co!t !)o)s or bro,e!. w th a %e!c # # !e of a%%ro%r ate co#o)r&

/nked co!tacts ca! !ow be d st !") shed b* # !es of d ffere!t th c,!essdraw! w th st*#)s't*%e %e!s. to d st !") sh fa)#ts a!d )!co!for( t es fro(other roc, co!tacts. b)t !otes sho)#d st ## be added to co!f r( the r charactersabbre$ at o!s s)ch as


44/111


)!der#a ! b* s%ec f c for(at o!s& Do !ot co#o)r ! *o)r (a% hea$ #*. asf t were a f !a#


45/111


water%roof !,. a!d offer a reward for ts ret)r! f fo)!d& e "e!ero)s the #ossof *o)r !oteboo, ca! be d sastro)s& If !ecessar*. re%eat the !for(at o! !the #a!")a"e. a!d the ca## "ra%h*. of the co)!tr* *o) are wor, !" !& N)(ber !oteboo, %a"es b)t #ea$e the f rst few free for a! !de7 to be f ##ed ! da*

b* da*. w th the date. what was do!e a!d the %a"e !)(bers& Th s he#%s !ot

o!#* others who ha$e to )se *o)r !oteboo,. b)t a#so *o)rse#f whe! *o) co(eto #oo, for !for(at o! whe! wr t !" *o)r re%ort fro( !otes (ade wee,s.so(et (es (o!ths. #ater& Re(e(ber that *o) ,ee% a !oteboo, to refer to. so(a,e t eas* to do so& As, *o)rse#f


46/111


Figure 7.3 Page from a field notebook (A"3). The column on the left showsthe registered number of specimens collected. The observation number refer-ring to the locality ( avange /ran) appears in the same column on the previ-ous notebook page. The cross-section on the lower part of the page needs nolocality@observation number as the section line is shown on the field slip and on the map


47/111


Figure 7.4 &nother specimen notebook page ( A0). ote the comment onweather and the reason for the re-e+amination. There is both a locality num-ber (


48/111


4& &2 S,etchesUse s,etchesto s)%%#e(e!t!oteboo,descr %t o!s whe!e$er %oss b#e&S,etchessho)#d show d (e!s o!s. or at the $er* #east. so(e !d cat o! of sca#e& I!,'! co(%#e7 s,etches #ater. es%ec a##* those wh ch show $er* f !e deta #s&F ")re 6&3 s a! e7a(%#e of a !oteboo, s,etch redraw! for %)b# cat o! + ar!es

88-&

4& &/ Cross'sect o!sThe )!dersta!d !" of the str)ct)re of a! area s a ded b* %#ott !" cross'sect o!s ! *o)r !oteboo, a#o!" se#ected # !es ! the f e#d +Sect o! 2& & -&The r %rese!ce ! a !oteboo, s (ost )sef)# for a!*bod* re$ ew !" the "eo#'o"* of the re" o! #ater a!d so(et (es to show the $a# d t* of a! !ter%retat o!far better tha! the ofte! bea)t f)##* draw! a!d co#o)red cross'sect o!s wh chacco(%a!*


49/111


50/111

FAIR C 1 MA1S AND THER ILLUSTRATI NS

eco!o( ca##* s "! f ca!t& The cr ter o! of what to show s (a !#* a (atter of co((o! se!se& The f ! shed fa r co%* sho)#d show the "eo#o"* of the re" o!! s)ch a (a!!er that the "eo#o" ca# for(at o!s ca! c#ear#* be d st !") shed.o!e fro( the other a!d. f the* are co!t !)o)s )! ts. t sho)#d be %oss b#e totrace the( fro( %#ace to %#ace across the (a% e$e! tho)"h %oor#* e7%osed o!

the "ro)!d& Str)ct)ra# s*(bo#s sho)#d be s)ff c e!t#* c#ear that the se?)e!ceof e$e!ts ca! be e#)c dated a!d the strat "ra%h* deter( !ed& Abo$e a##. the(a% sho)#d be !eat#* draw!. the co#o)rs s(ooth a!d d st !ct $e. a!d the

%r !t !" #e" b#e&It (a* be as,ed wh* so ()ch !for(at o!. %a !sta, !"#* co##ected ! the

f e#d. s o( tted fro( the fa r co%*& It s beca)se the fa r co%* s o!#* a %artof *o)r !ter%retat o!& It s esse!t a##* a! !de7 wh ch %ro$ des the bas s for )!dersta!d !" a!* acco(%a!* !" e7%#a!ator* re%ort& The (a% s !ot a! e!d! tse#f. b)t t sho)#d st ## be ab#e to sta!d o! ts ow!. show !" the "e!era#

feat)res of the "eo#o"* ! a c#ear a!d co!c se (a!!er&

8.% Transferrin# Topo#raphyA fa rco%* (a% s )s)a##* draw! o! a fresh co%* of the or " !a# to%o"ra%h c

base (a% )sed ! the f e#d& If for the #ac, of a! or " !a# base (a%. or beca)sethe o!#* base (a% *o) had was hea$ #* c#)ttered w th co#o)red "eo"ra%h c!for(at o! or w th co#o)r #a*ered co!to)rs. the fa r co%* w ## ha$e to be(ade o! trac !" f #(. the! s)ff c e!t to%o"ra%h* ()st be traced off t to(a,e the "eo#o"* )!dersta!dab#e& Th s s ted o)s b)t t s !ecessar*& I! $er*(o)!ta !o)s d str cts. s)ff c e!t re# ef (a* so(et (es be show! b* trac !"off e$er* seco!d or e$e! f fth co!to)r& Draw the co!to)rs ! brow! )!#ess


51/111


!o!'tra!s%are!t %a%er (a%& If the %r !ted "eo"ra%h c deta # o! the we##')sedf e#d s# %s does !ot f t that o! the bra!d !ew fa r co%* base (a%. do !ot

be s)r%r sed& Th s s ow !" to shr !,a"e d)e to weather !". a!d s %robab#*s# "ht#* d ffere!t across the %a%er tha! t s )% a!d dow! t. a res)#t of howthe %a%er was (ade& If "r d s?)ares are !ot a#read* o! both s# %s a!d base

(a%. draw *o)r ow! "r d. a!d ad@)st each f e#d s# % to the best f t as *o) tracethe "eo#o"*. s?)are b* s?)are& A # "ht'tab#e s !ot d ff c)#t to (a,e& S !, aw !dow of o%a#esce!t 1ers%e7 or frosted "#ass +abo)t 0J30 c(s s?)are-)sh !to a % ece of %#*wood #ar"er tha! *o)r fa r co%* (a%& Mo)!t t o! awe##'$e!t #ated bo7& L "ht the w !dow fro( be#ow w th two short t)be # "hts+*o) ca! e$e! )se batter*'%owered )oresce!t # "hts-& To )se. (o$e the %artof the (a% *o) are wor, !" o! o$er the w !dow *o) w ## f !d th s #ess t r !"+a!d coo#er- to )se tha! a # "ht'tab#e w !dow the s :e of the base (a%. a!dchea%er to (a,e&

8. ,etterin# and Symbolsad %r !t !" ca! r) ! a! otherw se we##'draw! (a% wh #st "ood #etter !" ca!ofte! (%ro$e a %oor#* drafted o!e&


52/111


53/111


Figure 8.1 0ayout of a fair copy map showing the arrangement of e+plana-tory matter. ote the terminations to the cross-section lines shown on the faceof the map! this is to ensure that there is no ambiguity over the e+act positionswhere section lines end

d ff c)#t to a%%#* o$er #ar"e areas. es%ec a##* f those areas ha$e !tr cate bo)!dar es rre")#ar dr* !" (ar,s s%o # the res)#t& Co#o)red %e!c #s " $ee7ce##e!t res)#ts w th a ( ! ()( of %ract ce& La* o! the co#o)r "e!t#* a!dw th care a!d. f !ot dar, e!o)"h. add a!other #a*er o! to% of the f rst& S(ooththe co#o)r to a (ore e$e! t !t b* r)bb !" the s)rface w th a t ss)e or cotto!swab. or b* )s !" a


54/111


SCALE 200000 0 00 00

Metres

N N

N

MN GN30 E 0 0

Figure 8.2 Scales and northpoints for fair copy maps. Two e+amples of a bar scale are shown and a selection of northpoints. &void the arty -point on theleft. The two simple true -points on the far right are from transfer lettering

sheets. The composite northpoint in the centre is made up from transfer sheets. ote that $ and G are representative only; they show e+aggerated anglesbecause the true angles are too small to plot clearly especially G F >F *.This is conventional

A#wa*s ,ee% *o)r reader ! ( !d tr* to fo##ow a s*ste( wh ch does !otforce h ( to ,ee% #oo, !" bac, to the e7%#a!at o! to f !d o)t what th !"s(ea!& Re#ate *o)r co#o)rs to ( !era#o"*& For !sta!ce. f a hor!b#e!de sch sts show! ! %a#e "ree!. or o$er#a d w th "ree! dots. a!d a b ot te sch sts show! ! brow!. or s o$er#a d w th brow! dots. the! *o)r readers w ##

%robab#* f !d *o)r (a% eas er to fo##ow. tha! f those areas were show! ! %)r%#e or b#)e& Note. howe$er. that the )se of co#o)r does !ot ob$ ate the!eed for for(at o! #etters the* a#so he#% *o). *o)rse#f. to co#o)r *o)r (a%correct#*&

8.8 "ross-sectionsD s%#a* cross'sect o!s ! the (a% (ar" !s whe!e$er %oss b#e. so that a## "eo'#o" ca# !for(at o! s ,e%t to"ether& If sect o!s ha$e to be draw! se%arate#*.

30


55/111


draw the( a## o! the sa(e sheet so that the* ca! be eas #* co(%ared& Showo! the fa r co%* (a% the %os t o!s of a## sect o!s %rese!ted b* # !es draw! o!the face of the (a%. w th the e!ds of each sect o! # !e c#ear#* !d cated b* ashort cross'# !e. as ! F ")re 8& 9 a!d a#wa*s draw cross'sect o!s so that the r !orther! or easter! e!ds are at the r "ht'ha!d s de of the sheet the* are draw!

o!& A#tho)"h the hor :o!ta# a!d $ert ca# sca#es of the sect o! w ## )s)a##* bethe sa(e. both a hor :o!ta# bar sca#e a!d a "rad)ated $ert ca# sca#e sho)#d

be %ro$ ded& F !a##*. "eo#o" sts sho)#d c)rb the r (a" !at o! o! fa r co%*sect o!s a!d !ot show !ter%retat o!s dow! to (%robab#e de%ths for wh chthe* ca! ha$e !o %oss b#e e$ de!ce& Th s does !ot (ea! that h*%othet ca#cross'sect o!s sho)#d !e$er be draw!. b)t the r %ro%er %#ace s ! *o)r re%ort.w th s)%%ort !" te7t& !#* fact)a# sect o!s sho)#d for( %art of a fact)a# (a%&

8.9 34erlays

Do !ot o$ercrowd a fa r co%* (a% w th s%ec a# sed !for(at o! ! add t o! to"eo#o"*. s)ch as rose d a"ra(s. @o !t (eas)re(e!ts a!d str)ct)ra# stat st cs&Th s !for(at o! s better draw! o! tra!s%are!t %a%er or f #( as a! o$er#a*to the (a%& o) !eed !ot # ( t the !)(ber of o$er#a*s& I! add t o! to those(e!t o!ed abo$e. the* ca! !c#)de fo#d a7es9 s)b's)rface co!to)rs o! s%ec f c

beds deter( !ed fro( dr ##ho#es9 so%ach*tes. so%#eths. "eoche( ca# co!to)rsa!d e$e! "eo%h*s ca# !for(at o!& Not o!#* ca! o$er#a*s be s)%er (%osedo! the fa r co%* (a%. the* (a* be )sef)##* o$er#a d o! each other&

A! o$er#a* sho)#d be the sa(e s :e as the fa r co%* sheet a!d ha$e thesa(e "e!era# for(at& Show the (ar" !s of the (a% area a!d. beca)se theo$er#a* a!d the (a% are of d ffere!t (ater a#s wh ch d stort d ffere!t#* w tht (e. draw


56/111


Draw !" %ac,a"es s)ch as orel,raw a!d &dobe /llustrator a##ow f e#ds# %s to be co!$erted !to a %rofess o!a#'#oo, !" f !a# fa r co%* (a%& Us !"these software %rod)cts. bo)!dar* # !es. "eo#o" ca# s*(bo#s. a!d co#o)redfor(at o!s ca! be draw! o! sca!!ed base (a%s or sca!!ed f e#d s# %s&

8. Te t )llustrations#ac, a!d wh te te7t ##)strat o!s are !eeded ! !ear#* a## "eo#o" ca# re%orts.!c#)d !" (a%s of $ar o)s sorts. s)ch as e!#ar"ed deta #s of s(a## areas.as ! F ")re 2& 3. a!d redraw! !oteboo, s,etches. as ! F ")re 6&3& ee%s)ch f ")res as s (%#e as %oss b#e9 show o!#* the sa# e!t %o !ts& So(et (ess,etches ca! be traced fro( %hoto"ra%hs. b)t a"a ! trace off o!#* the %r !c '

%a# o)t# !es& )t# !e s,etches are far (ore co(%rehe!s b#e to the reader tha!)!s, ##ed art st c atte(%ts to show e$er* deta # fa thf)##* +F ")re 6&3-& St c,'dow! sheets of st %%#es a!d cross'hatch !". so#d )!der the !a(es of 0etra-

tone hartpak a!d %ip-a-tone ca! e!ha!ce *o)r draw !". as ! F ")re &3&S,etches ca! a#so be co(%)ter'draw!. as ! F ")re /& 4&

3


57/111


58/111

CR SS'SECTI NS AND THREE'DIMENSI NAL ILLUSTRATI NS

to a## !te!ts a!d %)r%oses %art of that (a%9 *o) (a* e$e! redraw t #ater !the (ar" ! of *o)r f !a# (a%&

Draw cross'sect o!s as f *o) are #oo, !" ! a "e!era# wester#* or !orther#*d rect o!. so that the so)ther!. so)th'wester! a!d wester! e!ds of the sect o!a#wa*s a%%ear o! the #eft'ha!d s de of the sheet of %a%er t s draw! o!

a!d the !orther!. !orth'easter! a!d wester! e!ds o! the r "ht& Bhe!e$er %oss b#e draw the( to c)t across the str ,e of beds as c#ose to a r "ht a!"#eas %oss b#e9 f there s a broad sw !" ! str ,e across the (a%. cha!"e thed rect o! of *o)r sect o!'# !e at a few we##'se%arated %o !ts to ,ee% t as!ear#* %er%e!d c)#ar to the str ,e as %oss b#e& Nor(a##*. to a$o d d stort o!.hor :o!ta# a!d $ert ca# sca#es sho)#d be the sa(e. b)t where d %s are !o (oretha! 0 . a! e7a""erated $ert ca# sca#e s %er( ss b#e. b)t a#wa*s state thetr)e d % o! the sect o!&

& &3 Ser a# cross'sect o!sSer a# cross'sect o!s are draw! a#o!" re")#ar#* s%aced %ara##e# # !es. )s)a##*o! #ar"e'sca#e %#a!s )sed for ( ! !" or e!" !eer !" %)r%oses& The* (a*

be draw! at r "ht a!"#es to the str ,e of the str)ct)re. b)t (ore )s)a##*the* are draw! %ara##e# to o!e set of "r d coord !ates& The r ob@ect s toshow %ro"ress $e cha!"es ! the "eo#o"* +see be#ow ! Sect o! &3&3 a!dF ")re &/-&

& &2 Te7t f ")resS (%# f ed cross'sect o!s are fre?)e!t#* )sed as te7t f ")res to ##)strate s%e'c f c str)ct)res descr bed ! a re%ort& The $ert ca# sca#e ca! be #e" t (ate#*e7a""erated to c#ar f* s%ec f c %o !ts&

9.% $lottin# and (ra in# "ross-sections& & Co!str)ct o!1oor#* draw! cross'sect o!s are so ofte! e!co)!tered ! %rofess o!a# # fe thatar es)( e of the %rocess s " $e! be#ow. a#tho)"h (ost readers w ## ha$ea#read* bee! ta)"ht th s (ethod ear#* ! the r "eo#o"* co)rses&

& Draw the # !e of sect o! (

AJA ) o! the face of the (a%. (ar, !" eache!d of the # !e w th a short cross'# !e +F ")re 8& -&

& Faste! the (a% to a draw !" board w th the sect o!'# !e %ara##e# to the botto( ed"e of the board&

3& Ta%e to the (a%. a few ce!t (etres be#ow the sect o! # !e. a str % of %a%er o! wh ch %#ot the sect o!&

2& Draw a base # !e o! the trac !" %a%er %ara##e# to the sect o! # !e o! the(a%& The! draw a ser es of %ara##e# # !es at the chose! co!to)r !ter$a#abo$e t +F ")re & +a--&

32


59/111


60/111


/& Ta%e dow! a %#ast c r)#e or stee# stra "ht'ed"e so that t ca!!ot (o$e.we## be#ow a!d %ara##e# to the base # !e&

6& * s# d !" a set's?)are +tr a!"#e- a#o!" the stra "ht'ed"e. dro% a %er' %e!d c)#ar dow! to the a%%ro%r ate e#e$at o! o! the sect o! %a%er fro(e$er* %o !t where the sect o! c)ts a co!to)r # !e o! the (a% +F ")re

& +a--& >o ! these %o !ts to " $e the %rof #e of the to%o"ra%h*&4& Ca#c)#ate the apparent dip ! the # !e of sect o! for e$er* str ,e5d %

!tersected b* the sect o! # !e +see Sect o! & & -& Mar, the %os t o!of each str ,e5d % s*(bo# o! the %rof #e a!d %#ot the a%%are!t d % as ashort # !e + J c(- +F ")re & +b--&

8& E7te!d the str ,e # !e of a!* str ,e5d % s*(bo# )!t # t (eets the sect o!# !e o! the (a%. for a!* str ,e s*(bo# #* !" c#ose to the cross'sect o!

b)t !ot act)a##* cross !" t& Ca#c)#ate ts a%%are!t d %. a!d %#ot t o! thecross'sect o! %rof #e as before& The d sta!ce *o) (a* %ro@ect a str ,e

s a (atter of "eo#o" ca# @)d"e(e!t& Bhere there s ob$ o)s e7)re.e7te!d the str ,e # !e to fo##ow ts c)r$e to (eet the # !e of sect o!+F ")re & +b--&

& St ## )s !" the set's?)are. dro% a %er%e!d c)#ar where$er the sect o! # !ecrosses a "eo#o" ca# co!tact o! the (a% a!d # "ht#* (ar, the %os t o!o! the %rof #e of the to%o"ra%h*&

0& L "ht#* s,etch ! the str)ct)re b* e7te!d !"


61/111


& &3 Dow!'%#)!"e %ro@ect o!sThe dow!'%#)!"e (ethod of cross'sect o! co!str)ct o! s the %referred (ethod! areas where the "eo#o" ca# str)ct)re s do( !ated b* fo#d !" a!d wherefo#ds ha$e h !"e # !es w th a co!sta!t a!"#e of %#)!"e& The (ethod ass)(esthat the "eo(etr* of the str)ct)res re(a !s )!cha!"ed f fo##owed ! the

d rect o! of the fo#d h !"e # !es& Th s a##ows %o !ts #* !" o! a "eo#o" ca#co!tact o! the (a% to be %ro@ected ! the d rect o! of the h !"e # !es o!to thesect o! %#a!e&

& &2 Co!str)ct o!

& Draw the se#ected # !e of sect o! AJA o! the (a%. a!d a cross'sect o!te(%#ate w th a base# !e of #e!"th AJA a!d a set of hor :o!ta#s re%re'se!t !" d ffere!t e#e$at o!s +F ")re & -&

& Se#ect a "eo#o" ca# co!tact o! the (a%&3& Choose a! arb trar* %o !t 1 o! the co!tact a!d draw a # !e thro)"h t !

the %#)!"e d rect o! to (eet the sect o! at 1 &1 s the %ro@ected %os t o!of 1 ! the cross'sect o!&

2& Meas)re the d sta!ce d fro( 1 to 1 ! rea# )! ts& The d sta!ce d s %os t $e or !e"at $e de%e!d !" o! whether the d rect o! of %#)!"e sfro( 1 towards 1 or fro( 1 towards 1 res%ect $e#*&

1

d

31

A A

A A

/00

200H

Figure 9.2 ,rawing a cross-section down plunge method

34


62/111


/& 1#ot the %ro@ected %o !t ! the cross'sect o! at a! e#e$at o! H " $e! b*

H h ' d ta! +a!"#e of %#)!"e-

where h s the e#e$at o! of the "ro)!d at 1 +rather tha! 1 -&6& Re%eat ste%s 3J/ for other %o !ts o! the co!tact. a!d @o ! the %ro@ected

%o !ts ! the cross'sect o!& Th s shows the fo#ded sha%e of the co!tact! the cross'sect o!&

4& Re%eat for other bo)!dar es&

A! (%orta!t ad$a!ta"e of th s (ethod s that the cross'sect o! s co!str)ctedfro( !for(at o! ta,e! fro( across the (a%. !ot @)st fro( a#o!" the # !eof sect o!&

& &/ a#a!ced sect o!sTh s s a (ethod of reco!str)ct !" the )!fo#ded or " !a# s)rface a!d e# ( '!at !" thr)st sheets to ca#c)#ate the a(o)!t of shorte! !"& a#a!ced sect o!sha$e !o %#ace ! a boo, o!


63/111


9.+ Three-dimensional )llustrationsThree'd (e!s o!a# d a"ra(s "reat#* he#% readers of re%orts to )!dersta!dthe so# d "eo#o"* of the area co!cer!ed& The r %re%arat o! (a* a#so he#%*o)r ow! )!dersta!d !" too& There are two bas c %ro@ect o!s isometric a!dobli7ue & oth are s (%#e to co!str)ct&

&3& Iso(etr c %ro@ect o!U!# ,e tr)e %ers%ect $e. so(etr c %ro@ect o!s ha$e !o $a! sh !" %o !ts a##

%ara##e# # !es re(a ! %ara##e# ! the d a"ra(& The two hor :o!ta# coord '!ates are !c# !ed at 30 to the EJB base# !e +F ")re &2-& The $ ewer sees the faces of a c)be. for !sta!ce. as three e?)a#'s ded %ara##e#o"ra(s+F ")re &2+a--& Geo#o" ca# !for(at o! draw! o! the faces of a! so(etr c

b#oc, ()st be d storted to f t the(& Do th s b* draw !" a "r d o$er *o)r "eo#o" ca# !for(at o!. (a% or cross'sect o!. a!d a#so o! the faces of the

so(etr c b#oc,. the! tra!sfer !for(at o! to the b#oc, b* e*e. "r d s?)are b*"r d s?)are. or b* recta!")#ar coord !ates&

o) ca! a#so )se so(etr c %ro@ect o! as a fra(ewor, for ##)strat o!s&F ")re &2+b- shows the %r !c %#e& 1ads of so(etr c %a%er ca! be bo)"ht a!dare a )sef)# a d to draw !" s)ch d a"ra(s& 1ers%ect $e %a%er s a#so a$a #ab#e

b)t best a$o ded&

&3& #oc, d a"ra(s#oc, d a"ra(s are the a%%# cat o! of so(etr c %ro@ect o!s where the c)be

has bee! (ade !to a recta!")#ar b#oc,& The* ca! be s%# t ! two or (ores# ces. or ha$e ste%s c)t !to the b#oc, to ##)strate s%ec f c %o !ts. b)t a$o do$erha!"s +F ")re &6-&

&3&3 b# ?)e %ro@ect o!I! ob# ?)e %ro@ect o!. the fro!t face of the bas c c)be s a! )!d stortedcross'sect o! ! the %#a!e of the %a%er +F ")re &2+c--& The s de of the c)be.

2/30 30

+a- +b- +c-

Figure 9.4 (a) &n isometric cube! (b) a fold drawn using the cube as a guide!(c) an obli7ue pro ection of the same cube

3


64/111


2/

Figure 9.5 =bli7ue pro ection of serial cross-sections.*ach cross-sectionis atrue cross-section but the distance between them is foreshortened by one-third

howe$er. s a %ara##e#o"ra( !c# !ed at 2/ to the EJB base# !e. w th d s'ta!ces reced !" fro( the $ ewer foreshorte!ed b* o!e'th rd to %re$e!t thec)be a%%ear !" recta!")#ar& b# ?)e %ro@ect o! ca! a#so be ada%ted as a

b#oc, d a"ra(. b)t o!e %art c)#ar )se s ! draw !" ser a# cross'sect o!s+F ")re &/-&

&3&2 Fe!ce +%a!e#- d a"ra(sFe!ce d a"ra(s. as d st !ct fro( co#)(!ar sect o!s. are three'd (e!s o!a###)strat o!s& Strat "ra%h* or # tho#o"* s show! o!


65/111


Figure 9.6 Simple block diagram split with two halves separated and with steps

Figure 9.7 4ence or panel diagram illustrating stratigraphic variations in

a region. /t gives a better spatial impression than a columnar section (c.f. 4igure C.?)

2


66/111


Figure 9.8 Photograph of an egg-crate model (courtesy of S.A. $atthews)

are %art c)#ar#* )sef)# ! (o)!ta !o)s re" o!s where the "eo#o"* has bee!co(%# cated b* nappes a!d o$erthr)st !" +F ")re &8-&

&2& G#ass'sheet (ode#sFor so#$ !" #ar"e'sca#e #oca# sed %rob#e(s ! de%th. (ode#s ca! be (ade?) c,#* fro( w !dow "#ass or 1ers%e7 sheets& Trace %ara##e# cross'sect o!so!to the "#ass w th the %e!s )sed to wr te o! o$erhead %ro@ector tra!s'

%are!c es& S)%%ort the( $ert ca##* ! a "roo$ed tro)"h'# ,e o%e!'e!ded bo7&Corr)"ated cardboard st)c, to the s de of the bo7 w ## )s)a##* " $e "roo$es! %os t o!s s)ff c e!t#* acc)rate to ser$e the %)r%ose of the (ode#&

G#ass (ode#s are fre?)e!t#* )sed b* the ( ! !" !d)str* to show the so# d"eo#o"* whe! %#a!! !" o%erat o!s& I! ( ! !". (ode#s ca! a#so be (ade w thhor :o!ta# #e$e# %#a!s draw! o! "#ass sheets a!d (o)!ted o!e abo$e a!other&The wr ter has )sed Mecca!o as s)%%orts for th s %)r%ose&

2


67/111

0GE L GICAL RE1 RTS

The co(%#et o! of a!* %er od of "eo#o" ca# (a%% !" s )s)a##* fo##owed b*a "eo#o" ca# re%ort to e7%#a ! the "eo#o"* of the re" o! co$ered& I! fact.

%rofess o!a# "eo#o" sts %robab#* s%e!d (ore of the r t (e %re%ar !" re%orts+w th the atte!da!t #aborator* wor, a!d (a% draft !"- tha! the* do ! thef e#d& The ob@ect of wr t !" a re%ort. or for that (atter a %a%er or thes s. sto co(()! cate deas to others a!d. a#tho)"h there s !o reaso! whatsoe$er wh* "eo#o" ca# wr t !" sho)#d !ot be ! "ood c#ear E!"# sh. t se#do( s9 a!doh! B& ar!es w th R chard >& L s#e002 >oh! B #e* K So!s. Ltd IS N 0'240'82 86'

23


68/111


69/111

GE L GICAL RE1 RTS

!ot hed"e the r res%o!s b # t es& The* sho)#d ha$e the co)ra"e to co(( tthe(se#$es to the r o% ! o!s o! %a%er9 that s what the* are %a d for&

!.+ ,ayoutA!* sc e!t f c re%ort ca! be bro,e! dow! !to a !)(ber of bas c %arts&

These are

T t#e %a"e+co!te!ts-AbstractI!trod)ct o!Ma ! bod*Co!c#)s o!sRefere!cesA%%e!d ces

I! short re%orts. so(e of these %arts (a* be o!#* a few # !es #o!"& I! others.e$e! the I!trod)ct o! (a* !c#)de se$era# s)b'sect o!s a!d the


70/111

GE L GICAL RE1 RTS

0&3&2 Head !"s a!d s)b'head !"sThe bod* of the re%ort w ## )s)a##* be d $ ded !to sect o!s. a!d f)rther s)b'd $ ded !to two #ower cate"or es. each w th ts ow! t*%e of head !"&The (a ! sect o!s are e?) $a#e!t to the cha%ters of a boo,& Each starts o!a fresh %a"e w th ts head !"s ca% ta# sed a!d ce!tred o! the %a"e& Sect o!s

co!ta ! s)b'sect o!s w th the r head !"s e ther ce!tra# sed or at the #eft ha!d(ar" !. de%e!d !" o! the ho)se r)#es of *o)r e(%#o*er. b)t !ow )s !" )%%er a!d #ower case& Do !ot )!der# !e head !"s for f *o)r re%ort +or %a%er- sse!t to a %r !ter for %)b# cat o!. )!der# ! !" te##s co(%os tors to %r !t thosewords ! ta# cs& S)b's)b'head !"s brea, s)b'sect o!s )% !to s(a##er )! tsa!d these head !"s are a"a ! t*%ed at the #eft'ha!d (ar" ! of the %a"e a!d)s)a##* ta# c sed. so(et (es fo##owed b* a dash. co#o! or a w der s%ace&B th the w des%read )se of word'%rocessors. *o) ca! of co)rse %rod)ce *o)r ow! ta# cs. a!d a#so bo#d t*%e. a!d #ar"er t*%es to e(%has se the h erarch*

of head !"s& Here we o!#* (a,e "e!era# sed s)""est o!s&

9 Section eadin#& S)b'sect o! head !"C.


71/111

GE L GICAL RE1 RTS

It s a#so a )sef)# %#ace to ac,!ow#ed"e a!* he#% " $e! to the wr ter. both !the f e#d a!d ! the %re%arat o! of the re%ort&

!.5 Main ody of the &eportHard a!d fast r)#es ca!!ot be " $e! o! what sho)#d be !c#)ded ! a re%ort9

that de%e!ds o! the s)b@ect. b)t (a!* "eo#o" ca# re%orts are bas ca##* adescr %t o! a!d e7%#a!at o! of the "eo#o"* of a # ( ted area. so(et (es co$'er !" o!#* a few te!s of s?)are , #o(etres& Nor(a##*. the (a ! bod* of s)cha re%ort w ## co!s st of sect o!s w th head !"s s ( #ar to those show! be#ow&

0&/& Re" o!a# "eo#o"*efore e(bar, !" o! a deta #ed acco)!t of the "eo#o"* (a%%ed. t he#%sthe reader f the (a ! feat)res of the area are o)t# !ed f rst& I! $er* shortre%orts. "e!era# "eo#o"* ca! be !c#)ded ! the !trod)ct o!. to"ether w th

the re" o!a# "eo#o"*& I! #o!"er re%orts. a se%arate sect o! s !eeded. s)%%orted b* at #east o!e te7t f ")re show !" the bare o)t# !es of the (a ! "eo#o" ca#)! ts o! a s(a##'sca#e (a%. %referab#* w th so(e !d cat o! of str)ct)re a!d

%#ace !a(es& Note that the US Geo#o" ca# S)r$e* !s sts that a!* %#ace !a(e(e!t o!ed ! the te7t ()st a%%ear o! so(e (a% w th ! the re%ort& Th s s!ot a#wa*s adhered to b* other or"a! sat o!s. to the fr)strat o! of readers of the r re%orts&

0&/& Strat "ra%h*. etcTh s sect o! descr bes the roc,s ! "eo#o" ca# se?)e!ce. that s. the o#destroc,s f rst& If the strat "ra%h* s co(%#e7. a! !trod)ctor* s)b'sect o! (a*

be !eeded. w th se%arate sect o!s for each of the (a ! for(at o! "ro)% !"s&A te7t f ")re show !" the "eo#o" ca# s)ccess o! a!d th c,!esses. co#o)redw th the same t !ts as those o! the (a ! "eo#o" ca# (a%. s a "reat he#%to the reader& The roc,s (a* be descr bed ! ()ch the sa(e wa* as the*are descr bed ! *o)r f e#d !otes +Sect o! 6& - e7ce%t !ow *o) a#so ha$ethe be!ef t of e7a( ! !" th ! sect o!s. #aborator* wor,. co!s)#tat o!s w thco##ea")es a!d refere!ce to # terat)re&

The wa* ! wh ch the strat "ra%h* s treated ()st de%e!d o! the "eo#o"*tse#f& I! so(e cases. sect o! head !"s (a* be de$oted to


72/111

GE L GICAL RE1 RTS

f e#d e$ de!ce& Str)ct)ra# "eo#o"* s a! e7ce##e!t e7a(%#e of a s)b@ect whereo!e d a"ra( ca! sa$e a wea#th of te7t& Iso(etr c d a"ra(s are es%ec a##*he#%f)# a!d are ()ch eas er to draw tha! the* #oo,. a!d e$e! (ore so )s !"a co(%)ter +Sect o! &3-&

0&/&2 Meta(or%h s(Meta(or%h s( (a* deser$e a sect o! of ts ow!. b)t #o" ca##*. t (a* ofte!

be %art of the str)ct)ra# sect o!& The wa* ! wh ch these two s)b@ects aretreated s a (atter for the @)d"e(e!t of the wr ter&

0&am

Documents

Baisc Geological Mapping