1,1001,2001,3000.0

0.10.2

0.3

0.40.5

0.60.7

0.80.9

1.0

1.11.2

1.3

1.4

1,000 900

0

0 1 KILOMETER

1 MILE

1,300 1,200 1,1000.00.10.2

0.3

0.40.50.60.7

0.8

0.91.0

1.11.2

1.31.4

1,000 900

800 700 600 500 400 300

800 500 400 300600700

200 100

100200

TckTmb

(Tcm)

Tlmo

Tck

(Tex)

(QTu)

TcmTlmo

Calvert Formation

Crystalline basement rocks

Raised rim

Quaternary to upper Miocene deposits, undifferentiated

Fractured, faulted and (or) brecciated crystalline basement rock

Melt zone ?

Exmore tsunami-breccia deposits

VERTICAL EXAGGERATION X2

Northwest

D

Horizontal distances keyed to shot points(1,300 to 100) along the navigation track

Southeast

D´

SEC

TIO

NA–

A´

Inner rim faultsCompaction faults

Annular trough

Tw

o-w

ay tr

avel

time,

in s

econ

ds

Inner rim

Compaction faults Compaction faultsInner basin

CHESAPEAKE BAY SEISMIC PROFILE (D–D´) AND GEOLOGIC INTERPRETATION

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

2,250 2,150 2,0502,200

0

0

1 MILE

1 KILOMETER

2,100 2,000 1,950

2,250 2,1502,200 2,100 2,000 1,950

(Kp)

Tcm

Tck

(Tex)

Tmb

(QTu)

Tlmo

Disruptionboundary

PotomacFormation

Crystalline basement rocks

Quaternary to upper Miocene deposits undifferentiated

Exmore tsunami-breccia deposits

Horizontal distances keyed to shotpoints(2,250 to 1,950) along the navigation track

Northwest

C

Tw

o-w

ay tr

avel

time,

in s

econ

ds

Southeast

C'

faults

Outer rim

VERTICAL EXAGGERATION X2

Compaction faultsOuter rim

Annular trough

YORK RIVER SEISMIC PROFILE (C–C´) AND GEOLOGIC INTERPRETATION

(57F8)(58F127) (58F82)59

73 6986

(55F20) (56F16)(57F7) (58F38)

(59F2)

(58F57)

(56G73)9349

5355

57 64 67

8450corehole

65, 66

47(60E3)

Kiptopekecorehole

(63F50)88

Jamestown

(58F50, 58F67)Newport News

Park 1 and 2 coreholes

125

FEET

SEA LEVEL

-250

-500

-750

-1,000

-1,250

-1,500

-1,750

-2,000

TeTsm

Ty

Qt

Te

To

Qt

Tcl

Tpp

(Tn)

Ty

Qt

Ty

Tcm

Qt

(Ta)(Te)

(Tsm)

(Ty)

Tcr

(Tck)

To

(Tex)

To

(Tcl)

(Tcm)

(Tmb)

Tmb

Tmb

Tex

Tck

Tcl

(Tck)

(Tex)

(Kp)

(Tm)

(Qt)

Marlboro Clay

Nanjemoy FormationAquia Formation

Bottom ofNNP2

Disruptionboundary

Potomac Formation

Crystalline basement rocks

St. Marys Formation

Eastover Formation

Yorktown Formation

Quaternary depositsEastville

paleochannel

Calvert Formation (lower Miocene)

Chesapeake Bayimpact crater

megablock beds

Exmore tsunami-brecciadeposits

ChickahominyFormation

Calvert Formation(middle Miocene)

Exmore tsunami-brecciadeposits

Chickahominy Formation

Jam

es R

iver

Jam

es R

iver

Jam

es R

iver

Chesapeake BayAtlanticOcean

Inner basin Annular troughAnnular trough

Claremont

Lower York-James Peninsula

Outer rim of crater

Approximate location of (C–C') seismic profile Approximate location of (D–D') seismic profile

VERTICAL EXAGGERATION X 166.6HORIZONTAL SCALE 1:250,000

West

B

East

B'

STRATIGRAPHIC CROSS SECTION B–B´SCALE 1:250 000

Locations of cross section B–B' and profiles C–C' and D–D'; also shown on plate 1

2F

1DS

10M

88K

131

EM

133H

134CM 135JB

128E

127W

55JN 65, 66

15A

G

F

CB

A´

D

D´ B´

A

G´

E´F´

E

C´

VirginiaBeach

Norfolk

NewportNews

Hampton

Williamsburg

Gloucester Point

Jamestown

Reedville

Exmore

Chincoteague

CapeCharles

Tappahannock

WestPoint

Claremont

Fractured, faulted and (or) brecciated crystalline basement rock

Crystalline basement rocks

Aquia Formation (upper Paleocene)

Potomac Formation (Lower Cretaceous)

Marlboro Clay (Eocene and Paleocene?)

Nanjemoy Formation (lower Eocene)

Chesapeake Bay impact crater megablock beds (upper Eocene?)

Exmore tsunami-breccia deposits (upper Eocene)

Quaternary to upper Miocene deposits, undifferentiated

Chickahominy Formation (upper Eocene)

Calvert Formation (middle Miocene)

Newport News unit of Calvert Formation (lower Miocene)

St. Marys Formation (upper Miocene)

Eastover Formation (upper Miocene)

Quaternary deposits, undifferentiated

Chowan River Formation (upper Pliocene)

Yorktown Formation (upper and lower Pliocene)

Piney Point Formation (middle Eocene)

59(57F8) Borehole or continous corehole — Number keyed to plate 1; number

in parentheses refers to local number shown in appendix 1A; altitudes of tops of stratigraphic units are shown in appendix 1B; boreholes and coreholes projected into the line of section on plate 1

Newport News unit of Calvert Formation (lower Miocene), Old ChurchFormation (upper Oligocene), and Delmarva beds (lower Oligocene), undivided

Old Church Formation (upper Oligocene) and Delmarva beds(lower Oligocene), undivided

Qt

Te

Tsm

Tcm

Tcl

To

Tck

QTu

Tlmo

Tex

Tmb

Ty

Tpp

Tn

Tm

Ta

Kp

Tcr

EXPLANATION

INTERIOR—GEOLOGICAL SURVEY, RESTON, VIRGINIA—1999

SECTION B–B' AND SEISMIC PROFILES FROM YORK RIVER (C–C´) AND CHESAPEAKE BAY (D–D´) By

David S. Powars and T. Scott Bruce1999