December 2, 2009

Reading Ch. 14 Final Exam date: TU, Dec. 15

• Material covered: Ch. 13, 14, 15, 16

Monster worm and sea star frenzyDeep under the Antarctic ice, a rare, colourful burst of starfish and 3m-long monster worms has been filmed by a BBC camera crew. Filmed in time-lapse, the extraordinary swarm of deep-sea creatures gathers to feed in a frenzy on the body of a seal, which had sunk to the ocean floor. Such a bounty of food may only occur once every ten years in the ice-cold waters of McMurdo Sound, Antarctica. The images were taken by divers filming for the natural history series Life. The time-lapse sequence revealed the feeding frenzy of hundreds of huge worms, starfish, brittle stars and sea-urchins.

Recap Eastern margin

• Rifting, lava expulsionEX: The Palisades (NY-NJ)

Southern margin• Depositional basin, evaporites

Gulf of Mexico

Interior• Erosion and deposition

Navajo Sandstone (Zion NP)

Western margin• Undergoing compression

Picking up exotic terranes

http://ca.water.usgs.gov/groundwater/gwatlas/summary/geology.htmlhttp://homepage.ufp.pt/biblioteca/GlossarySaltTectonics/Pages/PageS.htmlhttp://www.planetware.com/picture/new-york-state-hudson-river-valley-us-ny156.htm

Sonoma Orogeny Island arc collision

• Forearc basin (Great Valley Grp)Volcanic & ocean sediments

• Accretionary prism (Fransciscan Cx)blueschists

• Foreland basin (Morrison Fmn)Volcanic & terrestrial sediments

http://www.geol.umd.edu/~tholtz/G102/102meso1.htmhttp://www.es.ucsc.edu/~afisher/Courses/Eart205/GradSeminarPhotos.html

Cordilleran Orogeny 1st phase: Nevadan orogeny

• Granitic magma intrusions Ex: Sierra Nevadas Ex: Idaho batholith

http://www.eugenecarsey.com/camp/alabamahills/arches2.htmhttp://higheredbcs.wiley.com/legacy/college/levin/0471697435/chap_tut/chaps/chapter15-04.html

Cordilleran Orogeny 2nd phase: Sevier orogeny

• Low angle thrusts Sevier thrust belt

http://en.wikipedia.org/wiki/Image:Lasvegasgeography.jpghttp://www.geology.wisc.edu/~chuck/Classes/Mtn_and_Plates/mthttp://geology.isu.edu/Digital_Geology_Idaho/Module5/mod5.htmns_westernUS.html

Spring Mtns, NV

Cordilleran Orogeny 3rd phase: Laramide orogeny

• Uplift of basement rock and overlying sediments

• Located further east Why??

• Very shallow angle thrust No melting Transfer of compressional forces

http://www.geol.umd.edu/~tholtz/G102/102meso2.htmhttp://www.geology.wisc.edu/~maher/air/air15.htm

Sheep Mtn anticline, WY

Cordilleran Orogeny

http://pubs.usgs.gov/dds/dds-81/Intro/TopographicData/DEM/DEM.htmlhttp://www.umt.edu/geosciences/faculty/sears/animation/latecretaceous.htm

Interior Craton Interior Seaway in late Cretaceous

• Covered ~1/3 land area• Marine carbonate deposition

Niobrara Fmn

• Oil, coal, gas origins

http://cedarandsand.blogspot.com/feeds/posts/defaulthttp://www.geo.wvu.edu/~wilson/geol1/lec43b/EHist7.htm

http://esp.cr.usgs.gov/research/fossils/ammonites.html

Niobrara Fmn, KS

Morrison Fmn

Life in the Mesozoic: Marine Seafloor

Paleozoic fauna goneBryozoans, crinoids, blastoids,

tabulates, fusulinids

http://www.geo.vu.nl/~smit/inoceramus/inoceramid.htmhttp://www.ucmp.berkeley.edu/cnidaria/scleractinia.htmlhttp://www.geol.umd.edu/~jmerck/geol100/lectures/31.htmlhttp://www.humboldt.edu/~natmus/lifeThroughTime/Cretaceous.web/index.htm

‘Marine revolution’• Bivalves, gastropods took over

Ex: Inoceramids

• Crinoids replaced by spiny or burrowing echinoids

• Reef buildersScleractinid corals dominate earlyRudistids clams dominated later

Mesozoic Life: Water Column

Ammonoids• Changes in suture designs

Zig-zag to U-shaped to branched

• Mesozoic index fossil

http://www.abc.net.au/dinosaurs/fact_files/ea/sealife/belemnite.htmhttp://www.bedfordmuseum.org/collections/fossils/belemnites_2.htm

Belemnites• ‘ancient’ squids

Planktonic life• Diatoms• Coccolithophores• Foraminiferans: globigerinids

Marine Vertebrates Bony fishes

• Primitive sturgeons• Teleosts with mobile jaws,

swim bladdersEx: Xiphactinus

http://www.bbc.co.uk/science/seamonsters/factfiles/xiphactinus.shtmlhttp://www.artistwd.com/joyzine/australia/articles/dinosaurs/freshwater_plesiosaur.phphttp://www.exn.ca/dinosaurs/story.asp?id=2000032152&name=creatures

Reptiles• Plesiosaurs

Large reptiles

• IchthyosaursCompletely aquatic (live births)

• Mosasaurs

Marine Vertebrates

Megalodon (shark)• Great White relative

http://www.fossilien.de/seiten/haizaehne/megalodon.htm