November 30, 2009

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

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.

Refresher…late Paleozoic Geology

• Absaroka transgression• Cratonic deformation

Ouachita belt

– Ancestral Rockies Alleghanian orogeny

– Final Appalachian

• Formation of Pangea

Life• Marine

Major carbonate reefs Ray finned fishes, sharks

• Terrestrial primitive gymnosperms Insects (arthropods) Amphibians and first reptiles

• Permian extinction

Mesozoic Era

Time frame• 250-65 mya

Age of Reptiles Breakup of Pangea

http://www.museulourinha.org/images/dinos_ilustracao.jpg

Breakup of Pangea

Occurred late Triassic through Cretaceous• N. America and Africa split• Greenland and Europe split

Newark rifts• Stretching crust• Basalt injections

The Palisades, NJ

Palisades(basaltic sill)

http://piercehaviland.com/Scenic/Palisades/index.htmhttp://www.semp.us/publications/biot_reader.php?BiotID=348http://www.math.montana.edu/~nmp/materials/ess/geosphere/inter/activities/exploration/index.html

http://www.sfr.cas.psu.edu/Stauffer/nsf/malawi.htmhttp://scienceblogs.com/eruptions/2009/11/the_rifting_of_africa.php

2005 eruptions

East African Rift Valley

Weathering of uplifted regions• Newark Supergroup

Red, non-marine sediments

Formation of aulacogens • Basins bounded by faults

Breakup of Pangea

Reptile tracks, CT

Breakup of Pangea North Atlantic Ocean basin

• Rapidly widening

http://quakeinfo.ucsd.edu/~hedlin/erth10/Lecture16/white-cliffs.jpeghttp://geography.howstuffworks.com/terms-and-associations/pangaea-supercontinent.htm/printable

Gulf of Mexico• Restricted basin• Evaporite deposition

LA salt domesPetroleum traps

Chalk deposition• White Cliffs of Dover

Interior Craton Red sediments transported west

• Moenkopi Formation

Quartz sands deposited• Navajo Sandstone, UT

Flaming Gorge, WY

http://3dparks.wr.usgs.gov/capitol2/html/3d155.html

Moenkopi Fn

Chinle Fn

Wingate Sandstone

Navajo Sandstone, UT

Interior Craton Changes in sea level

• Sundance Formation

http://www.fhsu.edu/biology/cbennett/research_photos.htmlhttp://www.geo-sciences.com/images_geology-2.htmhttp://www3.interscience.wiley.com:8100/legacy/college/levin/0470000201/chap_tutorial/ch11/chapter11-4.html

Sundance Fn, WY

Gypsum Springs, CO

Dinosaur National Park, UT

Erosion of western highlands• Morrison Formation

Cordillera Belt Western margin activity intensified Most of western margin is ‘foreign’

• suspect and exotic terranes Ex: Wrangell Mts, AK

http://www.my-photo-blog.com/category/travel/alaska/wrangell-st-eliashttp://pubs.usgs.gov/dds/dds-81/Intro/TopographicData/DEM/DEM.htmlhttp://www.umt.edu/geosciences/faculty/sears/animation/latecretaceous.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.htm