Tectonics and Stratigraphy

Tectonics and Stratigraphy

7 Major Plates

• African Plate, covering Africa - Continental plate • Antarctic Plate, covering Antarctica - Continental plate • Australian Plate, covering Australia (fused with

Indian Plate between 50 and 55 million years ago) - Continental plate

• Eurasian Plate covering Asia and Europe - Continental plate

• North American Plate covering North America and north-east Siberia - Continental plate

• South American Plate covering South America - Continental plate

• Pacific Plate, covering the Pacific Ocean - Oceanic plate

What Drives Tectonics?

• Definition : The cycle of movement in the asthenosphere that causes the plates of the lithosphere to move. Heated material in the asthenosphere becomes less dense and rises toward the solid lithosphere, through which it cannot rise further. It therefore begins to move horizontally, dragging the lithosphere along with it and pushing forward the cooler, denser material in its path. The cooler material eventually sinks down lower into the mantle, becoming heated there and rising up again, continuing the cycle. See also plate tectonics.

Convection

Types Of Boundaries

• Divergent

- rift valleys

• Convergent

-ocean to ocean

- ocean to continental

- continental to continental

Focus On!!!

• Convergent

• Where?

- The Himalayas

Himalayas

• Indian Plate collides with the Eurasian

• Pictures shows the migration of India from around 71mya to 10mya

Broken into Sections

• Quaternary

-upper

- middle

-Lower

• Paleozoic

• Precambrian

• Tertiary Leucogranite

Top to Bottom

Quaternary

• Age form .1 ma to .8 ma

• Consists of alluvial sediments

-Alluvial sediments- clay or slit or gravel carried by rushing streams and deposited where the stream slows down

Upper, Middle and Lower

• Range from the Tertiary down to the Triassic 1.8 to 243 ma

• Consists Siwalik Formation

• Which the Upper, Middle, and Lower are composed of sandstone and shale

Paleozoic

• Upper part

• 248-443 may

• Consists of mainly Limestone and Marl

*Marl-calcium carbonate or lime-rich muds or mudstones which contain variable amounts of clays and calcite or aragonite.

Paleozoic

• Lower Part

• 443-548ma

• Consists of Phyllite and Quartzite

*Phyllite- is a type of foliated metamorphic rock primarily composed of quarts, sericite mica, and chlorite; the rock represents a gradiation in the degree of metamorphism between slate and mica schist.

Precambrian

• Upper

• 543-1200 ma

• Consists of Phyllite and Quartzite

Precambrian

• Lower

• 1200-2500 ma

• Consists of Gneiss and Migmatite

*Migmatite- form under extreme pressure b/w igneous and metamorphism

Cited Work and References

• Websites• U.S. Geological Survey Special Publication:• wc.pima.edu/.../setting/geology_platetec.htm• http://wc.pima.edu/~bfiero/tucsonecology/setting/

images/plates_ooc01.gif• gpc.edu/~pgore/Earth&Space/GPS/platetect.html:

Pamela J.W. GoreGeorgia Perimeter College

• http://www.cotf.edu/ete/modules/msese/earthsysflr/plates3.html

• http://www.cotf.edu/ete/modules/msese/elevator.html• http://mediatheek.thinkquest.nl/~ll125/en/crust.htm

Con’t

• Kious, W.J., and Tilling, R.I., 1996, THIS DYNAMIC EARTH--THE STORY OF PLATE TECTONICS: U.S. Geological Survey Special Publication, 77 p

• Courtillot, Vincent and Vink, G.E., 1983, HOW CONTINENTS BREAK UP: Scientific American, v. 249, no. 1, pp. 42-49

• Bird, J.M., ed., 1980, PLATE TECTONICS (revised ed.): Washington, D.C., American Geophysical Union, 986 p.