(03)DeepTime&Deserts

(03)DeepTime&Deserts - GEOLOGY 20 - LECTURE 3 DEEP...

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1 GEOLOGY 20 - LECTURE 3 DEEP TIME & DESERTS (Ch. 3 & 6 in Harden - read selectively!) Geologic Time (aka “Deep Time”) Key events in the history of Earth . . . . you don’t need to memorize the following information. You only need to memorize a few key dates and time periods - see chart on p.43 in Harden textbook or go to http://www.ucmp.berkeley.edu/help/timeform.html 4.6 b.y.a. (billion years ago) - birth of the solar system and Earth, based on the ages of certain meteorites (meteorites are rocky remnants of the original solar material that never became part of the sun, a planet or a moon) 3.9 b.y. - oldest rocks recognized on Earth 3.7 b.y. - oldest recognizable single-celled bacteria 1.7 b.y. - oldest rocks in California 1.5 b.y. - oldest recognizable single-celled organisms with nuclei 1.0 b.y. - origin of sexual reproduction 700 m.y.a. (million years ago) - first multi-celled animals Up to this point in time, California is unrecognizable as a geographic entity - what we would today call eastern California is under a shallow sea and the rest of California is not formed yet - the shoreline of the North American continent is over in Utah and Arizona 540 m.y. - first animals with hard shells living in the shallow oceans that covered eastern portions of California (no Sierra Nevada, no Central Valley, no Coast Ranges, no Cascades, no southern California mountains and basins) - 540 m.y. marks the boundary between the Precambrian Eon (almost 90% of all geologic time) and the Paleozoic Era 480 m.y. - first fish 420 m.y. - first land plants (invasion of the land begins) 380 m.y . - first amphibians 320 m.y. - first reptiles
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2 During the Paleozoic, the area that eventually becomes California is underwater (very shallow to very deep). 250 m.y.
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This note was uploaded on 04/22/2008 for the course GEL 20 taught by Professor Osleger during the Spring '08 term at UC Davis.

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(03)DeepTime&Deserts - GEOLOGY 20 - LECTURE 3 DEEP...

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