GSC 111 Lecture 16: Lecture 16 Late paleozoic Life and Paleogeography (Carboniferous and Permian
26 Nov 2017
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Late paleozoic life and paleogeography (carboniferous an permian) Limestones and coal deposits in the tropics. Collision of laurentia and small island arc. Collision of euramerica and gondwana land (mississippian) Form on floodplains and shallow coastal swamps. Associated with repeated transgressive-regressive sea level cycles (cyclothems) Eustatic (global) sea level changes due to advance an retreat of glaciers (milankovitch cycles) Carboniferous to early permian: deep foreland basins. End permian: shallow seas retreat from midcontinent. Reef margin steepened as sea levels rose. Bottom of delaware basin became stagnant- uninhabitable for life. Volcanic arc thrust onto and accreted to continent. Increased oxygen lead to higher respiratory function an greater flight capacity. Amniote egg- life cycle no longer tied to freshwater. Rise of reptiles- advance jaw an bladed teeth. Terrestrializatio(cid:374) of pla(cid:374)t life (cid:862)the ca(cid:373)bria(cid:374) explosio(cid:374) for pla(cid:374)ts(cid:863) Vegetation= global reduction in co2 an increase in o2. Increased burial: anoxic environments, absence of lignin decomposers. Increased weathering of silicate rocks: root action, organic acid production.
