ERTH 2401 Lecture 4: The Mesozoic Landscape: Where Dinosaurs Roamed
3 Nov 2015
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Earth paleogeographic change (600 million years: modern day, quaternary (0. 01 million years ago, miocene (20 mya, oligocene (35 mya) Eocene (50 mya: cretaceous/tertiary boundary (65 mya) Late jurassic (150 mya: middle jurassic (170) Large earth changes during dino era: triassic, early jurassic, late jurassic, early cretaceous, late cretaceous, latest cretaceous, cretaceous/tertiary boundary. Six unconformity bounded sequences of world-wide sea-level changes through geological time. Note: 2 maxima 500 and 75ma 350m above present level. 3 minima 600, 200 ma and present 150m below present level. Cratonic sequences of north america *see diagram: tejas, zuni, absaroka, kaskaskia, tippecanoe, sauk. Transgression (highstand) shoreline moves landward: regression (lowstand) shoreline moves seaward. Stillstand intermediate pause between rise and fall. Sea level change: have shaped the earth through geological history. Eustatic: global sea-level changes 100 to 10ma: relative: local or regional changes ma or less, unconformity large time or depositional gaps in stratigraphy.
