Earth History GEOL 2110

Midterm 2Preparation/Review

Style of Questions

• Matching term w/ definition

• Short definition of concepts/processes

• Name some of multiple characteristics

• 25% of points from Part II Quizzes

REVIEW PowerPoints!!

Understand Figures in Text.

Focus on the Narrative – the great book of the Earth, chapter by chapter.

The PrecambrianIN MINNESOTA

Know the Eons/Eras

4 Main Tectonic Events in MN

General Ages of the 4 main events

Characteristic rock types of the four main events.

Continents formed from each event

Summary of Early Earth Events

SudburyImpact

SUPERCONTINENT - RODINIA

What causes break-up?

Contributions to the Cambrian Explosion of Life

• End of the extreme snowball earth glaciation

• Tectonic break-up of Rodinia increases niches

• Potentially higher atmospheric O2 promotes calcite exoskeleton secretion

• Increased nutrients associated with more rifting and volcanic activity

• Abundant cyanobacterial mats for molluscs and other small invertebrates to graze

• Development of predators

• Tiering of biotic activity on the sea floors

Paleozoic Era and its 8 Periods

KNOW• Order of Periods•Characteristic Rock Types• Paleogeography•Depositional Environments• Trangressive Sequences•Characteristic Organisms•Tectonic Events

Cambrian COrdovician OSilurian SDevonian DMississippian M

CarboniferousPennsylvanian PPermian P

Cambrian ChasingOrdovician Ostriches onSilurian SandDevonian DunesMississippian Makes

Carboniferous CathyPennsylvanian Pee herPermian Pants

Early Paleozoic Era

Early Paleozoic Era

Early Paleozoic Era

The Ordovician “Explosion”

Changes in Ordovician from Cambrian Fauna

• more complex food chain

• extend higher above the seabed

• hard part made of calcite rather than phospate

Middle Paleozoic

Middle Paleozoic

Sedimentary Rocks and Depositional Environments

FlyschMolasseCoal Beds Evaporites (gypsum, halite)High-angle Cross-bedded SandstoneOrganic Reef ComplexesCarbonates (limestone and dolostone)Quartz sandstone Shale and SiltstoneIron FormationGraywacke/Shale

Middle Paleozoic

The Age of Fishes

Plants colonize the land!Invasion of the LandVascular Plants take Root

Late Paleozoic

Late Paleozoic

Late Paleozoic

PermianCraton Tilts West / Seas Retreat / Climate Dries

Late Paleozoic – All Genera Established

The Great Permo-Triassic Extinction90-95% of all marine species die out, and land life too

Proposed Causes - Global cooling due to Gondwana glaciation- Reduced marine habitat due to the creation of Pangea - Extreme climatic changes- Oxygen depletion due to exposure of coal deposits- Upwelling of CO2 from deep ocean waters – hypercapnia- Intense outpouring of basalt in SerbiaNO EVIDENCE OF A METEOR IMPACT AT LEAST!

Summary of Paleozoic Tectonics

North American Paleozoic Orogenies

Acadian/Caledonian

Appalachian/Hercynian

Taconian

Gondwanaland

REMEMBER -IT’S ALL ABOUT THE STORY!

Good Luck!