EARLY PALEOZOIC EVENTS CAMBRIAN PALEOGEOGRAPHY Development of a shallow epeiric or epicontinental...

EARLY PALEOZOIC EVENTSCAMBRIAN PALEOGEOGRAPHY

Development of a shallow epeiric or epicontinental sea

Continent situated on the equator, so waters most likely warm

Significant carbonate deposits accumulate

Deep water sediments (shales) are accumulating on margins


Cambrian stromatolitesPetrified Sea GardensSaratoga Springs, NY


Nonconformity

Tapeats Ss.

Bright Angel Sh.

Mauv Ls.

EARLY PALEOZOIC EVENTSCAMBRIAN PALEOCLIMATE

EARLY PALEOZOIC EVENTSORDOVICIAN PALEOGEOGRAPHY

Ordovician named after the Ordovices, an early Celtic tribe named by Charles Lapworth as a compromise in 1879


Ordovician continents still centered along Equator


Ouachita Terrane

Broken off Laurentia

Forms a microcontinent

Will collide with South America


Taconic Orogenic Belt

Begins development along margins of Laurentia and Baltica


Global sea level is highGondwanaland moving towards South Pole


Gondwanaland moving towards South PoleLeads to glaciation at the end of Ordovician

EARLY PALEOZOIC EVENTS

ORDOVICIAN PALEOGEOGRAPHYSea level high

Canadian Shield being covered by sediments

Shallow water carbonates in the mid-continent regions with mudcracks and stromatolites in Early Ordovician

EARLY PALEOZOIC EVENTS

ORDOVICIAN PALEOGEOGRAPHYCarbonate deposition ended in the Middle Ordovician

Region was downwarped

Caused by closing of the Iapetus Ocean along a subduction zone

Prior to the Taconic orogeny, the "east" coast of what is now the United States was located near the Hudson River valley, Philadelphia, Washington, DC and extended to western South Carolina.

The Taconic Orogeny added land to Proto North America that is now the western portions of New England and the Canadian Maritime provinces. This collision added land and raised mountains southward through northern New Jersey, south-eastern Pennsylvania, Virginia and North Carolina.

Occurred approximately 460-480 myBP



The Taconic island chain began to collide with Proto North America about 470 to 450 million years ago

The energy of ongoing impacts was still raising mountains from Canada to Virginia 430 million years ago.

The Iapetus Ocean, which had been the shoreline for Proto North America, is closing as Western and Eastern Avalonia, following behind the Taconic arc, are heading for collision with the recently-extended coast of Proto North America.


TAC

Taconic Island Chain

EAV

Eastern Avalon Terrane

WAV

Western Avalon Terrane

Taconic Orogeny

Latest

Earliest


St. Peter Sandstone

EARLY PALEOZOIC EVENTS CAMBRIAN PALEOGEOGRAPHY Development of a shallow epeiric or epicontinental...

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