Week 4 - Early Paleozoic Flashcards
What is the Early Paleozoic?
A geological time period spanning from the Cambrian to the Devonian, characterized by significant evolutionary events and tectonic changes.
What major ocean separated early Britain and Ireland?
The Iapetus Ocean.
What are the main geological periods of the Early Paleozoic?
Cambrian, Ordovician, Silurian, and Devonian.
What is the Wilson Cycle?
A theory describing the opening and closing of ocean basins due to plate tectonics.
What major tectonic event led to the closure of the Iapetus Ocean?
The Caledonian Orogeny.
What continents were involved in the formation of Britain and Ireland?
Laurentia and Avalonia.
What does paleomagnetism tell us about past continental positions?
It helps determine past latitudes based on magnetic inclination in rocks.
What significant evolutionary event occurred in the Cambrian?
The Cambrian Explosion, a rapid diversification of life.
What type of fossil evidence is abundant from the Cambrian?
Trilobites.
What was the position of Avalonia during the Early Cambrian?
It was a microcontinent moving towards Laurentia.
What major extinction event occurred at the end of the Ordovician?
The End-Ordovician Mass Extinction.
What climatic event is associated with the Late Ordovician?
The Hirnantian glaciation.
What geological feature is evidence of Ordovician glaciation?
Striated glacial pavements.
What was a key development in marine life during the Silurian?
The diversification of fish.
What geological changes happened in the Late Silurian/Early Devonian?
The final collision of Avalonia and Laurentia, forming early Britain.
What type of fossils are common in Devonian strata?
Brachiopods and early fish fossils.
How did Scotland’s pre-Devonian geology differ from southern Britain?
Scotland was part of Laurentia, while England and Wales were part of Avalonia.
What does sedimentary rock distribution tell us about past climates?
It reflects atmospheric circulation and precipitation patterns.
How do stratigraphic logs help understand tectonic history?
They show differences in sediment deposition and deformation.
