Week 5 - Late Paleozoic Flashcards
What are the key themes of the Late Paleozoic?
New Red Sandstone, Old Red Sandstone, Limestone & Coal, Assembly of Pangaea, Colonization of the land, Atmospheric oxygen & CO₂ changes.
What are the major geological changes in the Late Paleozoic?
Assembly of Pangaea, Variscan Orogeny, closure of the Rheic Ocean, formation of Palaeotethys.
What are the major rock units of the Late Paleozoic in Britain?
Old Red Sandstone, New Red Sandstone, Carboniferous Limestone, and Coal Measures.
What is the significance of the Old Red Sandstone?
It represents continental red beds deposited in river and desert systems during the Devonian.
What was the climate like during Old Red Sandstone deposition?
Arid to semi-arid conditions, with oxidation forming red coloration.
What is the Rhynie Chert, and why is it important?
A fossil deposit in Scotland containing early vascular plants, arthropods, and fungi preserved by silica from hot springs in the Devonian.
What was Prototaxites?
A giant Devonian fungus that grew up to 8 meters tall, dominating early terrestrial ecosystems.
What was Ichthyostega, and why is it important?
One of the first tetrapods, marking the transition from aquatic to terrestrial vertebrates in the Late Devonian.
What were the dominant plants of Carboniferous coal forests?
Lycopsids like Lepidodendron, ferns, and early seed plants
How did Carboniferous coal formation affect global CO₂ levels?
Burial of organic material in coals reduced atmospheric CO₂, contributing to an ice age.
What was Arthropleura?
A giant Carboniferous millipede, over 2 meters long, one of the largest terrestrial arthropods.
What major climate shift occurred in the Late Carboniferous?
The Earth entered a glacial period due to CO₂ drawdown from coal formation.
What major paleogeographic change occurred during the Permian?
The full assembly of Pangaea, bringing extreme climates and desertification.
What is the Zechstein Formation, and why is it important?
A Permian evaporite deposit in Europe, significant for oil and gas reservoirs.
How did atmospheric oxygen levels change during the Late Paleozoic?
Oxygen reached its highest known levels (~35%), leading to giant arthropods.
What was the main cause of the Permian-Triassic mass extinction?
Massive volcanic eruptions (Siberian Traps), leading to climate change and ocean anoxia.
What major orogeny (mountain-building event) occurred in the Late Paleozoic?
The Variscan Orogeny, caused by the collision of Laurussia and Gondwana.
What conditions led to Carboniferous Limestone formation?
Warm, shallow tropical seas covered much of what is now the British Isles, allowing carbonate sediments to accumulate.
What is the significance of Carboniferous Limestone?
It forms extensive rock formations and is an important aquifer and reservoir rock for oil and gas.
What is karst topography, and how is it related to Carboniferous Limestone?
Karst topography is a landscape formed by the dissolution of limestone, creating caves, sinkholes, and underground rivers.
How long ago was the Devonian period?
The Devonian lasted from 419 to 359 million years ago (Ma).
When was the Carboniferous Period?
The Carboniferous lasted from 359 to 299 Ma.
How long ago was the Permian period?
The Permian lasted from 299 to 252 Ma.
What is Laurussia?
A Paleozoic supercontinent formed by the collision of Laurentia, Baltica, and Avalonia during the Silurian-Devonian periods.
What major mountain-building event was caused by Laurussia’s formation?
The Caledonian Orogeny, which formed the Caledonides in Scotland, Scandinavia, and Greenland.
What happened to Laurussia during the Carboniferous?
It collided with Gondwana, contributing to the formation of Pangaea.
What parts of the UK were originally part of Avalonia?
England and Wales, but not Scotland, which was part of Laurentia.
What was Avalonia?
A microcontinent that existed during the Early Paleozoic before merging with other landmasses.
