What is the Lower Cretaceous?
Q: What is the Lower Cretaceous?
A: The Lower Cretaceous is the first geological epoch in the Cretaceous period. It began 145 million years ago and ended 100.5 million years ago, lasting for about 46 million years.
Q: Where is the Lower Cretaceous best displayed?
A: The Lower Cretaceous is best displayed in England, where it is composed of two series of rocks with a major rise in sea level between them.
Q: What are the two parts of the Lower Cretaceous?
A: The two parts of the Lower Cretaceous are Wealden Beds and Greensands. The Wealden Beds were laid down in freshwater or brackish conditions while Sands came from a flood plain and Clays came from a coastal lagoonal plain. The Greensands were an olive-green sandstone deposited in the sea and overlaid by Gault Clay, which was a formation of stiff blue clay deposited in a calm, fairly deep water marine environment.
Q: How does sea level differ between Upper and Lower Cretaceous?
A: In the Lower Cretaceous, sea level was much lower than in Upper Cretaceous. In Southern England during this time period, it was a huge tropical river delta whereas during Upper Creteceous it was just offshore on what was then continental shelf at its highest level for Mesozoic era.
Q: How long did this stage last?
A: This stage lasted for about 46 million years, making it longest stage within Phanerozoic eon.
Q: What type of environment did Wealden Beds form under?
A: Wealden Beds formed under freshwater or brackish conditions with Sands coming from flood plain of huge tropical braided river and Clays coming from coastal lagoonal plain.
