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Geology's Missing Billion Years Found?
10 Nov
Summary
- A new theory suggests deep Earth processes explain missing geological time.
- Continental uplift and glacial erosion are key factors in a new model.
- The Great Unconformity may link to the Cambrian explosion's timing.
A groundbreaking paper proposes a novel theory to unravel one of geology's enduring mysteries: the Great Unconformity. This geological feature, characterized by young sediments atop ancient basement rock, signifies a billion years of missing Earth history.
The new hypothesis, developed by Australian researchers, suggests that the missing rock layers once existed but were eroded away. Their models indicate that deep Earth mantle convection, a slow churning of hot rock beneath the crust, caused continental blocks to uplift approximately a billion years ago.
This uplift exposed ancient crystalline basement rock. Subsequently, global ice sheets are thought to have eroded these exposed layers during an ice age around 700 million years ago. As continents subsided, new sediment layers formed on the scoured rock, creating the Great Unconformity.
Researchers further speculate that this glacial erosion may have altered seawater chemistry, potentially triggering the Cambrian explosion, a pivotal period of life's diversification around 540 million years ago. This theory aligns with existing observations of glacial erosion and continental drift.
