New Evidence Confirms That Earth Was Unstable Before the Asteroid Impact That Wiped Out the Dinosaurs
New proof gleaned from Antarctic seashells confirms that Earth was already unstable before the asteroid effect that wiped out the dinosaurs.
Northwestern University researchers are the 1st to measure the calcium isotope composition of fossilized clam and snail shells, which was back to the Cretaceous-Paleogene mass extinction occasion. The researchers discovered that—within the run-as much as the extinction occasion—the shells’ chemistry shifted in response to a surge of carbon within the oceans.
This carbon influx was possible because of long-term eruptions from the Deccan Traps, a 200,000-sq.-mile Volcanic province positioned in trendy India. Through the years main as much as the asteroid impression, the Deccan Traps spewed huge quantities of carbon dioxide (CO2) into the atmosphere. The focus of CO2 acidified the oceans, instantly affecting the organisms living there. The research can be printed within the January 2020 subject of the journal Geology, which comes out later this month.
Seashells are mostly composed of calcium carbonate, the identical mineral present in chalk, limestone, and a few antacid tablets. Carbon dioxide in water dissolves calcium carbonate. In the course of the formation of the shells, CO2 probably has impacts shell composition even without dissolving them. For this research, the researchers studied shells collected from the Lopez de Bertodano Formation, a very well-preserved, fossil-rich area from the west side of Seymour Island in Antarctica.
The researchers stated that understanding how the Earth responded to previous extreme warming and CO2 input might help us to prepare for a way the planet will respond to present, human-caused climate change.