Scientists have found geological evidence that large mountain systems similar to the Himalayas existed in Antarctica during the formation of Gondwana. Their erosion may have contributed to enriching the oceans with nutrients and promoting the development of animal life. This is reported in a study published in the journal Earth and Planetary Science Letters, U.N.N. reports.
Details
The authors of the study, Bei Chen and Ian Campbell, examined detrital zircons—minerals whose composition and age help reconstruct the geological history of rocks. The scientists concluded that the roots of ancient mountains formed during the assembly of Gondwana are preserved beneath the Antarctic ice sheet. According to their calculations, during the Cambrian interval studied, approximately 46% of the zircons in the weighted global database came from Antarctica. Among grains associated with formation under high pressure, this share was 55%. These figures characterize the mineral database studied, not the area of the ancient mountains.
Marine sediments near Antarctica’s coast help scientists study the continent’s geology hidden beneath the ice. Glaciers erode rocks and carry their fragments into the ocean, where the material can be obtained by drilling the seafloor.
In a related paper published in Communications Earth & Environment, Chen, Campbell, and Richard A. K. Arkulus analyzed the ages and trace-element contents of 1,712 zircon grains. The oxygen and hafnium isotope compositions were also examined for some of the samples. The predominant age group of the minerals was 650–450 million years. The researchers link it to tectonic processes during the era of Gondwana’s formation. The authors estimate that the studied material originated from glacial drainage areas covering approximately 90% of Antarctica’s territory.
How ancient mountains could have influenced the development of life
The hypothesis linking large-scale mountain building with the development of complex life is based on the consequences of erosion. The erosion of mountains supplied the oceans with nutrients, particularly phosphorus and iron, which supported biological productivity. According to the authors’ interpretation in the new study, increased photosynthesis and the subsequent burial of organic carbon contributed to the accumulation of oxygen. This may have created favorable conditions for the development of animals and the Cambrian explosion—a period of rapid growth in their diversity.
Context
In 2022, researchers from the Australian National University had already described ancient “supermountains” that may have reached the height of the Himalayas and extended for up to 8,000 kilometers. One of the stages of this mountain-building process that they identified occurred 650–500 million years ago.
We should note
Somewhat earlier, it became known that scientists had identified a rare dinosaur fossil from Antarctica that had been kept in a drawer for decades.