A groundbreaking study published in Science Advances proposes a startling theory: the mass extinction event known as the Sinsk event, which occurred roughly 513 million years ago during the Cambrian period, may have been triggered by dramatic tectonic activity linked to the supercontinent Gondwana.
Lead researcher Paul Myrow, a sedimentologist from Colorado College, and his team uncovered compelling evidence linking the demise of ancient reefs and the altering of oceanic conditions to tectonic events within Gondwana. By examining rock layers in Antarctica’s Transantarctic Mountains and on Kangaroo Island, Australia, they discovered consistent patterns that pointed to a shared geologic history between the two regions.
The findings suggest that as Gondwana underwent significant tectonic shifts, including mountain-building events, shallow oceans adjacent to the newly formed mountains experienced subsidence, causing the drowning of archaeocyathid reefs. Erosion from the rising mountains then buried these reefs under layers of sediment.
Moreover, the study highlights the role of large igneous provinces, which emerged due to tectonic activities, in exacerbating the extinction event. These volcanic formations released copious amounts of greenhouse gases, leading to global warming and disrupting oceanic circulation. This disruption, akin to a phenomenon seen in modern-day climate change concerns, resulted in the suffocation of many marine organisms, particularly those reliant on oxygen-rich environments.
Myrow emphasizes the significance of their findings, noting the clarity with which the sequence of events leading to the Sinsk event is elucidated. While large igneous provinces have been previously implicated in extinction events, the study provides unprecedented clarity regarding their role in the Sinsk event.
These revelations underscore the intricate interplay between tectonic activity, climate change, and extinction events in Earth’s history, shedding new light on our understanding of ancient ecosystems and their susceptibility to environmental perturbations.
