What was the true cause of the infamous mass extinction at the end of the Cretaceous period? In this article, we will be evaluating two rival theories.
Impact Theory VS. ______?
The most currently accepted asteroid impact theory basically says: “A giant asteroid wiped out the dinosaurs”. In 1980, Nobel Prize-winning physicist Luis Walter Alvarez and his geologist son Walter published a theory that a historic layer of iridium-rich clay was caused by a large asteroid colliding with Earth. There is another notable theory by Gerta Keller, a professor of paleontology and geology at Princeton. Despite numbers of other theories proposed by other scientists, Alvarez’s theory has triumphed all others in the field since its inception.
Deccan Traps Theory
However, a crucial part of Alvarez’s theory actually supports Gerta Keller’s opposing “Deccan Traps Theory”. Alvarez’s main evidence for his impact theory, the layer of iridium-rich clay, wasn’t just one layer, but multiple separate layers. Alvarez defended his theory against the opposition who highlighted this hole in his theory and explained the extra layers at different depths by saying that it wasn’t just one asteroid, but multiple. While this is possible, I think Keller’s theory is much more plausible.
We must recognize that Gerta Keller is a woman in science. Intellectual women have been undermined and had their ideas stolen by men for years. I believe that the lack of popularity of Keller’s theory can be attributed to the fact that she was a woman.
What are the Deccan Traps?
The Deccan Traps are a plateau that was formed by molten lava around 66 million years ago. The Deccan Traps cover around 500,000 square kilometers of western India.
Deccan Volcanism
Keller’s theory involves the concept of “Deccan Volcanism”. Deccan Volcanism refers to 4 or 5 volcanic eruptions in the Deccan Traps that occurred before the KTB(Cretaceous–Tertiary) mass extinction. Each of these eruptions created massive flows of lava that can be seen in the fossil record.
These eruptions also likely caused intense climate change, along with releasing tons upon tons of toxic gases into the atmosphere. The destruction of the global environment led to the eventual extinction of countless species.
Combo Theory?
Many believe that this environmental destruction contributed to the decline of many species in this period but didn’t “wipe them out”. Some scientists believe after all of the destruction, some sort of impact was the final nail in the proverbial coffin. This combined Deccan traps-impact theory has grown in popularity in recent years as more evidence surfaces to support it.
