PLATE TECTONICS OF THE NORTH AMERICAN CONTINENT AT THE KP BOUNDARY AND IMPLICATIONS FOR A TERRESTRIAL CAUSE IN THE GREAT KP EXTINCTION CONTROVERSY

The debate rages on over the exact cause of the mass extinctions that occurred at the Cretaceous-Paleogene boundary of 65 Ma. The most widely accepted hypothesis states that a huge asteroid crashed into the Earth sending dust and debris into the atmosphere. Other scientists claim that the KP boundary layer contains evidence of a volcanic origin. Most, however, point to the Deccan Traps of India as the cause of the Extinctions.

This paper will introduce a new hypothesis on the KP Extinctions of 65 Ma, and will attempt to show that all of the evidence found within the KP boundary layer can also be explained by another event that was also occurring at the same time as the Deccan Traps of India, but on the other side of the world from it. This event has been recorded geologically by the presence of the Franciscan mélange and Coast Range Ophiolite that make up most of California. All of the materials found within the KP boundary layer: high levels of iridium, glass spherules, and shocked quartz, can also be explained by the closing off of a mid-ocean ridge and/or ocean island hotspot as it was being thrust beneath the continental plate of North America, 65 million years ago. From the Coast Range Thrust, to the uplifting of the Laramide Orogeny, resulting in the disappearance of the Western Interior Seaway; this paper will explore the geologic record of the North American continent to gain a complete understanding of what was happening, tectonically, at the KP boundary and will propose that the extinctions were the result of terrestrial rather than extraterrestrial forces.