WorldWide Drilling Resource®

21 WorldWide Drilling Resource ® OCTOBER 2020 Core Samples Provide Insight Adapted from Information by the University of Texas The planet was a violent place 200 million years ago. It was struck by mountain-sized asteroids at least three times, chains of volcanoes erupted sending ash and greenhouse gases around the world, and tectonic plates shifted, breaking up the single supercontinent, Pangea. During all of the chaos, several plants and animals simply vanished in a shake-up of life on earth scientists have yet to explain. Learning more about that period of time requires drilling, and then studying, core samples from deep beneath the surface. One core sample in particular has researchers excited. The quarter-mile-long core sample was taken from the Petrified Forest National Park in Arizona in 2013. Recently, researchers have been able to deter- mine the age of the core and piece together a continuous, unbroken stretch of earth’s history from 225 million to 209 million years ago. This timeline offers insight into what used to be a geologic dark age, and will help scientists inves- tigate the abrupt environmental changes from the late Triassic Period, and how they affected plants and animals at the time. To determine the age of each layer, researchers examined the core samples for tiny crystals of the mineral zircon, which are thrust into the sky during volcanic eruptions. Zircons are a date stamp for the sediments they are buried with, when the age of the crystals are compared with traces of ancient magnetism stored in the rocks, a precise geological timeline evolves. According to Adam Marsh, a paleontologist for the Petrified Forest National Park, although there are a great deal of fossils from this period all over North America, until now, there was little information on the late Triassic’s timeline because most of what scientists knew came from studying outcrops of exposed rock pushed to the surface by tectonic movements. The research is the latest outcome of the Colorado Plateau Coring Project, funded by the National Science Foundation and the International Continental Scientific Drilling Program. Editor’s Note: In between our print issues, the WWDR Team prepares an electronic newsletter called E-News Flash . This newsletter is filled with articles not included in our print issue. Based on readership, this was the most popular article of th e month. Get in on the action and subscribe today at: ENV Before the rock core from the Petrified Forest was recovered, most of what was known about the late Triassic Period came from searching for signs of the Chinle Formation on rocky outcrops such as this one. Photo by Randall Irmis / Natural History Museum of Utah courtesy of the University of Texas.