Many Colorado River runners find themselves drawn to the geology cut by the river. It is easy to become fascinated by the different strata, their colors, and how they shape the canyon walls that bound the river. But the geology of the river is more than a rock record. It is a biological treatise of the world. As one floats by exposed strata, one is provided a fascinating glimpse of how life emerged and evolved across our planet. While we often tell riverside tales of the plants and animals fossilized in the rock, we often overlook those dramatic moments when the rock record is punctuated by mass extinctions.
This evening, the locations of those events along the river will be briefly described before we focus on the calamitous cause of one of those mass extinctions: the Chicxulub impact cratering event that generated a global environmental calamity and extinguished most life on Earth 66 million years ago. Hear one of the discoverers of the Chicxulub crater describe how that impact event caused wildfires, acid rain, and a warmer climate in the region now drained by the Colorado River. Presented by Dr. David Kring, who has been studying and teaching Arizona geology for 30 years.
Location: Lowell Observatory, at the Giclas Lecture Hall in the Steele Visitor Center, 1400 W Mars Hill Rd.