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Science Cafe is held the first Wednesday of every month at McMullan's Irish Pub (4650 W. Tropicana Ave). Doors open at 6:30 p.m. with trivia and the presentation starting promptly at 7 p.m.

Bring friends and family for informal public discussions with leading scientists on interesting topics. Grab some dinner while listening.

Cody Colleps, Ph.D., an assistant professor in ÐÔÊӽ紫ý's Department of Geoscience will be giving a talk titled, "A Rock’s Tale Told by the Noblest of Gases: How Helium in Minerals can Constrain Rates and Dates of Geological Processes". 

Abstract:

The ability to track a rock’s thermal history—from the time its individual crystals solidified from a molten magma to the present day when exposed at Earth’s surface—is vital to understand the tectonic and climatic processes that shaped Earth’s landscape into what we see today. Geologists often apply Geochronology and Thermochronology to obtain dates (or ages) to constrain the timing of processes such as magmatism, mountain uplift, erosion, and sedimentation on timescales on the order of millions, to even billions, of years. Numerous mineral dating systems exist with varying temperature sensitivities, including the lesser known, but equally important, (U-Th)/He low-temperature thermochronometric dating system for the minerals zircon and apatite, which can be applied track a rock’s exhumation pathway from ~10 km depth up to the surface. This system revolves around (1) the radiogenic production of helium from uranium and thorium, and (2) helium’s thermally activated diffusion out of individual zircon or apatite crystals—once diffusion of helium stops inside a mineral at low temperatures, the (U-Th)/He dating clock begins. Join me as I demonstrate how measuring helium from single, microscopic minerals can provide insights into global-scale geologic interactions.