I've been on three 4-8 week long field season with the LGRP and 2 weeks helping at the HSPDP Magadi Lake drill site in Kenya.
My fieldwork includes geologic mapping, fault identification, tephra identification, sedimentology, stratigraphic sections, and providing geologic support for other scientists like paleontologists, anthropologists and archaeologists. |
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In the lab, I prepare tephra samples for electron microprobe analyses. Tephra is a volcanic deposit of volcanic glass shards, crystals, or generally whatever the volcanic eruption ejected out and fell to the ground. Ash, small pieces of glass, and crystals can blanket the ground for hundreds of miles and even across oceans carried by the winds. When a volcano erupts the magma/lava quenches so fast it creates glass shards that contain unique elemental abundances for each eruption. This unique geochemical fingerprint allows geologists to correlate tephra units and associated sediments across basins and even continents.
Preparation includes sieving, acid treatment, magnetic separation, heavy liquid separation, creating epoxy sample mounts, polishing and carbon coating. To analyze the prepared samples I use wavelength-dispersive spectrometry on a JOEL JXA 8530F Electron Microprobe using JOEL software. I analyze 9 major elements (Si, Al, Ca, Na, K, Fe, Mg, Ti, and Mn) of volcanic glass shards for chemical characterizations. Chemical characterizations can provide a geochemical fingerprint to establish isochronous markers in the stratigraphic record. |
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