BEFUS EARTH

Ingo Sonder and Alison Graettinger led a large community experiment at University of Buffalo where shallow dynamite explosions were used to mimic volcanic blasts. Kenny Befus assisted with drone data collection and photogrammetry. 

Geostationary thermal infrared data was combined with ground-based seismic monitoring to understand the build up and eruption of La Soufriere Volcano. James Thompson concluded that combined analyses will improve the community's evaluation of volcanic eruptions

Diamonds entrap mantle inclusions and shield them from alteration. Diamonds from Guyana provide a window into the subcratonic mantle below northern South America. Roy Bassoo showed the harzburgite cratonic root is dry, viscous, old, and reduced.

Anna Ruefer characterized the external morphology and vesicularity of thousands of quartz-hosted rhyolite embayments. Forms and textures vary widely within and across targeted eruptions. We speculated that the diverse embayment textures preserve disequilibrium stories that can be used to better understand magmatic processes. 

Guyana's alluvial diamonds have been mined from rivers deep in the Amazon jungle for the past century but they had never previously been studied. PhD student Roy Bassoo used diamond texture and composition to demonstrate they are likely detrital in origin, shed from the Paleoproterozoic Roraima Supergroup.

Osmium isotopes and Platinum Group elements spike in 5 sediment layers in Hall's Cave, Texas. One spike is at the same time as the start of the Younger Dryas cooling event. We show that the prevailing hypothesis of an extraterrestrial impactor is wrong. Instead, cryptotephra from distant volcanic eruptions are a much more likely explanation for the unradiogenic signature in the spikes in the sediments.

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Associated products: Altimetric Stats, This picked up a lot of Press (Example)

PhD student Roy Bassoo describes diamond characteristics from specimens collected at Crater of Diamonds, Arkansas. Roy uses a field trip narrative to share the science, which includes morphology, inclusion composition, and mantle conditions. 

We measured the abundance of hydrogen isotopes in melt inclusion glasses trapped within quartz phenocrysts from the Bishop Tuff. The hydrogen isotope ratios range from -40 to -60 per mil. These values are not modified by degassing, AFC processes, or diffusion. Instead, the likely record the composition of the rhyolite reservoir. ​

A Cambrian quartzite in the Blue Ridge mountains of Virginia record penetrative strain at subgreenschist facies. Quartz was dynamically recrystallized in a wet environment that averages 100 to 400 ppm, but ranges up to 2,000 ppm. Hydrolytic weakening permitted the high strain in such cold rocks. 

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We present elastic thermobarometry using Raman spectroscopy to the petrology community. We provide good and bad case studies to transparently demonstrate​ the application of the technique. We also share a Matlab software that allows a potential user to explore any host-inclusion mineral pair. 

Master's student Tyler Leggett published his work using stunning drone imagery to better understand the emplacement dynamics of rhyolite lavas. We focused on the South Coulee lava flow in Mono Craters, CA. Ridge spacing and block size distributions were used to calculate flow criteria, including eruptive timescales, strain rates, and flow velocity.

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Associated products: Panum video, NPR video on explosions   

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We share an experimentally-calibrated numerical model that simulates the growth of plagioclase in silicic magma. Our experiments provide kinetic constraints on plagioclase growth rate relative to the degree of disequilibrium in the system. The model allows a user to interrogate natural plagioclase populations. 

X-ray micro diffraction measurements indicate that volcanic stresses are preserved in quartz crystals from Yellowstone and Long Valley caldera. The source of the <300 MPa of residual stress remains uncertain but may be produced by force chains in the magma reservoir or stresses associated with the brittle failure of viscous melt. 

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Quartz phenocrysts from the Lava Creek Tuff, Yellowstone caldera, contain empty reentrants. The reentrants are preserved vestiges of bubbles in the pre-eruptive chamber. They tell us the magma was bubbly in the reservoir.

We performed high temperature, continuous decompression experiments using a starting material of pumice from Pinatubo's climactic 1991 eruption. Plagioclase microlites nucleate and grow systematically in response to supersaturation-dependent disequilibrium. 

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We calibrate the pressure-dependent Raman shift of feldspars using a diamond anvil cell coupled with Raman spectroscopy. The calibration allows Raman spectroscopy of feldspars to be used to quantify PT conditions for magmatic rocks, low- to high-grade metamorphic rocks, and the mantle.

Obsidian pyroclasts from Mono Craters, CA contain heterogenous water and carbon dioxide contents. This indicates the clasts are assembled from welding of magma and ash during magma ascent.

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We measured volatile contents and observed vesicle textures in obsidian pyroclasts from Mono Craters, CA. The pyroclasts formed following fragmentation through processes of sintering and relaxation.