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The Leyva Canyon Volcano, Big Bend Ranch State Park, Presidio Co., Texas., John C. White, Kevin M. Urbanczyk, Kelly Watson
The Leyva Canyon Volcano, Big Bend Ranch State Park, Presidio Co., Texas., John C. White, Kevin M. Urbanczyk, Kelly Watson
EKU Faculty and Staff Scholarship
Leyva Canyon volcano is an Oligocene (37.3 to 27.1 Ma) trachyte shield volcano whose eruptive and volcaniclastic deposits of rhyolite and trachyte lavas, ash-flow tuffs, lahars, and associated sedimentary rocks comprise the Leyva Canyon Member of the Rawls Formation. The lavas and tuffs originated from vents located near the present-day "Bofecillos vent" in the central Bofecillos Mountains, approximately 5 km west of the Sauceda Ranger Station in Big Bend Ranch State Park in southernmost Presidio County, Texas. The pyroclastic and volcaniclastic units form the distinctive cliffs and caves at the periphery of the Bofecillos Mountains, with the caves developing in …
Volatiles And Trace Element Contents In Melt Inclusions From The Zoned Green Tuff Ignimbrite (Pantelleria, Sicily): Petrological Inferences., Pierangelo Romano, John C. White, Alessandro Ciulla, Ida Di Carlo, Claudia D'Oriano, Patrizia Landi, Silvio G. Rotolo
Volatiles And Trace Element Contents In Melt Inclusions From The Zoned Green Tuff Ignimbrite (Pantelleria, Sicily): Petrological Inferences., Pierangelo Romano, John C. White, Alessandro Ciulla, Ida Di Carlo, Claudia D'Oriano, Patrizia Landi, Silvio G. Rotolo
EKU Faculty and Staff Scholarship
The island of Pantelleria is one of the best known localities of bimodal mafic-felsic magmatism (alkali basalt and trachyte-pantellerite). Among the felsic rocks, the coexistence in a single eruption of products of both trachyte and pantellerite compositions is limited to few occurrences, the Green Tuff (GT) ignimbrite being one of these. The GT is compositionally zoned from pantellerite (70.1 wt% SiO2, mol Na+K/Al = 1.86, 1871 ppm Zr) at the base to crystal-rich (>30 vol%) comenditic trachyte (63.4 wt% SiO2, mol Na+K/Al = 1.10, 265 ppm Zr) at the top, although the pantellertic compositions dominate the erupted volume. We …