Miércoles Geológico 17 de MARZO, 2021
JURASSIC MARINE ECOLOGY HIDDEN IN PUCARÁ CHERT MICROFACEIS
Pucará Group rocks across the Yauli Dome area channel the distribution of ore-bearing mineral deposits, with chert rock playing an important role in lithologic behavior. Detailed paleoecological analysis of these rocks demonstrated their character, lithology, and marine biotic components in the work of S. Rosas and colleagues. We add scrutiny to the chert rocks, and to the role of siliceous sponge fossils in preserving, spreading, and retaining the current distribution of resistant lithology that shapes the region. Paleongologically, the chert rocks reveal a huge expansion of sponge animals in the aftermath of the Triassic-Jurassic mass extinction. Ongoing work is testing the role of global ocean chemical cycles, climate, and local-scale habitat changes on this pivitol interval in global marine ecosystems.
Anita Ritterbush is an Assistant Professor in the Department of Geology and Geophysics at the University of Utah, where she researches biomineralized large-scale deposits in chert and carbonate rock. She also studies the swimming habits of ammonites. Generous mentoring by Silvia Rosas, with geologic guidance by Julio Zarate, Carlos Astorga, and colleagues across the region helped launch her career studying strange and wonderful sponge rocks.