UCD School of Earth Sciences Seminar with David Moecher - Fulbright Ireland Scholar 2022 (University
27/04/2022 13:00
27/04/2022 14:00
Hybrid (Covid-19 permitting)
Hybrid (Covid-19 permitting)
Event Attendance Instructions
Zoom link will be circulated on Mondays. Contact ucdsesseminars@ucd.ie for more information.
David Moecher (Fulbright Ireland Scholar 2022, Universtiy of Kentucky) will talk on "The Great Reach of the Hot, Giant, Long-Lived Grenville Orogen: Its Influence on the Neoproterozoic to Phanerozoic Clastic Sedimentary Record of Laurentia and Amazonia".
Abstract: The Grenville orogen,
formed during assembly of Rodinia, is described as one of Earth’s largest,
longest-lived, and hottest orogens. The subsequent exhumation and erosion of
the Grenville, starting ca. 1.0 Ga and lasting to ca. 0.6 Ga, generated a
clastic wedge deposited by a pancontinental river system that covered Laurentia
– the “Great Grenvillian Sedimentation Event” (GGSE) of Rainbird et al.
(2012). The clastic wedge was subsequently eroded by the end of the
Neoproterozoic during formation of the “Great Unconformity” across Laurentia.
The Grenvillian sediments were recycled through multiple Phanerozoic orogenies
and by a second pancontinental river system during formation of Pangea.
Amazonia is widely proposed as the continent that collided with southeastern
Laurentia during the Grenville orogeny and may have experienced ‘spillover’ of
sediment derived from the Laurentian Grenville. A new detrital zircon U-Pb
dataset from southwestern Brazil, in tandem with published detrital zircon data
for Neoproterozoic to modern Amazonian clastic systems, indicates the absence
of significant Laurentian Grenville input to Amazonia, i.e., there was no GGSE
in Amazonia. Some aspects of the detrital zircon record in Amazonia are
consistent with Laurentian input.