NPGS meeting – May 2

Nevada Petroleum and Geothermal Society Monthly Dinner Meeting:  Thursday May 2, 2013 (6:30 PM)
Where:  Ramada Reno Hotel, 1000 E 6th St, Reno, NV
Speaker:  Sean P. Long, Research Professor, NBMG, UNR

Title:  What can the mid-Tertiary unconformity tell us about deformation and erosion in the Nevadaplano?

Abstract
The hinterland of the Sevier orogenic belt in Nevada and western Utah has been interpreted as an ancient, high-elevation orogenic plateau, or ‘Nevadaplano’ that extensionally collapsed during Tertiary time. To illustrate the pre-extensional structural relief of this region, a new paleogeologic (or ‘subcrop’) map showing the distribution of Neoproterozoic to Triassic sedimentary rocks exposed beneath a regional Paleogene unconformity is presented.  In addition, using published isopach maps of depositional thickness of Neoproterozoic to Triassic rocks, the paleogeologic map has been converted into a map that contours the thickness of rock eroded between the top of the Triassic section and the Paleogene subcrop level, and therefore illustrates magnitudes and spatial patterns of synorogenic erosional exhumation.

Several implications of these datasets are explored, including constraints on the map patterns of regional-scale contractional structures, and correlations between hinterland structures and structures in the frontal Sevier thrust belt.  Interestingly, much of the hinterland region exhibits low (ca. 2 km) structural relief, indicating that the majority of regionally-distributed, surface-breaking normal faulting that dismembered the orogenic highland and produced the high structural relief observed today had to be post-Oligocene.  Finally, some similarities and differences between the Sevier and Central Andean orogenic plateaus are explored.

New RSVP format

RSVP for the May 2nd Monthly Dinner Meeting by clicking on the following link:

https://docs.google.com/forms/d/1NNJzrjvEADFxSVqcALIcQgyy-tWaFtiLmDyPymL7bmo/viewform

Please RSVP no later than Tuesday, April 30th, at 4:00 PM.  Thank you!
Boart Longyear will be hosting the bar.