72-5 Geologic Mapping and Thermometry of the Luning-Fencemaker Thrust Belt Region: Constraints on the Evolution of the Auld Lang Syne Back-arc Basin
Session: Toe to Toe: Cordilleran Systems from Trench to Retroarc Domains (Posters)
Poster Booth No.: 265
Presenting Author:
Ryan ParkynAuthors:
Parkyn, Ryan M1, Zuza, Andrew V2(1) Nevada Geosciences, University of Nevada, Reno, Reno, Nevada, USA; Nevada Bureau of Mines and Geology, University of Nevada, Reno, Reno, Nevada, USA, (2) Nevada Geosciences, University of Nevada, Reno, Reno, Nevada, USA; Nevada Bureau of Mines and Geology, University of Nevada, Reno, Reno, Nevada, USA,
Abstract:
The thermal structure of orogenic belts is a primary influencer of lithospheric strength and subsequent deformation. The North American Cordilleran retroarc has experienced multiple tectono-thermal events such as back-arc opening, closure, and magmatism throughout the Mesozoic. To better understand the dynamics and kinematics of back-arc processes, here we present field and analytical observations from the ancient Mesozoic Auld Lang Syne (ALS) back-arc basin (BAB). The ALS BAB is located within the central latitudes of North American Cordillera and experienced high back-arc heat flow, heating from thrust related burial during back-arc closure, and heating from subsequent plutonism. This investigation seeks to constrain the kinematic and thermal evolution of the ALS BAB. Geologic mapping and structural analyses in the Jungo Hills area, west of Winnemucca, Nevada, show greenschist to amphibolite grade Triassic metapelites that exhibit range-scale overturned isoclinal folding and fold-nappe thrust transport along major thrust flats. Raman spectroscopy of carbonaceous material (RSCM) peak-temperature thermometry combined with temperature versus depth curves may be diagnostic in determining the origin of peak temperatures. Monotonic structural depth versus temperature trends may reflect Jurassic heating during Luning-Fencemaker thrust burial, whereas patchy localized hotspots likely correspond to local Late Cretaceous heating around major stocks and plutons. The integration of structural mapping with peak temperature data from RSCM allows us to assess the Cordilleran back-arc basin’s dominant thermal signature in the Mesozoic and compare our results with modern analogous BABs.
Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025
doi: 10.1130/abs/2025AM-7710
© Copyright 2025 The Geological Society of America (GSA), all rights reserved.
Geologic Mapping and Thermometry of the Luning-Fencemaker Thrust Belt Region: Constraints on the Evolution of the Auld Lang Syne Back-arc Basin
Category
Topical Sessions
Description
Session Format: Poster
Presentation Date: 10/19/2025
Presentation Room: HBGCC, Hall 1
Poster Booth No.: 265
Author Availability: 3:30–5:30 p.m.
Back to Session