Detrital Thermochronometry Reveals That the Topography Along the Antarctic Peninsula is Not a Pleistocene Landscape

Abstract

This is the author manuscript accepted for publication and has undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as

Quantifying Tectonic and Glacial Controls on Topography in the Patagonian Andes (46.5°S) From Integrated Thermochronometry and Thermo‐Kinematic Modeling

“…However, the glacial buzz‐saw mechanism is restricted to regions dominated by warm‐based glaciers that are characterized by high erosional efficiency (Brozović, et al., 1997). Cooler climate conditions at higher latitudes and/or higher elevations favor the development of cold‐based glaciers characterized by decreased erosive capacity (Clinger et al., 2020; Thomson et al., 2010; Yanites & Ehlers, 2012). Under these circumstances, glaciers rather protect bedrock from erosion and preserve (high) topography (e.g., Pedersen et al., 2014; Tomkin & Braun, 2002).…”

Glacial Catchment Erosion From Detrital Zircon (U‐Th)/He Thermochronology: Patagonian Andes

“…Nevertheless, these mechanisms are poorly understood and the uncertain distribution of subglacial erosion and temporal variations in glacial mechanics complicate investigations (e.g., Fernandez et al, 2011;Herman et al, 2011;Humphrey & Raymond, 1994;Ugelvig & Egholm, 2018). Observational data capable of testing model predictions of glacial erosion and sediment production are limited, and so far derive largely from thermochronologic methods (Clinger et al, 2020;Ehlers et al, 2015;Stock et al, 2006;Tranel et al, 2011) and Raman spectroscopy of carbonaceous material to track the provenance of eroded material below glaciers Jiao et al, 2018).…”

“…Second, a detrital sample is collected (e.g., from fluvial, glacial, or hillslope sediments) and the grain-age distribution is measured. Third, the observed detrital grain age distribution is interpreted for the location from which the sediment was sourced based on the observed (or modeled, e.g., Clinger et al, 2020;Whipp & Ehlers, 2019) bedrock ages. Tracer thermochronology has been used as a provenance tool in a variety of studies in present-day fluvial, hillslope, glacial, and deglaciated settings (Clinger et al, 2020;Ehlers et al, 2015;Fox et al, 2015;Glotzbach et al, 2013Glotzbach et al, , 2018Lang et al, 2018;McPhillips & Brandon, 2010;Reiners et al, 2007;Riebe et al, 2015;Stock et al, 2006;Tranel et al, 2011;Vermeesch, 2007).…”

“…Third, the observed detrital grain age distribution is interpreted for the location from which the sediment was sourced based on the observed (or modeled, e.g., Clinger et al, 2020;Whipp & Ehlers, 2019) bedrock ages. Tracer thermochronology has been used as a provenance tool in a variety of studies in present-day fluvial, hillslope, glacial, and deglaciated settings (Clinger et al, 2020;Ehlers et al, 2015;Fox et al, 2015;Glotzbach et al, 2013Glotzbach et al, , 2018Lang et al, 2018;McPhillips & Brandon, 2010;Reiners et al, 2007;Riebe et al, 2015;Stock et al, 2006;Tranel et al, 2011;Vermeesch, 2007). Different methods have been used to interpolate bedrock age data, or compare predicted and observed age distributions (e.g., Glotzbach et al, 2013;Riebe et al, 2015;Stock et al, 2006;Vermeesch, 2007) and caveats such as heterogeneous mineral fertility or grain size effects on the age distributions have been investigated (Glotzbach et al, 2018;Lukens et al, 2020;Riebe et al, 2015;Tranel et al, 2011).…”

“…However, without a bedrock age-elevation profile within the catchment, identification of the distribution of erosion is difficult. Despite the advances of previous studies for understanding catchment geomorphic processes, few studies to date have applied tracer thermochronology to glaciated settings (Clinger et al, 2020;Ehlers et al, 2015;Glotzbach et al, 2013;Lang et al, 2018;Stock et al, 2006;Tranel et al, 2011), and our knowledge of where modern or ancient glaciers derived sediment from is incomplete. Tracer thermochronology observations are needed to evaluate glacial erosion and transport laws used in process-based glacial surface process models (e.g., Bernard et al, 2020;Braun et al, 1999;Headley & Ehlers, 2015;Herman & Braun, 2008;Herman et al, 2011;MacGregor et al, 2009;Tomkin & Braun, 2002;Yanites & Ehlers, 2016).…”