Detrital zircon record of Neogene exhumation of the central Alaska Range: A far-field upper plate response to flat-slab subduction

Research Article| July 01, 2015 Detrital zircon record of Neogene exhumation of the central Alaska Range: A far-field upper plate response to flat-slab subduction Patrick R.K. Brennan; Patrick R.K. Brennan Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, 550 Stadium Mall Dr., West Lafayette, Indiana 47907, USA †Current address: Chevron Energy Technology Company, Houston, Texas 77002, USA; PBrennan@chevron.com. Search for other works by this author on: GSW Google Scholar Kenneth D. Ridgway Kenneth D. Ridgway Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, 550 Stadium Mall Dr., West Lafayette, Indiana 47907, USA Search for other works by this author on: GSW Google Scholar GSA Bulletin (2015) 127 (7-8): 945–961. https://doi.org/10.1130/B31164.1 Article history received: 16 Jul 2014 rev-recd: 21 Nov 2014 accepted: 14 Jan 2015 first online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Patrick R.K. Brennan, Kenneth D. Ridgway; Detrital zircon record of Neogene exhumation of the central Alaska Range: A far-field upper plate response to flat-slab subduction. GSA Bulletin 2015;; 127 (7-8): 945–961. doi: https://doi.org/10.1130/B31164.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Far-field deformation in the upper plate of many ancient and modern convergent margins is commonly attributed to flat-slab subduction processes. Recent studies have suggested that the high topography of the central Alaska Range (Alaska, USA), for example, is the far-field deformational response to Neogene shallow subduction processes in southern Alaska. In this study, we analyze six stratigraphically controlled detrital zircon samples from Miocene–Pliocene sandstone of the Tanana foreland basin to evaluate the temporal and spatial links between exhumation of the central Alaska Range and shallow subduction. The Tanana basin, located north of the central Alaska Range, contains ∼2 km of Neogene strata. Lower Miocene strata from the basin have detrital zircon ages with dominant Precambrian populations. These grain ages are attributed to sediment derivation from the Yukon composite terrane source area located at the northern edge and north of the Alaska Range. During the early–middle Miocene the provenance of the Tanana basin switched to a distinctly Mesozoic source signal. These Mesozoic-age grains are attributed to sediment derived from source areas within and south of the Alaska Range. The early–middle Miocene change in provenance from predominantly Precambrian to Mesozoic sediment sources, in the context of previously published basin analysis studies, is interpreted to represent the onset of Neogene uplift of the central Alaska Range. The timing of exhumation of the central Alaska Range is important not only for understanding the tectonics of the highest mountain range in North America, but additionally because recent modeling studies predict that this range is one of the first expected products of Neogene flat-slab subduction along the southern Alaska convergent plate boundary. Results of our study provide a needed chronologic framework to fully evaluate the temporal and spatial upper plate responses to shallow subduction processes. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.