Orographic precipitation, erosional unloading, and tectonic style

Research Article| March 01, 1993 Orographic precipitation, erosional unloading, and tectonic style Paul F. Hoffman; Paul F. Hoffman 1School of Earth and Ocean Sciences, University of Victoria, Victoria, British Columbia V8W 2Y2, Canada Search for other works by this author on: GSW Google Scholar John P. Grotzinger John P. Grotzinger 2Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 Search for other works by this author on: GSW Google Scholar Geology (1993) 21 (3): 195–198. https://doi.org/10.1130/0091-7613(1993)0212.3.CO;2 Article history first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Paul F. Hoffman, John P. Grotzinger; Orographic precipitation, erosional unloading, and tectonic style. Geology 1993;; 21 (3): 195–198. doi: https://doi.org/10.1130/0091-7613(1993)0212.3.CO;2 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 SocietyGeology Search Advanced Search Abstract Comparative tectonics of the Thelon (1.97 Ga) and Wopmay (1.88 Ga) orogens of north-west Canada and the Grenville (1.1 Ga) and Alleghany (0.3 Ga) orogens of eastern North America support geophysical models linking orographic precipitation and erosion to tectonic style. Paleomagnetic data imply that the Thelon and Grenville orogenic fronts were favorably situated to face trade winds and experience monsoonal precipitation. High rates of uplift could have been balanced by erosional unloading. Consequently, the orogenic fronts are deeply eroded and lack thin-skinned foreland thrust-and-fold belts. Tectonic progradation was achieved instead by thermal activation of the orogenic footwall. Foreland basins, where preserved, are overfilled with sediments that are dominantly fluvial to shallow marine, compositionally mature, and progradationally stacked. The Wopmay and Alleghany orogenic fronts developed in rain shadows. Erosional unloading could not offset even modest rates of tectonically driven uplift, resulting in mass flow onto the foreland manifested by thin-skinned thrust-and-fold belts and associated foreland basins. Foreland basins are underfilled and well preserved, containing sediments that are dominantly deep water, compositionally immature, and aggradationally stacked. The nature of the Mauritanide orogenic front is consistent with it being the windward complement of the Alleghany front. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.