Research Article| November 01, 1939 Geological reconnaissance in northern Sierra Madre Occidental of Mexico ROBERT E. KING ROBERT E. KING Search for other works by this author on: GSW Google Scholar GSA Bulletin (1939) 50 (11): 1625–1722. https://doi.org/10.1130/GSAB-50-1625 Article history received: 06 Aug 1936 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation ROBERT E. KING; Geological reconnaissance in northern Sierra Madre Occidental of Mexico. GSA Bulletin 1939;; 50 (11): 1625–1722. doi: https://doi.org/10.1130/GSAB-50-1625 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 INTRODUCTIONGENERAL STATEMENTThe crests of the Sierra Madre Occidental, in the western part of Mexico, form the boundary between the west coast States of Sonora and Sinaloa and the interior States of Chihuahua and Durango. These plateau-like crests, carved from gently inclined volcanic rocks, are in contrast to the Sierra Madre Oriental, in eastern Mexico, which consists for the most part of parallel ridges carved from folded sedimentary rocks.The western Sierra Madre takes form south of the International Boundary by the coalescing of mountain ranges which in southern New Mexico and Arizona are more or less isolated. South of the boundary, the plains between the mountains become narrower, and the volcanic rocks spread out in a broad plateau. The western edge of the plateau, at an elevation of 6000 feet or more, breaks off toward the Gulf of California in lofty escarpments (PL 2), which are trenched by . . . 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.