Crustal thickening during Proterozoic metamorphism and deformation in New Mexico

Research Article| February 01, 1986 Crustal thickening during Proterozoic metamorphism and deformation in New Mexico Jeffrey A. Grambling Jeffrey A. Grambling 1Department of Geology, University of New Mexico, Albuquerque, New Mexico 87131 Search for other works by this author on: GSW Google Scholar Author and Article Information Jeffrey A. Grambling 1Department of Geology, University of New Mexico, Albuquerque, New Mexico 87131 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1986) 14 (2): 149–152. https://doi.org/10.1130/0091-7613(1986)14<149:CTDPMA>2.0.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Jeffrey A. Grambling; Crustal thickening during Proterozoic metamorphism and deformation in New Mexico. Geology 1986;; 14 (2): 149–152. doi: https://doi.org/10.1130/0091-7613(1986)14<149:CTDPMA>2.0.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 Proterozoic rocks in northern and central New Mexico underwent simultaneous metamorphism and deformation, tentatively dated at 1410 Ma. Structural relationships record a minimum of 20%–30% shortening during the latter part of deformation, and chemical zoning in garnet and plagioclase indicates a 20% increase in depth of burial during the same interval. Locally, deformation thickened the upper continental crust by at least 20%. This crustal thickening was distributed over a broad area and caused rocks across 75 000 km2 to recrystallize at peak metamorphic conditions near 525 °C and 4 kbar. The metamorphic terrane cooled isobarically, at rates less than 5 °C/m.y. Such slow cooling may be normal at middle crustal depths. Preservation of the regionally uniform peak metamorphic conditions reflects an unusual tectonic history: heat from the metamorphic event outlasted deformation, and the terrane was not subjected to rapid uplift following its thermal peak. 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.