Two high-pressure–low-temperature serpentinite-matrix mélange belts, Motagua fault zone, Guatemala: A record of Aptian and Maastrichtian collisions

Research Article| January 01, 2004 Two high-pressure–low-temperature serpentinite-matrix mélange belts, Motagua fault zone, Guatemala: A record of Aptian and Maastrichtian collisions George E. Harlow; George E. Harlow 1Department of Earth and Planetary Sciences, American Museum of Natural History, Central Park West at 79th Street, New York, New York 10024-5192, USA Search for other works by this author on: GSW Google Scholar Sidney R. Hemming; Sidney R. Hemming 2Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964-8000, USA Search for other works by this author on: GSW Google Scholar Hans G. Avé Lallemant; Hans G. Avé Lallemant 3Department of Earth Science, MS-126, Rice University, Houston, Texas 77005-1892, USA Search for other works by this author on: GSW Google Scholar Virginia B. Sisson; Virginia B. Sisson 3Department of Earth Science, MS-126, Rice University, Houston, Texas 77005-1892, USA Search for other works by this author on: GSW Google Scholar Sorena S. Sorensen Sorena S. Sorensen 4Department of Mineral Sciences, NHB-119, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560-0119, USA Search for other works by this author on: GSW Google Scholar Geology (2004) 32 (1): 17–20. https://doi.org/10.1130/G19990.1 Article history received: 01 Jul 2003 rev-recd: 15 Sep 2003 accepted: 16 Sep 2003 first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation George E. Harlow, Sidney R. Hemming, Hans G. Avé Lallemant, Virginia B. Sisson, Sorena S. Sorensen; Two high-pressure–low-temperature serpentinite-matrix mélange belts, Motagua fault zone, Guatemala: A record of Aptian and Maastrichtian collisions. Geology 2004;; 32 (1): 17–20. doi: https://doi.org/10.1130/G19990.1 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 SocietyGeology Search Advanced Search Abstract Left-lateral motion along the North American–Caribbean plate boundary has juxtaposed two high-pressure–low-temperature (HP-LT) belts from separate Cretaceous collisions. These two belts have quite different ages and different suites of high-pressure assemblages, yet they both contain jadeitite, a relatively rare rock type. This part of the plate boundary zone follows the Motagua River Valley in Guatemala, where it separates the Maya block (North American plate) from the Chortís block (Caribbean plate). On both sides of the bounding Motagua fault, tectonic slices of serpentinite-matrix mélange host the HP-LT rocks. South of the fault, the mélange slices contain eclogite, lawsonite eclogite, glaucophane eclogite, and blueschist blocks. North of the fault, the mélange slices contain omphacite metabasite, albitite, and garnet amphibolite blocks, but lack intact eclogite. In addition to the dissimilar rock assemblages, 40Ar/39Ar geochronology of phengitic micas yields 77–65 Ma for northern and 125–113 Ma for southern blocks. These data suggest that the southern belt formed during Early Cretaceous (Aptian), northeastward-dipping subduction of the Farallon plate and collision of the Chortís block with western Mexico. The block was then displaced southeastward along this suture. In contrast, the northern belt records subduction related to the Maastrichtian collision of an extension of the Chortís block, perhaps the Nicaraguan Rise, with the Maya block. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.