Zongo-San Gabán zone: Eocene foreland boundary of the Central Andean orogen, northwest Bolivia and southeast Peru

Abstract

Research Article| January 01, 1988 Zongo-San Gabán zone: Eocene foreland boundary of the Central Andean orogen, northwest Bolivia and southeast Peru E. Farrar; E. Farrar 1Department of Geological Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada Search for other works by this author on: GSW Google Scholar A. H. Clark; A. H. Clark 1Department of Geological Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada Search for other works by this author on: GSW Google Scholar D. J. Kontak; D. J. Kontak 1Department of Geological Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada Search for other works by this author on: GSW Google Scholar D. A. Archibald D. A. Archibald 1Department of Geological Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada Search for other works by this author on: GSW Google Scholar Author and Article Information E. Farrar 1Department of Geological Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada A. H. Clark 1Department of Geological Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada D. J. Kontak 1Department of Geological Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada D. A. Archibald 1Department of Geological Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1988) 16 (1): 55–58. https://doi.org/10.1130/0091-7613(1988)016<0055:ZSGNZE>2.3.CO;2 Article history First Online: 02 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 E. Farrar, A. H. Clark, D. J. Kontak, D. A. Archibald; Zongo-San Gabán zone: Eocene foreland boundary of the Central Andean orogen, northwest Bolivia and southeast Peru. Geology 1988;; 16 (1): 55–58. doi: https://doi.org/10.1130/0091-7613(1988)016<0055:ZSGNZE>2.3.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 Discordant muscovite and biotite K-Ar dates of samples taken in six transects through the Cordillera Oriental of southeast Peru and northwest Bolivia, combined with 40Ar/39Ar age spectra, reveal a northwest-trending, structurally cryptic, tectonothermal zone of late Eocene age (ca. 38 Ma) that overprints Triassic and older igneous and metamorphic rocks. The zone is at least 450 km long but is less than 25 km wide; temperatures along its northeast boundary are estimated to have reached 350 °C. No Paleogene magmatism has been recognized that could account for the thermal resetting of the K-Ar isotopic system. Uplift, erosion, and southwest-verging thrusting accompanied the development of this domain, which defined the foreland boundary of the orogen prior to inception of northeast-verging Andean thrusting in Miocene time. It is proposed that this tectonothermal zone, the Zongo-San Gabán zone (ZSGZ), which involves thrusting and basement shortening, is the southerly manifestation of the Incaic compressional deformation, which produced the thin-skinned Marañón thrust and fold belt (MTFB) north of the Abancay deflection of central Peru. 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.