Metamorphic P-T-t evolution deciphered from episodic monazite growth in granulites of the Chencai Complex and implications for the Early Paleozoic orogeny, West Cathaysia Terrane, South China
0
Citation
0
Reference
10
Related Paper
Abstract:
EPMA data, monazite U-Pb data and P-T estimates using conventional geothermometers and geobarometers for felsic granulite, Chencai Complex, West Cathaysia terrane, South ChinaKeywords:
Orogeny
Continental Margin
Passive margin
Margin (machine learning)
Cite
Citations (7)
The compositions of detrital monazites from deposits of Vendian – Lower Paleozoic sequences of Podolian Transnistria are studied. Each monazite crystal has been dated by Th-U-total Pb method and age spectra of monazites obtained for 7 samples from Vendian, Cambrian and Ordovician strata sequences (total amount 780 crystals). It is established that a younger monazites appeared firstly at Dgurdgev time. Their role increases significantly in Upper Vendian sequences and peaks (67%) in the Ordovician sandstones.
Cite
Citations (0)
Understanding Neoproterozoic crustal evolution is fundamental to reconstructing the Gondwana supercontinent, which was assembled at this time. Here we report evidence of Cryogenian crustal reworking in the Madurai Block of the Southern Granulite Terrane of India. The study focuses on a garnet-bearing granite–charnockite suite, where the granite shows in situ dehydration into patches and veins of incipient charnockite along the contact with charnockite. The granite also carries dismembered layers of Mg–Al-rich granulite. Micro-textural evidence for dehydration of granite in the presence of CO2-rich fluids includes the formation of orthopyroxene by the breakdown of biotite, neoblastic zircon growth in the dehydration zone, at around 870°C and 8 kbar. The zircon U–Pb ages suggest formation of the granite, charnockite, and incipient charnockite at 836 ± 73, 831 ± 31, and 772 ± 49 Ma, respectively. Negative zircon εHf (t) (−5 to −20) values suggest that these rocks were derived from a reworked Palaeoproterozoic crustal source. Zircon grains in the Mg–Al-rich granulite record a spectrum of ages from ca. 2300 to ca. 500 Ma, suggesting multiple provenances ranging from Palaeoproterozoic to mid-Neoproterozoic, with neoblastic zircon growth during high-temperature metamorphism in the Cambrian. We propose that the garnet-bearing granite and charnockite reflect the crustal reworking of aluminous crustal material indicated by the presence of biotite + quartz + aluminosilicate inclusions in the garnet within the granite. This crustal source can be the Mg–Al-rich layers carried by the granite itself, which later experienced high-temperature regional metamorphism at ca. 550 Ma. Our model also envisages that the CO2 which dehydrated the garnet-bearing granite generating incipient charnockite was sourced from the proximal massive charnockite through advection. These Cryogenian crustal reworking events are related to prolonged tectonic activities prior to the final assembly of the Gondwana supercontinent.
Cite
Citations (0)
Research Article| November 01, 2014 Late Paleozoic assembly of the Alexander-Wrangellia-Peninsular composite terrane, Canadian and Alaskan Cordillera Luke P. Beranek; Luke P. Beranek † 1Department of Earth Sciences, Memorial University of Newfoundland, 300 Prince Philip Drive, St. John's, Newfoundland and Labrador A1B 3X5, Canada †E-mail: lberanek@mun.ca. Search for other works by this author on: GSW Google Scholar Cees R. van Staal; Cees R. van Staal 2Geological Survey of Canada, 625 Robson Street, Vancouver, British Columbia V6B 5J3, Canada Search for other works by this author on: GSW Google Scholar William C. McClelland; William C. McClelland 3Department of Earth and Environmental Sciences, University of Iowa, 121 Trowbridge Hall, Iowa City, Iowa 52242, USA Search for other works by this author on: GSW Google Scholar Nancy Joyce; Nancy Joyce 4Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario K1A 0E8, Canada Search for other works by this author on: GSW Google Scholar Steve Israel Steve Israel 5Yukon Geological Survey, P.O. Box 2703 (K-14), Whitehorse, Yukon Y1A 2C6, Canada Search for other works by this author on: GSW Google Scholar GSA Bulletin (2014) 126 (11-12): 1531–1550. https://doi.org/10.1130/31066.1 Article history received: 14 Jan 2014 rev-recd: 04 Apr 2014 accepted: 12 May 2014 first online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Luke P. Beranek, Cees R. van Staal, William C. McClelland, Nancy Joyce, Steve Israel; Late Paleozoic assembly of the Alexander-Wrangellia-Peninsular composite terrane, Canadian and Alaskan Cordillera. GSA Bulletin 2014;; 126 (11-12): 1531–1550. doi: https://doi.org/10.1130/31066.1 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 SocietyGSA Bulletin Search Advanced Search Abstract Late Paleozoic assembly of the Alexander-Wrangellia-Peninsular composite terrane is recorded by two phases of regional deformation, metamorphism, and magmatism within basement complexes of the Alexander (Craig and Admiralty subterranes), Wrangellia, and Peninsular terranes in the Canadian and Alaskan Cordillera. New secondary ion mass spectrometry (SIMS) and chemical abrasion-isotope dilution-thermal ionization mass spectrometry (CA-ID-TIMS) zircon U-Pb ages, whole-rock major- and trace-element and Nd-Sr isotope geochemical compositions, and geological field observations of late Paleozoic igneous rocks were used to identify the precise timing and significance of this tectonism in the Saint Elias Mountains region of southwestern Yukon and eastern Alaska. Middle to Late Pennsylvanian (301–307 Ma) igneous rocks, herein assigned to the Barnard Glacier suite, were preferentially emplaced along the Wrangellia-Craig subterrane boundary and mainly comprise syenitic plutons that intrude Paleozoic country rocks with evidence of Pennsylvanian or older (D1) deformation. We propose that Barnard Glacier suite magmatism was produced by a slab breakoff event after the consumption of a narrow backarc ocean basin and early Pennsylvanian collision between the Wrangellia-Peninsular arc and Craig subterrane passive margin. Early Permian (284–291 Ma) dioritic to granodioritic rocks, herein assigned to the Donjek Glacier suite, comprise the vestiges of an extensive magmatic system within the Craig subterrane of southwestern Yukon and southeastern Alaska. The available data suggest that the Donjek Glacier suite represents part of a short-lived, Early Permian arc that initiated along the outboard margin of the Craig subterrane–Wrangellia–Peninsular block after Pennsylvanian collision and slab breakoff. At two field localities in southwestern Yukon, Paleozoic country rocks with D1 fabrics are also intruded by sills and dikes of the Donjek Glacier suite that show evidence of ca. 285 Ma regional deformation and metamorphism (D2). Field evidence for Early Permian tectonism in the Saint Elias Mountains implies direct connections with coeval deformation and metamorphism in the Admiralty subterrane, a microcontinent in the Admiralty Island region of southeastern Alaska that developed separately from the Craig subterrane prior to the Early Permian. D2 tectonism was likely related to the entry of the Admiralty subterrane margin into the Early Permian subduction zone, which resulted in collision and final amalgamation of the Alexander-Wrangellia-Peninsular composite terrane. Our tectonic scenarios require the currently accepted configuration of the Alexander terrane (composite of the Craig and Admiralty subterranes) to have only existed after the Early Permian collision between the Admiralty subterrane and the previously assembled Craig subterrane–Wrangellia–Peninsular terrane. Biogeographic and other geological data suggest that the two-part assembly of the Alexander-Wrangellia-Peninsular composite terrane took place along a convergent margin to the north of the Cordilleran pericratonic arc terranes (Yukon-Tanana, Quesnellia, and others), in between the paleo–Pacific Ocean and paleo–Arctic Ocean realms, to the northwest of the supercontinent Pangea. The assembly of the Alexander-Wrangellia-Peninsular composite terrane might have been associated with the Early to Middle Permian subduction polarity flip recognized in the Cordilleran pericratonic realm, which led to the closure of a backarc ocean basin and Late Permian arc-continent collision along the western margin of North America. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
Cite
Citations (4)
Overprinting
Sillimanite
Cordierite
Cite
Citations (7)
Indian Shield
Cite
Citations (0)
Late Paleozoic assembly of the Alexander-Wrangellia-Peninsular composite terrane is recorded by two phases of regional deformation, metamorphism, and magmatism within basement complexes of the Alexander (Craig and Admiralty subterranes), Wrangellia, and Peninsular terranes in the Canadian and Alaskan Cordillera. New secondary ion mass spectrometry (SIMS) and chemical abrasion-isotope dilution-thermal ionization mass spectrometry (CA-ID-TIMS) zircon U-Pb ages, whole-rock major- and trace-element and Nd-Sr isotope geochemical compositions, and geological field observations of late Paleozoic igneous rocks were used to identify the precise timing and significance of this tectonism in the Saint Elias Mountains region of southwestern Yukon and eastern Alaska. Middle to Late Pennsylvanian (301–307 Ma) igneous rocks, herein assigned to the Barnard Glacier suite, were preferentially emplaced along the Wrangellia-Craig subterrane boundary and mainly comprise syenitic plutons that intrude Paleozoic country rocks with evidence of Pennsylvanian or older (D1) deformation. We propose that Barnard Glacier suite magmatism was produced by a slab breakoff event after the consumption of a narrow backarc ocean basin and early Pennsylvanian collision between the Wrangellia-Peninsular arc and Craig subterrane passive margin. Early Permian (284–291 Ma) dioritic to granodioritic rocks, herein assigned to the Donjek Glacier suite, comprise the vestiges of an extensive magmatic system within the Craig subterrane of southwestern Yukon and southeastern Alaska. The available data suggest that the Donjek Glacier suite represents part of a short-lived, Early Permian arc that initiated along the outboard margin of the Craig subterrane–Wrangellia–Peninsular block after Pennsylvanian collision and slab breakoff. At two field localities in southwestern Yukon, Paleozoic country rocks with D1 fabrics are also intruded by sills and dikes of the Donjek Glacier suite that show evidence of ca. 285 Ma regional deformation and metamorphism (D2). Field evidence for Early Permian tectonism in the Saint Elias Mountains implies direct connections with coeval deformation and metamorphism in the Admiralty subterrane, a microcontinent in the Admiralty Island region of southeastern Alaska that developed separately from the Craig subterrane prior to the Early Permian. D2 tectonism was likely related to the entry of the Admiralty subterrane margin into the Early Permian subduction zone, which resulted in collision and final amalgamation of the Alexander-Wrangellia-Peninsular composite terrane. Our tectonic scenarios require the currently accepted configuration of the Alexander terrane (composite of the Craig and Admiralty subterranes) to have only existed after the Early Permian collision between the Admiralty subterrane and the previously assembled Craig subterrane–Wrangellia–Peninsular terrane. Biogeographic and other geological data suggest that the two-part assembly of the Alexander-Wrangellia-Peninsular composite terrane took place along a convergent margin to the north of the Cordilleran pericratonic arc terranes (Yukon-Tanana, Quesnellia, and others), in between the paleo–Pacific Ocean and paleo–Arctic Ocean realms, to the northwest of the supercontinent Pangea. The assembly of the Alexander-Wrangellia-Peninsular composite terrane might have been associated with the Early to Middle Permian subduction polarity flip recognized in the Cordilleran pericratonic realm, which led to the closure of a backarc ocean basin and Late Permian arc-continent collision along the western margin of North America.
Cite
Citations (31)
Upper Proterozoic rocks of the Avalon zone constitute much of the eastern basement of the New England Appalachians and have played a major role in its evolution. Avalonian rocks in southeastern New England are a composite of at least two distinct assemblages definable as terranes, the Esmond–Dedham and the Hope Valley. These terranes appear to have had differing interactions with rocks derived from the North American continent, with major tectonic modifications and/or transport occurring in late Paleozoic time. The Esmond–Dedham terrane lacks any clear previous relationships to other rocks in the region and probably was newly accreted during late Paleozoic...
Basement
Cite
Citations (32)
Cite
Citations (8)