Bibliographische Detailangaben
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Personen und Körperschaften:
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Palin, R M (VerfasserIn); Searle, M P (VerfasserIn); St-Onge, M R (VerfasserIn); Waters, D J (VerfasserIn); Roberts, N M W (VerfasserIn); Horstwood, M S A (VerfasserIn); Parrish, R R (VerfasserIn); Weller, O M (VerfasserIn); Chen, S (VerfasserIn); Yang, J (VerfasserIn) |
| Format: |
Elektronische Zeitschrift
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| Sprache: |
English
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| veröffentlicht: |
Elsevier BV, 2014 |
| Gesamtaufnahme: |
GEM: Geo-mapping for Energy and Minerals
, Gondwana Research 2013 p. 1-25, Earth Sciences Sector, Contribution Series
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| Schlagwörter: |
Monazite;
Migmatites;
Metamorphic Rocks;
Metamorphic Facies;
Metamorphic Petrology;
Pressure-Temperature Conditions;
Tectonic Interpretations;
Tectonic Setting;
Tectonic Environments;
Petrography;
South Lhasa Block;
Himalayan Range;
Tibetan Plateau;
Zeitschrift;
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| Quelle: |
GEOSCAN
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| Zusammenfassung: |
A combined geochronological and petrological study of pelitic migmatites fr...
A combined geochronological and petrological study of pelitic migmatites from the northwestern flank of the eastern Himalayan syntaxis has constrained the timing and P - T conditions of two high-grade metamorphic events that affected the south Lhasa block (Asian margin) and provides newinsight into the tectonothermal evolution of the India - Asia collision. U(-Th) - Pb dating of in situ monazite shows that upper amphibolite-facies sillimanite-grademetamorphismand consequent partial melting occurred between c. 71 and 50 Ma at P - T conditions above 6.3 ± 1.2 kbar and 750 ± 30 °C. Further partialmelting at upper amphibolite-facies kyanite-grade conditions occurred between c. 44 and 33 Ma at minimum P - T conditions of 10.4 ± 1.0 kbar and 698 ± 20 °C. These data are interpreted to record a south Lhasa blockmid-crustal sillimanite-grade melting event in the Late Cretaceous to Early Eocene related to regional heat advection caused by coeval and prolonged emplacement of Gangdese batholith units. This was followed by a higher pressure and lower temperature kyanite-grade melting event during the Middle Eocene to Early Oligocene associated with deformation and crustal thickening in the south Lhasa block, coeval with kyanite-grade metamorphism along the Himalaya, as a result of the on-going India - Asia collision. These partially-melted crustal lithologies offer potential sources (or otherwise analogs for sources) for the Miocene emplacement of adakitic intrusions previously documented in the eastern Himalayan syntaxis region.
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