Basin Analysis of the Albian–Santonian Xigaze Forearc, Lazi Region, South-Central Tibet
AffiliationUniversity of Arizona, Department of Geosciences
MetadataShow full item record
PublisherSEPM-SOC SEDIMENTARY GEOLOGY
CitationBasin Analysis of the Albian–Santonian Xigaze Forearc, Lazi Region, South-Central Tibet 2016, 86 (8):894 Journal of Sedimentary Research
JournalJournal of Sedimentary Research
RightsCopyright © 2016, SEPM (Society for Sedimentary Geology)
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at email@example.com.
AbstractThe Xigaze forearc basin records the evolution of the southern Lhasa terrane convergent margin, largely affected by Neo-Tethyan subduction processes, prior to the Paleocene Tethyan Himalaya-Eurasia collision. New geologic mapping and U-Pb detrital-zircon geochronologic data from the Lazi region, 340 km southeast of Lhasa, show that forearc basin sedimentation began ca. 110 Ma conformably atop the Yarlung-Tsangpo ophiolitic melange. By this time, the arc-trench system along the southern margin of the Lhasa terrane (Eurasia) consisted of an accretionary complex, overlying ophiolitic melange, the Xigaze forearc basin, and the Gangdese magmatic arc. There is no geological evidence in the Lazi region for more than one subduction zone between the southern Lhasa terrane margin and India. Sedimentological facies analysis from Albian to Santonian clastic and carbonate sedimentary rocks preserved in the Xigaze forearc basin indicate deep-marine sedimentation characterized by hemipelagic carbonate and volcanogenic sediment-gravity-flow deposits. Sandstone modal petrographic and U-Pb detrital-zircon geochronologic data reveal Asian continental margin, Gangdese magmatic arc, and central to northern Lhasa terrane provenance. During this time, basin fill was deposited in cycles of high and low sediment flux characterized by alternating successions of clastic turbidite inner- to outer-fan deposits and hemipelagic limestone and marlstone sequences. Along-strike differences in the timing of initial forearc basin sedimentation are likely the result of intra-basin topography and/or diachronous development of ophiolitic forearc basement.
Note12 month embargo. First available online Aug 12 2016.
VersionFinal accepted manuscript