The Himalayan leucogranite occurs as two extensive(>1000 km) E-W trending belts on the Tibetan Plateau with the unique features. The leucogranite comprised biotite granite, two-mica/muscovite granite, tourmaline gr...The Himalayan leucogranite occurs as two extensive(>1000 km) E-W trending belts on the Tibetan Plateau with the unique features. The leucogranite comprised biotite granite, two-mica/muscovite granite, tourmaline granite and garnet granite, which have been identified in previous studies, as well as albite granite and granitic pegmatite that were identified in this investigation. Fifteen leucogranite plutons were studied and 12 were found to contain rare-metal bearing minerals such as beryl(the representative of Be mineralization), columbite-group minerals, tapiolite, pyrochlore-microlite, fergusonite, Nb-Ta rutile(the representative of Nb-Ta mineralization), and cassiterite(the representative of Sn mineralization) mainly based on the field trip,microscope observation and microprobe analysis. The preliminary result shows that the Himalayan leucogranite is commonly related to the rare-metal mineralization and warrants future investigation. Further exploration and intensive research work is important in determining the rare-metal resource potential of this area.展开更多
Abstract Sisorid catfishes are primarily limited in distribution to rivers of the Himalayan region and Tibetan Plateau. These species have external morphologies that are adapted for extremely fast-flowing riverine sys...Abstract Sisorid catfishes are primarily limited in distribution to rivers of the Himalayan region and Tibetan Plateau. These species have external morphologies that are adapted for extremely fast-flowing riverine systems. Given the diversity of the group and the above qualities of these catfishes, this lineage serves as an ideal group for inferring the geological history of this region based on their phylogenetic relationships reflecting evolu- tionary history. We sequenced the complete mitochondrial genome and four nuclear genes of representative sisorids distributed across river systems in China. Phylogenetic analyses strongly support the monophyly of the Sisoridae and the glyptosternoids. An analysis of the reconstructed ancestral states derived from inferred genealogical relationships suggests that the evolution of this lineage was accompanied by convergent evolution in morphological traits that were presumably in response to environmental pressure involving the rapid flowing river system that were generated during the uplift of the Tibetan Plateau （UTP）. Molecular dating indicates that the Chinese sisorids and the glyptosternoids originated at the later Miocene （~ 10.9-9.8 Mya）, and with further biogeographic analyses indicates that the species of Sisoridae likely originated from a widely distributed ancestor. Moreover, the divergence of the Sisoridae in China can be divided into two phases consis- tent with the UTP. All of these results indicate that the diversification and dispersal events in this lineage occurred as a result of drainage systems formed during and after the UTP in the late Miocene and Quaternary periods.展开更多
Placing precise constraints on the timing of the India-Asia continental collision is essential to understand the successive geological and geomorphological evolution of the orogenic belt as well as the uplift mechanis...Placing precise constraints on the timing of the India-Asia continental collision is essential to understand the successive geological and geomorphological evolution of the orogenic belt as well as the uplift mechanism of the Tibetan Plateau and their effects on climate,environment and life.Based on the extensive study of the sedimentary record on both sides of the Yarlung-Zangbo suture zone in Tibet,we review here the present state of knowledge on the timing of collision onset,discuss its possible diachroneity along strike,and reconstruct the early structural and topographic evolution of the Himalayan collided range.We define continent-continent collision as the moment when the oceanic crust is completely consumed at one point where the two continental margins come into contact.We use two methods to constrain the timing of collision onset:(1) dating the provenance change from Indian to Asian recorded by deep-water turbidites near the suture zone,and(2) dating the age of unconformities on both sides of the suture zone.The first method allowed us to constrain precisely collision onset as middle Palaeocene(59±l Ma).Marine sedimentation persisted in the collisional zone for another 20-25 Ma locally in southern Tibet,and molassic-type deposition in the Indian foreland basin did not begin until another 10-15 Ma later.Available sedimentary evidence failed to firmly document any significant diachroneity of collision onset from the central Himalaya to the western Himalaya and Pakistan so far.Based on the Cenozoic stratigraphic record of the Tibetan Himalaya,four distinct stages can be identified in the early evolution of the Himalayan orogen:(1) middle Palaeocene-early Eocene earliest Eohimalayan stage(from 59 to 52 Ma):collision onset and filling of the deep-water trough along the suture zone while carbonate platform sedimentation persisted on the inner Indian margin;(2) early-middle Eocene early Eohimalayan stage(from 52 to 41 or 35 Ma):filling of intervening seaways and cessation of marine sedimentation;(3) late Eocene-Oligocene late Eohimalayan stage(from 41 to 25 Ma):huge gap in the sedimentary record both in the collision zone and in the Indian foreland;and(4) late Oligocene-early Miocene early Neohimalayan stage(from 26 to 17 Ma):rapid Himalayan growth and onset of molasse-type sedimentation in the Indian foreland basin.展开更多
基金supported by the National Natural Science Foundation of China (Grants Nos. 41230315 and 41130313)the Fundamental Research Funds for the Central Universities (Grants No. 020614380057)
文摘The Himalayan leucogranite occurs as two extensive(>1000 km) E-W trending belts on the Tibetan Plateau with the unique features. The leucogranite comprised biotite granite, two-mica/muscovite granite, tourmaline granite and garnet granite, which have been identified in previous studies, as well as albite granite and granitic pegmatite that were identified in this investigation. Fifteen leucogranite plutons were studied and 12 were found to contain rare-metal bearing minerals such as beryl(the representative of Be mineralization), columbite-group minerals, tapiolite, pyrochlore-microlite, fergusonite, Nb-Ta rutile(the representative of Nb-Ta mineralization), and cassiterite(the representative of Sn mineralization) mainly based on the field trip,microscope observation and microprobe analysis. The preliminary result shows that the Himalayan leucogranite is commonly related to the rare-metal mineralization and warrants future investigation. Further exploration and intensive research work is important in determining the rare-metal resource potential of this area.
基金supported by the National Natural Science Foundation of China (31090254, 30770300 and U1036603)the Chinese Academy of Sciences (KSCX2-EW-Q-12)the endowment of William S. Barnickle, Saint Louis University, St. Louis, Missouri, USA
文摘Abstract Sisorid catfishes are primarily limited in distribution to rivers of the Himalayan region and Tibetan Plateau. These species have external morphologies that are adapted for extremely fast-flowing riverine systems. Given the diversity of the group and the above qualities of these catfishes, this lineage serves as an ideal group for inferring the geological history of this region based on their phylogenetic relationships reflecting evolu- tionary history. We sequenced the complete mitochondrial genome and four nuclear genes of representative sisorids distributed across river systems in China. Phylogenetic analyses strongly support the monophyly of the Sisoridae and the glyptosternoids. An analysis of the reconstructed ancestral states derived from inferred genealogical relationships suggests that the evolution of this lineage was accompanied by convergent evolution in morphological traits that were presumably in response to environmental pressure involving the rapid flowing river system that were generated during the uplift of the Tibetan Plateau （UTP）. Molecular dating indicates that the Chinese sisorids and the glyptosternoids originated at the later Miocene （~ 10.9-9.8 Mya）, and with further biogeographic analyses indicates that the species of Sisoridae likely originated from a widely distributed ancestor. Moreover, the divergence of the Sisoridae in China can be divided into two phases consis- tent with the UTP. All of these results indicate that the diversification and dispersal events in this lineage occurred as a result of drainage systems formed during and after the UTP in the late Miocene and Quaternary periods.
基金supported by the National Natural Science Foundation of China(Grant No.41525007)the Stratigraphic Pilot Science and Technology Projects of the Chinese Academy of Sciences(Class B)(Grant No.XDB03010400)
文摘Placing precise constraints on the timing of the India-Asia continental collision is essential to understand the successive geological and geomorphological evolution of the orogenic belt as well as the uplift mechanism of the Tibetan Plateau and their effects on climate,environment and life.Based on the extensive study of the sedimentary record on both sides of the Yarlung-Zangbo suture zone in Tibet,we review here the present state of knowledge on the timing of collision onset,discuss its possible diachroneity along strike,and reconstruct the early structural and topographic evolution of the Himalayan collided range.We define continent-continent collision as the moment when the oceanic crust is completely consumed at one point where the two continental margins come into contact.We use two methods to constrain the timing of collision onset:(1) dating the provenance change from Indian to Asian recorded by deep-water turbidites near the suture zone,and(2) dating the age of unconformities on both sides of the suture zone.The first method allowed us to constrain precisely collision onset as middle Palaeocene(59±l Ma).Marine sedimentation persisted in the collisional zone for another 20-25 Ma locally in southern Tibet,and molassic-type deposition in the Indian foreland basin did not begin until another 10-15 Ma later.Available sedimentary evidence failed to firmly document any significant diachroneity of collision onset from the central Himalaya to the western Himalaya and Pakistan so far.Based on the Cenozoic stratigraphic record of the Tibetan Himalaya,four distinct stages can be identified in the early evolution of the Himalayan orogen:(1) middle Palaeocene-early Eocene earliest Eohimalayan stage(from 59 to 52 Ma):collision onset and filling of the deep-water trough along the suture zone while carbonate platform sedimentation persisted on the inner Indian margin;(2) early-middle Eocene early Eohimalayan stage(from 52 to 41 or 35 Ma):filling of intervening seaways and cessation of marine sedimentation;(3) late Eocene-Oligocene late Eohimalayan stage(from 41 to 25 Ma):huge gap in the sedimentary record both in the collision zone and in the Indian foreland;and(4) late Oligocene-early Miocene early Neohimalayan stage(from 26 to 17 Ma):rapid Himalayan growth and onset of molasse-type sedimentation in the Indian foreland basin.
