Geological mapping and crustal shortening of central Tibet
 Li Youshe 2004
A Dissertation Submitted to the State University of New York at Albany in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy
College of Arts and Sciences, Department of Earth & Atmospheric Sciences
Advisor: W.S.F. Kidd

ABSTRACT
Three geological maps in scale of 1:250,000 along the INDEPTH 3 survey line were made according to our field investigations in 1998 and 1999, extrapolated using TM image interpretation, combined with results from other previous work. This dissertation summarizes relevant geological information with references, including stratigraphy and fossil ages mainly from Chinese literature and discusses structure and shortening amount and the constraints on the ages. The Baingoin sheet of the geological map covers an area from N31 to N32;30', from E88;30' to E90;30'. The detailed structural and stratigraphic cross sections indicate about 50% shortening of the early-mid Jurassic, about 30% shortening of the early Cretaceous, about 15-20% shortening of the late Cretaceous and Paleogene, and only gentle tilting or no disturbance of Neogene in most places. The Shuanghe sheet of the geological map covers an area from N32;30' to N34;00', from E87;30' to E89;30'. The detailed structural and stratigraphic cross sections show that the strata of Jurassic and Triassic age are moderately to strongly folded throughout this region and cut in places by thrusts, with N-S shortening amounts up to about 50%. Deformation of late Cretaceous and Paleogene strata varies from one place to another. Generally, they are also folded, and cut in places by thrusts. A N-S shortening amount of about 15%-20% is very roughly estimated. The Dogai Coring sheet of the geological map covers an area from N34 to N35;30', from E88 to E90. Further work is needed to constrain the shortening deformation of the Tertiary red beds across the area. The first detailed geological map (Scale: 1:100,000) in the northeastern Nyainqentanglha region and two structural and stratigraphic cross sections are presented based on our field observations. Three fault systems have been recognized: (1) sinistral strike-slip ductile shear zone within the low-grade metamorphic rocks; (2) reverse faulting, along which the low-grade metamorphic rocks are thrust over the red clastics, and which appears to cut the unconformity; (3) sinistral strike-slip fault along the south front of the range, which cuts both of the above-mentioned faults.

Li, Y., 2004. Geological mapping and crustal shortening of central Tibet. Unpublished PhD dissertation, State University of New York at Albany. 157 pp., +xi;  8 folded maps.
University at Albany Science Library call number:  SCIENCE MIC Film QE 40 Z899 2004 L5
Copies of this PhD dissertation can be ordered from Proquest UMI

        Front matter (title, table of contents, abstract, acknowledgements) - 0.15MB pdf file
        Figure pages in dissertation (colour and greyscale photos and figures, with captions): - 22.7MB pdf file

    Plate 1 - Indepth III project route and seismometer locations (on TM and MSS image base, scale ~1:710,000)
                    (false-colour image mosaic with map overlay annotations) - 10.4MB pdf file
    Plate 2 - Geological map of the northeastern Nyainqentanglha, Tibet
                    (coloured geological map; scale ~1:86,000) - 0.1MB pdf file
    Plate 3 - Landsat TM image of the Baingoin region, central Tibet
                    (false-colour TM satellite image; scale ~1:278,000) - 5.7MB pdf file
    Plate 4 - Geological map of the Baingoin region, central Tibet
                    (coloured geological map; scale ~1:278,000) - 2.4MB pdf file
    Plate 5 - Landsat TM image of the Shuanghe region, north-central Tibet
                    (false-colour TM satellite image; scale ~1:275,000) - 6.4MB pdf file
    Plate 6 - Geological map of the Shuanghe region, north-central Tibet
                    (coloured geological map; scale 1:~275,000) - 2.1MB pdf file
    Plate 7 - Landsat TM image of the Dogai Coring region, north-central Tibet
                    (false-colour TM satellite image; scale ~1:285,000) - 6.4MB pdf file
    Plate 8 - Geological map of the Dogai Coring region, north-central Tibet
                    (coloured geological map; scale ~1:277,000) - 1.7MB pdf file

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