Stratigraphy of the Tethys Himalaya in Zanskar, Ladakh: initial report.

Abstract

The sedimentary sequence of the stratigraphy of the Tethys Himalays succession has been subdivided in three parts, from Late Precambrian to Eocene. The Late Pan-African Episode (Late Precambrian-Ordovician) is represented by a complete sedimentary cycle. The Epicontinental Stage (Late Ordovician-Late Carboniferous) is characterized by low sedimentation rates under transitional to shallow-marine conditions. The Passive Continental Margin Stage (Permian-Eocene) begins with basaltic flows. The Triassic starts with pelagic and condensed nodular limestones. Important clay influx occurred during the Ladinian. The carbonate platform resumed in the latest Triassic and Early Jurassic. After a major sedimentary gap, chamosite/goethite oolites, shales and sandstones were deposited in the Callovian, followed in the Late Jurassic by clay sedimentation on a mid-outer shelf. Marked increase in terrigenous detritus characterized the Early Cretaceous, when an important volcanic episode affected the continental margin. During the following transgressive stage (Turonian-Early Campanian), grey nodular limestones were deposited. A renewal of terrigenous influx followed (Campanian-Early Maastrichtian). A carbonate ramp resumed in the Late Maastrichtian, capped by deltaic quartzarenites, and by open to restricted shelf carbonates of Paleocene-earliest Eocene age. The passive margin sequence is capped by subaerial fluvio-deltaic red beds derived from volcanic rocks of the active margin, and thus marking the final welding of the Indian Plate against Eurasia. - from Authors