Tectonostratigraphy of the Shyok Suture Zone in Ladakh, NW India.

Abstract

This thesis explores the timing and nature of the tectonic collision between India, Eurasia, and an intra-oceanic arc in the western Himalaya. Chapter One presents the results of a geological mapping campaign in the Shyok-Nubra confluence region of Ladakh, in northwest India. It provides lithological descriptions of the major geological units in the Shyok suture zone, and also compiles tectonostratigraphic correlations with exposures in northern Pakistan to develop a tectonic reconstruction of the southern Eurasian margin in Jurassic-Paleocene time. Chapter Two presents U-Pb zircon dates that constrain the age of the significant tectonic boundaries between the Eurasian margin and the Kohistan-Ladakh arc. Chapter Three presents paleomagnetic results that constrain the latitude of the Kohistan-Ladakh arc in the Paleocene. Chapter Four presents paleomagnetic results that constrain the latitude of the Eurasian margin in the Late Cretaceous and discusses the paleogeography of the India-Eurasia collision. This thesis constrains the age of the Shyok suture zone using multiple lines of evidence and shows that the Shyok suture zone records final closure of the ocean between India and Eurasia in the Eocene.