Paleomagnetic Investigation of Rock Formations from Junggar Basin, NW China

University Of California-Santa Cruz, Santa Cruz CA

Investigators

Abstract

Plate tectonic theory postulates that the Earth's lithosphere is broken into tectonic plates or blocks that move and slide past or toward each other over geological time. Our knowledge of the kinematics and duration of collisional events between various Chinese tectonic blocks and Siberia is still poorly known. Similarly, the accretionary history of the Central Asian fold belt itself is contentious. A lack of basic information regarding the tectonic assembly of asia hinders our understanding of the complex tectonic history of this region. The primary goal of this research is to study the Paleozoic and Mesozoic rocks from the Junggar Basin, Northwest China, to address key questions that are currently debated: Terrane Accretionary History of the Central Asian Belt; Coherence of the Junggar Basin; and Excessive Crustal Shortening. A common thread running through the proposed work is to obtain reliable paleomagnetic data bearing on the tectonic and geodynamic evolution of Asia, including the sequence of configurations leading up to collision of oceanic terranes and continental blocks along its southern margin and the large-scale displacements and rotations that ensued during the long process of accretion. To address these questions we are collecting paleomagnetic and geochronologic samples from the Junggar Basin. In addition to the scientific objectives of this research, the project is contributing to the education of graduate and undergraduate students in a STEM discipline and is promoting significant international collaboration with scientists from Taiwan and The Peoples Republic of China. Geophysical insight and refinement of paleogeographic maps from this study may help identify the ancient environments that were conducive to the formation of the rare-metal mineralization and petroleum potential in the central Asian belt region. The scientific results from this project will be germane to a broad range of scientists studying continental tectonics with interests ranging from the growth of the lithosphere to deep-mantle dynamics to examining questions regarding possible relations between plume activity, large igneous province production, and geomagnetic polarity superchrons. The data from this study will be presented at national meetings, reported to the NSF, and disseminated in peer-reviewed, high-profile international journal articles and web-based paleomagnetic database for wider dissemination. This award is co-funded by NSF's Office of International Science and Engineering.