Intensified tectonic deformation and uplift of the Altyn Tagh range recorded by rock magnetism and growth strata studies of the western Qaidam Basin, NE Tibetan Plateau

• Middle Mio–Pliocene magnetic proxies from the western Qaidam Basin
• A sharp change of rock magnetic results at about 10 Ma
• Seismostratigraphy data, paleocurrent, and provenance were also studied.
• The significant deformation of the Altyn Tagh range might be main driving force.

As the tectonical and geographical northern edge of the Tibetan Plateau, the evolution of the Altyn Tagh range has attracted wide attention. Precise dating of its activities is believed essential for understanding the possible mechanisms of the Tibetan Plateau uplift and its effects on climate changes. Under the framework of basin–mountain coupling, both magnetic susceptibility and rock magnetic researches were carried out in this study on the Late Cenozoic sediments of the Honggouzi (HGZ) section (ca. 17–5 Ma) in the western Qaidam Basin to explore the tectonic and climatic evolution as well as their interactions of the Altyn Tagh range.The obtained magnetic susceptibility record in the HGZ section displayed a two-step variation, which kept relatively low and stable values for sediments from the stratigraphic levels of 120–596 m (ca. 17–10 Ma) (stage I), but increased rapidly from 596 to 1014 m (ca. 10–5 Ma) (stage II). The rock magnetic results revealed that paramagnetic minerals or clay minerals, maghemite and hematite are dominant in stage I, which were replaced by magnetite and maghemite in stage II. A detailed comparison of magnetic susceptibility record in the HGZ section with regional tectonic and climate records was carried out. Combined with sedimentary facies, lithology and angular unconformity in the sequence, as well as seismostratigraphy data, paleocurrent and provenance analyses, the possible mechanisms for the magnetic susceptibility variation were explored. The results indicated a direct link between magnetic susceptibility change and the uplift of the Altyn Tagh range at ca. 10 Ma.

The significant deformation and uplift of the Altyn Tagh range at ~ 10 MaFigure optionsDownload as PowerPoint slide