Jorge A. Vazquez Qicheng Fan Haibo Zou 2020 <div id="abstracts" class="Abstracts u-font-serif"><div id="ab0005" class="abstract author" lang="en"><div id="as0005"><p id="sp0055">Post-collisional potassic volcanic rocks on the Tibetan Plateau are widespread, but geologically young (&lt;375&nbsp;ka) volcanism suitable for<span>&nbsp;</span>²³⁸U-²³⁰Th geochronology is rare on the plateau. The geologically young Ashikule volcanic field from northern Tibet offers an excellent opportunity for studying high-resolution timescales of magmatism in continental collision zones. Here we report U-Th crystallization ages of zircons from Ashishan volcano and Wulukeshan volcano within the Ashikule volcanic field. In this study, we have identified 3 pulses of zircon crystallization at circa 70&nbsp;ka, 105&nbsp;ka, and 290&nbsp;ka for Ashishan volcanic rocks and 1 pulse of zircon crystallization at circa 115&nbsp;ka for Wulukeshan. Comparison of high-resolution zircon crystallization ages of 70&nbsp;ka and 105&nbsp;ka with respective eruption ages indicate that the zircon crystal residence time for the Ashishan volcano is short (&lt;5 kyr). The presence of 290-ka zircon in a different Ashishan lava flow suggests the 270-ka volcanic pulse previously reported for other volcanoes in Ashikule volcanic field also occurred at Ashishan. The zircon crystallization age of ~115&nbsp;ka for Wulukeshan volcano suggests that Wulukeshan volcano erupted later than previously inferred. Similar zircon age spectrums of ~105–115&nbsp;ka for Ashishan and Wulukeshan volcanoes suggest a common interconnected subsurface magma reservoir for these two young volcanoes during Pleistocene time. Our new high-resolution U-Th zircon age data reveal that post-collisional potassic magmas below northern Tibet erupted soon after their formation (&lt;5 kyr), in spite of their passage through thick continental crust. The high abundance (~60%) of geologically old (&gt;375&nbsp;ka) zircons demands for crystal-scale isotope studies of the widespread post-collisional lavas in continental collision zones, as the complexities cannot be resolved by bulk analysis methods alone.</p></div></div></div><ul id="issue-navigation" class="issue-navigation u-margin-s-bottom u-bg-grey1"></ul> application/pdf 10.1016/j.lithos.2020.105418 en Elsevier Timescales of magmatic processes in post-collisional potassic lavas, northwestern Tibet article