Abstract
To better understand the Neotethyan paleogeography, a paleomagnetic and geochronological study has been performed on the Early Cretaceous Sangxiu Formation lava flows, which were dated from ~135.1 Ma to ~124.4 Ma, in the Tethyan Himalaya. The tilt-corrected site-mean characteristic remanent magnetization (ChRM) direction for 26 sites is Ds = 296.1°, Is = −65.7°, ks = 51.7, α95 = 4.0°, corresponding to a paleopole at 5.9°S, 308.0°E with A95 = 6.1°. Positive fold and reversal tests prove that the ChRM directions are prefolding primary magnetizations. These results, together with reliable Cretaceous-Paleocene paleomagnetic data observed from the Tethyan Himalaya and the Lhasa terrane, as well as the paleolatitude evolution indicated by the apparent polar wander paths (APWPs) of India, reveal that the Tethyan Himalaya was a part of Greater India during the Early Cretaceous (135.1–124.4 Ma) when the Neotethyan Ocean was up to ~6900 km, it rifted from India sometime after ~130 Ma, and that the India-Asia collision should be a dual-collision process including the first Tethyan Himalaya-Lhasa terrane collision at ~54.9 Ma and the final India-Tethyan Himalaya collision at ~36.7 Ma.
Highlights
Which includes a first collision of the Tethyan Himalaya with Asia at ~50–55 Ma and a final continent-continent collision of the Indian craton with the Tethyan Himalaya at ~20–25 Ma14 or ~40 Ma12,20
Considering that the sedimentary rocks often suffer from compaction-induced inclination shallowing[20,30,31,32], whereas the volcanic rocks are immune from its effect, we carried out a combined geochronologic and paleomagnetic study on the Early Cretaceous Sangxiu Formation (Fm) lava flows in the Tethyan Himalaya
Samples ZL1 and ZL23 yield weighted mean 206Pb/238U ages of 135.1 ± 0.7 Ma and 124.4 ± 0.7 Ma, respectively. These new ages are well consistent with the age of ~133 ± 3 Ma reported by Zhu et al.[33], indicating that the Sangxiu volcanics erupted during the Early Cretaceous
Summary
Which includes a first collision of the Tethyan Himalaya with Asia at ~50–55 Ma and a final continent-continent collision of the Indian craton with the Tethyan Himalaya at ~20–25 Ma14 or ~40 Ma12,20. Considering that the sedimentary rocks often suffer from compaction-induced inclination shallowing[20,30,31,32], whereas the volcanic rocks are immune from its effect, we carried out a combined geochronologic and paleomagnetic study on the Early Cretaceous Sangxiu Formation (Fm) lava flows in the Tethyan Himalaya. These new high-quality and well-dated paleomagnetic data can significantly attribute to the two issues mentioned above. The volcanic strata consist of pillowed and massive, sparsely amygdaloidal basalts and minor dacites
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
