Li Youjuan

• Associate Professor at Institute of Geology and Geophysics, Chinese Academy of Sciences

Plain Language Summary The Chang'e‐5 basalts provide a valuable insight into the history of late lunar volcanic activity. High‐precision chronological studies are essential to accurately quantify the history of late lunar volcanism. However, the eruption period of the Chang'e‐5 basalt cannot be resolved within the accuracy of the existing Lead (Pb)...

The timing, tempo, and causative mechanisms of Ocean Anoxic Event 1a (OAE1a), one of several such abrupt perturbations of the Mesozoic global carbon cycle, remain uncertain. Mudstones interbedded with tuffs in Hokkaido, Japan preserve carbon and osmium isotope shifts recording OAE1a. U-Pb zircon ages of tuffs constrain the OAE1a onset to 119.55 +0....

The timing of the onset of magnetochron M0r and its duration are disputed, reflecting both a limited set of radioisotopic dates and uncertain magnetostratigraphic correlations. We present a chronostratigraphic framework for a reversed polarity interval based on two chronometers (40Ar/39Ar, U-Pb) and newly published paleomagnetic data from the Qings...

The precision and accuracy of ⁴⁰ Ar/ ³⁹ Ar dates are ultimately linked to co‐irradiated reference materials of known age. Here we provide new data from the SK01 sanidine, which was analysed in three different laboratories to evaluate it as a ⁴⁰ Ar/ ³⁹ Ar reference material. Aliquots of 5 mg, incrementally heated in two laboratories, yielded indisti...

The oldest Oldowan tool sites, from around 2.6 million years ago, have previously been confined to Ethiopia's Afar Triangle. We describe sites at Nyayanga, Kenya, dated to 3.032 to 2.581 million years ago and expand this distribution by over 1300 kilometers. Furthermore, we found two hippopotamid butchery sites associated with mosaic vegetation and...

In Liaoning Province, Northeastern China, the Early Cretaceous Jehol Biota records significant evolution and radiation of fauna in terms of diversity, abundance and complexity. The alluvial-to-fluvial Lujiatun and lacustrine Jianshangou beds of the lower Yixian Formation yield exceptionally well-preserved three-dimensional and articulated dinosaur...

The Lower Cretaceous Jiufotang Formation in western Liaoning Province, northeastern China contains important vertebrate fossils of the late Jehol Biota, e.g., the four-winged non-avian dinosaur Microraptor. This formation documents the late phase of the Jehol Biota, producing the most abundant fossil records of the Mesozoic birds. However, the prec...

The development history of high topography in the northeastern (NE) Tibetan Plateau is essential to test various plateau growth models and understand plateau construction. We present integrated provenance data from the NE Qaidam Basin, south of the Qilian Shan. Results show an increase in carbonate lithics, an increase in Al2O3/SiO2 ratios, a negat...

Many geological contexts lack suitable material for commonly applied absolute dating methods. Even if some regions contain potentially datable materials, they may be inappropriate for dating by existing geochronological techniques. Paleoanthropological localities on the Homa Peninsula, southwestern Kenya, have yielded important paleoanthropological...

Plain Language Summary Development of the largest orogenic plateau in the world, the Tibetan Plateau, is at the center of many Earth models. We study the exhumation history of the East Kunlun Shan in the northeastern Tibetan Plateau using low‐temperature thermochronology. Apatite (U‐Th)/He thermochronology serves as a useful method to reveal exhuma...

Tectonic activity and climate change are regarded as two important driving forces on the evolution of large-scale drainage. The evolution of the Irtysh River and Ulungu River, two large-scale drainage systems in the northern Junggar Basin, can provide a key constraint on the uplift of the Altai Mountains and Central Asian aridification. However, we...

The Qilian Shan, at the northeastern frontier of the Tibetan Plateau, is a key area for studying the expansion mechanism of the Tibetan Plateau. Although previous thermochronology and paleomagnetic studies indicate Neogene northward expansion of the northern Qilian Shan, there is a distinct temporal gap in knowledge relative to the tectonic history...

LA-ICP-MS(laser ablation-inductively coupled-mass spectrometry)has been recently used for rapid, accurate and precise U-Pb geochronology on zircon grains. In this paper, we adopted an Agilent 7900 quadrupole ICP-MS coupled with a Resolution M50-LR 193nm excimer laser system to establish integrated measurement procedures. Before analysis, the system...

The northern Tibetan Plateau, north of the Qaidam Basin and south of the Hexi Corridor (China), consists of a series of WNW- to NW-trending elongated mountain ranges. Deciphering the time-space deformation pattern of these ranges is central to understanding the mechanism of plateau formation and to the controversial issue of whether Tibet has under...

Chrome chlorites are usually found as secondary phases formed by hydrothermal alteration of chromite deposits and associated mafic/ultramafic rocks. Here, we report the ⁴⁰Ar/³⁹Ar age of chrome chlorites separated from the Luobusa massive chromitites which have undergone secondary alteration by CO2-rich hydrothermal fluids. The dating results reveal...

We provide a stringent age constraint on the Upper Cretaceous terrestrial strata based on ⁴⁰Ar/³⁹Ar dating of a continuous volcanic-sedimentary sequence drilled from Jiaolai Basin in Shandong Province, eastern China. The volcanic-sedimentary sequence, which is mainly composed of basaltic rocks interbedded with thin-bedded siltstone and fine sandsto...

(U-Th)/He isotopic dating has been developed very quickly in recent years, due to the recognition that the thermal history of rock at low temperature can be effective revealed by such dating method. In particular, He closure temperature in apatite(40~80℃) is very low, so apatite(U-Th)/He ages can reflect the thermal history information of the low-t...

Precise time constraints of the main extrusive phase of the Emeishan large igneous province (ELIP) remain unresolved because basalts commonly do not contain suitable minerals for U–Pb dating, whereas previous ⁴⁰Ar/³⁹Ar studies on basalts yielded tectonothermal overprint ages. The timing for the ELIP was deduced from indirect dating of minor intrusi...

In this study (U-Th)/He dating of the Penglai zircons, which occur as abundant megacrysts in Neogene alkaline basalts in northern Hainan Province, south-eastern China, was undertaken. A weighted mean age of 4.06 ± 0.35 Ma (2s) with a mean square weighted deviation (MSWD) of 1.79 was obtained from eighteen fragments of four zircon megacrysts using s...