Elemental concentrations of the siliciclastic sediments from a sedimentary basin provide clues on paleoweathering, paleoclimate, provenance, and tectonic setting of the basin. Records for Permo–Triassic mass extinction and climatic fluctuations are commonly traced from the sediments in the Gondwana basins. Nevertheless, our understanding on sedimentation, provenance, and regional tectonics of the Raniganj Basin, a Gondwana basin in the eastern India is poor. Minerals including clay particles and major and trace element concentrations of the siliciclastic sediments from different formations of the Raniganj Basin have been studied to establish the paleo-weathering, paleoclimate, provenance, and tectonic settings of the basin. This study suggests that the Talchir Formation experienced cold and dry climatic conditions at the sediment source area, while the Barakar, Raniganj, and Panchet formations had prevailing semiarid climates. The sources of the siliciclastic sediments are from the felsic rocks of the Chotanagpur Granite Gneissic Complex (CGGC). Further, the geochemical results suggest a rift-like (passive) tectonic setting for the Raniganj Basin, while few samples represent the collision tectonic setting of the basement CGGC, formed due to collision of major Indian blocks during the Paleo-Neoproterozoic time.

The size of basalt fragments in Chang'E-5 (CE-5) regolith are small (< 6 mm²), resulting in large variation on the estimated bulk composition of CE-5 basalt. For example, the estimated TiO₂ content of CE-5 basalt ranges from 3.7 wt% to 12.7 wt% and the Mg# (molar percentage of Mg/[Mg + Fe]) also shows a wide range (26.2 − 42.4). Preliminary experimental studies have shown that these geochemical characteristics of CE-5 basalt are critical for investigating the crystallization sequence and formation mechanism of its parent magma. This study presents new experimental data on the distribution coefficient of titanium between pyroxene and lunar basaltic magma . Combining with available literature data, we confirm that is affected by crystallization conditions such as pressure and temperature, but it is mainly controlled by the CaO content of pyroxene. Comparing with previous experimental results under similar conditions, we parameterized the effect as , where X_CaO is the CaO content in pyroxene in weight percentage. The new experimental results suggest that pyroxene with high TiO₂ content (> 2.5 wt%) in CE-5 basalt is not a product of equilibrium crystallization, and the CaO content in pyroxene is also affected by cooling rate of its parent magma. The TiO₂ content in the CE-5 parent magma is estimated to be about 5 wt% based on the Mg# of pyroxene and its calculated CaO content, which is consistent with those estimated from olivine grains.