Sedimentological and paleoecological aspects of the Norian–Rhaetian transition (Late Triassic) in the Xuanhan area of the Sichuan Basin, Southwest China

Palynofacies analysis for interpreting paleoenvironment and hydrocarbon potential of Triassic–Jurassic strata in the Sichuan Basin, China

“…This may indicate proximal and oxic shelf environment (Tyson, 1995;Batten, 1996). These data are in agreement with floodplain to lagoonpeat swamp environment, implied by the dark grey to black mudstones with a few thin coal seams in members I and VII of the Xujiahe Formation (Li et al, 2014;Lu et al, 2019).…”

“…et al, 2016Li, L.Q. et al, , 2018Lu et al, 2019). Our recent cyclostratigraphy study implies that, the Xujiahe Formation spans from 207.2 Ma to 201.3 Ma at the Qilixia section .…”

“…III, V and VII are dominated by mudstones and shales interbedded with thin sandstone beds and coal seams; while members II, IV and VI are characterized by grey to whiteÀgrey sandstones that are interbedded with thin, laminated mudstones (Wang et al, 2010(Wang et al, , 2017Li, L.Q. et al, 2016;Lu et al, 2019) (Fig. 2).…”

“…upward-fining and upward-coarsening cycles in members II, IV and VI of the Xujiahe Formation indicate proximal alluvial fan-braided river-fluvial-deltaic deposition environment; mudstones and coal seams with abundant plant fossils in members III and V represent floodplain to lacustrine environment(Li et al, 2014;Lu et al, 2019); upward-fining conglomerate to mudstones in the Zhenzhuchong Formation suggest proximal fan delta environment(Cheng et al, 2014).…”

Late Cretaceous to Miocene Paleoclimatic changes in the Indian Ocean: insights from the deepwater Mannar Basin, Sri Lanka

“…The Cretaceous to Neogene period was a time of known fluctuations in greenhouse gas concentration, warm global temperature episodes, sea-level highstands, and stagnate oceanic circulation (e.g., Arthur et al 1985;Raymo and Ruddiman 1992;Pearson and Palmer 2000;Zachos et al 2001;Hong et al 2020;Yang et al 2020). These fluctuations are documented by stratigraphic and sedimentological features (Davies et al 1995;Lu et al 2019), paleontological and palynological data (Kaiho et al 1999;Gupta and Kumar 2019), petrography and geochemistry (Dypvik et al 2011;Teng et al 2019), and isotopic geochemistry (Bains et al 1999;Pälike et al 2006;Hong et al 2020). It is widely accepted that the tectonic evolution of Asia has played a crucial role in many of these Earth systems phenomena over this critical period in the Earth's history.…”