Characteristics and evolution of inertinite abundance and atmospheric pO2 during China’s coal-forming periods

Abstract

Coal, especially the inertinite in it, is highly sensitive to climate changes, showing an obvious response to paleoclimate conditions, in particular, to paleo-oxygen concentration (pO2). In this study, the inertinite abundance data of typical coal-forming periods in China were systematically collected and analyzed. Its characteristics and control factors were studied, and its evolution was established. Based on inertinite abundance data, pO2 evolution curves of various coal-forming periods in China were established, which fluctuated between 15% and 30% during the entire Phanerozoic. The inertinite abundance in coal deposits during Paleozoic in China was basically consistent with that of other areas of the world, while it was quite different globally from the Mesozoic to the Cenozoic. The results show that the inertinite abundance in coal deposits is controlled by pO2 and other factors including climatic zones, plant differentiation, sedimentary environments, and tectonic activities. The inertinite abundance in coal deposits in China during the Jurassic was high, suggesting dry paleoclimate of inland China.

Widespread wildfires linked to early Albian Ocean Anoxic Event 1b: Evidence from the Fuxin lacustrine basin, NE China

“…From this it can be interpreted that pO2 levels during the early Albian were much higher than the minimum needed for sustained combustion, and even reached a situation where fires become common. The high pO2 levels would have led to greatly increased plant flammability, which is consistent with a global record of widespread wildfires during the Lower Cretaceous (Belcher et al, 2010;Diessel, 2010;Wang et al, 2021a;Wang et al, 2019bWang et al, , 2020b.…”

“…Wildfires have played an important role in Earth system changes since the Silurian period when land plants first appeared on Earth and profoundly influenced global ecosystem patterns and processes (Glasspool et al, 2004;Glasspool et al, 2015;Lu et al, 2021). Charcoal, as the byproduct of wildfires, is recorded from the late Silurian (~420 Ma) to the present (Scott and Glasspool, 2006) and provides evidence for wildfire events in the rock record (Scott and Glasspool, 2007;Scott, 2010;Shao et al, 2012;Wang et al, 2019a;Wang et al, 2021a).…”

“…Although the origin of inertinite is still under frequent debate, more recent studies have concluded that inertinite is synonymous with charcoal and is almost exclusively considered as the byproduct of wildfires (e.g., Scott and Glasspool, 2007;Diessel, 2010;Glasspool and Scott, 2010;Glasspool et al, 2015). Inertinite is common throughout much of the Cretaceous Period (Diessel, 2010;Wang et al, 2021a), and recent evidence indicates widespread and frequent wildfires occurred during the Cretaceous (Bond and Scott, 2010;Brown et al, 2012;Sender et al, 2014;Moore et al, 2021;Wang et al, 2019bWang et al, , 2021b. Thus, the Cretaceous has been considered as a "high-fire" world (Brown et al, 2012).…”

“…Wildfires respond strongly to atmospheric oxygen concentration (pO2), and variations in the occurrence and abundance of inertinite in the Earth's history have been used to estimate pO2 levels (Jones and Chaloner, 1991;Wildman et al, 2004;Belcher et al, 2010;Glasspool and Scott, 2010;Shao et al, 2012;Glasspool et al, 2015;Hou et al, 2020;Wang et al, 2021a). Related studies have revealed that pO2 above the present-day level of 21% would enable fuels to burn more frequently, while pO2 levels below 18.5% would suppress fire frequency (Belcher et al, 2010).…”

Control of Structural Landform Evolution on Karst Groundwater Cycle in a Large‐Scale Anticlinorium

“…Multilayer complex karst aquifers were formed and controlled the distribution and movement of karst groundwater. At this period, the paleoclimate changed from semi‐humid to semi‐dry, and the CO 2 concentration was high, but the rainfall was less (Brown et al 2012; Wang et al 2021), so the karstification was weak.…”