Characteristics of Early Cretaceous wildfires in peat-forming environment, NE China

作者：Shuai Wang,Long-Yi Shao,Zhi-Ming Yan,Ming-Jian Shi,Yun-He Zhang

摘要：Inertinite maceral compositions in coals from the Early Cretaceous Erlian, Hailar, and Sanjiang Basins in NE China are analyzed in order to reveal palaeowildfire events and palaeoclimate variations. Although huminite is the dominant maceral group in the studied basins, the inertinite group, as a byproduct of palaeowildfires, makes up a considerable proportion. Occurrence of inertinite macerals indicates that wildfires were widespread and frequent,and supports the opinion that the Early Cretaceous was a "high-fire" interval. Inertinite contents vary from 0.2% to 85.0%, mostly within the range of 10%–45%, and a model-based calculation suggests that the atmospheric oxygen levels during the Aptian and Albian(Early Cretaceous) were around 24.7% and 25.3% respectively. Frequent fire activity during Early Cretaceous has been previously related to higher atmospheric oxygen concentrations. The inertinite reflectance, ranging from 0.58%Ro to 2.00%Ro, indicates that the palaeowildfire in the Early Cretaceous was dominated by ground fires, partially reaching-surface fires. These results further support that the Cretaceous earliest angiosperms from NE China were growing in elevated O2 conditions compared to the present day.

發文機構：College of Geoscience and Surveying Engineering

關鍵詞：INERTINITECoalWildfirePalaeo-atmosphericoxygenlevelANGIOSPERMEarlyCretaceousNEChina

分類號： P[天文地球]