Evidence of palaeo-wildfire during the Early Cretaceous: macro-charcoal from the Chijinpu Formation (early Aptian) of northwestern China

It is indisputable that large parts of the Cretaceous can be considered as a particular 'high-fire' interval, supported by numerous published records of palaeo-wildfires during this period. The presence of charcoal is widely accepted as direct evidence of palaeo-wildfires. In this study, macroscopic charcoal from the Early Cretaceous Chijinpu Formation in the Zhongkouzi Basin, Beishan area, northwestern China, is reported and described. These charcoal fragments serve as reliable evidence of palaeo-wildfires that occurred in northwestern China during the Early Cretaceous. Based on anatomical characteristics, the charcoal remains were identified to gymnosperms, most probably conifers, which is in accordance with previous palaeobotanical records from the Chijinpu Formation. It is reasonable to infer that wildfire played a significant role in the ecosystems of this region. We consider that the forests with rich conifers and the dry climatic conditions, were probably conducive to the ignition and spread of wildfires. Conifers, in particular, could have played a significant role in this process by providing abundance and flammable fuel sources for the fire. The present study contributes new evidence to our knowledge of the Early Cretaceous wildfires and enriches our knowledge of the vegetation and environmental conditions in the study area.