Repeated occurrence of palaeo-wildfires during deposition of the Bahariya Formation (early Cenomanian) of Egypt

Haytham El Atfy,André Jasper,Tarek Anan,Dieter Uhl

doi:10.1186/s42501-019-0042-6

Abstract

The Upper Cretaceous (early Cenomanian) Bahariya Formation of Egypt has an outstanding reputation for its wealth of vertebrate remains, including a variety of iconic dinosaurs, like the carnivorous Spinosaurus and Carcharodontosaurus, as well as the herbivorous Aegyptosaurus and Paralititan. Besides these dinosaur fossils, the Bahariya Formation yielded also a wealth of invertebrate and plant remains, but even today many aspects concerning the continental palaeoenvironments reflected in these deposits (including the occurrence of palaeo-wildfires) have not been studied in detail. So far six distinct macro-charcoal bearing levels could be identified within the type section of the Bahariya Formation at Gabal El Dist profile, one of the most prolific outcrops of this formation in terms of fossil occurrence located in the north of the Bahariya Oasis, Western Desert, Egypt. Most of the charcoal investigated by means of SEM originates from ferns, pointing to a considerable proportion of this plant group within the palaeo-ecosystems that experienced fires. Gymnosperms and (putative) angiosperms have less frequently been identified. The collected data present evidence that the landscapes at the northern shores of Gondwana repeatedly experienced palaeo-wildfires, adding extra proof to previous statements that the Late Cretaceous was a fiery world on a global scale.

Highlights

For almost a century different proxies, such as charcoal, coal macerals like fusinite and semifusinite, as well as pyrogenic polyaromatic hydrocarbons have widely been used to reconstruct the history of palaeo-wildfires throughout the Earth’s deep time history (e.g. Potonié 1929; Harris 1958; Alvin 1974; Scott 2000, 2010; Scott et al 2014)
The occurrence of macro-charcoal in sediments of the Bahariya Formation at the Bahariya Oasis, Egypt has previously been mentioned by a number of authors (e.g. Dominik 1985; Nothdurft et al 2002), without providing any conclusive evidence that the material really represents charcoal, and it is not clear whether these reports can be used as evidence for the occurrence of wildfires or not
We present such evidence for the repeated occurrence of palaeo-wildfires during deposition of the Bahariya Formation in the form of macro-charcoal originating from six distinct levels at the Gabal El Dist profile at the Bahariya Oasis

Summary

Introduction

For almost a century different proxies, such as charcoal, coal macerals like fusinite and semifusinite, as well as pyrogenic polyaromatic hydrocarbons have widely been used to reconstruct the history of palaeo-wildfires throughout the Earth’s deep time history (e.g. Potonié 1929; Harris 1958; Alvin 1974; Scott 2000, 2010; Scott et al 2014). Dominik 1985; Nothdurft et al 2002), without providing any conclusive evidence (sensu Scott 2000, 2010) that the material really represents charcoal, and it is not clear whether these reports can be used as evidence for the occurrence of wildfires or not. We present such evidence for the repeated occurrence of palaeo-wildfires during deposition of the Bahariya Formation in the form of macro-charcoal originating from six distinct levels at the Gabal El Dist profile at the Bahariya Oasis. This evidence confirms the previous claims about the occurrence of charcoal in the Bahariya Formation, and adds reliable information on the so far only known occurrence of Cenomanian palaeo-wildfires all over Africa

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