三叠纪—侏罗纪之交准噶尔盆地南缘野火记录及全球对比

三叠纪—侏罗纪之交(距今约201 Ma)是地球历史上的关键时期,中大西洋火成岩省(Central Atlantic magmatic province,CAMP)快速地侵位和喷发,给全球的表生系统带来巨大的环境压力,其中之一是被广泛报道的同期野火事件.但此前的报道多集中在CAMP直接作用范围区内,对其是否具有全球性,以...

Wildfire Records Across the Triassic - Jurassic Boundary in the Southern Margin of the Junggar Basin,and Global Correlations

The Triassic-Jurassic transition （~201 Ma） was a critical period in the Earth’s history. The rapid emplacement and eruption of the Central Atlantic Magmatic Province （CAMP） put huge environmental pressure on the global surface ecosystem. One example was the synchronous wildfire events reported widely. However， previous reports have commonly focused on the area directly influenced by the CAMP. It is debatable whether the wildfire events were a global or a regional phenomenon. This study systematically collected samples across the Triassic?Jurassic boundary （TJB） in the Haojiagou section at the southern margin of the Junggar Basin， Xinjiang. Abnormally high values of combustive-derived polycyclic aromatic hydrocarbons （PAHs） were found around the TJB. The anomalies correspond well with the Hg/TOC peaks， indicating the CAMP emplacement or eruptions. This is the first report on wildfire records across the Triassic?Jurassic transition in high-latitude terrestrial strata outside the CAMP region. It is concluded from integrated global TJB correlations that the sharply rising wildfire frequency was triggered by the CAMP effect， but CAMP volcanism itself was not the direct igniting source. Increased wildfire frequency is inferred as a global event beyond the regions of CAMP activity， and similar wildfire records across the TJB could be observed on a global scale.