Regional investigation of extinction-recovery patterns during the Toarcian (Lower Jurassic) hyperthermal event

下侏罗纪的托瓦良阶段标志着一个极端环境扰动的时期，包括全球碳循环的变化，快速变暖到“超热”条件，以及大陆风化和径流的增加。这些事件与当代南半球的卡鲁-费拉大火成岩省的喷发有关。在北半球的许多海相沉积盆地中，高温条件导致沉积停滞，从而导致沉积物和水柱缺氧，并沉积了独特的富含有机物的层状黑色页岩（相关效应通常称为Toarcian Oceanic Anoxic Event - TOAE）。这些具有挑战性的条件导致了大型动物（特别是底栖动物）和微化石群的灭绝事件。从这一事件中恢复是缓慢的（数百万年），只有在TOAE之后环境条件改善时才会发生。在约克郡的克利夫兰盆地以及更远的德国和法国，TOAE和相关的灭绝和恢复模式都有很好的记录。它最近也得到了全球的认可，例如在加拿大。然而，在南欧的许多海相盆地中，层状黑色页岩相要么发育较弱，要么不存在，但在托瓦西亚阶段仍然存在明显的生物更替模式，以及快速和极端变暖的证据。这有力地表明，虽然在托瓦纪期间海洋氧含量的变化是区域性的，但变暖是一种全球现象，对环境和生物变化具有主要控制作用。因此，托瓦西亚阶段可以让我们了解人为全球变暖现在和未来的后果。

The Toarcian Stage of the Lower Jurassic marks a period of extreme environmental perturbations, including changes to the global carbon cycle, rapid warming to 'hyperthermal' conditions, and increased continental weathering and run-off. These events have been linked to the eruption of the Karoo-Ferarr Large Igneous Province in the contemporary Southern hemisphere. In many of the marine sedimentary basins in the Northern hemisphere the hyperthermal conditions led to stagnation, consequent sediment and water column de-oxygenation and the deposition of distinctive organic-rich laminated black shales (linked effects often termed the Toarcian Oceanic Anoxic Event - TOAE). These challenging conditions caused an extinction event in the macrofauna (particularly the benthos) and in microfossil groups. Recovery from this event was slow (several millions of years) and occurred only when environmental conditions improved after the TOAE. The TOAE and associated pattern of extinction and recovery is well recorded in the Cleveland Basin of Yorkshire, and further afield in Germany and France. It has also recently been recognized globally, in, for example, Canada. However, in many marine basins in Southern Europe laminated black shale facies are either weakly developed, or absent, yet there are still distinct patterns of biotic turnover during the Toarcian Stage as well as evidence for rapid and extreme warming. This strongly indicates that while changes in marine oxygen levels during the Toarcian where regional in extent, warming was a global phenomenon and had a primary control on both environmental and biotic changes. As such, the Toarcian Stage has lessons to teach us about the consequences of anthropogenic global warming now and in the future.