Both the Chicxulub and Boltysh impact events are associated with the K-Pg boundary. While Chicxulub is firmly linked to the end-Cretaceous mass extinction, the temporal relationship of the ~24-km-diameter Boltysh impact to these events is uncertain, although it is thought to have occurred 2 to 5 ka before the mass extinction. Here, we conduct the first direct geochronological comparison of Boltysh to the K-Pg boundary. Our ⁴⁰Ar/³⁹Ar age of 65.39 ± 0.14/0.16 Ma shows that the impact occurred ~0.65 Ma after the mass extinction. At that time, the climate was recovering from the effects of the Chicxulub impact and Deccan trap flood volcanism. This age shows that Boltysh has a close temporal association with the Lower C29n hyperthermal recorded by global sediment archives and in the Boltysh crater lake sediments. The temporal coincidence raises the possibility that even a small impact event could disrupt recovery of the Earth system from catastrophic events.

Chicxulub 和 Boltysh 撞击事件都与 K-Pg 边界有关。虽然希克苏鲁伯与白垩纪末大灭绝密切相关，但直径约 24 公里的博尔蒂什撞击与这些事件的时间关系尚不确定，尽管人们认为它发生在大灭绝前 2 至 5 ka。在这里，我们对 Boltysh 与 K-Pg 边界进行了首次直接地质年代比较。我们的⁴⁰ Ar/ ³⁹Ar 年龄为 65.39 ± 0.14/0.16 Ma，表明撞击发生在大灭绝后~0.65 Ma。当时，气候正在从希克苏鲁伯撞击和德干圈闭洪水火山活动的影响中恢复。这个年龄表明 Boltysh 与全球沉积物档案和 Boltysh 火山口湖沉积物记录的下 C29n 超高温有密切的时间关联。时间上的巧合增加了一种可能性，即即使是很小的撞击事件也可能破坏地球系统从灾难性事件中的恢复。