Lipar Matej, Barham Milo, Danišík Martin, Šmuc Andrej, Webb John A, McNamara Kenneth J, Šoster Aleš, Ferk Mateja
Anton Melik Geographical Institute, Research Centre of the Slovenian Academy of Sciences and Arts, Ljubljana 1000, Slovenia.
Timescales of Mineral Systems Group, School of Earth and Planetary Sciences, Curtin University, Perth 6845, Australia.
Sci Adv. 2024 Oct 4;10(40):eadp0414. doi: 10.1126/sciadv.adp0414. Epub 2024 Oct 2.
Karst landforms provide insights into landscape evolution and paleoclimate but are inherently challenging to date. An ancient interval of particularly intense weathering of Western Australian Pleistocene aeolianites is recorded in a spectacular pinnacle karst landscape with associated ferricrete nodules. (U-Th)/He dating of the ferricrete nodules revealed an age of 102.8 + 10.6/-11.4 thousand years, corresponding to marine isotope stage 5c. The (U-Th)/He age thus directly dates the wettest interglacial period in the region over the last 500 thousand years, which was responsible for the dissolution that formed the pinnacles. The reliability of the ferricrete (U-Th)/He age is supported by bounding optically stimulated luminescence and U-Th dates on associated aeolianites and carbonate precipitates, respectively. A (U-Th)/He approach is globally applicable to aeolianites with associated ferricretes, allowing more accurate dating of the environmental changes affecting these lithologies, and temporally constraining rapid Pleistocene climatic oscillations to better contextualize the associated evolution of the biosphere.
喀斯特地貌为景观演化和古气候研究提供了线索，但对其进行年代测定本身具有挑战性。在西澳大利亚更新世风成岩特别强烈的风化作用的一个古老时期，被记录在一个壮观的峰林喀斯特地貌以及相关的铁质结核中。对铁质结核进行的（铀-钍）/氦年代测定显示其年龄为102.8 + 10.6/-11.4千年，对应于海洋同位素阶段5c。因此，（铀-钍）/氦年龄直接测定了该地区过去50万年中最湿润的间冰期，正是这一时期的溶解作用形成了这些尖顶。铁质结核（铀-钍）/氦年龄的可靠性分别得到了相关风成岩的边界光释光年龄和碳酸盐沉淀物的铀-钍年龄的支持。（铀-钍）/氦方法在全球范围内适用于伴有铁质结核的风成岩，能够更准确地测定影响这些岩性的环境变化的年代，并在时间上约束更新世快速的气候振荡，以便更好地将相关的生物圈演化置于背景之中。
