The upper carbonate member of the Kaibab Formation in northern Arizona (USA) was subaerially exposed during the end Permian and contains fractured and zoned chert rubble lag deposits typical of karst topography. The karst chert rubble has secondary (authigenic) silica precipitates suitable for estimating continental weathering temperatures during the end Permian karst event. New oxygen and hydrogen isotope ratios of secondary silica precipitates in the residual rubble breccia: (1) yield continental palaeotemperature estimates between 17 and 22 °C; and, (2) indicate that meteoric water played a role in the crystallization history of the secondary silica. The continental palaeotemperatures presented herein are broadly consistent with a global mean temperature estimate of 18.2 °C for the latest Permian derived from published climate system models. Few data sets are presently available that allow even approximate quantitative estimates of regional continental palaeotemperatures. These data provide a basis for better understanding the end Permian palaeoclimate at a seasonally-tropical latitude along the western shoreline of Pangaea.

中文翻译：

---

利用石瓦砾角砾岩中次生二氧化硅的氧和氢同位素组成，对二叠纪末期的大陆古温度进行地球化学分析：美国大峡谷的凯巴布组。

在美国亚利桑那州北部，凯巴布组的上层碳酸盐岩在二叠纪末期暴露于地下，并且含有典型的喀斯特地貌裂隙和带状cher石瓦砾滞后沉积物。喀斯特石瓦砾具有次生（自生）二氧化硅沉淀，适合估算二叠纪末岩溶事件期间的大陆风化温度。残余碎石角砾岩中次生二氧化硅沉淀物的新的氧和氢同位素比：（1）产生的大陆古温度估计在17至22°C之间；（2）表明，在辅助二氧化硅的结晶过程中，大气水起了作用。本文介绍的大陆古温度与从已发布的气候系统模型得出的最新二叠纪的全球平均温度估算值18.2°C大致一致。目前很少有数据集可以对区域大陆古温度进行近似的定量估计。这些数据为更好地了解Pangaea西部海岸线的季节性热带纬度上的二叠纪古气候提供了基础。