The temperature fluctuations in the Eocene climate are one of the most mysterious phenomena in Cenozoic climate dynamics, and they severely affected the marine and terrestrial biospheres. However, quantitative and comprehensive temperature reconstructions for middle Eocene climatic variations remain limited due to fragmentary paleotemperature records, especially in the easternmost proto-Paratethys sea (Kuqa Depression), where traditional paleoclimatic proxies are restricted by the occurrence of extensive and thick evaporite deposits. In this study, we reconstruct middle Eocene sea surface temperatures (SST) and even air temperatures in the Kuqa Depression based on 584 homogenization temperatures (T_h) for fluid inclusions in cumulate and chevron halite crystals from cores DW1 and KL4. The T_h values from core DW1 have ranges of 10.5–45.7 °C, the T_h values from core KL4 have ranges of 12.6–35.2 °C. The measured T_h values are mainly concentrated within 20–30 °C, and an average T_h value of 25.6 °Crepresents the SST and is consistent with previous coeval research results. The highest recorded T_h is 45.7 °C, clearly representing local hot climate conditions. The average and maximum SST in the middle Eocene Kuqa Depression are cooled by 5.2–11.3 °C and 6.5–14.1 °C, respectively. The cooling trend in the Kuqa Depression occurred in response to global and Tethyan realm cooling in the middle Eocene, but the cooling amplitude in the study area was greater than that of the global climate. The T_h data for primary halite fluid inclusions can effectively and quantitatively track past environmental and climatic variations, especially in evaporitic basins where traditional paleoclimatic proxies are often not available.

始新世气候的温度波动是新生代气候动力学中最神秘的现象之一，严重影响了海洋和陆地生物圈。然而，由于零散的古温度记录，尤其是在最东部的原始帕拉特里斯海（库车De陷）中，始新世中期气候变化的定量和全面的温度重建仍然受到限制，传统的古气候代理受到大量而厚厚的蒸发岩沉积物的限制。在这项研究中，我们基于584个均匀化温度（T _h），对来自DW1和KL4岩心的累积和人字形盐岩晶体中的流体包裹体，重建了中古始新世海温（SST）甚至库卡q陷中的气温。这DW1磁芯的T _h值范围为10.5–45.7°C，KL4磁芯的T _h值范围为12.6–35.2°C。测得的T _h值主要集中在20-30°C范围内，平均T _h值为25.6°C表示SST，与先前的同期研究结果一致。最高记录的T _h为45.7°C，明显代表当地炎热的气候条件。中始新世库车De陷的平均和最大海温分别降低了5.2–11.3°C和6.5–14.1°C。库车De陷的降温趋势是响应中始新世的全球和特提斯地区降温而发生的，但研究区的降温幅度大于全球气候的降温幅度。主要盐岩流体包裹体的T _h数据可以有效和定量地跟踪过去的环境和气候变化，尤其是在蒸发盆地中，传统的古气候替代品通常不可用。