Late Eocene to early Oligocene quantitative paleotemperature record: Evidence from continental halite fluid inclusions

Abstract

Climate changes within Cenozoic extreme climate events such as the Paleocene–Eocene Thermal Maximum and the First Oligocene Glacial provide good opportunities to estimate the global climate trends in our present and future life. However, quantitative paleotemperatures data for Cenozoic climatic reconstruction are still lacking, hindering a better understanding of the past and future climate conditions. In this contribution, quantitative paleotemperatures were determined by fluid inclusion homogenization temperature (Th) data from continental halite of the first member of the Shahejie Formation (SF1; probably late Eocene to early Oligocene) in Bohai Bay Basin, North China. The primary textures of the SF1 halite typified by cumulate and chevron halite suggest halite deposited in a shallow saline water and halite Th can serve as an temperature proxy. In total, one-hundred-twenty-one Th data from primary and single-phase aqueous fluid inclusions with different depths were acquired by the cooling nucleation method. The results show that all Th range from 17.7°C to 50.7°C,with the maximum homogenization temperatures (ThMAX) of 50.5°C at the depth of 3028.04 m and 50.7°C at 3188.61 m, respectively. Both the ThMAX presented here are significantly higher than the highest temperature recorded in this region since 1954and agree with global temperature models for the year 2100 predicted by the Intergovernmental Panel on Climate Change.

Quantitative temperature records of mid Cretaceous hothouse: Evidence from halite fluid inclusions

“…This approach was widely employed for direct, quantitative paleo-temperature reconstructions including examples from the Precambrian-Cambrian (Meng et al, 2011b), Silurian (Losey and Benison, 2000), Permian (Benison and Goldstein, 1999; Zambito and Benison, 2013), Paleogene (Meng et al, 2013;Zhao et al, 2014), Quaternary (Lowenstein et al, 1998(Lowenstein et al, , 1999 and modern settings (Roberts and Spencer, 1995).…”

“…These evaporites have been dated by palynological means (Sattayarak et al, 1991;Smith et al, 1996;Racey and Goodall, 2009) and isotopic evidence (Hansen et al, 2002), as Albian to Cenomanian (roughly 112-93 Ma). Detailed petrological and sedimentological analyses demonstrated that the evaporitic rocks formed in a large isolated inland basin (Utha-Aroon, 1993;El Tabakh et al, 1999), that probably encountered marine flooding L.C. Wang et al, 2014;Wang et al, 2015).…”

“…According to L.C. Wang et al (2014), the Simao Basin and the Khorat Basin were connected during mid Cretaceous marine incursions implying that the salt-bearing sequences within both basins formed under the same environmental conditions. Jiao (2013) reported homogenization temperatures of single-liquid fluid inclusions of the Mengyejing Formation mainly concentrated within 35-65°C which are similar to our Th data from Laos.…”

Paleoclimatic information recorded in fluid inclusions in halites from Lop Nur, Western China

“…The cooling nucleation method has been widely used for paleotemperature reconstruction in geological periods, including the Precambrian 49 , Silurian 50,51 , Permian 52,53 , Cretaceous 54,55 , Paleogene 56,57 , and Quaternary 3,46 . In this study, following detailed petrographic observations of halite samples from the salt field and a drill core in Lop Nur, the cooling nucleation method was used to obtain the homogenization temperature of fluid inclusions.…”

Brillouin spectroscopy of fluid inclusions proposed as a paleothermometer for subsurface rocks

“…They include global proxies, for instance the isotopic ratio between 18 O and 16 O in ice cores23 or in shell of fossil marine organisms45; and local proxies, such as tree rings studies678, palynological studies9, and fluid inclusions (FIs)101112. FIs are present in virtually all rocks on Earth.…”