Homogenization temperature of fluid inclusions in Early-Middle Pleistocene halite from Liang Hole ZK02 in Dalangtan area, Qaidam Basin and its constraints on potash mineralization

doi:10.13745/j.esf.sf.2021.1.44

Abstract

Abstract: Using the cryogenic nucleation method we obtained 158 homogenization temperature measurements of fluid inclusions (pure liquid) in Early to Middle Pleistocene rock salt samples from Liang Hole ZK02 in Dalangtan area, Qaidam Basin. Micromorphological examination revealed inverted cubic fluid inclusions in chevron salt crystals, and no significant correlation was observed between the measured homogenization temperature and inclusion size. The results indicated the samples under investigation contained primary rock salt and fluid inclusions, and the maximum homogenization temperature can represent ancient summer temperatures. Subsequent testing suggested the maximum homogenization temperature in the Early Pleistocene ranged between 25-30 ℃, while high mud and sand contents in the salt rock implied the climate was mild with abundant fresh water injection in the early stage. In the late stage the salt content increased, reflecting intense drought; and at times when summer temperatures were higher than 40 ℃, high temperature and drought were evident. In the Middle Pleistocene, the temperature ranged largely between 30-35 ℃, and the highest temperature reached 50.6 ℃. Together, the range of maximum homogenization temperature and high salinity are indicative of high temperature and drought. Compared to the Early Pleistocene, the Middle Pleistocene saw increasing ambient temperature, salt content and drought severity, with aggravated temperature fluctuation, indicating a more unstable climate consistent with the general climate characteristics of the Middle Pleistocene worldwide. The salt distribution showed the climate instability in the Dalangtan area began to appear since the late Early Pleistocene. The metallogenic model of potassium-bearing brine from the pore of sandstone conglomerate in the Altun Mountain can be revised using the paleotemperature of fluid inclusions obtained from this study: In the mild, humid environment of the Early Pleistocene, weathered salt and N22 ancient salt were dissolved and filtered together to form brine in the sandstone pores, and high temperature evaporation in the Middle Pleistocene eventually led to the formation of brine deposit of the KCl sandstone conglomerate pore reservoir.

Key words: Qaidam Basin, Dalangtan area, Early-Middle Pleistocene, homogenization temperature of fluid inclusions

CLC Number:

P571
P578.32

FAN Fu, HOU Xianhua, ZHENG Mianping, MENG Fanwei, YANG Zhenjing, MIAO Qing. Homogenization temperature of fluid inclusions in Early-Middle Pleistocene halite from Liang Hole ZK02 in Dalangtan area, Qaidam Basin and its constraints on potash mineralization[J]. Earth Science Frontiers, 2021, 28(6): 105-114.

References

[1] 葛肖虹, 任收麦, 马立祥. 青藏高原多次隆升的环境效应[J]. 地学前缘, 2006, 13(6): 118-129.
[2] 李吉均, 方小敏. 青藏高原隆起与环境变化研究[M]∥面向21世纪的科技进步与社会经济发展(上册). 杭州: 中国科学技术出版社, 1999: 308.
[3] 吴文祥, 刘东生. 气候转型与早期人类迁徙[J]. 海洋地质与第四纪地质, 2001, 21(4): 103-109.
[4] 金海燕, 翦知湣, 乔培军, 等. 中更新世气候转型期西太平洋暖池的表层海水温度和氧同位素变化[J]. 海洋地质与第四纪地质, 2012, 32(4): 107-113.
[5] 鹿化煜, 安芷生. 洛川黄土粒度组成的古气候意义[J]. 科学通报, 1997, 42(1): 66-69.
[6] 杨胜利, 方小敏, 史正涛, 等. 青藏高原东部边缘“成都黏土”粒度记录的约500 ka BP的干旱化增强事件[J]. 海洋地质与第四纪地质, 2008, 2(28): 105-114.
[7] 葛肖虹, 刘俊来, 任收麦, 等. 青藏高原隆升对中国构造-地貌形成、气候环境变迁与古人类迁徙的影响[J]. 中国地质, 2014, 41(3): 698-714.
[8] 侯献华, 郑绵平, 张成君, 等. 柴达木盆地西部大浪滩140 ka以来沉积特征与古环境[J]. 地质学报, 2010, 84(11): 1623-1630.
[9] 侯献华, 郑绵平, 杨振京, 等. 柴达木盆地大浪滩130 kaBP以来的孢粉组合与古气候[J]. 干旱区地理, 2011, 34(2): 243-251.
[10] 施林峰, 郑绵平, 李金锁, 等. 柴达木盆地大浪滩梁ZK05钻孔的磁性地层研究[J]. 地质学报, 2010, 84(11): 1631-1640.
[11] 秦永鹏, 侯献华, 郑绵平, 等. 柴达木盆地大浪滩梁-ZK02孔的磁性地层及其古环境研究[J]. 地质论评, 2012, 58(3): 553-564.
[12] 刘兴起, 倪培. 表生环境条件下形成的石盐流体包裹体研究进展[J]. 地球科学进展2005, 20(8): 856-862.
[13] MENG F W, NI P, SCHIFFBAUER J D, et al.Ediacaran seawater temperature: evidence from inclusions of Sinian halite[J]. Precambrian Research, 2011, 184(1/2/3/4): 63-69.
[14] MENG F W, NI P, YUAN X L, et al. Choosing the best ancient analogue for projected future temperatures: a case using data from fluid inclusions of middle-late Eocene halites[J]. Journal of Asian Earth Sciences, 2013, 67/68: 46-50.
[15] ZHANG X Y, MENG F W, LI W X, et al.Reconstruction of Late Cretaceous coastal paleotemperature from halite deposits of the Late Cretaceous Nongbok Formation (Khorat Plateau, Laos)[J]. Palaeoworld, 2016, 25(3): 425-430.
[16] LOWENSTEIN T K, LI J, BROWN C B.Paleotemperatures from fluid inclusions in halite: method verification and a 100000 year paleotemperature record, Death Valley, CA[J]. Chemical Geology, 1998, 150(3/4): 223-245.
[17] BENISON K C, GOLDSTEIN R H.Permian paleoclimate data from fluid inclusions in halite[J]. Chemical Geology, 1999, 154(1/2/3/4): 113-132.
[18] HOVORKA S D, HOLT R M, POWERS D W.Depth indicators in Permian Basin evaporites[J]. Geological Society of London, Special Publications, 2007, 285(1): 335-364.
[19] ROBERTS S M, SPENCER R J.Paleotemperatures preserved in fluid inclusion in halite[J]. Geochimica et Cosmochimica Acta, 1995, 59(19): 3929-3942.
[20] ZACHOS J.Trends, rhythms, and aberrations in global climate 65 Ma to present[J]. Science, 2001, 292(5517): 686-693.
[21] ZHAO Y J, ZHANG H, LIU C L, et al.Late Eocene to early Oligocene quantitative paleotemperature record: evidence from continental halite fluid inclusions[J]. Scientific Reports, 2014, 4: 5776
[22] 孟凡巍, 倪培, 葛晨东, 等. 实验室合成石盐包裹体的均一温度以及古气候意义[J]. 岩石学报, 2011, 27(5): 1543-1547.
[23] 郑绵平, 侯献华, 于常青, 等. 成盐理论引领我国找钾取得重要进展[J]. 地球学报, 2015, 36(2): 129-139.
[24] 王亚东, 张涛, 迟云平, 等. 柴达木盆地西部地区新生代演化特征与青藏高原隆升[J]. 地学前缘, 2011, 18(3): 141-150.
[25] 付锁堂, 马达德, 陈琰, 等. 柴达木盆地油气勘探新进展[J]. 石油学报, 2016, 37(增刊1): 1-10.
[26] 付锁堂, 马达德, 郭召杰, 等. 柴达木走滑叠合盆地及其控油气作用[J]. 石油勘探与开发, 2015, 42(6): 712-722.
[27] 付锁堂. 柴达木盆地西部油气成藏主控因素与有利勘探方向[J]. 沉积学报, 2010, 28(2): 373-379.
[28] 张彭熹. 柴达木盆地盐湖[M]. 北京: 科学出版社, 1987: 32-46.
[29] 马妮娜, 郑绵平, 马志邦, 等. 柴达木盆地大浪滩地区表层芒硝的形成时代及环境意义[J]. 地质学报, 2011, 85(3): 433-444.
[30] ZAMBITO IV J J, BENISON K C. Extremely high temperatures and paleoclimate trends recorded in Permian ephemeral lake halite[J]. Geology, 2013, 41(5): 587-590.
[31] 郑绵平, 赵元艺, 刘俊英. 第四纪盐湖沉积与古气候[J]. 第四纪研究, 1998(4): 297-307.