Global Change: Quaternary Paleoclimate Record from Salt Cores (Death Valley, Saline Valley and Bristol Dry Lake, California)

全球变化：盐芯的第四纪古气候记录（死亡谷、盐谷和布里斯托尔干湖，加利福尼亚州）

• 批准号: 9218717
• 负责人: Tim Lowenstein
• 金额: $ 34.08万
• 依托单位: SUNY at Binghamton
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-01-15 至 1996-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9218717&HistoricalAwards=false
• 关键词: Global; Change; Quaternary; Paleoclimate; Record

Halite-bearing evaporites occur to substantial depths in 3 arid closed-basins in the western U.S. and preserve a record of paleoclimate for more than 2 million years. This project will examine the paleoclimate record in salt deposits from these basins over the last 3 glacial-interglacial cycles (approximately 300,000 years) using existing samples and materials from 2 boreholes to be drilled to depths of 100 m. Emphasis will be on chemical analyses of fluid inclusions in crystals of primary halite and other evaporite minerals to obtain: activity of H2O and the major element chemistry (microthermometry and leachate analysis), hydrogen and oxygen isotopic composition of fluid inclusion waters (Mass spectrometry), and atmospheric gas composition, for those crystals which contain trapped air (quadrupole mass spectrometry). Fluid inclusions and supplementary data (sedimentology, mineralogy, petrography) may potentially be used to interpret paleoclimates, in terms of: (1) basin aridity, (2) relative temperatures, (3) atmospheric chemistry, (4) lacustrine water chemistry and brine evolution, and (5) closed-basin depositional settings. Local and global influences on paleoclimate will be distinguished by comparing data with the record from a fourth closed-basin (Searles Lake), Great Basin vein calcites, polar ice cores, and the marine oxygen isotope record. Possible local influences of hydrothermal fluids on the hydrologic record will be examined at Bristol Dry Lake, where Holocene volcanic activity is well documented. Dating of halite will done using U-series methods and 36Cl, and will be supplemented by tephrachronology. Long term records of the hydrosphere and atmosphere are needed to document continental paleoclimates and how such climates have been influenced by global and local processes. Nonmarine evaporites and associated closed-basin sediments, because of the special climatic and hydrologic conditions necessary for their formation, hold great promise for understanding ancient continental climates.

含石盐的碳酸盐岩在3个干旱地区出现在相当深的地方。 在美国西部封闭的盆地，并保留记录， 古气候变化超过200万年。 该项目将 研究这些盆地盐沉积物中的古气候记录 在过去的3次冰期-间冰期循环中（约30万 使用2个钻孔的现有样品和材料， 钻到100米深。 重点是化学分析 原生岩盐和其他矿物晶体中的流体包裹体 蒸发矿物获得：活性H2O和主要 元素化学（微量测温和沥出液分析）， 流体包裹体沃茨氢氧同位素组成 (Mass光谱法）和大气气体成分，对于那些 含有滞留空气的晶体（四极质谱法）。 流体包裹体和补充资料（沉积学、矿物学、 岩相学）可以潜在地用于解释古气候， 在以下方面：（1）流域干燥度，（2）相对温度，（3） 大气化学;（4）湖水化学和卤水 演化;（5）封闭盆地沉积环境。 地方和 全球对古气候的影响将被区分为 将数据与第四个封闭盆地（Searles）的记录进行比较 湖），大盆地脉方解石，极地冰芯，和海洋 氧同位素记录 热液可能对当地产生的影响 水文记录上的液体将在布里斯托干地进行检查 湖，那里的全新世火山活动是有据可查的。 约会 石盐将使用U系列方法和36 Cl进行，并将 并辅以文字年代学。 需要对水圈和大气进行长期记录， 记录大陆的古气候以及这些气候是如何 受全球和地方进程的影响。 非海相碳酸盐岩和 由于特殊的气候条件， 和水文条件所需的形成，持有很大的 了解古代大陆气候的希望。