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热带西太平洋对现代全球气候系统有举足轻重的影响,其中"西太平洋暖池"区的变异对调节全球气候发挥着极为重要的作用。越来越多的证据表明在轨道—亚轨道尺度上暖池对全球古气候的变化也有着重要的调控作用,低纬热带西太平洋已成为近十几年来古海洋学研究的重点地区之一。从表层海水古温度和古生产力记录、千年尺度的快速气候变化、厄尔尼诺—南方涛动(El Nio-Southern Oscillation,ENSO)式变化以及暖池强弱变动及其位移等角度梳理了西太平洋暖池区古海洋学研究的现状,综述了目前对暖池区海洋环境演化及其气候效应的已有认识,针对目前暖池区古环境研究的状况探讨了未来工作中应重视的科学问题。 相似文献
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利用富钴结壳碳酸盐基岩有孔虫矿物标型重建古海洋温度 总被引：1，自引：0，他引：1
重建古海洋海表温度(SST),是研究地质历史时期气候变化控制过程的关键。组成有孔虫化石的矿物Mg/Ca值是海水温度的可靠代用指标,是重建古海洋SST的一个非常好的手段。麦哲伦海山区的富钴结壳和基岩中普遍存在有孔虫化石,这对重建该区的SST有重要意义。利用LA-ICP-MS测得西太平洋麦哲伦海山区富钴结壳碳酸盐基岩中8颗浮游有孔虫化石Globigerinoides sacculifer的Mg/Ca值为3.84±0.36(mmol/mol),通过线性公式:T(℃)=2.898Mg/Ca(mmol/mol)+13.76及已有的定年数据,得到0.91Ma±西太平洋麦哲伦海山区海表温度为24.9+1.1/-1.0℃,未能检索到前人关于该区0.91Ma±前海表温度数据。 相似文献
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末次盛冰期中国海古地理轮廓及其气候效应 总被引：6，自引：1，他引：6
本文是联合国政府间海洋委员会西太平洋分委员会(ＩＯＣ／ＷＥＳＴＰＡＣ)发起的“西太平洋古地理图编图计划”中国海部分的初步成果，用１０１个站位的１４Ｃ测年和２２个站位的氧同位素资料编制了本次盛冰期(２００００—１５０００ａＢ．Ｐ．)资料图、古地理图和古海洋图等三张图件。末次盛冰期低海面时中国海轮廓发生重大改观：陆架出露约１．５５×１０６ｋｍ２；表层海流改组以及表层海水温度剧降(比现代低３．５—６℃)，比当时同纬度开放大洋表层海水温度下降剧烈。海区面积减少和表层海水温度下降使中国海蒸发量大大降低。根据海陆蒸发速率差异和表层海水温度与蒸发作用之间的关系，估算出末次盛冰期中国海年蒸发量比现代降低约１２×１０(１１)—２０×１０(１１)ｍ3，或相当现代中国年降雨量的１／５—１／３。同时，末次盛冰期陆架暴露、地表反照率增高使地表对太阳辐射吸收作用减弱。总之，冰期旋回中国海在气候变化中起着重要作用。然而，要获得中国气候演化中海洋因素的定量或半定量数据尚需大量实际资料和数值模拟方能实现。 相似文献
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海水溶解磷酸盐氧同位素组成的测定 总被引：2，自引：0，他引：2
生物磷酸盐和水分子间的氧同位素分馏主要受温度和生物活动控制, 因此磷酸盐氧同位素组成既可以测量古温度又可以示踪磷循环。近年来磷酸盐氧同位素研究受到较多关注, 除了传统的生物体磷灰石古温度测量外, 这些研究大多是关于磷循环的。磷酸盐的氧同位素组成可以示踪海洋中磷的源区和生物对磷的利用效率。由于海水的组成十分复杂, 测量前必须对样品进行富集、分离和纯化处理。目前, 加州大学(Santa Cruz)Paytan教授和耶鲁大学Blake教授的实验室已建立了海水溶解磷酸盐氧同位素的测量方法, 二者各有优缺点。我们结合了这两种方法的优点, 并对一些步骤进行了改进, 建立了海水溶解磷酸盐氧同位素组成的测量方法。通过向海水样品中加入NaOH, 形成Mg(OH)2来富集海水中的PO43-, 也可同时除去部分杂质离子和溶解有机质; 通过将PO43-转化为CePO4沉淀来进一步除去杂质离子, 然后用阳离子交换树脂除Ce3+, 再通过阴离子交换树脂柱来除溶解有机质。最后将磷酸盐转换为Ag3PO4沉淀, 在1350℃裂解Ag3PO4, 产生的O2和石墨反应形成CO用IRMS测定。结果显示富集、分离和纯化过程可以获得纯的Ag3PO4颗粒, 不会产生PO43-的氧同位素分馏。测量Ag3PO4用量仅为0.3 mg, 标准偏差在±0.2‰~±0.3‰之间。 相似文献
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提出解释反应过程动力学和实验及实际P—T参考坐标系间位移的计算端员反应的精度及准确度的新方法。对最近收集的实验数据的应用证明,采用单独一组实验数据,在变质温度(～900K)条件下的一端员反应位置的估算精度(1δ)可以在±100×10~5到±310×~5Pa以及准确度的最低估算值(1δ)可以在±270×10~5到±410×10~5Pa的等级,这取决于如何精确划定反应界限并假定压力和温度的1δ可能系统误差分别为±250×10~5Pa和±5℃。采用5种不同研究的钙铝榴石—钙长石—蓝晶石—石英(GASP)反应位置的准确度估算在900K条件下为±350×10~到±380×10~5Pa之间,这取决于是否采用独立的标准样校准了各个研究结果。 相似文献
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安徽沙溪斑岩铜（金）矿床成岩成矿热历史探讨 总被引：12，自引：1，他引：11
采用Ｒｂ－Ｓｒ方法,测定沙溪斑岩铜（金）矿成矿岩体年龄为１４３．３７±５．１７Ｍａ;采用＾４０Ａｒ／＾３９Ａｒ快中子活化定年法,测定沙溪斑岩铜（金）矿成矿年龄为１２３．６±０．７Ｍａ;成矿岩体从固结成岩到成矿经历了２０Ｍａ。根据Ｒｂ－Ｓｒ和Ｋ－Ａｒ同位素体系封闭温度的不同,估算出沙溪岩浆热液成矿系统热衰减速率平均为２０℃／Ｍａ。单一的由成矿小岩体所提供的热能难以维持如此长时间热液成矿活动,矿区晚期 相似文献
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对Ag_2S-Bi_2S_3体系相图重新测定发现,硫铋银矿温度稳定范围是从室温直到其熔点773±5℃。在二元体系Ag_2S-Bi_2S_3内,硫铋银矿有一狭窄的固溶体区,在600℃时其组分变化范围是50.0+—54mol%Bi_2S_3,500℃时是50.0+—53.5mol%Bi_2S_3,400℃时是50.0+—52.5mol%Bi_2S_3。与此同时,α-AgBiS_2是在高于195±5℃富Ag_2S条件下稳定,低于此温度,转变为硫铋银矿。α-AgBiS_2在600℃时,其组分变化范围为46.5—50.0mol%Bi_2S_3,500℃时为47.0—50.0mol%Bi_2S_3,400℃时为48.0—50.0mol%Bi_2S_3。铜银铅铋矿纯银端元Ag_2Bi_4S_7最高稳定温度是697±5℃。高于此温度,转变为硫铋银矿和液相。块硫铋银矿(AgBi_3S_5)为同成分熔化,其熔点为745±5℃。 相似文献
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皖东侵入岩矿物Rb-Sr和Ar-Ar年代学及其与氧同位素平衡之间的关系 总被引：11，自引：0，他引：11
为探讨花岗质岩石中矿物O同位素平衡与Rb Sr矿物等时线年龄有效性之间的关系 ,测定了皖东屯仓与横山两个石英二长岩体中单矿物的Rb Sr和O同位素组成以及角闪石和黑云母的Ar Ar年龄。屯仓岩体的石英 -角闪石对温度为 5 4 5± 2 5℃ ,石英 -黑云母对温度为 4 6 0± 2 0℃ ,石英 -斜长石对温度 385± 4 0℃。横山岩体的石英 -角闪石对温度为 5 30± 2 5℃ ,石英 -黑云母对温度为 390± 15℃和石英 -斜长石对温度 2 85± 35℃。反映封闭体系中矿物在冷却过程中的退化交换再平衡。矿物间的氧同位素平衡对应于有地质意义的Rb Sr矿物等时线年龄。屯仓岩体的全岩 -角闪石 -斜长石Rb Sr等时线年龄 (12 8.4± 4 .7Ma)与角闪石的Ar Ar年龄 (12 5 .5 1± 0 .5 5Ma)在误差范围内一致 ,全岩 -角闪石 -斜长石 -黑云母Rb Sr等时线年龄 (12 0 .3± 2 .6Ma)与黑云母的Ar Ar年龄 (118.0± 0 .1Ma)一致。横山岩体的全岩 -角闪石 -斜长石Rb Sr矿物等时线年龄 (10 8± 15Ma)比角闪石的Ar Ar年龄 (12 5 .7± 1.8Ma)低 ,全岩 -角闪石 -斜长石 -黑云母Rb Sr等时线年龄 (118.6± 1.2Ma)小于黑云母的Ar Ar年龄 (12 0 .0± 0 .2Ma)。Rb Sr等时线年龄小于Ar Ar年龄是由于长石的蚀变引起的。大的等时线误差是由于Rb/Sr比值变化范围太小 相似文献
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Magnesium/calcium, Sr/Ca, and Na/Ca atom ratios were determined in the calcite and aragonite regions of Mytilus edulis shells which were grown in semi-artificial ‘seawater’ solutions having varying Mg/Ca, Sr/Ca, and Na/Ca ratios. These ratios were measured by instrumental neutron activation, atomic absorption, and electron microprobe analytical techniques. Strontium/calcium ratios in both calcite and aragonite were linearly proportional to solution Sr/Ca ratios. Magnesium/calcium ratios in calcite increased exponentially when solution Mg/Ca ratios were raised above the normal seawater ratio; whereas in aragonite, Mg/Ca ratios increased linearly with increases in solution Mg/Ca ratios. Sodium/calcium and sulfur/calcium ratios in calcite covaried with Mg/Ga solution ratios. Conversely, in aragonite, Na/Ca ratios varied linearly with solution Na/Ca ratios.Magnesium is known to inhibit calcite precipitation at its normal seawater concentration. We infer from the results of the work reported here that Mytilus edulis controls the Mg activity of the outer extrapallial fluid, thus facilitating the precipitation of calcitic shell. Increases in sulfur content suggest that changes in shell organic matrix content occur as a result of environmental stress. Certain increases in Mg content may also be correlated to stress. Sodium/calcium variations, and their absolute amounts in calcite and aragonite, are best explained by assuming that a substantial amount of Na is adsorbed on the calcium carbonate crystal surface. Strontium/calcium ratios show more promise than either Mg/Ca or Na/Ca ratios as seawater paleochemistry indicators, because the Sr/Ca distribution coefficients for both aragonite and calcite are independent of seawater Ca and Sr concentrations. 相似文献
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Pedro S. Freitas Leon J. Clarke Christopher A. Richardson 《Geochimica et cosmochimica acta》2006,70(20):5119-5133
The relationship between potential elemental proxies (Mg/Ca, Sr/Ca and Mn/Ca ratios) and environmental factors was investigated for the bivalve Pecten maximus in a detailed field study undertaken in the Menai Strait, Wales, U.K. An age model constructed for each shell by comparison of measured and predicted oxygen-isotope ratios allowed comparison on a calendar time scale of shell elemental data with environmental variables, as well as estimation of shell growth rates. The seasonal variation of shell Mn/Ca ratios followed a similar pattern to one previously described for dissolved Mn2+ in the Menai Strait, although further calibration work is needed to validate such a relationship. Shell Sr/Ca ratios unexpectedly were found to co-vary most significantly with calcification temperature, whilst shell Mg/Ca ratios were the next most significant control. The temporal variation in the factors that control shell Sr/Ca ratios strongly suggest the former observation most likely to be the result of a secondary influence on shell Sr/Ca ratios by kinetic effects, the latter driven by seasonal variation in shell growth rate that is in turn influenced in part by seawater temperature. P. maximus shell Mg/Ca ratio to calcification temperature relationships exhibit an inverse correlation during autumn to early spring (October to March-April) and a positive correlation from late spring through summer (May-June to September). No clear explanation is evident for the former trend, but the similarity of the records from the three shells analysed indicate that it is a real signal and not a spurious observation. These observations confirm that application of the Mg/Ca proxy in P. maximus shells remains problematic, even for seasonal or absolute temperature reconstructions. For the range of calcification temperatures of 5-19 °C, our shell Mg/Ca ratios in P. maximus are approximately one-fourth those in inorganic calcite, half those in the bivalve Pinna nobilis, twice those in the bivalve Mytilus trossulus, and four to five times higher than Mg/Ca ratios in planktonic and benthonic foraminifera. Our findings further support observations that Mg/Ca ratios in bivalve shell calcite are an unreliable temperature proxy, as well as substantial taxon- and species-specific variation in Mg incorporation into bivalves and other calcifying organisms, with profound implications for the application of this geochemical proxy to the bivalve fossil record. 相似文献
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We conducted paired measurements of the Mg/Ca ratio and δ18O of planktonic foraminifera, Globigerina bulloides, from a sediment core (MD01‐2420) off central Japan in the northwest Pacific, to reconstruct current movements since the Last Glacial Maximum (LGM). These methods make it possible to determine the magnitude and timing of the sea surface temperature (SST) changes and to reconstruct the variations of the past seawater δ18O (δ18Ow) off central Japan. The amplitude of Mg/Ca‐based SST changes between the Holocene and the LGM was about 10°C. The strong resemblance of the SSTs estimated from both methods, Mg/Ca‐based and δ18O‐based, suggests that the SST changes were caused primarily by latitudinal displacement of the Kuroshio–Oyashio currents and no distinct change in the carbonate dissolution of the core. The southward migration of the water mass was 5–6° in latitude at the LGM. The values for regional δ18Ow changes, which were obtained by subtracting the ice volume contribution from the calculated δ18Ow, describe the millennial‐scale water mass migration over the last 30 kyr. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
14.
颗石藻元素地球化学研究进展 总被引：2，自引：0，他引：2
颗石藻元素地球化学研究在古海洋学研究中有着重要意义。目前开始研究的主要有Sr/Ca和Mg/Ca比值。研究发现,颗石的Sr/Ca比值主要受颗石藻生长和钙化速度控制,其次受温度影响;而Mg/Ca比值主要与温度有关,属种间受影响程度有差别。样品清洗和单种分离是颗石藻元素地球化学分析的重点和难点。倒置显微镜挑出单种颗石是目前最为方便且准确的分析方法。颗石Sr/Ca比值可以用来反映古生产力,Mg/Ca比值可以用来重建古温度。 相似文献
15.
Justin B. Ries 《Geochimica et cosmochimica acta》2006,70(4):891-900
The Mg/Ca ratio of seawater has varied significantly throughout the Phanerozoic Eon, primarily as a function of the rate of ocean crust production. Specimens of the crustose coralline alga Neogoniolithon sp. were grown in artificial seawaters encompassing the range of Mg/Ca ratios shown to have existed throughout the Phanerozoic. Significantly, the coralline algae’s skeletal Mg/Ca ratio varied in lockstep with the Mg/Ca ratio of the artificial seawater. Specimens grown in seawater treatments formulated with identical Mg/Ca ratios but differing absolute concentrations of Mg and Ca exhibited no significant differences in skeletal Mg/Ca ratios, thereby emphasizing the importance of the ambient Mg/Ca ratio, and not the absolute concentration of Mg, in determining the Mg/Ca ratio of coralline algal calcite. Specimens grown in seawater of the lowest molar Mg/Ca ratio (mMg/Ca = 1.0) actually changed their skeletal mineralogy from high-Mg (skeletal mMg/Ca > 0.04) to low-Mg calcite (skeletal mMg/Ca < 0.04), suggesting that ancient calcitic red algae, which exhibit morphologies and modes of calcification comparable to Neogoniolithon sp., would have produced low-Mg calcite from the middle Cambrian to middle Mississippian and during the middle to Late Cretaceous, when oceanic mMg/Ca approached unity. By influencing the original Mg content of carbonate facies in which these algae have been ubiquitous, this condition has significant implications for the geochemistry and diagenesis of algal limestones throughout most of the Phanerozoic. The crustose coralline algae’s precipitation of high-Mg calcite from seawater that favors the abiotic precipitation of aragonite indicates that these algae dictate the precipitation of the calcitic polymorph of CaCO3. However, the algae’s nearly abiotic pattern of Mg fractionation in their skeletal calcite suggests that their biomineralogical control is limited to polymorph specification and is generally ineffectual in the regulation of skeletal Mg incorporation. Therefore, the Mg/Ca ratio of well-preserved fossils of crustose coralline algae, when corrected for the effect of seawater temperature, may be an archive of oceanic Mg/Ca throughout the Phanerozoic. Magnesium fractionation algorithms that model algal skeletal Mg/Ca as a function of seawater Mg/Ca and temperature are presented herein. The results of this study support the empirical fossil evidence that secular variation of oceanic Mg/Ca has caused the mineralogy and skeletal chemistry of many calcifying marine organisms to change significantly over geologic time. 相似文献
16.
Adriana Dueñas-Bohórquez Régine Elisabeth da Rocha Jelle Bijma 《Geochimica et cosmochimica acta》2011,75(2):520-532
In order to investigate the interindividual and ontogenetic effects on Mg and Sr incorporation, magnesium/calcium (Mg/Ca) and strontium/calcium (Sr/Ca) ratios of cultured planktonic foraminifera have been determined. Specimens of Globigerinoides sacculifer were grown under controlled physical and chemical seawater conditions in the laboratory. By using this approach, we minimised the effect of potential environmental variability on Mg/Ca and Sr/Ca ratios. Whereas temperature is the overriding control of Mg/Ca ratios, the interindividual variability observed in the Mg/Ca values contributes 2-3 °C to the apparent temperature variance. Interindividual variability in Sr/Ca ratios is much smaller than that observed in Mg/Ca values. The variability due to ontogeny corresponds to −0.43 mmol/mol of Mg/Ca ratio per chamber added. This translates into an apparent decrease of ∼1 °C in Mg/Ca-based temperature per ontogenetic (chamber) stage. No significant ontogenetic effect is observed on Sr incorporation. We conclude that the presence of a significant ontogenetic effect on Mg incorporation can potentially offset Mg/Ca-based temperature reconstructions. We propose two new empirical Mg/Ca-temperature equation based on Mg/Ca measurements of the last four ontogenetic (chamber) stages and whole foraminiferal test: Mg/Ca = (0.55(±0.03) − 0.0002(±4 × 10−5) MSD) e0.089T and, Mg/Ca = (0.55(±0.03) − 0.0001(±2 × 10−5) MSD) e0.089T, respectively, where MSD corresponds to the maximum shell diameter of the individual. 相似文献
17.
Marius N. Müller Ba?ak K?sakürek Ruth Gutperlet Ulf Riebesell Anton Eisenhauer 《Geochimica et cosmochimica acta》2011,75(8):2088-5818
Calcium and magnesium concentrations in seawater have varied over geological time scales. On short time scales, variations in the major ion composition of seawater influences coccolithophorid physiology and the chemistry of biogenically produced coccoliths. Validation of those changes via controlled laboratory experiments is a crucial step in applying coccolithophorid based paleoproxies for the reconstruction of past environmental conditions. Therefore, we examined the response of two species of coccolithophores, Emiliania huxleyi and Coccolithus braarudii, to changes in the seawater Mg/Ca ratio (≈0.5 to 10 mol/mol) by either manipulating the magnesium or calcium concentration under controlled laboratory conditions. Concurrently, seawater Sr/Ca ratios were also modified (≈2 to 40 mmol/mol), while keeping salinity constant at 35. The physiological response was monitored by measurements of the cell growth rate as well as the production rates of particulate inorganic and organic carbon, and chlorophyll a. Additionally, coccolithophorid calcite was analyzed for its elemental composition (Sr/Ca and Mg/Ca) as well as isotope fractionation of calcium and magnesium (Δ44/40Ca and Δ26/24Mg). Our results reveal that physiological rates were substantially influenced by changes in seawater calcium rather than magnesium concentration within the range estimated to have occurred over the past 250 million years when coccolithophores appear in the fossil record. All physiological rates of E. huxleyi decreased at a calcium concentration above 25 mmol L−1, whereas C. braarudii displayed a higher tolerance to increased seawater calcium concentrations. Partition coefficient of Sr was calculated as 0.36 ± 0.04 (±2σ) independent of species. Partition coefficient of Mg2+ increased with increasing seawater Ca2+ concentrations in both coccolithophore species. Calcium isotope fractionation was constant at 1.1 ± 0.1‰ (±2σ) and not altered by changes in seawater Mg/Ca ratio. There is a well-defined inverse linear relationship between calcium isotope fractionation and partition coefficient of Sr2+ in all experiments, suggesting similar controls on both proxies in the investigated species. Magnesium isotope ratios were relatively stable for seawater Mg/Ca ratios ranging from 1 to 5, with a higher degree of fractionation in Emiliania huxleyi (by ≈0.2‰ in Δ26/24Mg). Although Mg/Ca ratios in the calcite of coccolithophores and foraminifera are similar, the former have considerably higher Δ26/24Mg (by >+3‰), presumably due to differences in calcification mechanisms between the two taxa. These observations suggest, a physiological control over magnesium elemental and isotopic fractionation during the process of calcification in coccolithophores. 相似文献
18.
Ann D. Russell Bärbel Hönisch Howard J. Spero 《Geochimica et cosmochimica acta》2004,68(21):4347-4361
We investigate the sensitivity of U/Ca, Mg/Ca, and Sr/Ca to changes in seawater [CO32−] and temperature in calcite produced by the two planktonic foraminifera species, Orbulina universa and Globigerina bulloides, in laboratory culture experiments. Our results demonstrate that at constant temperature, U/Ca in O. universa decreases by 25 ± 7% per 100 μmol [CO32−] kg−1, as seawater [CO32−] increases from 110 to 470 μmol kg−1. Results from G. bulloides suggest a similar relationship, but U/Ca is consistently offset by ∼+40% at the same environmental [CO32−]. In O. universa, U/Ca is insensitive to temperature between 15°C and 25°C. Applying the O. universa relationship to three U/Ca records from a related species, Globigerinoides sacculifer, we estimate that Caribbean and tropical Atlantic [CO32−] was 110 ± 70 μmol kg−1 and 80 ± 40 μmol kg−1 higher, respectively, during the last glacial period relative to the Holocene. This result is consistent with estimates of the glacial-interglacial change in surface water [CO32−] based on both modeling and on boron isotope pH estimates. In settings where the addition of U by diagenetic processes is not a factor, down-core records of foraminiferal U/Ca have potential to provide information about changes in the ocean’s carbonate concentration.Below ambient pH (pH < 8.2), Mg/Ca decreased by 7 ± 5% (O. universa) to 16 ± 6% (G. bulloides) per 0.1 unit increase in pH. Above ambient pH, the change in Mg/Ca was not significant for either species. This result suggests that Mg/Ca-based paleotemperature estimates for the Quaternary, during which surface-ocean pH has been at or above modern levels, have not been biased by variations in surface-water pH. Sr/Ca increased linearly by 1.6 ± 0.4% per 0.1 unit increase in pH. Shell Mg/Ca increased exponentially with temperature in O. universa, where Mg/Ca = 0.85 exp (0.096*T), whereas the change in Sr/Ca with temperature was within the reproducibility of replicate measurements. 相似文献
19.
使用标准化壳体重量法和传统壳体重量法分别对中国南海(South China Sea,简称SCS)站表层沉积物和MD06-3052岩心沉积物样品进行了测试,获得了浮游有孔虫种属Globigerinoides ruber(G. ruber)的标准化壳体重量和传统壳体重量.通过对SCS站表层沉积物中G. ruber标准化壳体重量与传统壳体重量的比较,认为在该海域使用标准化壳体重量替代性指标能够更好的排除壳体粒径的干扰.通过对MD06-3052岩心中G. ruber标准化壳体重量与南极Vostok冰心的CO2浓度(pCO2)曲线进行对比,认为标准化壳体重量方法能够较好的反映出表层海水[CO32-]的变化.标准化壳体重量方法快速简便,指示性好,在探讨晚更新世以来表层海水在全球碳循环的重要作用中,是一个很有潜力的指标. 相似文献
20.
石笋流体包裹体中的惰性气体及其在重建长江中游古温度变化中的作用 总被引：2，自引：0，他引：2
文中讨论了一种评估古气温变化的新方法。我们成功地利用石笋流体包裹体所捕获的Xe/Ar比值,重建了末次冰盛期以来盛行东亚季风的长江中游地区的气候演化。一种表达成ln(CXe/CAr)的对数式被证明与冷暖周期变化具有密切的关系。从研究的石笋中所提出的δ13C与Mg/Ca曲线一般随区域古气温波动而变化,但不能排除其中有另类气候信号的叠加。我们的工作则明确地指出,流体包裹体所记录的Xe/Ar在各种反映温度变化的替代指标中可能是最好的一种。整体而言,ln(CXe/CAr)曲线与那些基本随暖期和冷期振荡的曲线保持一致。将稀有气体曲线与δ13C和Mg/Ca信号整合对比之后,我们在研究区划分出末次冰盛期以来8组暖/冷旋回。整合后的气温变化模式合理地解释了过去20000年里的区域环境变化。 相似文献