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geography, Palaeoclimatology, Palaeoecology, (1): , , , et al., 南海北坡ODP1146站第四紀粘土礦物記錄:: 地球科學, (3): , ., , , et al., Terrestrial records of a regional weathering profile at the PaleoceneEocene boundary in the Williston Basin of North Bulletin, (34): and 郭正堂, , 2007(02): , H., , , et al., Clay record of climate change since the midPleistocene in Jiujiang, south , (1): , L., , , et al., Variations of illite/chlorite ratio in Chinese loess sections during the last glacial and interglacial cycle: Implications for monsoon Research Letters, (20): , ., , and , The distribution of clay minerals in the World Sea Research and Oceanographic Abstracts, (4): , , 北京: , , Clay minerals in sandstones: controls on formation, distribution and evolution, in Clay Mineral Cements in , Blackwell Publishing , H., , , et al., Clay mineralogy and geochemistry and their palaeoclimatic interpretation of the Pleistocene deposits in the Xuancheng section, southern of Quaternary Science, (5): , H., , , et al., Authigenic palygorskite in Miocene sediments in Linxia basin, Gansu, northwestern Minerals, (1): , H., , , et al., Oligocene clay mineralogy of the Linxia Basin: evidence of paleoclimatic evolution subsequent to the initialstage uplift of the Tibetan and Clay Minerals, (5): , C., , , et al., Climatic and tectonic evolution in the North Qaidam since the Cenozoic: Evidence from sedimentology and of Earth Science, (3): , S., , , et al., Chemical weathering of monsoonal eastern China: implications from major elements of of Asian Earth Sciences, : , 程日輝, and 劉昌嶺, , 2002(02): , ., , and , Boron in Holocene illites of the dovey estuary, wales, and its relationship to palaeosalinity in , (3): , Jr, Geochemical method for determining paleosalinity, in Clays and Clay , , ., , and , An interpretation of boron contents within a Palaeoproterozoic volcanosedimentary succession: Pretoria Group, Transvaal Supergroup, South Research, (4): , C., , , et al., Late Eocene clay boronderived paleosalinity in the Qaidam Basin and its implications for regional tectonics and Geology, : , ., , and , Temperature and pH controls over isotopic fractionation during adsorption of boron on marine et Cosmochimica Acta, (9): , , Isotopic positions of boron in sediments and their Science, (1): , B., , , et al., Boron isotopes geochemistry of the Changjiang basin et Cosmochimica Acta, (20): , Y., , , et al., Boron isotopic positions of brine, sediments, and source water in Da Qaidam Lake, Qinghai, et Cosmochimica Acta, (4): , , The effect of pH and temperature on the isotopic fractionation of boron between saline brine and Geology, (3): , H., , , et al., Boron isotope geochemistry of salt sediments from the Dongtai salt lake in Qaidam Basin: Boron budget and Geology, : , 肖應凱, 馬云麒, et al., , 2016(05): , ., Mineralogy and sedimentation of recent deepsea clay in the Atlantic Ocean and adjacent seas and Bulletin, (7): , 馬榮華, 張路, et al., , 2010(06): and 竇鴻身, , 北京: and 陽坤, 中國區(qū)域高時空分辨率地面氣象要素驅(qū)動數(shù)據(jù)集, 寒區(qū)旱區(qū)科學數(shù)據(jù)中心, , 沉積巖中黏土礦物和常見非黏土礦物X , 北京: , , ., , and , An improved method for the highprecision isotopic measurement of boron by thermal ionization mass Journal of Mass Spectrometry and Ion Processes, (2): .項目的研究內(nèi)容、研究目標,以及擬解決的關(guān)鍵科學問題(此部分為重點闡述內(nèi)容);l 項目的研究內(nèi)容(1)湖泊沉積物粘土礦物與湖區(qū)周邊表土粘土礦物的關(guān)系研究研究湖泊表層沉積物粘土礦物種類、相對含量與湖區(qū)周邊表土粘土礦物的異同,揭示湖泊周邊表土對湖泊表層沉積物中粘土礦物的影響。因此,本項目將基于湖泊粘土礦物可以反映流域內(nèi)物質(zhì)來源和氣候環(huán)境變化的理論,在我國青藏高原和蒙新高原選擇具有一定海拔、緯度、溫度、降水和鹽度等自然梯度的湖泊33個,開展湖泊表層沉積物粘土礦物與氣候環(huán)境要素的相關(guān)性研究,通過對湖泊表層沉積物粘土礦物組成、含量、微形態(tài)及粘土礦物中元素含量和硼同位素的分析和測試,確定湖泊粘土礦物與湖泊周邊表土粘土礦物的相關(guān)性;研究在天然湖泊這一復雜的自然系統(tǒng)中,湖泊粘土礦物是否受湖水水化學條件等其它要素的影響;建立湖泊表層沉積物中粘土礦物與湖區(qū)周邊氣候要素(溫度、降水、相對濕度)的相關(guān)性,并探討因海拔高度和緯度效應引起的溫度、降水及相對濕度變化與湖泊粘土礦物的關(guān)系,評估它們在古氣候重建中的可靠性和適用性。C)和年均降水(200~500mm)變化大;(2)湖泊的水深(n100~n102m)和面積(n100~n103km2)變化大;(3)湖泊大多以封閉性湖泊為主,湖水鹽度變化范圍大(n100~n102g/L)。而且由于不同的湖泊存在不同的影響因素,例如面積、水深、湖水的水化學條件(湖水的化學組成、鹽度等)、湖區(qū)周邊表土粘土礦物組成和不同地理位置的湖泊所受的氣候要素(溫度、降水、相對濕度)的不同,對表層沉積物粘土礦物種類、相對含量、結(jié)晶度、元素、硼同位素及微形態(tài)會產(chǎn)生怎樣的影響以及是否有特征礦物出現(xiàn)(例如坡縷石等),不同地點的湖泊表層沉積物中的粘土礦物相對含量是否會像表土一樣,也受到當?shù)貧夂蛞貜娏业挠绊??我國是世界上湖泊分布眾多的國家之?6, 47,其中分布于青藏高原和蒙新高原的湖泊,%%46,這些湖泊具有如下幾個顯著的特征:(1)主要分布于我國內(nèi)陸干旱半干旱地區(qū),具有20176。所以中國表土中的粘土礦物分布與氣候帶的分布具有較好的吻合性,顯示出氣候是影響表土粘土礦物形成的主要因素6, 45。而且張艷靈等(2016)44采用三步離子交換法提取粘土沉積物中硼的回收率高于90%,未觀察到明顯的硼同位素分餾,可滿足粘土沉積物酸溶相中硼同位素組成高精度測定的需要。Wang and Xiao(2001)42對鹵水pH值和溫度對鹽湖鹵水和粘土沉積物間硼同位素分餾的影響進行了詳細的實驗研究,結(jié)果發(fā)現(xiàn)溫度的影響并不明顯,但鹵水pH值的影響卻十分顯著,特別是在高pH值下出現(xiàn)了反分餾,即11B富集在沉積物中。Shirodkar and Xiao(1997)39 對青海柴達木盆地鹽湖粘土沉積物的硼同位素組成進行了研究,柴達木盆地鹽湖粘土沉積物的δ11B ‰, 這種寬的變化范圍與鹵水中硼同位素組成有關(guān)。到目前為止,基于粘土礦物中的硼含量來重建古鹽度變化已經(jīng)被廣泛應用到了各種時間尺度上的沉積物當中36, 37。此外,大量研究表明,粘土中硼元素的含量可以指示其形成時水介質(zhì)的古鹽度值33。另外,單一粘土礦物的微細結(jié)構(gòu)也可以進一步得到鹽湖沉積環(huán)境方面的信息,如對伊利石結(jié)晶度、蒙皂石屬性、綠泥石類型、混層礦物膨脹度等方面的研究。碎屑蒙皂石多為不平整001面的片狀或者球狀集Qiu等(2014)32通過對中國東部表土粘土礦物元素的調(diào)查研究,發(fā)現(xiàn)氣候是對表土粘土礦物中元素化學風化起主要控制作用,并且粘土礦物中元素化學風化指數(shù)的空間分布顯示出明顯的緯度效應。港灣狀形貌特征指示其可能受強烈的