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东昆仑山北缘典型流域硼元素地表循环研究进展
Research Progress on Surface Boron Cycles in a Typical Basin in Northern Margin of Eastern Kunlun Mountains
东昆仑山北缘的那棱格勒河流域不仅是青藏高原地热、河流、盐湖并存且联系补给的典型区域,更是研究高山-深盆转换带硼元素富集成矿的热点流域。针对流域尺度硼元素迁移过程中的同位素分馏影响,系统阐述硼元素特性及其同位素示踪的优势和局限性,解析那棱格勒河流域地热水、河水、盐湖卤水的高硼元素富集特征与水化学一致性,辨析河流与盐湖的高硼物质来源。基于当前那棱格勒河流域地表水体硼元素富集与成矿研究现状,提出研究河流、源汇过程需探讨风化、示踪方法需量化指标等关键问题,以期深入理解青藏高原“地热-河流-盐湖”系统中硼元素地表循环过程。
[Objectives] Under the background of a new round of technological revolution and industrial transformation, boron is one of the important mineral sources required by global strategic emerging industries. China’s industrial development has a high demand for boron resources, but high-quality reserves are insufficient. As an important area of liquid boron reserves, the Qaidam Basin has great potential for boron resource development. The Nalenggele River watershed, located on the southern margin of this basin, is not only a typical area where hot springs, rivers, and salt lakes coexist and are hydrologically connected, but also a hotspot for studying the enrichment and mineralization of boron in the mountain-basin transition zone. [Methods] In this paper, the chemical characteristics of boron and the advantages and limitations of boron isotope tracing were systematically expounded. The boron enrichment features and hydrochemical consistency of regional geothermal water, river water, and salt lake brine water were also analyzed. Based on prior studies, the sources of high boron content in the rivers and salt lakes were discussed. [Results] 1) Boron isotopes were effective and sensitive tools for source identification,but their quantitative application in process assessment was inherently constrained by necessary preconditions due to its fractionation-prone property. 2) Geothermal waters,river waters,and salt lake waters in the Nalenggele River Basin were uniformly characterized by high boron concentrations,which was in contrast to other surface waters in the northern margin of the Eastern Kunlun Mountains. 3) Although multiple geochemical processes influenced the chemical composition of surface waters,geothermal water input constituted a dominant control on boron enrichment in the Nalenggele River Basin. [Conclusions] Based on current research on boron enrichment and mineralization in the study area,identifying the boron sources of riverine systems,quantifying weathering contributions during source-to-sink processes,and developing quantitative tracers are key research priorities.These results are expected to advance the understanding of surface boron cycling within the “hot springs-rivers-salt lakes” system in the Qinghai-Tibet Plateau.
东昆仑山北缘 / 地表水体 / 硼富集 / 物源 / 硼同位素
northern margin of the Eastern Kunlun Mountains / surface waters / boron enrichment / boron sources / boron isotope
| [1] |
林勇杰, 郑绵平, 刘喜方. 青藏高原盐湖硼矿资源[J]. 科技导报, 2017, 35(12): 77-82.
青藏高原赋有丰富的盐类矿产资源，尤以富含硼为其重要特征之一，形成地球上独特的外生硼成矿带，为中国已知最有远景的外生硼矿产区。青藏高原盐湖硼矿资源分为固体类型和液体类型，液体硼矿居多且有较大资源远景，但目前以开发利用固体硼矿为主。青藏高原盐湖不同水化学类型硼矿具有不同矿物组合和有用矿物，因此盐湖固体硼矿矿石类型繁多。目前，青藏高原已发现的硼酸盐矿物有14种，盐湖固体硼矿矿石类型分为硼砂型、镁硼酸盐-钠硼解石型、柱硼镁石-库水硼镁石型、库水硼镁石型和钠硼解石-柱硼镁石型。中国硼矿资源量虽大，但可利用资源十分有限，供需矛盾十分突出，因此推进青藏高原富硼盐湖的综合开发利用和扩大找硼研究工作，具有重要的科学与经济意义。
(
|
| [2] |
袁建国, 屈云燕, 刘秋颖, 等. 中国硼矿资源供需趋势分析[J]. 中国矿业, 2018, 27(5):9-12,27.
(
|
| [3] |
魏新俊. 柴达木盆地盐湖钾硼锂资源概况及开发前景[J]. 青海国土经略, 2002(增刊1): 64-69.
(
|
| [4] |
|
| [5] |
As one of the areas with numerous lakes on the Tibetan Plateau, the Hoh Xil region plays an extremely important role in the fragile plateau eco-environment. Based on topographic maps in the 1970s and Landsat TM/ETM+ remote sensing images in the 1990s and the period from 2000 to 2011, the data of 83 lakes with an area above 10 km2 each were obtained by digitization method and artificial visual interpretation technology, and the causes for lake variations were also analyzed. Some conclusions can be drawn as follows. (1) From the 1970s to 2011, the lakes in the Hoh Xil region firstly shrank and then expanded. In particular, the area of lakes generally decreased during the 1970s-1990s. Then the lakes expanded from the 1990s to 2000 and the area was slightly higher than that in the 1970s. The area of lakes dramatically increased after 2000. (2) From 2000 to 2011, the lakes with different area ranks in the Hoh Xil region showed an overall expansion trend. Meanwhile, some regional differences were also discovered. Most of the lakes expanded and were widely distributed in the northern, central and western parts of the region. Some lakes were merged together or overflowed due to their rapid expansion. A small number of lakes with the trend of area decrease or strong fluctuation were scattered in the central and southern parts of the study area. And their variations were related to their own supply conditions or hydraulic connection with the downstream lakes or rivers. (3) The increase in precipitation was the dominant factor resulting in the expansion of lakes in the Hoh Xil region. The secondary factor was the increase in meltwater from glaciers and frozen soil due to climate warming. |
| [6] |
|
| [7] |
周立. 柴达木盆地水资源供需关系及生态保护[M]. 西宁: 青海人民出版社, 2000.
(
|
| [8] |
徐威. 那棱格勒河冲洪积平原地下水循环模式及其对人类活动的响应研究[D]. 长春: 吉林大学, 2015.
(
|
| [9] |
姜春发, 杨经绥, 冯秉贵, 等. 昆仑开合构造[M]. 北京: 地质出版社, 1992.
(
|
| [10] |
|
| [11] |
李银川, 董戈, 雷昉, 等. 硼同位素分馏的实验理论认识和矿床地球化学研究进展[J]. 地学前缘, 2020, 27(3): 14-28.
硼是一种中等挥发性元素,具有<sup>11</sup>B和<sup>10</sup>B两个稳定同位素。两个同位素间高达10%的相对质量差使其在地质过程中引起高达-70‰至+75‰的硼同位素变化。硼在自然界主要与氧键合形成三配位(BO<sub>3</sub>)和四配位(BO<sub>4</sub>)结构,因而<sup>11</sup>B和<sup>10</sup>B间同位素分馏主要受控于三配体(BO<sub>3</sub>)和四面体(BO<sub>4</sub>)间配分。本文综述了低温和高温地质过程的硼同位素分馏的理论和实验研究进展。在溶液中B(OH)<sub>3</sub>和${B(OH)^{-}_{4}}$间硼同位素分馏受pH和热力学p-T条件控制,实验和理论表征获得常温常压条件下的B(OH)<sub>3</sub>和$B(OH)^{-}_{4}$间同位素分馏系数(α<sub>3-4</sub>)变化范围为1.019 4至1.033 3。低温条件下矿物(如碳酸盐、黏土矿物(蒙脱石和伊利石)、针铁矿、水锰矿、硼酸盐)与溶液间硼同位素分馏行为除了受p-T-pH影响外,矿物表面吸附引起的分馏效应十分显著。在中高温过程(蒙脱石伊利石化、富硼电气石和白云母矿物与热液流体,以及硅酸盐熔体与流体)中硼同位素分馏行为受到硼配位构型、化学成分以及物理化学条件的控制。随着硼同位素分馏机理研究的深入以及越来越完善的地质储库硼同位素端员特征表征,硼同位素地球化学指标可以灵敏示踪成矿物质来源、探究成矿作用与成因模式和重建成矿过程物理化学条件。目前矿床硼同位素地球化学研究的难点在于实现不同赋存相(如流体、矿物和熔体)中硼配位键合结构和硼同位素组成的精细化表征。
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Boron is a moderately volatile element with two stable isotopes 11B and 10B. As much as 10% relative mass difference between the two isotopes leads to significant variation in boron isotopic composition from -70‰ to +75‰ in nature. Boron is always bound to oxygen forming tetrahedral (BO4) and trigonal (BO3) coordination structures. The isotope fractionation between10B and 11B is mainly controlled by their partition between the two structures. In this study, we gave a comprehensive review on the advances in equilibrium fractionation of boron isotopes in various processes. In solution, the boron isotope fractionation factor between B(OH)3 and ${B(OH)^{-}_{4}}$ (α3-4) is controlled by pH and thermodynamic p-T conditions. At ambient conditions, the α3-4 values ranged from 1.0194 to 1.0333 by experimental and theoretical approaches. In addition to p-T-pH controls, boron isotope fractionation, caused by mineral surface adsorption between minerals (carbonates, clay minerals (montmorillonite and illite), goethite, hydromanganese, borate, etc.) and solution, is significant at low temperature. In medium and high temperature processes, boron isotope fractionation during illitization of smectite, tourmaline and muscovite minerals and in hydrothermal fluids or silicate melts and fluids are controlled by boron coordination, chemical composition, and physicochemical conditions. With further understanding of boron isotope fractionation mechanisms in individual process and isotopic distribution in various geological reservoirs, boron isotopes may be considered as sensitive indices for tracing ore-forming material sources, exploring ore-forming processes and genesis models, as well as reconstructing physicochemical conditions during ore formation. To better constrain geological concerns using boron isotopes in ore deposit geochemistry, the remaining challenges are to achieve fine characterizations of boron coordination and isotopic compositions in different host phases, such as fluids, minerals and melts. |
| [12] |
|
| [13] |
|
| [14] |
|
| [15] |
|
| [16] |
|
| [17] |
|
| [18] |
|
| [19] |
|
| [20] |
|
| [21] |
|
| [22] |
|
| [23] |
|
| [24] |
|
| [25] |
|
| [26] |
|
| [27] |
|
| [28] |
|
| [29] |
|
| [30] |
|
| [31] |
|
| [32] |
|
| [33] |
|
| [34] |
韩凤清, 陈彦交, 韩继龙, 等. 青海囊谦高浓度盐泉硼同位素地球化学特征及其地质意义研究[J]. 地球学报, 2016, 37(6):723-732.
(
|
| [35] |
|
| [36] |
The single-stage separation factors for boron isotopes between an ion-exchange resin and an external solution were determined, using an ion-exchange breakthrough operation. The lighter isotope boron-10 was considerably enriched in the anion-exchange resin phase. The separation factor was very much influenced by the boric acid concentration in the external solution, but not as much influenced by the kind of the anion exchange resin used and operation temperature. The separation factor increased with a decrease in the boric acid concentration of external solution from 1.008 (0.501 mol/l) to 1.016 (0.010 mol/l). The value of the separation factors obtained experimentally were compared with those estimated on the basis of the theory of the two-phase distribution of isotopes.
|
| [37] |
|
| [38] |
|
| [39] |
It is pointed out that the possibility of chemical separation of isotopes is a quantum effect. This permits a direct calculation of the difference in the free energies of two isotopic molecules. Tables and approximation methods are given which permit a rapid calculation of equilibrium constants if the frequency shifts on isotopic substitution are known. Several applications are discussed.
|
| [40] |
可可西里综合科学考察队. 青海可可西里地区自然环境[M]. 北京: 科学出版社, 1996.
( Hoh Xil Integrated Scientific Expedition Team. Physical Environment of Hoh Xil Region, Qinghai[M]. Beijing: Science Press, 1996. (in Chinese))
|
| [41] |
|
| [42] |
朱允铸, 李争艳, 吴必豪, 等. 从新构造运动看察尔汗盐湖的形成[J]. 地质学报, 1990, 64(1): 13-21.
(
|
| [43] |
|
| [44] |
张彭熹. 柴达木盆地盐湖[M]. 北京: 科学出版社, 1987.
(
|
| [45] |
肖应凯, P·V·Shirodkar, 刘卫国, 等. 青海柴达木盆地盐湖硼同位素地球化学研究[J]. 自然科学进展, 1999, 9(7):616-618.
(
|
| [46] |
杨贵林, 张静娴. 柴达木盆地水文特征[J]. 干旱区研究, 1996, 13(1): 7-13.
(
|
| [47] |
|
| [48] |
|
| [49] |
|
| [50] |
|
| [51] |
陈克造, 杨绍修, 郑喜玉. 青藏高原的盐湖[J]. 地理学报, 1981, 36(1):13-21.
前言 青藏高原棋布着世界最高海拔的盐湖,构成高原自然景观的重要特色之一。就其分布之广、数量之多、发育之好,皆占我国首位,成为我国盐湖资源的重要宝库。目前,在青藏高原123个盐湖中（图2）,已见到40多种盐类矿物,其中天青石（S<sub>r</sub>SO<sub>4</sub>）、芒硝、硼酸盐、钾盐等,具有工业价值。
(
|
| [52] |
袁见齐, 霍承禹. 青海察尔汗盐湖钾盐矿床成因的若干问题[J]. 地球科学, 1981, 6(1): 207-213.
(
|
| [53] |
袁见齐, 霍承禹, 蔡克勤. 高山深盆的成盐环境: 一种新的成盐模式的剖析[J]. 地质论评, 1983, 29(2): 159-165.
(
|
| [54] |
|
| [55] |
|
| [56] |
朱允铸, 李文生, 吴必豪, 等. 青海省柴达木盆地一里坪和东、西台吉乃尔湖地质新认识[J]. 地质论评, 1989, 35(6): 558-565.
(
|
| [57] |
郑绵平, 刘喜方, 赵文. 西藏高原盐湖的构造地球化学和生物学研究[J]. 地质学报, 2007, 81(12): 1698-1708.
(
|
| [58] |
李文鹏, 何庆成. 察尔汗盐湖物质来源的讨论[J]. 河北地质学院学报, 1993, 16(3): 254-263.
(
|
| [59] |
|
| [60] |
|
| [61] |
马茹莹, 韩凤清, 马海州, 等. 青海可可西里盐湖水化学及硼同位素地球化学特征[J]. 地球学报, 2015, 36(1):60-66.
(
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