长江中下游成矿带岩浆岩体三维空间结构:来自重磁三维反演的证据

长江中下游成矿带是我国重要的铁铜多金属矿产资源基地,燕山期中酸性岩浆岩对铜、铁、金等各种内生金属矿床的形成起着举足轻重的作用,识别和厘定岩浆岩体特别是隐伏岩体的三维分布形态对成矿动力学研究和深部找矿预测工作都有着重要意义。我们采用重磁三维物性反演技术,获得长江中下游成矿带磁化率和密度差三维模型,根据物性与岩性对应关系,识别和分析了区内岩浆岩体三维空间结构。推测了区内存在5个主要的岩浆活动中心,探讨了岩浆流动形式与轨迹。根据重磁三维反演反映的长江中下游岩浆岩三维分布特征,结合区域莫霍面、均衡重力异常和重磁多尺度边缘检测结果,以及区域成矿背景,预测了5个找矿远景区。结果表明,重磁三维反演技术是一种行之有效的岩浆岩体识别手段,通过对反演所得磁化率、密度分布情况的分析,可识别、圈定隐伏或半隐伏岩体,并可定量获取岩体三维形态特征,从而为寻找与火山岩、侵入岩体有关的金属矿产提供指示信息。     

长江中下游成矿带(江苏段)硫铁矿床成矿模式

通过分析长江中下游成矿带(江苏段)区域成矿地质条件、硫铁矿典型矿床及区域成矿特征,建立了陆相火山岩型和矽卡岩型硫铁矿床成矿模式.结合典型矿床成矿、物化探异常特征,提出长江中下游成矿带(江苏段)硫铁矿床找矿模型,这对于该区域找矿预测具有指导意义.     

长江中下游成矿带溧水盆地(次)火山岩的年代学及其意义

溧水火山岩盆地是长江中下游地区众多中生代火山岩盆地之一,在盆地内自下而上发育有龙王山组、大王山组、姚家边组和甲山组粗面质火山岩和若干个同源的次火山侵入岩体。针对溧水盆地火山岩-次火山岩进行系统的锆石U-Pb年代学研究,结果显示,龙王山组玄武质粗面岩的锆石U-Pb年龄为135 Ma±1 Ma,大王山组粗安岩的锆石U-Pb年龄为131 Ma±1 Ma,姚家边组粗安岩的锆石U-Pb年龄为128 Ma±1 Ma,另外1个粗安斑岩体的年龄为131 Ma±1 Ma,它们均为早白垩纪岩浆活动的产物。上述年龄数据与长江中下游地区其他盆地火山岩的年龄基本一致,表明长江中下游地区中生代火山岩的喷发时代主要集中在135Ma~127Ma之间,均受制于中国东部岩石圈减薄的伸展构造背景。     

长江中下游成矿带及邻区地壳速度结构：来自利辛-宜兴宽角地震资料的约束

为了理解长江中下游地区在中生代成矿的深部动力学过程,Sinoprobe-03-02项目于2011年9月至10月,在跨宁芜矿集区和郯庐断裂带实施了从安徽利辛至江苏宜兴450km长的宽角反射/折射地震剖面。速度剖面结果显示,Moho面深度和地壳速度结构在郯庐断裂两侧东西方向存在明显的差异:(1)在东部扬子块体内部,地壳覆盖层厚3~5km,西部的合肥盆地下方,则达到4~7km。(2)剖面平均Moho面深度为30~32km左右,在郯庐断裂下方,Moho面深度在35km左右;在宁芜矿集区下方,Moho面整体深度偏浅,达30~31km左右,但局部范围内,Moho面深度至34km左右。(3)剖面的下地壳平均速度在6.5~6.6km/s左右,在宁芜矿集区下方,下地壳速度偏低,为6.4~6.5km/s左右。剖面上地幔顶部的速度结构平均在8.0~8.2km/s。在宁芜矿集区下方,速度偏低,为7.9~8.1km/s左右。(4)郯庐断裂带的下方,从地表开始,还存在20多千米长的低速异常带,一直延伸到Moho面附近。剖面的宁芜矿集区下方Moho面上隆、下地壳及上地幔的低速异常等壳幔结构特征,预示下地壳不以榴辉岩残体为主,支持燕山期地幔岩浆的上涌和侵入并成矿,是热上涌物质的源地。     

长江中下游成矿带及邻区地壳结构——MASH成矿过程的P波接收函数成像证据？

利用长江中下游成矿带多学科深部探测剖面于2009年11月至2011年3月间采集的天然地震数据,通过天然地震接收函数成像等分析研究,得到了研究区地壳和上地幔结构的清晰图像。接收函数成像结果显示研究区内Moho面深度存在着明显的起伏变化,在长江中下游成矿带(指剖面穿过的长江中下游成矿带宁芜矿集区,下同)下方存在着"幔隆构造"。在剖面东南端(即扬子克拉通北缘),Moho面相对稳定,深度约为30km;在茅山和江南断裂附近,Moho面存在上下起伏现象;在剖面中部或宁芜矿集区下方,Moho面存在明显隆起,深度只有28km;在郯庐断裂带下方,Moho面明显加深,深度达到36km;进一步向北到华北地台南缘,Moho面深度逐渐恢复到了32km左右的平均深度水平。其次,我们在接收函数成像结果中发现,长江中下游成矿带与其周边下地壳结构存在着明显的差异,成矿带的下地壳具有显著的地震波方位各向异性。扬子克拉通北缘的下地壳呈高速的近水平状结构,地震波各向异性特征不明显;与此相比,长江中下游成矿带的下地壳虽然也呈近水平状结构特征,但是,对于沿成矿带走向方向传播的地震波,其下地壳具有高速特征,而对于垂直于成矿带走向方向上传播的地震波,其下地壳却又表现为低速特征,这意味着成矿带的下地壳存在着平行于成矿带走向(即近北东—南西)方向的地震波各向异性,我们解释其是下地壳熔融并沿成矿带走向水平流动导致矿物晶体定向排列的结果。最后,在郯庐断裂以西的华北地台南缘观测到一条从上地壳延伸到中下地壳的南南东向倾斜的转换震相,我们推测它可能是合肥盆地内地壳伸展构造的反映。此外,我们发现接收函数成像结果中观测到的"幔隆构造"与远震P波层析成像结果在成矿带下方150km深度上显示的上地幔低速异常(江国明等,另文发表)存在着良好的对应关系,我们解释它们是软流圈物质上涌的遗迹。综合天然地震接收函数成像、远震P波层析成像和前人关于岩浆岩等方面的研究成果,我们认为长江中下游成矿带现今的下地壳可能是中生代发生成矿作用的多级岩浆房系统的一部分,成矿带的形成可能是类似MASH过程的产物。首先,软流圈物质上涌导致了长江中下游成矿带及其周边拉张环境的形成,在其上部地壳中形成了一系列伸展构造;然后,软流圈物质通过底侵进入长江中下游成矿带的原下地壳并与原下地壳物质发生同化作用,形成类埃达克质岩浆;接着,类埃达克质岩浆沿着伸展、拆离构造上升到地壳浅部形成不同层次的岩浆房和侵入岩体,并与围岩作用形成矿床。     

长江中下游成矿带宣城矿集区重磁场特征与找矿启示

宣城矿集区位于长江中下游成矿带东段的安徽省南陵-宣城盆地,是长江中下游成矿带新一轮找矿工作的重点勘查区。为查明成矿深部背景,发掘成矿潜力,亟待了解深部结构特征。本文使用地面测量1：25 000重力和1：10 000磁力数据,通过重磁场分离和密度、磁化强度三维反演,结合岩矿石的密度、磁化率等物性测量结果,以及区域地质和矿床资料,以期揭示深部构造及与成矿关系。研究结果表明,新河庄背斜、陈家湾向斜、马山埠背斜和昆山向斜等褶皱构造横向上剩余密度正负差异显著呈相间分布的深部特征,垂向上褶皱构造的最大深度约为2 km;在褶皱构造下方分布北西浅、往南东逐渐加深的低密度、低磁性层,推测可能为研究区内茅山-九连山推覆构造的滑脱面。马山埠背斜轴部花岗闪长斑岩附近的重高磁高组合异常是铜山-荞麦山矽卡岩型矿床的找矿线索,然而成矿岩体规模较小,深部磁化强度弱,马山埠背斜附近深部找矿潜力有限。茶亭矿区呈重高磁高组合异常特征,同时成矿的石英闪长玢岩岩体与围岩灰岩、上覆火山岩磁性差异明显,这些特征是重要的找矿线索。文章研究结果证实,茶亭下方-400~-1900 m磁化强度正异常区域对应茶亭铜金矿床,这为在研究区其他地点深部进一步寻找斑岩型、隐爆角砾岩型铜金矿床提供了地球物理依据。     

长江中下游成矿带铁-铜成矿系统结构的地球物理探测: 综合分析

成矿系统是在深部过程驱动下形成的、具有自组织的能量及物质迁移-汇聚系统。系统在形成和演化过程中,在岩石圈不同尺度上留下“痕迹”,这种“痕迹”可以通过地球物理、地球化学和遥感等方法进行探测或观测。文章尝试在成矿系统理论框架下,对近10多年来在长江中下游成矿带进行的多尺度地球物理、地球化学探测结果进行分析,识别典型陆内成矿系统“源区”“通道”“场所”的地球物理、地球化学“痕迹”,尝试构建陆内成矿系统的空间结构模型。主要结论有:(1)长江中下游晚中生代的大规模铁、铜多金属成矿作用是一个完整的成矿系统。该系统包括3个子系统,分别为与高钾钙碱性岩浆岩有关的夕卡岩-斑岩成矿子系统、与橄榄安粗岩有关的陆相火山岩铁(硫)成矿子系统和与碱性岩有关的铜-金(铀)成矿子系统。(2)成矿系统的“源区”来自富集地幔的熔融、底侵,并在壳/幔边界与下地壳物质的混合,具有多级分布特点。幔源岩浆与地壳物质混合的比例决定了成矿金属的类型。(3)成矿带发育的“鳄鱼嘴”构造是铁铜成矿系统的主干“通道”。成矿系统“末端”矿质沉淀的“场所”主要受近地表褶皱、断裂、层间滑脱断层,以及由它们形成的断裂(裂隙)网络控制。(4)区域磁异常、放射性和地球化学异常是成矿系统残留“痕迹”的响应和“标识”。通过分析不同尺度的“标识”特征,可以深入认识成矿系统的空间结构,并可用于深部成矿预测。     

长江中下游成矿带的幔根构造与深部找矿

长江中下游铁铜金多金属成矿带,正处于华北板块与扬子板块碰撞造山带的断裂构造部位.由于岩石圈大尺度不连续和地壳减薄无山根的成矿背景,促使燕山期热事件成为断裂-盆地-岩浆-成矿带的响应.区内Ⅰ型花岗岩是地幔基性岩浆底侵与壳幔相互作用的结果,包体研究和透明地震反射区资料证明它们具有软流圈上涌与下地壳拆沉作用的印记,也是幔根构造的源地.正因为透岩浆流体作用,形成大量金属矿床,因而这些矿床的成矿时代具有突发性和规律性,同时成矿物质来源具有多源性和不均匀性;成矿流体具有同一性和矿床类型的多样性;成矿期次具有叠加改造性.从S、Pb、Sr、H、O、C、Si、Cu等同位素组成取得的信息,也可作为幔根构造壳幔同熔成矿的佐证.按照幔根构造成矿机理分析,预测本区仍有第二成矿空间(-500~-2 000 m),建议以"类埃达克岩(体)"为中心的地区,可作为新一轮找矿的首选区.运用综合方法(遥感、磁、电、重、地震及深穿透地球化学等),以探明深部与下古生界碳酸盐岩的接触带为主攻目标,建立四维成矿模型,确定找矿靶区,尽快进行钻探验证.     

长江中下游成矿带岩石圈结构与成矿动力学模型——深部探测(SinoProbe)综述

岩石圈结构和深部过程对理解成矿带和大型矿集区的形成十分重要。岩石圈尺度的地球动力学过程将在地壳中留下各种结构的或物质的"痕迹",这些"痕迹"可以通过地球物理的手段去探测。为深入理解长江中下游成矿带形成的深部动力学过程,作者在国家深部探测专项(SinoProbe)和国家自然科学基金重点项目支持下,在长江中下游成矿带开展了综合地球物理探测。方法包括宽频地震、深地震反射、广角反射/折射和大地电磁测深。数据处理和反演结果取得一系列新发现:(1)成矿带上地幔顶部存在低速体,在中心深度300km处有一向SW倾斜的高速体;(2)S波接收函数证实成矿带岩石圈较薄,只有50~70km;横波分裂结果显示,成矿带上地幔各向异性方向和强度与邻区有较大区别,显示平行成矿带(NE-SW向)的上地幔变形和流动;(3)深反射地震揭示成矿带上地壳曾发生强烈挤压变形,以紧闭褶皱、逆冲和推覆为特征;在宁芜火山岩盆地、长江断裂带和郯庐断裂之下出现"鳄鱼嘴"构造,指示上下地壳在挤压变形过程中解耦;深反射地震证实发生过陆内俯冲和叠瓦,并认为是岩石圈增厚和拆沉的主导机制;(4)广角反射和大地电磁反演给出了跨成矿带地壳剖面的速度和电性结构,速度和电阻率分布总体上与构造单元相吻合。本文分析和解释了这些发现的地质意义,并结合近年在长江中下游地区的地球化学研究进展,提出了成矿带地球动力学模型。该模型认为:中、晚侏罗世陆内俯冲、岩石圈拆沉、幔源岩浆底侵和MASH过程造就了长江中下游世界级成矿带的形成。     

长江中下游成矿带矽卡岩型矿床矿物包裹体激光拉曼分析结果及其地质-地球化学意义

矽卡岩矿床各种硅酸盐矿物中熔融包裹体和流体-熔融包裹体的显微测温资料和相成分让我们提出过大量矽卡岩是岩浆成因的建议。在本文中,我们提供沿长江中下游成矿带的许多矽卡岩矿床包含在石榴子石和辉石里的熔融包裹体和流体-熔融包裹体的激光拉曼分析结果,目的是证明所研究的并与Cu-Fe-Au矿床共生的矽卡岩系岩浆成因。我们的研究结果显示,熔融包裹体只含固体相和微量气相。流体-熔融包裹体除了含大量固相外,还含微量流体和气相以及没有被仪器检测到的气体。固体相与包裹体寄主矿物相同或类似。流体相主要为水或盐水溶液和包括C6H6、C3H6、C3H8、CH4、CO2和O2的气体。我们提出,熔融包裹体和流体-熔融包裹体是原始岩浆的最好代表。这就证明,矽卡岩组合是由一个原生岩浆直接结晶而成。此外,我们还讨论了岩浆矽卡岩形成的温度、分布范围和规模、形成机制和与Cu-Fe-Au矿化作用的联系。     

Three-dimensional P-wave Velocity Structure Modelling of the Middle and Lower Reaches of the Yangtze River Metallogenic Belt: Crustal Architecture and Metallogenic Implications

In this study, we compiled and analyzed 69310 P-wave travel-time data from 6639 earthquake events. These events (M ≥ 2.0) occurred from 1980s to June 2019 and were recorded at 319 seismic stations (Chinese Earthquake Networks Center) in the study area. We adopted the double-difference seismic tomographic method (tomoDD) to invert the 3-D P-wave velocity structure and constrain the crust-upper mantle architecture of the Middle and Lower Reaches of the Yangtze River Metallogenic Belt (MLYB). A 1-D initial model extracted from wide-angle seismic profiles was used in the seismic tomography, which greatly reduced the inversion residual. Our results indicate that reliable velocity structure of the uppermost mantle can be obtained when Pn is involved in the tomography. Our results show that: (1) the pattern of the uppermost mantle velocity structure corresponds well with the geological partitioning: a nearly E–W-trending low-velocity zone is present beneath the Dabie Orogen, in contrast to the mainly NE-trending low-velocity anomalies beneath the Jiangnan Orogen. They suggest the presence of thickened lower crust beneath the orogens in the study area. In contrast, the Yangtze and Cathaysia blocks are characterized by relatively high-velocity anomalies; (2) both the ultra-high-pressure (UHP) metamorphic rocks in the Dabie Orogen and the low-pressure metamorphic rocks in the Zhangbaling dome are characterized by high-velocity anomalies. The upper crust in the Dabie Orogen is characterized by a low-velocity belt, sandwiched between two high velocity zones in a horizontal?direction, with discontinuous low-velocity layers in the middle crust. The keel of the Dabie Orogen is mainly preserved beneath its northern section. We infer that the lower crustal delamination may have mainly occurred in the southern Dabie Orogen, which caused the mantle upwelling responsible for the formation of the granitic magmas emplaced in the middle crust as the low-velocity layers observed there. Continuous deep-level compression likely squeezed the granitic magma upward to intrude the upper crustal UHP metamorphic rocks, forming the ‘sandwich’ velocity structure there; (3) high-velocity updoming is widespread in the crust-mantle transition zone beneath the MLYB. From the Anqing-Guichi ore field northeastward to the Luzong, Tongling, Ningwu and Ningzhen orefields, high-velocity anomalies in the crust-mantle transition zone increase rapidly in size and are widely distributed. The updoming also exists in the crust-mantle transition zone beneath the Jiurui and Edongnan orefields, but the high-velocity anomalies are mainly stellate distributed. The updoming high-velocity zone beneath the MLYB generally extends from the crust-mantle transition zone to the middle crust, different from the velocity structure in the upper crust. The upper crust beneath the Early Cretaceous extension-related Luzong and Ningwu volcanic basins is characterized by high velocity zones, in contrast to the low velocity anomalies beneath the Late Jurassic to Early Cretaceous compression-related Tongling ore field. The MLYB may have undergone a compressive-to-extensional transition during the Yanshanian (Jurassic–Cretaceous) period, during which extensive magmatism occurred. The near mantle–crustal boundary updoming was likely caused by asthenospheric underplating at the base of the lower crust. The magmas may have ascended through major crustal faults, undergoing AFC (assimilation and fractional crystallization) processes, became emplaced in the fault-bounded basins or Paleozoic sequences, eventually forming the many Cu-Fe polymetallic deposits there.     

Basement Characteristics and Crustal Evolution of the Copper-Gold Metallogenic Belt in the Middle and Lower Reaches of the Yangtze River: Some Isotope Constraints

Studies of the Pb, Sr and Nd isotopic composition of Mesozoic intrusive rocks indicate that the basement of the copper-gold metallogenic belt of the middle and lower reaches of the Yangtze River has "two-layer structure" and partly has "multi-layered structure", and is inhomogeneous and shows the distinct feature of E-W provincialism. The calculated model lead ages (t1) are mostly greater than 2600 Ma, and the model neodymium ages (TDM) vary from 953 to 2276 Ma and concentrate in two time intervals: 1800-2000 Ma and 1200-1600 Ma. It is concluded that the basement of the MBYR is composed of the Late Archaeozoic to Middle Proterozoic metamorphic series and that the crust was initiated in the Archaean and continued to grow in the Early and Middle Proterozoic, and the proportion of new crust formed by mantle differentiation during the Late Proterozoic is low.     

庐枞矿集区与钨矿床有关的花岗岩的年代学及地球化学特征:岩石成因及其对长江中下游晚白垩世成矿的启示

长江中下游是中国东部一个重要的与中生代岩浆作用有关的Cu-Au-Mo-Fe矿成矿带。近期勘查工作在庐枞矿集区东顾山地区深部首次发现了与隐伏花岗岩密切相关的钨钼多金属矿化。岩石学和岩石地球化学研究结果表明,隐伏花岗岩具有高硅富碱高钾、贫铁贫镁及铝弱饱和的特征,属于高钾钙碱性系列岩石;具有富集Rb、Th、U等强不相容元素和轻稀土元素,亏损Nb、P、Ti、Y等高场强元素,低ε_(Nd)(t)(-18.2~-17.1)和相对高的((~(87)Sr/~(86)Sr)_i)(0.70596~0.70631)的特征,推测其岩浆来源于扬子下地壳的部分熔融,岩浆在就位之前经历了一定程度的分异结晶作用。利用LA-ICP MS锆石U-Pb定年获得96.7±1.3Ma的锆石年龄,表明其属于晚白垩世早期岩浆活动的产物。结合区域成岩成矿时空格架,认为东顾山地区隐伏花岗岩及与之有关的钨钼多金属矿化可能代表了长江中下游成矿带的新一期成岩成矿事件。     

Late Mesozoic magmatism of the Jiurui mineralization district in the Middle–Lower Yangtze River Metallogenic Belt, Eastern China: Precise U–Pb ages and geodynamic implications

The Middle–Lower Yangtze River metallogenic belt (MLYRMB), extending from Daye in Hubei Province in the west to Zhenjiang in Jiangsu Province in the east, hosts a number of large polymetallic (Cu–Au–Mo, Fe, Zn, Pb, and Ag) deposits and constitutes one of the most important metallogenic belts in China. The Cu–Au–Mo deposits in the Jiurui district are an important component of the MLYRMB. In this study we carried out precise and detailed zircon U–Pb dating for all types of magmatic rocks from the Wushan ore deposit in the Jiurui district. Three samples of Cu–Au–Mo-related porphyries from different ore belts at Wushan were analyzed and yielded zircon U–Pb ages of 148.0 ± 1.0 Ma, 145.4 ± 0.9 Ma and 147.3 ± 0.9 Ma, respectively. A series of dykes were emplaced immediately following the Cu–Au–Mo-related porphyries at Wushan. A dark-colored basic dyke which intruded into the granodiorite porphyry at Wujia gold deposit near Wushan was dated at 144.5 ± 1.2 Ma. Two lamprophyre dykes taken from the north ore belt at Wushan underground mining stops were dated at 143.6 ± 0.9 Ma and 144.3 ± 0.9 Ma, respectively. A late-stage dyke which was also taken from the Wushan north ore belt yielded an age of 142.6 ± 1.0 Ma and might represent the end of magmatism in the Wushan ore deposit. These new geochronological data demonstrate that the time range of magmatism in the Wushan ore deposit is approximately between 148 Ma and 143 Ma, showing that the magmatic activity at Wushan was rapid and intensive. The ages of Cu–Au–Mo-related porphyries from other areas in the Jiurui district, such as the Dongleiwan, Yangjishan and Chengmenba ore deposits, were also measured and yielded zircon U–Pb ages of 141.5 ± 1.7 Ma, 143.4 ± 1.4 Ma and 146.6 ± 1.0 Ma, respectively. Combined with those previously reported zircon U–Pb age results from the Jiurui district, the present age data set demonstrates that extensive magmatism in the Jiurui district was coeval and intensive, marked by a magmatic activity in the age range of 148 to 138 Ma and peaked between 148 Ma and 142 Ma. According to the statistics of all those precise zircon U–Pb ages, the Cu–Au–Mo-related porphyries in the Edong and Tongling districts in the MLYRMB show similar ages, and they have a slightly younger peak age and a longer duration than that of the Jiurui district. The geographic shape of the MLYRMB in the Cretaceous shows an arcuate structure, the Jiurui district is located at the transitional point of the arcuate structure and the Edong and Tongling districts are situated on both sides of the arcuate structure. Considering that the Jiurui district has a slightly older peak age and a shorter duration of magmatic activity than that in the Edong and Tongling districts, it seems that the arcuate structure of the MLYRMB played an important role in the formation of these Cu–Au–Mo-related porphyries. Consequently, we suggest that the genesis of the Late Mesozoic magmatic rocks along the MLYRMB may have been due to a tectonic activity developed from southeast to northwest, which probably has a close relationship with the subduction of the paleo-Pacific plate beneath the Eurasian plate in Mesozoic times.     

水稳定同位素示踪的冰川流域水文模拟及不确定性研究

水文模拟不确定性长期以来是制约寒区水文发展的瓶颈问题。水稳定同位素示踪为认识冰川流域径流过程提供了重要“指纹”信息,但仍缺乏有效模型将该信息与冰川水文模型耦合,而且同位素信息对冰川流域水文模型不确定性的约束效果也有待检验。将水稳定同位素信息（δ¹⁸O）与冰川流域水文模型FLEX^G相耦合,实现对冰川流域水稳定同位素和径流过程的耦合建模（FLEX^G-iso）,并在乌鲁木齐河源1号冰川流域进行模拟检验和径流分割。结果表明：模型不仅对2013—2016年径流过程有良好的模拟效果,还可以重现水稳定同位素、冰川物质平衡等重要过程。利用水稳定同位素这一辅助数据,提高了模型参数的识别能力,减少了模拟过程中各水源的相互妥协效应和不确定性范围。2013—2016年1号冰川断面径流32%~34%来自融雪,48%~51%来自融冰,0%~7%来自地下水,12%~15%来自降雨径流。水稳定同位素对雪和冰川相关中间过程有明显的约束能力,原有模型对融冰贡献的模拟偏高约7%。FLEX^G-iso模型的建立有助于推动寒区水文学理论和方法的发展,以及寒区水资源、生态环境保护等相关决策制定。