天然碱矿床及其盐湖形成机理初探

通过对天然碱矿床的地质环境、共伴生矿物组合 ;碱湖形成条件、盐类矿物组合、卤水化学特征 ;热泉及其逸出气体主要化学成分的研究 ,提出了天然碱矿床及碱湖的成碱机理。     

海拉尔盆地盐湖及碳酸盐成因

本文根据野外考察和室内分析资料，全面总结了该区盐湖概况、矿物组成、卤水成分及盐元素的物质来源，提出了碱湖的形成和天然碱的成因机理。     

施加不同量外源氮和互为伴生种下碱蓬和盐地碱蓬生物量变化的野外模拟实验北大核心CSCD

2017年5月2日～6月27日,在黄河三角洲滨海湿地生态试验站中,采用野外模拟实验方法,布设了108根PVC管,在盐地碱蓬(Suaeda salsa)和碱蓬(Suaeda glauca)互为伴生种条件下,移栽两种植物,在每根管中,优势种的种植密度分别为4株和2株,伴生种的种植密度为1株;在无伴生种条件下,优势种的种植密度为1株。考虑黄河三角洲地区氮沉降情况,以尿素作为外源氮,设置了0 g/m^2氮、15 g/m^2氮和30 g/m^2氮3种外源氮输入量,开展了碱蓬和盐地碱蓬的生物量变化研究。研究结果表明,在有伴生种条件下,当每根PVC管中优势种的种植密度为4株和2株时,随着氮输入量提高,碱蓬和盐地碱蓬平均单株生物量都显著增高;在无伴生种的条件下,当外源氮输入量为15 g/m^2氮和30 g/m^2氮时,碱蓬生物量[(58.050±2.560) g/株和(58.740±3.170) g/株]显著高于无外源氮输入[(20.850±0.640) g/株],盐地碱蓬生物量[(82.640±1.330) g/株和(111.960±6.400) g/株]显著高于无外源氮输入[(37.500±1.750) g/株]。外源氮输入量提高促进了盐地碱蓬和碱蓬生物量的积累,盐地碱蓬生物量增加幅度更大,对盐地碱蓬生长的促进作用更强。     

可可西里地区错达日玛陨坑湖成因初探

本文根据可可西里地区综合调查资料和地球资源卫星遥感信息的研究，分析了错达日玛环形构造体系网络及湖泊地貌构型特征的动力条件，从而确定了错达日玛陨坑湖的成因类型，并建立了陨坑湖形成过程的演化模式．     

艾比湖的湖岸地貌及其反映的湖面变化

艾比湖为一典型的内陆干旱区封闭型湖泊,干旱区的湖泊对气候和环境变化的响应非常敏感,该湖自形成以来的变化湖岸地貌中留下了很好的记录,对湖积堤和湖成阶地的系统研究以及对湖各平原的分析结果展现了艾比湖的湖在变化过程。     

柴达木盆地碱山深钻的硼同位素地球化学特征

沉积物硼(B)同位素组成可以反映其地质成因及经历的地质过程,因此在许多领域的研究中都有较为广泛的应用。通过对位于柴达木盆地碱山背斜顶部的SG-1b钻孔沉积物(7.3～1.6 Ma)水溶组分的B同位素研究,发现钻孔沉积物B含量在38.55～172.3μg/g之间,平均含量为87.6μg/g;δ~(11)B值的变化范围在3.61‰～16.26‰之间,平均值为10.65‰,B含量与δ~(11)B值具有一定的正相关关系。进一步分析表明,受到碱山背斜构造隆升以及晚新生代以来气候干旱化的影响,柴西古湖逐渐咸化萎缩,沉积环境以及碳酸盐含量、粘土矿物含量及其矿物组合等也在发生变化,B含量和δ~(11)B值自钻孔底部向上的逐步增加以及后期的急剧增加,与水溶离子含量以及矿物和粒度等的变化一致,这说明柴达木盆地晚中新世以来湖泊沉积物的B含量和δ~(11)B值可以很好地反映研究区气候和湖水的演化过程,共同指示了研究区自7.3 Ma以来气候的持续干旱化和湖水盐度的逐步增加,以及3.3Ma以来干旱化和湖水浓缩过程的加剧。     

冰湖的界定与分类体系——面向冰湖编目和冰湖灾害研究

冰川湖泊（简称冰湖）不仅是高山区重要的水资源,而且是许多冰川灾害的孕育者和发源地,在冰冻圈科学、气候变化和山地灾害研究中具有重要地位。本文系统讨论了现有冰湖定义及存在的问题,从冰湖编目和冰湖灾害研究视角提出冰湖的定义,指出现有冰湖研究主要是基于“以现代冰川融水为主要补给源或在冰碛垄洼地内积水形成的天然水体”这一冰湖定义的。同时,从冰湖形成机理、地貌形态和空间分布位置将冰湖划分为冰川侵蚀湖（冰斗湖、冰川槽谷湖和其他冰川侵蚀湖）、冰碛阻塞湖（终碛阻塞湖、侧碛阻塞湖、冰碛垄热融湖）、冰川阻塞湖（冰川前进阻塞湖和其他冰川阻塞湖）、冰面湖、冰下（内）湖和其他冰川湖6大类及8个亚类,并给出各冰湖类型相应的遥感判识指标和定量指标,以期建立具有普适性和可操作性的冰湖分类体系。     

达里诺尔湿地水环境和鱼类多样性调查Ⅲ.达里湖水体中的氮和磷含量及分布

达里湖是达里诺尔湿地的重要组成部分.2019年,对达里湖开展了野外调查并采集了水样,测定了水样的氮、磷含量和非离子氨含量与水体pH的关系,并将研究结果与以往的达里湖相对应的调查资料进行比较,探讨了达里湖水体中氮、磷含量特征的形成及其对达里湖鱼类物种多样性的影响.研究结果表明,2019年7月,达里湖水体中的CODCr和C...     

西藏喜马拉雅山区危险冰湖及其溃决特征

喜马拉雅山区的冰湖溃决主要属终碛湖溃决。野外考察和编目研究的结果表明，终碛湖占各类高山冰湖总数的1/2和总水体的3/4。鉴别出34个危险终碛湖，其水体容量在10×10~6—30×10~6m~3之间，平均水深31m，实测最大水深在70m左右。危险终碛湖绝大多数形成于小冰期最后一次冰退阶段，由于其形态特征和现代冰川的直接影响而具有潜在的溃决危险；讨论了终碛湖溃决的特征，主要因素及其周期性。     

内蒙古自治区红格尔地区晚石炭世碱长花岗岩岩体特征分析研究

红格尔地区碱长花岗岩体分布于查干敖包庙西、巴彦哈拉特尔敖包和准和热木音苏莫等地。岩石均呈肉红色,主体岩性为中细粒-中粒-中粗粒碱长花岗岩、角闪碱长花岗岩、文象碱长花岗岩,少量二长和正长花岗岩,不含或含极少量暗色矿物,呈岩枝、岩株状产出。岩石具混源特性,形成于后碰撞环境。     

近22 ka以来吉兰泰盐湖的环境变化及成盐过程

 根据研究区及毗邻地区第四纪地层沉积特征资料,运用层序地层学的基本方法,对吉兰泰盐湖22 ka BP以来的环境变化和成盐过程进行初步分析。同时,将其划分为6个阶段:冷干期（22.0~14.0 ka BP）,淡水湖演化阶段;冷湿期（14.0~10.0 ka BP）,仙女木期气候颤动期,湖水开始咸水化;暖湿期（10.0~7.0 ka BP）,咸水湖阶段;暖湿转干期（7.0~6.0 ka BP）,咸水湖阶段,亦是湖泊“成盐事件”的预备阶段;冷干期（6.0~4.7 ka BP）,盐湖阶段气候干湿交替,也是盐湖的成盐发展期;凉干期（4.7 ka BP至今）,是盐湖的成盐旺期,盐湖湖水不断缩减,加之周围沙漠的不断吞噬,盐湖开始由干盐湖向沙下湖发展。吉兰泰地区距今22 ka以来的古环境变化及气候转型,不仅是对全球古气候变化的响应,而且对盐湖矿产资源的成盐事件及区域可持续发展具有重要意义。     

盐湖形成过程中银的迁移形式及富集条件

本文研究了盐湖形成过程中银的迁移形式及富集条件．在热液中银主要以Ａｇ（ＨＳ）￣－＿２·Ａｇ（ＮＨ３）·ＡｇＣｌ络合物形式迁移；在表生条件下银主要以Ａｇ（Ｓ２Ｏ３）络合物形式迁移．它们在盐湖中被演化为ＡｇＣｌ络合物，由于湖水大量蒸发、盐类大量结晶析出，导致盐湖卤水中银的富集．     

Quaternary evolution of ephemeral playa lakes on the Southern High Plains of Texas, USA: cyclic variation in lake level recorded in sediments

Ephemeral playa lakes on the Southern High Plains northeast of Amarillo, Texas, are underlain by more than 10 m of Quaternary lake deposits. Sediments beneath 12 lakes were examined in 76 hollow-stem auger cores and in excavations. Stacked depositional cycles recognized in lake sediments record repeated phases of (1) initial highstand, (2) ephemeral lake, and (3) lake shrinkage and prolonged exposure. Sedimentary and soil structures show that during all phases the lakes were ephemeral, but that the duration and frequency of flooding varied, which caused variation in the relative amounts of accumulation, deflation, and soil formation. The highstand phase is documented by wave-cut benches and lake sediments that extend beyond present lake margins. Mud transported as suspended load was deposited from ponded water. Desiccation resulted in mudcracks and allowed deposition of eolian sand, but exposure episodes were relatively short or infrequent, and vertic soil formation, oxidation of organic material, and deflation of sand were minimal. Decreased frequency and duration of flooding resulting in increased pedogenic modification under conditions similar to those under which modern playa lake sediments accumulate. Eolian silt deposited on dry lake beds and clays deposited in flooded lakes were mixed by vertic soil processes during repeated wetting and drying. Organic material was partly oxidized and partly translocated down roots and cracks, and interbedded upland facies were gleyed. Episodes of lake shrinkage and more frequent exposure are recorded by reddening and formation of calcic horizons within lake muds. Red-brown eolian loam prograded across lake sediments, and calcic soils developed on it. These grassland slope facies record decrease in the size of the playa lakes.     

Comment on “Is there a paleolimnological explanation for ‘walking on water’ in the Sea of Galilee?”

In a recent paper, Nof et al. (J Paleolimnol 35:417–439, 2006) suggest a physical mechanism which could account for the formation of ice on Lake Kinneret (Sea of Galilee) in northern Israel. Based on the sea surface temperature record of sediment cores from the Mediterranean Sea the authors argue that centennial-scale cold events had the potential to trigger local ‘springs ice’ formation on the lake in the past. Here, we demonstrate that a closer inspection of the paleoceanographic record in combination with correlation and regression analyses of meteorological data provides no evidence for such cold events in the lake region during the last 10,000 years. Thus, the formation of ‘springs ice’ on Lake Kinneret was unlikely at least since the beginning of the Neolithic.     

LAKE EFFECT OBSERVATIONS IN MILWAUKEE,WISCONSIN

Field observations of temperature, humidity, and wind conditions were taken during mesoscale lake breeze, synoptic-aided lake breeze, and synoptic-scale lake effect situations in Milwaukee, Wisconsin. Measurements were made along two east-west transect routes to document Lake Michigan's cooling impact. Lake breezes are characterized by significant changes in weather parameters: a sharp drop in temperature, a rise in dew point, an increase in relative humidity, and a shift from offshore to onshore winds. Temperature contrasts between lakefront and inland envirionments exceed 5°C. Lake cooling is confined to a coastal zone extending 8.0 km inland. Synoptic-aided lake breezes combine mesoscale lake breeze formation with the added influence of developing synoptic onshore winds. These situations are characterized by earlier time of occurrence, greater inland movement, and reduce land-lake thermal contrasts. Synoptic lake effect is produced by steady prevailing onshore winds from the northeast or east under the control of the large-scale pressure pattern. The greatest degree of lake cooling occurs under synoptic lake effect conditions, with widespread impact extending well inland. Maximum temperature differences between nearshore and inland locations exist in spring, the season of greatest land-lake thermal contrast. [Key Words: Lake effect, lake breeze, mesoscale climatology, Lake Michigan.]     

Definition and classification system of glacial lake for inventory and hazards study

Glacial lakes are not only the important refresh water resources in alpine region, but also act as a trigger of many glacial hazards such as glacial lake outburst flood (GLOF) and debris flow. Therefore, glacial lakes play an important role on the cryosphere, climate change and alpine hazards. In this paper, the issues of glacial lake were systematically discussed, then from the view of glacial lake inventory and glacial lake hazards study, the glacial lake was defined as natural water mainly supplied by modern glacial meltwater or formed in glacier moraine’s depression. Furthermore, a complete classification system of glacial lake was proposed based on its formation mechanism, topographic feature and geographical position. Glacial lakes were classified as 6 classes and 8 subclasses, i.e., glacial erosion lake (including cirque lake, glacial valley lake and other glacial erosion lake), moraine-dammed lake (including end moraine-dammed lake, lateral moraine-dammed lake and moraine thaw lake), ice-blocked lake (including advancing glacier-blocked lake and other glacier-blocked lake), supraglacial lake, subglacial lake and other glacial lake. Meanwhile, some corresponding features exhibiting on remote sensing image and quantitative indices for identifying different glacial lake types were proposed in order to build a universal and operational classification system of glacial lake.     

THE CLIMATOLOGY OF LAKE EFFECT IN MILWAUKEE,WISCONSIN

Prevailing onshore winds off Lake Michigan in the warm season (April-October) cause cooling along the adjacent coast during the day. Mesoscale lake breeze formation occurs most frequently in August. Synoptic-aided lake breezes, which combine mesoscale inputs with existing large-scale conditions, are most prevalent in May. Lake breezes are favored by high pressure and airmass weather patterns. Synoptic lake effect dominates in April; large-scale onshore flow is often produced by high pressure, post-cold front, and pre-warm front weather conditions. Overall, lake cooling is experienced 60% of the time during the warmer months. The highest frequency of lake effect is found in May. The cooling impact of Lake Michigan across the Milwaukee area is maximized since spring is the season of greatest contrast in land and lake temperatures. Lake-effect conditions in the cool season (November-March) occur less frequently. Onshore flow off the warmer lake reduces cooling at night along the Milwaukee shoreline. Synoptic lake effect is dominant, with a peak in March. Lake snow and mesoscale land breeze developments are most frequent in midwinter, when large land-lake thermal contrasts exist during outbreaks of cold polar air under high pressure patterns. [Key words: lake effect, climatology, mesoscale, onshore winds.]     

Conditions for deposition of annually laminated sediments in small meromictic lakes: a case study of Lake Suminko (northern Poland)

A three-year field study was conducted in Lake Suminko, Poland, to gain an understanding of the limnological variables that influence the formation and spatial extent of annually laminated sediments in the lake. The water body is divided into three depth strata, the mixolimnion, chemocline and monimolimnion, each defined by distinct values of temperature, electrical conductivity and oxygen concentration. Typical for meromictic lakes, the monimolimnion remains perennially anoxic and is rich in dissolved solids and nutrients. The annual pattern of particle flux in Lake Suminko is closely related to biochemical processes in the euphotic zone. During winter months we observed very low accumulation rates of non-carbonaceous matter, while during the rest of the year, three periods of calcite deposition were recorded (April, July–August, and October–November). The periods of high calcite deposition corresponded with algal blooms and oxygen concentration maxima. Two principal factors contribute to meromixis in Lake Suminko: (1) the basin is sheltered, preventing wind mixing, and (2) biochemical processes in the lake associated with high lacustrine productivity. Meromictic conditions must control the formation and preservation of laminated sediments in the lake because preserved laminations occur only in areas where the lake floor lies below monimolimnetic waters.     

冰湖的界定与分类体系——面向冰湖编目和冰湖灾害研究（英文）

Glacial lakes are not only the important refresh water resources in alpine region, but also act as a trigger of many glacial hazards such as glacial lake outburst flood(GLOF) and debris flow. Therefore, glacial lakes play an important role on the cryosphere, climate change and alpine hazards. In this paper, the issues of glacial lake were systematically discussed, then from the view of glacial lake inventory and glacial lake hazards study, the glacial lake was defined as natural water mainly supplied by modern glacial meltwater or formed in glacier moraine's depression. Furthermore, a complete classification system of glacial lake was proposed based on its formation mechanism, topographic feature and geographical position. Glacial lakes were classified as 6 classes and 8 subclasses, i.e., glacial erosion lake(including cirque lake, glacial valley lake and other glacial erosion lake), moraine-dammed lake(including end moraine-dammed lake, lateral moraine-dammed lake and moraine thaw lake), ice-blocked lake(including advancing glacier-blocked lake and other glacier-blocked lake), supraglacial lake, subglacial lake and other glacial lake. Meanwhile, some corresponding features exhibiting on remote sensing image and quantitative indices for identifying different glacial lake types were proposed in order to build a universal and operational classification system of glacial lake.     

论四川盆地下、中三叠统蒸发岩的生成模式、成盐机理及找钾展望

四川盆地早中三叠统蒸发岩极为发育,时空分布甚广。蒸发岩的生成模式可分为两大类和四个亚类。即Ⅰ,潮间环境的为(1)泻湖盐湖;Ⅱ,潮上环境的为(2)滨海盐湖;(3)近岸盐湖和(4)远岸盐湖。不同生成模式中,其成盐机理虽对成钾皆不够理想,但仍有希望找到钾盐矿的地区和层段。