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1.
Sun Dapeng 《中国海洋湖沼学报》1990,8(1):50-65
It is well known that there are two patterns of potash deposition in lacustrine facies: “tear drop pattern” (the Dabsan saline
lake is a typical example) and “bull's eye pattern”. Potash-forming in tear drop pattern is still continuing.
The 2,678 m A. S. L. lake in the middle of the Qarhan playa in the Qaidam Basin covers an area of 210 km2, and has an average depth of 0.39 m. Its MgCl2 type surface brine is 280–340 g/l in salinity and mainly consists of Na, K, Mg and Cl. As a rule, the potash deposits occur
as evaporite distributed in tear drop pattern at the northern and northeastern lakeshore zones. They mostly consist of carnallite
and halite, occasionally sylvite. The deposition is very unstable and controlled principally by the varying supply of deposit
materials from the Golmud River in the south.
The potash deposits were formed when concentration of the surface brine reached a certain degree in the main evaporating season.
Their forming process followed some crystalization paths in the phase diagram for the Na, K, Mg/Cl H2O equilibrium system.
Such a sedimentary model of potash deposits in the lacustrine facies is relatively common in nature. Under the extremely arid
climate, differential concentration of the nonhomogeneous potassium-rich surface brine produced the potash deposits. Qarhan
Salt Lake also had the same pattern of potash depositions and so, in a sense, the Dabsan saline lake is the continuation of
the Qarhan salt lake in terms of potash formation.
Schmalz (1970) put forward two distributive patterns for evaporite: “tear drop pattern” and “bull's eye pattern”. These patterns
exist in both marine and continental salt-bearing basins (including recent salt lakes), and are controlled by the conditions
of physical geography, hydrogeology, sedimentology and climatology of each basin. In his works (Sun, 1981; 1984; 1986; 1988)
on the origins of potash deposits, the author always referred to them as two models of potash formation.
The “tear drop pattern” is one of the salt-forming models and also an important potash-forming model. This paper deals with
the formative mechanism of the tear drop pattern potash deposition by presenting the Dabsan saline lake as an example and
elucidates on the distributive characteristics and formative processes of potash deposits in the lake. 相似文献
2.
Yu Shengsong 《中国海洋湖沼学报》1986,4(4):383-403
There are 37 lakes in the Qaidam Basin: 1 freshwater lake, 6 brackish-water lakes, 2 saline-water lakes and 28 salt lakes.
The pH value of salt lake brines is 7.014 on the average, and the average total mineralization is 340.75 g/1. Their water
bodies belong mainly to the five-component equilibrium system,: Na, K, Mg//SO4, Cl-H2O, which can be further grouped into sodium-magnesium sulfate subtype, magnesium sulfate subtype, chloride transition subtype
and chloride type water by their hydrochemical property. The salt lake brines of the first salt forming epoch (N2−Q3) were of the sulfate type. In the second salt forming epoch (Q3−Q4), some of them were of the chloride type.
The pH value of brines decreases with the increase of total mineralization. The pH value is lower when the total mineralization
is from 50–310 g/l and higher when the total mineralization is from 310–355 g/l, however, when the total mineralization is
higher than 355 g/l, the pH value decreases slowly again.
The total mineralization of the chloride type and the chloride transition subtype brine is higher than the sulfate type, being
310–530 g/l, 310–470 g/l, and less than 355 g/l in that order.
Of the 40 chemical compositions in the saline lake brines in Qaidam Basin, potassium is mainly concentrated in the chloride
type and chloride transition subtype brine, boron and lithium mainly in the sulfate type. Evaporation experiments show that
boron and lithium are accumulated in concentrated brine until crystallization of bischofite takes place. Potassium is also
accumulated in concentrated brine during the salt forming stage, but its concentration decreases with the increase of total
mineralization during the potassium forming stage.
This paper was published in Chinese inOcean. et Limn. Sinica;15 (4):341–359, 1984. 相似文献
3.
4.
Zheng Xiuqing 《地球科学与环境学报》1997,(2)
本文应用系统分析观点、数理统计方法研究了察尔汗盐湖首采区晶间卤水分异的特征,认为晶间卤水的分异是在外部环境系统作用下,盐湖卤水系统整体发展、演化的结果。 相似文献
5.
鄂尔多斯盆地西缘麻黄山地区延8储层特征 总被引:4,自引:0,他引:4
通过对延8储层铸体薄片、扫描电镜、孔渗测定、压汞资料等分析,延8储层具有以下特征:研究区北边富长石、南边富石英,具有不同的物源;砂岩粒度以中粒为主,细粒和粗粒次之;主要的储集空间为粒间孔和粒内溶孔;由于大量的长石、岩屑被溶,孔隙度、渗透率不呈正态分布,均偏大,溶蚀作用形成的大量微孔造成高束缚水饱和度,产纯油或含水率极低;砂体厚度、岩石相和成岩作用共同控制着储集层的物性。结果表明,位于河道中部弱胶结的中砂岩具有良好的储集性能。 相似文献
6.
盐沉淀是含水层CO2封存中需要关注的问题。当前,大多数数值模拟没有考虑盐沉淀引起的地层孔隙度和渗透率变化对流体流动的反馈作用。以鄂尔多斯盆地刘家沟组地层为例,利用TOUGH2软件建立了一个二维模型。通过修改程序源代码,使得模型能考虑盐沉淀对流体流动的反馈作用。模拟结果表明,刘家沟组地层在CO2注入20 a时,盐沉淀的反馈作用使得注入井附近地层压力提升达到了0.87MPa,储层注入性损失7.17%。地层水盐度对盐沉淀及其反馈作用的影响最大,CO2注入速度的影响次之,地层渗透率的影响最小。在地层水盐度较高时,固体盐饱和度显著增加,从而造成地层渗透率明显下降。当地层水盐度为0.24时,盐沉淀造成注入性损失45.32%,引起的地层压力提升达到了12.14MPa。因此,需要特别关注高盐度地层水引起的盐沉淀及其反馈作用。 相似文献
7.
In order to understand the diagenesis and its influence on Porosity and Permeability of sandstones from Yingcheng Formation in Jinshan field,aPPlying thin sections,casting and scanning electron microsc... 相似文献
8.
Ding-ding Du Cheng-jun Zhang Muhammad Saleem Mughal Xiao-yu Wang Dembele Blaise Jun-ping Gao Yuan Ma Xin-rong Luo 《山地科学学报》2018,15(3):532-547
The Northern Qaidam Basin is located at the northeastern part of the Qinghai-Tibetan Plateau. It contains very thick Cenozoic terrestrial clastic sediments, which records the formation of the northern Qaidam Basin due to compressional deformation during the Indo-Asian collision. In this paper, we used detrital apatite fission-track thermochronology, including 4 sandstones and 2 conglomerates samples from the Lulehe section, to reveal the Cenozoic evolution of the northern Qaidam Basin. Fission-track dating indicated the source region of the Lulehe section has experienced important cooling and uplifting in the Late Cretaceous (at ~85.1 Ma and ~65 Ma) and the Eocene (~52 Ma), respectively. The AFT age distribution on the section suggested that the provenance of Lulehe section sediments were mainly derived from the south Qilian Shan (Qilian Mountains) and Altun Shan (Altun Mountains), and two significantly provenance changes may occur at 43.4-46.1 Ma and ~37.8 Ma, respectively. The results may have strong constrains on the Cenozoic deformation and tectonic evolution of the northern Qaidam Basin and Qinghai-Tibet Plateau. 相似文献
9.
黄岗潜凹陷岩盐矿床是山东省地质科学研究院近年发现的一大型岩盐矿产地,预测岩盐矿总资源量超过240×10~8t。本文在总结黄岗潜凹陷岩盐矿勘查成果的基础上,对区内岩盐矿沉积地质特征及成矿规律、岩相分布规律等进行了初步总结分析。岩盐矿赋矿层位为古近纪官庄群大汶口组中段,岩性为深灰色泥岩、粉砂质泥岩与灰白色膏质泥岩、石盐岩互层,是一套含石盐、石膏的浅湖—咸湖相沉积建造,其盖层为新近纪黄骅群和第四系。岩盐矿层赋存形态简单,呈层状产出,产状稳定,走向近EW向,倾向近S向,倾角平缓,一般3°,局部断层附近可达10°。区内揭露岩盐矿层31层,埋深1079.75~1730.86m,单矿层平均厚度0.25~24.64m,单层最厚53.96m,累计平均厚度175.45m,单孔累计最大厚度320.23m,是山东迄今单孔控制最大的厚度,NaCl平均品位44.11%~96.08%。岩盐矿石矿物成分较为简单,主要盐类矿物成分为石盐和硬石膏,杂质矿物主要为黏土质矿物;矿石主要化学组分为NaCl,其次为CaSO_4,其他组分含量甚微;矿石结构主要为中粗粒他形—半自形粒状结构,矿石构造主要为块状构造;岩盐矿划分为结晶块状石盐矿石和石膏石盐混生石盐矿石2种自然类型,矿石工业类型初步确定为石膏质石盐矿石。黄岗潜凹陷盆地为一套浅湖—咸湖相沉积,大致反映了含盐水体淡化—浓缩—淡化的蒸发沉积过程;平面上初步划分石盐岩相区和膏泥岩相区2个岩相分布区,其中石盐岩相区靠近成盐盆地局部沉积中心,发育厚层岩盐矿。黄岗潜凹陷西南部含盐地层总体表现为向南倾伏的单斜形态;区域重力资料显示,该区靠近盆地局部沉积中心,具有较大的岩盐矿找矿潜力。区内岩盐矿层厚、质纯、埋深适中,初步评价具备建设盐穴储气储能库的地质条件,矿床开发利用前景广阔。 相似文献
10.
11.
查明北部湾盆地福山凹陷流沙港组致密油成藏条件并分析其控制因素,对于进一步明确致密油分布、厘定有利探区具有重要的指导意义。基于地震、录井、测井、岩心及分析化验等资料的综合分析,对北部湾盆地福山凹陷流沙港组有效烃源岩、有利储层、源储匹配关系等进行了研究。结果表明,流沙港组在最大湖泛期于皇桐和白莲两次凹内形成优质烃源岩,具有有机质丰度高、热演化程度适中的特点,提供了致密油形成的物质基础;受多物源供给影响,致密砂岩深入两次凹内,具有源储叠置、分布广泛的特点,溶蚀孔隙与构造裂缝发育,有利于致密油的近源运移与富集;主要烃源岩进入生油高峰期时凹陷构造已基本定型,无大型断裂发育,相对稳定的构造条件有利于致密油形成和保存。因此,福山凹陷流沙港组具备致密油成藏的有利条件,致密油纵向上主要分布在流一下亚段和流二段,平面上主要分布在皇桐次凹和白莲次凹,其形成和分布主要受控于优质烃源岩展布、富溶蚀孔隙"甜点"储层分布及有利的源-储叠置组合。 相似文献
12.
渤海坳陷下第三系砂岩普遍含有两类油气包裹体,即原生油气包裹体和次生油气包裹体,它们分别记录了本区两次油气运移、聚集成藏过程。次生油气包裹体个体大、分布广、含量明显高于原生油气包裹体,其主要充填分布在次生溶蚀孔隙和裂隙中。均一温度测量、包裹体成分和生物标志化合物分析结果综合表明,次生油气包裹体记录的第二次油气运移是区内最主要的一次油气聚集成藏过程,其油气来源于下第三系湖相泥质烃源岩。本区次生溶蚀孔隙是在早第三纪晚期构造抬升过程中,由大气淡水淋滤作用形成的。结合地质演化特征分析认为,渤中坳陷目前油气勘探的重点应是浅部下第三系地层,而不是深部其他地层。早第三纪晚期构造运动、沉积 相似文献
13.
针对川东北铁山及周缘飞仙关组滩相储集体成因复杂的问题,采用宏观和微观相结合的方法研究表明,研究区主要储集空间类型有铸模孔、粒内溶孔、晶间孔和残余粒间孔。储集物性较差,以次生孔隙为主。储层孔渗关系不具单一特征,多为低孔、低渗的裂缝-孔隙型和孔隙-裂缝型储层。飞仙关组滩相储集体的成因主要受控于海平面的升降、构造作用及埋藏溶蚀作用。鲕粒滩体主要沿台地边缘发育,由于海平面的旋回升降,鲕粒滩体多期次暴露,发生大气淡水溶蚀作用,虽然压实作用和多期胶结作用使得孔渗性变差,但是在埋藏溶蚀和构造升降的共同作用下使得次生孔隙发育,极大地提高了储层的储集性能。 相似文献
14.
Weimin Li Yongjiang Liu Zhiming Sun Xiaohong Ge Shoumai Ren Junling Pei Sihua Yuang Xinzhuan Guo 《世界地质(英文版)》2006,9(1)
In order to better understand the tectonic evolution of the Qaidam Basin. The authors carried out a paleomagnetic study on 39 samples of 7 sites from Hongsanhan section, northwest Qaidam Basin. Stepwise thermo-demagnetization isolated a high-temperature component (HTC), which passes the fold and reversal tests at 95% confidence level. It suggests that the HTC should be primary. Unblocking temperature (about 685℃) and the experiment of isothermal remanence indicate that hematite is the mainly carrier of the remanence. A tilt-corrected mean direction is: Ds=7.1°, Is=38.5°, α95=7.4°. Corresponding to a palaeopole at, φ=250.1°E, λ=72.0°N, A95=6.8°, Compared with the reference APWP of Eurasia, the sampling area occurred a non-significant rotation (3.4°±5.5°) relative to Eurasia since Eocene due to the affect of left-lateral Altyn fault, Based on the paleomagnetic results of early Cretaceous and Teritary within the Qaidam block, we can obtained the mean clockwise rotations from the samples deposited from 160 Ma to 45 Ma is 24.5°±9.0°, and from 38 Ma to present is -0.5°±7.5° relative to present geomagnetism respectively. During the Mid Eocene (45~38 Ma) rotation phase, there should existing an important early tectonic event in northern part of the present-day Tibetan Plateau, which probably represents one of large-scale strike-slip events of the Altyn strike-slip fault. 相似文献
15.
青海湖是我国最大的内陆咸水湖,是世界著名的湿地,但随着周围地区荒沙漠化环境的恶化,其土地荒漠化也不断加剧。本文对青海湖地区土地荒漠化的自然特征和社会经济特征进行了分析,明确了荒漠化的环境背景。在此基础上,结合青海湖地区荒漠化土地普查与监察工作的范围和内容,采用ASTER卫星影像图对湖区周围地区进行解译,并利用解译数据对荒漠化土地进行等级划分,分析土地荒漠化的空间分布格局,对荒漠化作出综合评价。 相似文献
16.
Distribution characteristics of boron and lithium in brine of Zhacang Caka salt lake,Xizang (Tibet), China 总被引:1,自引:0,他引:1
Zheng Xiyu 《中国海洋湖沼学报》1984,2(2):218-227
17.
刘天仇 《中国地理科学(英文版)》1995,5(4):344-354
STUDIESONWATERSTAGEFLUCTUATIONOFYAMZHOLAKEINXIZANGLiuTianchou(刘天仇)(TibetanBureauofWaterResourceandHydrologicalSurvey,Lhasa350... 相似文献
18.
依据已有调研资料,对影响和制约察尔汗盐湖钾矿资源开发的开采方式、固液转化、尾卤贫化矿层等关键矿山环境问题进行了分析,指出开展盐湖资源水盐均衡监测是防止钾矿资源贫化、实现钾矿资源有效开采、制定盐湖资源开发保护规划的基础,为盐湖资源开发和管理提供了一种较为科学的技术思路。 相似文献
19.
杭锦旗地区独贵加汗区带是鄂尔多斯盆地北部天然气勘探开发的重要对象,区带内下石盒子组砂岩储层非均质性强,含气饱和度差异大,前人对致密储层发育特征及其孔隙演化历史研究不够系统和深入。基于钻井岩心、岩石薄片及相关测试等资料,在统计、对比分析独贵加汗区带下石盒子组砂岩储层岩石学与物性特征的基础上,通过成岩作用分析,厘定控制储层孔隙发育的主要因素,进而重建主要储层段的孔隙演化历史。研究表明,杭锦旗地区独贵加汗区带下石盒子组砂岩多属超低渗透储层,局部存在裂缝发育的高渗透率段;压实作用和胶结作用对研究区储层孔隙演化起破坏性作用,减孔率分别为84.8%和7.1%,而溶蚀作用为建设性成岩作用,增孔率9.5%;盒一段储层现今孔隙度基本继承了早白垩世末期的特征,孔隙演化历经早成岩阶段A期压实与胶结作用快速减孔,B期持续压实减孔,中成岩A期溶蚀增孔作用与压实-胶结减孔作用并存及B期变化微弱等过程。 相似文献
20.
Component data of the saline lakes in Xizang were obtained from field observations in recent years (1976, 1978). Laboratory
studies show that there are nearly 37 chemical components in 63 lakes brine and 27 evaporative minerals in nearly 40 saline
lakes that reach their depositional stage. Their formative conditions, distributive properties, assemblage properties of some
salt minerals, and mechanisms affecting the components of the saline lakes are discussed. A sedimentary model of the early
Holocene epoch saline lake is suggested. This work is an aid not only to the understanding of the formation of the saline
lakes in the said area, but also to the use of their mineral resources.
This paper was published in Chinese inOcean. Limn. Sinica, 1983,14 (4): 342–352. 相似文献