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101.
Abdul A. Rahaman E. Sosamma M. Ambikadevi 《International Journal of Salt Lake Research》1993,2(1):1-15
The hydrobiology of two Indian solar salt works was investigated. A salient feature was variability in physico-chemical and
biological characteristics. The filamentous cyanophyceansLyngbya majuscula andOscillatoria salina and the chlorophyceanXenococcus aceervatus were the major primary producers. Significant fauna were protozoans, rotifers and copepods.Artemia was present in only one set of solar salt pans, where it was dominant. The study illustrates the importance ofArtemia in the biological management of solar salt works.
This paper is dedicated to Thiru. K. Ayyaru Vandayar, Member, Governing body, A.V.V.M. Sri Pshpam College (Autonomous), Poondi,
on his sixtieth birthday 相似文献
102.
J. C. Stormont 《Geotechnical and Geological Engineering》1990,8(1):35-56
Summary Discontinuous behaviour is being observed and measured in the vicinity of excavations constructed in a bedded salt formation 650 m below ground surface for the Waste Isolation Pilot Plant (WIPP) Facility. The 2 m thick salt layer in the immediate roof acts as a beam, shearing along a thin overlying anhydrite/clay seam. Vertical separations between the immediate roof layer and the overlying strata are often observed at the anhydrite/clay seam above the centre of excavations of larger span (11 m). The floor of the excavations is comprised of a 1 m thick salt layer underlain by a 1 m thick predominately anhydrite layer (referred to as MB139). Fractures in MB139 develop beneath most excavations, with increased fracture frequency with drift span and age. In the excavations of larger span (11 m), MB139 eventually debonds along the underlying clay layer. The salt layer overlying MB139 develops both shear and tension failure. In a few locations below excavations of large span, continuous fracture systems are developing from rib to rib through MB139 and the overlying salt. In the ribs, there is limited fracturing within the first metre of most larger excavations. Vertical fractures develop in pillars at most intersections. The discontinuous behaviour is qualitatively consistent with analyses of the formation behaving as a layered medium (elastic beam analysis) and limited tensile and compressive failure of the rock salt. The significance of the discontinuous behaviour is that it can dominate the effective fluid transport properties of the formation near the excavation, and therefore requires consideration in the design of repository seals. Discontinuous behaviour must be monitored and is an important factor in the maintenance programme designed to assure a safe underground environment. 相似文献
103.
针对叶县盐田的地质条件,上部无岩心钻进,采用大钻压、低转速、高泵压、大泵量喷射钻井的快速钻进技术;下部取心钻进,采用小钻压、高转速、低泵压、小泵量的取心钻进技术。采用防塌淡水泥浆与饱和盐水泥浆分别治理取得了较好的技术效果。 相似文献
104.
An atmospheric monitoring station is operated at Cape Matatula, American Samoa, by the Geophysical Monitoring for Climatic Change program under the National Oceanic and Atmospheric Administration. A nearly continuous record of condensation nucleus (CN) concentration and multiwavelength aerosol scattering extinction coefficient (sp) is available from mid-1977 to the present. This report presents the 1977–1983 data. The long-term mean of CN concentration is 274 cm-3 the long-term mean of sp (550 nm) is 1.54×10-5, and no significant long-term, annual, or diurnal trend is apparent in either data record. 相似文献
105.
Rock salt is approximately 1000 times more soluble than limestone and thus displays high rates of geomorphic evolution. Cave stream channel profiles and downcutting rates were studied in the Mount Sedom salt diapir, Dead Sea rift valley, Israel. Although the area is very arid (mean annual rainfall ≈ 50 mm), the diapir contains extensive karst systems of Holocene age. In the standard cave profile a vertical shaft at the upstream end diverts water from a surface channel in anhydrite or clastic cap rocks into the subsurface route in the salt. Mass balance calculations in a sample cave passage yielded downcutting rates of 0–2 mm s?1 during peak flood conditions, or about eight orders of magnitude higher than reported rates in any limestone cave streams. However, in the arid climate of Mount Sedom floods have a low recurrence interval with the consequence that long-term mean downcutting rates are lower: an average rate of 8·8 mm a?1 was measured for the period 1986–1991 in the same sample passage. Quite independently, long-term mean rates of 6·2mm a?1 are deduced from 14C ages of driftwood found in upper levels of 12 cave passages. These are at least three orders of magnitude higher than rates established for limestone caves. Salt cave passages develop in two main stages: (1) an early stage characterized by high downcutting rates into the rock salt bed, and steep passage gradients; (2) a mature stage characterized by lower downcutting rates, with establishment of a subhorizontal stream bed armoured with alluvial detritus. In this mature stage downcutting rates are controlled by the uplift rate of the Mount Sedom diapir and changes of the level of the Dead Sea. Passages may also aggrade. These fast-developing salt stream channels may serve as full-scale models for slower developing systems such as limestone canyons. 相似文献
106.
为研究宝顶山石窟区造象岩壁风化破坏及渗水危害的作用机理,选择不同类型风化产物进行定期采样监测。本文重点论述了外围岩石和造象岩壁风化产物的化学成分及矿物成分、风化产物可溶盐的化学特征及可溶盐类型,以及这些特征的多年变化规律,分析论证了可溶盐不同水化学成因类型的形成特征,为防风化防渗水危害治理措施提供可靠依据。 相似文献
107.
异常压力与油气分布 总被引:123,自引:2,他引:123
随着油气勘探活动的不断加深,国内外相继发现了许多异常高压油气田。据不完全统计,全世界已发现超压盆地180多个,其中160多个为富含油气盆地。异常高压油气田约占全球油气田30%左右,因此,对异常压力的研究,具有举足轻重的意义。本文介绍了异常地层压力的概念、特征及分类;详细论述了异常压力的成因,即烃类生成作用、欠压实作用、液态烃类的裂解作用、粘土矿物的后生成岩作用、构造作用、温度变化等;系统阐述了世界典型含油气盆地的超压形成机制、超压体系中油气初次运移机理以及超压与油气分布关系;并在此基础上,归纳总结出了五种超压油气藏成藏模式,即:(1)位于超压体系中的低渗超压油气藏;(2)位于超压层系中,以礁灰岩(或浊积砂岩)为储层的高压油气藏;(3)位于超压带上倾方向,以退覆三角洲平原和分流河道砂岩为储层的常压或过渡带超压油气藏;(4)位于超压带上、下部的超压油气藏;(5)位于远离超压体系的泄压区常压油气藏,本文对指导、加深新老油气区勘探具有实际应用价值。 相似文献
108.
109.
库车前陆褶皱-冲断带前缘秋里塔格构造带发育大量盐构造,其类型丰富多样。根据野外露头、钻井和地震资料识别出的盐构造样式主要有盐推覆、盐枕、盐墙、盐焊接、鱼尾构造、盐撤凹陷、突发构造、断层传播褶皱、断层转折褶皱和三角带构造等。秋里塔格构造带盐构造变形表现出明显的分段差异变形特征,其中西段却勒地区以古隆起(盐下)—盐枕(盐层)—逆冲推覆构造(盐上)为主;中段西秋地区以构造斜坡(盐下)—盐墙(盐层)—断层传播褶皱、向斜(盐上)为主;东段东秋地区则以断层转折褶皱(盐下)—盐推覆(盐层)—断层传播褶皱(盐上)为主。造成这种盐构造分段差异变形的主要控制因素包括基底断裂、含盐层系、构造转换带和变形空间等方面的差异性,其中基底构造和含盐层系的差异性起主导作用。 相似文献
110.
库车坳陷西段地区发育有巨厚膏盐层,喜马拉雅山末期构造运动使天山造山带大幅度向南挤压,造成大量盐体在库车前陆褶皱冲断带前缘被逆冲推覆至地表,地层并发生强烈的褶皱和逆冲推覆,所以在计算该区域地层向南推覆的总距离时,不仅要考虑平衡剖面技术所恢复出地层横剖面上的缩短量,另外还要考虑由于膏盐层塑性流动所造成上盘推覆体向南的滑移距离,本文综合利用平衡剖面技术和物理模拟实验方法求取了该研究区域的地层缩短量(24.5km)及上盘推覆体向南的滑移距离(3.969~14.727km),从而计算出库车坳陷西段的逆冲推覆距离为18.5~39.227km。 相似文献