GEOCHEMICAL EFFECTS OF MAJOR ELEMENTS DURING FLUID-ROCKS INTERACTION IN MARINWOBO FAULT IN THE SOUTH MARGIN AREAS OF ALTAI MOUNTAINS

There are four types of metamorphic rocks in the Marinwobo fault, i. e, cataclasite, mylonite,mictosite and migmatitic granite, and the formation of these rocks is due to the progressive metamorphism of the pyroclastics. The fluids play a very important role in the metamorphic process of these rocks in the Marinwobo fault, the most important feature is that the fluids not only result in the migration of the major elements of the deformation rocks, but also result in the volume loss of the deformation rocks in the deformation process. Thus the migration laws of the major elements in different stages of the progressive metamorphic process are discussed according to mass balance equations. Finally, the quantitative analysis of the mass loss and volume loss of the different rocks the in Marinwobo fault is discussed in this paper.     

Permian

Summary Late in the Carboniferous Period or early in the Permian ice covered much of Tasmania (Fig. 30b). The sub‐Permian surface had a relief of several thousand feet with particularly low areas near Wynyard and Point Hibbs and high areas near Cradle Mountain, Devonport, Deloraine, Wylds Crag and Ida Bay and a peninsula in eastern Tasmania (Fig. 30a).

The glaciers from an ice centre north‐west of Zeehan diverged about a higher area near Cradle Mountain. One tongue occupied a deep valley near Wynyard and a lobe fanned out south of the high area to occupy parts of northern and central Tasmania and to override some parts of the east coast peninsula.

West of Maydena the ice scoured shell beds and dumped the shell fragments in the till on the Styx Range. Thus the base of the ice may well have been below sea‐level. Carey and Ahmad (1961) suggested that the Wynyard Tillite was deposited below a “wet‐base” glacier. David (1908, p. 278) suggested deposition from “land ice in the form of a piedmont or of an ice‐sheet” but that near Wynyard the ice came down very close to, if not actually to, sea‐level. The extent of the glaciation and the distribution of erratics of western Tasmanian origin in eastern Tasmania make it seem likely that either a piedmont glacier or an ice‐sheet rather than mountain glaciation was involved.

Following retreat of the glaciers the sea covered the till, probably to a considerable depth, eustatic rise of sea‐level being much more rapid than isostatic readjustment.

The Quamby Group is underlain by or passes laterally into thin conglomerates and sandstones in a number of places, but most of the group appears to be of deep water, partially barred basin origin. Marine oil shales accumulated close to islands. Shallowing of the sea during deposition of the upper part of the Quamby Group seems to be indicated by the fauna and increasing sandiness in marginal areas. Instability in the source areas is shown by the presence of turbidity current deposits in the higher parts of the group. The Golden Valley Group, of Upper Sakmarian and perhaps Lower Artinskian age, was deposited in a shallower sea than the Quamby Group but the deposits are more extensive along the east coast peninsula and on the flanks of the Cradle Mountain island. This anomaly may be explained if the rate of deposition exceeded the rate of rise of sea‐level. The sediments of the Golden Valley Group became finer‐grained upwards in most parts of Tasmania probably indicating reduction in relief of the source area. Some instability is indicated by turbidity current deposits. Uplift of source areas in north‐western Tasmania early in Artinskian time resulted in the spreading of sand over the shallow silts of the Golden Valley Group onto the east coast peninsula and over the Cradle Mountain area. The sand formed a wide coastal plain containing lakes and swamps and the sea was restricted to a small gulf in southern Tasmania during the deposition of the lower part of the Mersey Group. During deposition of this group the sea rose once to form a long, narrow gulf extending as far north as Port Sorell and then retreated. This inundation resulted in the development of two cyclothems in many parts of Tasmania.

A little later in Lower Artinskian time the sea rose and covered most of Tasmania except perhaps the far north‐west. This wide transgression probably resulted from down‐warping as an eustatic rise in sea‐level would be expected to produce thickest deposition over the old gulf in southern Tasmania and along the axis of Mersey Group inundation but the zone of thickest Cascades Group crosses these at a high angle. During deposition of the Cascades Group marine life became very abundant in the shallow sea over which a few icebergs floated. During the Artinskian tectonic instability increased as shown by the increasing number of turbidites in the upper part of the Grange Mudstone and the lower part of the Malbina Formation. The sea became less extensive and the source areas in north‐western and north‐eastern Tasmania were uplifted. The zone of thickest deposition of the Malbina Formation trended north‐north‐westerly. The rapid succession of turbidity currents killed the benthonic fauna and it was only during deposition of the upper part of the formation possibly in Lower Kungurian time that life became abundant again in the Hobart area. The sea spread a little over the east coast peninsula and further instability is recorded in the Risdon Sandstone. The resulting turbidity currents killed the benthonic fauna and it never became properly established again in any part of Tasmania during the Permian. A wide shallow sea covered much of Tasmania and was bordered by low source areas during deposition of the Ferntree Group. The axis of greatest thickness had an almost meridional trend and lay west of that of the Malbina Formation. Late in the Permian, probably in the Tartarian, rejuvenation of the source areas, particularly in western Tasmania, and withdrawal of the sea, resulted in deposition of sands and carbonaceous silts of the Cygnet Coal Measures. The zone of greatest thickness was almost parallel to but west of that of the Ferntree Group.

The thickness of the Permian System and the sheet‐like character of many of the members and formations suggest shelf rather than geosynclinal deposition. The average rate of deposition was of the order of 1 ft. in ten thousand years (about 0–003 mm./annum). However, the sediments differ markedly from those on stable shelves in that many of them are poorly‐sorted. Some of the poor sorting may be attributed to deposition from drifting icebergs but some is due to tectonic instability.

Uplift and downwarping and movement of zones of maximum thickness have been deduced above and it is probable that the tectonic instability started as early as Lower Artinskian and it may have started during Sakmarian (upper part of Quamby Group). Maximum instability seems to have occurred in Middle or Upper Artinskian time (Malbina Formation) and it is probably significant that this was a time of considerable orogenic movement in New South Wales (part of the Hunter‐Bowen Orogeny, Osborne, 1950). Progressive westward movement of zones of maximum thickness of units in Upper Permian time seems to have occurred and this again is reminiscent of the situation at the time in New South Wales (Voisey, 1959, p. 201) but seems to have started later. Uplift and development of a major synclinal structure with a trend approximately north‐north‐westerly occurred late in Permian time.     

云开地区断裂构造对金矿的控制作用

云开地区断裂构造对金矿的控制主要表现在两个方面：其一,断裂带带内的大断裂及大断裂的次级断裂,分别控制着区内的金矿带、矿带内的主要金矿床（点）及金矿体;其二,断裂构造的力学性质、活动期次及构造岩发育程度等,控制或影响着金矿的矿石组构特征、矿化期次及矿化强度等。本文还对断裂构造的控矿机制进行了探讨。     

Tufa Accumulations in Ephemeral Streams: Observations from The Kimberley,north-west Australia

Four types of tufa occur along creeks draining the Oscar Range in the Kimberley region of Western Australia; stream-bed tufa, tufa dams, stream-bed tufa waterfalls, and rimstone pools. Well-developed tufa dam and waterfall formations occur at significant breaks of slope within the channel long profile. This suggests that disruption of the hydraulic flow regime and increased turbulence at these points has an important role to play in determining the location of tufa deposits. However, the best-developed stream-bed tufa deposits are located immediately upstream of dam and waterfall formations, which indicates that the evaporation of water ponded behind these flow obstructions may lead to calcium carbonate precipitation during the dry season. The presence of plant and cyanobacterial communities on, and the incorporation of organic material into, the best-developed tufa formations indicates that biological activity may have an important role to play in determining both the rate of tufa deposition and the internal structure of the resulting accumulations.     

断裂和裂缝的分形特征

在详细剖析断裂和裂缝组成和结构相似性的基础上, 计算了贝尔断陷T₅和T₂两层构造图上断裂信息维和10口井布达特群岩心裂缝信息维, 分析了影响断裂和裂缝信息维的因素, 达到了从断裂信息维去预测裂缝分布的目的.影响断裂和裂缝信息维的因素包括密度、延伸长度、断层性质以及岩性, 但从根本上讲断层性质及岩性对信息维影响体现在断裂的密度上, 因此信息维应该是断裂发育程度的度量, 利用断裂信息维与裂缝信息维关系、裂缝信息维与裂缝密度关系预测裂缝的分布, 有利的裂缝发育带有3个区域, 与现今见油气井分布吻合.      

跨断层埋地管道反应分析改进的Newmark方法

在断层错动下跨断层埋地管道反应模拟方法中,壳模型有限元方法较简化索模型解析方法能更好地反映管道壳体反应特性,而目前国内外规范仍多采用便于应用的简化索模型解析方法。基于壳模型有限元方法,与索模型解析方法的对比计算分析,探讨了两类方法的管道轴向拉伸应变计算值差异及引起差异的主要因素,并在管道跨断层交角较小（小于70°）的情况下,提出了基于管道埋藏土层波速值和断层错动量两个参数的改进Newmark方法。进一步地计算分析表明,对于不同的管道跨断层交角和管材特性情况,改进的Newmark方法对壳模型方法计算结果的拟合度达到了0.87。     

瞬变电磁法在断层含水性评价中的应用

本文介绍了瞬变电磁法在煤矿水文地质勘探中的具体应用效果.采用瞬变电磁法对落差较大断层的含(导)水性进行测量,不仅可有效地控制断层的空间位置,而且可定性地判断断层的富水性,其测量结果与已知水文地质资料吻合较好.     

青藏高原东北缘黄河黑山峡出口段阶地特征与断层活动

青藏高原东北缘黄河黑山峡出口地段夜明山 -长流水沟一带 ,黄河的河流阶地发育和保存的较好。阶地的形成不仅记录了青藏高原北部第四纪以来地壳的 7次隆升过程的特点 ,而且阶地的空间展布及其特征反映了断层F8(7) 和F2 0 1活动的特点。详细的观测研究表明F8(7) 以南发育并保存有 7级阶地 ,而F8(7) 和F2 0 1之间及F2 0 1以北仅保存有 5级阶地。所有的阶地都为基座阶地。其中Ⅰ和Ⅱ级阶地前缘在区内连续展布 ,横跨断层F8(7) 两侧的Ⅲ级阶地前缘仍保持连续 ,但阶地宽度陡然变宽 ,Ⅳ级阶地前缘即Ⅲ级阶地后缘左旋位移 15 0m左右。横跨断层F2 0 1两侧 ,Ⅱ级阶地宽度由 2 0 0m急剧变宽为 710m ,Ⅱ级以上阶地前缘左旋位移均在 4 0 0m左右。断层F8(7) 和F2 0 1两侧阶地宽度的变化和阶地前缘的左旋位移记录了断层F8(7) 和F2 0 1第四纪晚期活动的时空规律 ,为断层的活动性评价提供了良好的依据     

汶川地震断裂带科学钻探一号孔（WFSD-1）断层泥孔段泥浆体系的研究与应用

汶川地震断裂带科学钻探项目一号孔（WFSD-1）钻遇了30多米的断层泥。针对断层泥钻探的主要问题,对断层泥钻探泥浆体系进行了研究与应用,形成了具有高密度、低失水、低渗透、润滑减阻特点的泥浆体系,再加上重泥浆体系对地应力的平衡作用,成功地解决了断层泥的钻进取心问题,为顺利完成钻孔施工任务奠定了坚实的基础。