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1.
广西河池北香银多金属矿床同沉积断层的厘定及其发现意义 总被引：2，自引：1，他引：1
广西河池北香银多金属矿床已经进行了20多年的找矿勘探,基本探明了1～6号脉状矿体,但在找矿理论、矿床资源量上均未能取得实质性的突破,矿床资源也因此未能获得开发利用.通过工作,在矿区内发现了一组具有长期持续活动并控制着矿区内的沉积作用和后期构造活动特征的北西向同沉积断层,已知矿体的产状、空间分布均明显受到该同沉积断层的控制,因此该组构造具有控岩控矿特征.对比显示本矿区同沉积断层与大厂矿田的同沉积构造及其控矿特征具有相似性,在该组同沉积断层的上盘尤其与南北向、北东向构造交汇的部位是成矿的有利地段,脉状矿体的下部可能存在层状矿体.该组同沉积断层的发现开拓了北香地区找矿思路,为今后找矿勘探指明了方向. 相似文献
2.
本文通过已有资料综合分析,总结描述了矿区基本地质及金矿化地质特征,提出区内F2断层应为次要的导矿构造和主要容矿构造,提出下步的找矿方向,对指导该区找矿及勘查工作具有一定意义。 相似文献
3.
新疆东准噶尔卡拉麦里金矿带是新疆重要的金成矿带之一,相关学者开展了大量的生产和科研工作,取得了丰硕的找矿成果,积累了大量的研究。近年来,随着向深部探测工作的兴起和成矿预测方法的不断成熟,由定性研究向定量研究成为一种必然选择。研究在以往科研成果综合研究的基础上,建立基于ArcGis平台的数据库,应用证据权法开展卡拉麦里金矿带断层与金矿化空间定量评价研究,研究表明断层距离和断层密度为重要的证据权因子,断层距离在0~1500 m范围内,成矿作用最强,随着距离的增大,成矿作用变弱。断层密度在0.26~0.66为中高有利成矿区域。该研究成果对卡拉麦里金矿带深部及外围的找矿工作具有重要意义。 相似文献
4.
广西凤山县金牙金矿CSAMT法深部找矿预测研究 总被引：2，自引：0，他引：2
广西凤山县金牙金矿经过近30年的开采,现面临严重的资源危机,急需开展深部找矿工作。金牙金矿是滇黔桂地区较为典型的微细粒浸染型金矿,主要以断裂构造控制为主,为了查清矿区断层在深部的产状与延伸情况,笔者在该金矿区参与开展了CSAMT工作,布设了7条CSAMT剖面,通过带地形的二维反演计算,并结合矿区地质特征等对7条剖面进行解译,指出了矿区F1、F2控矿断裂在深部较准确的位置。经钻孔验证,取得了良好的找矿效果,表明CSAMT法在本区寻找金矿是有效的,可在滇黔桂地区深部找矿工作中发挥重要作用。 相似文献
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矿床,同步耦合断层和惯量差假说 总被引：3，自引：1，他引：2
根据找矿预测中发现的问题,从探索矿床的本质特征入手,重新定义了矿床。根据本文定义的“矿床”及其所规定的矿床学研究要点,又继续探索并发现了板块构造理论中的基本概念———转换断层的本质特征,并将具有此类特征的断层定义为“同步耦合断层”。产生同步耦合断层的地球动力学机制是：非均质的地球作变速自转时,在经向和纬向惯性力同时作用下,惯量不同的相邻板块因惯量差诱发的相对运动。为此,提出了新的地球动力学原理———惯量差假说。根据此假说的基本原理分别构思了地球自转处于减速期、过渡期和加速期的全球构造体系框架。指出同步耦合断层的张性耦合区是控制大型、超大型矿床成带分布的重要空间。以此认识指导找矿预测实践,取得了一定的成效。 相似文献
7.
运用成矿构造学分析、构造蚀变带填图和构造地球化学测量方法对产于滇中中生代红层地区的大团包铜矿区进行了综合方法找矿研究,并取得了以下认识:矿区成矿构造具有多期活动性,北东、北西断裂均为矿区有利的控矿构造,二者交汇部位是成矿有利的部位.4号勘探线是矿区的矿化中心,北东向构造矿化具明显的不均一性,以往仅局限于北东向构造找矿的认识是不全面的.围岩硅化和褪色化是一种特征的找矿标志,构造蚀变带填图应用于中生代红层地区经济快捷,富有成效.成矿构造分析着眼于成矿的空间问题和驱动力,构造蚀变带填图着眼于成矿过程中矿物岩石成分的变化,构造地球化学着眼于成矿过程中化学成分的变化,三者各具特色、互为补充、相互印证.根据综合方法找矿的研究成果,提出了三个可供工程验证的找矿靶区,即:4号勘探线的深部;F5断层及其与长冲菁断层(F2)的交汇部位;F1断层及其与长冲菁断层(F2)的交汇部位. 相似文献
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贵州南华纪古天然气渗漏沉积型锰矿通过成矿理论和找矿预测方法的创新,近年来不断取得巨大的找矿成果,在国内外产生重要影响,已成为国内最重要的锰矿床类型。本文通过对贵州二叠纪锰矿与南华纪锰矿矿床地质特征的对比研究发现:二者在成矿构造背景、同沉积断层(控矿构造)、成矿物质来源、矿石与地球化学特征、锰矿成矿系统特征等方面十分相似,在结构构造特征、沥青球特征、盖帽白云岩和冷泉碳酸盐岩等方面也存在一些差别。在此基础上,贵州二叠纪锰矿通过借鉴和运用贵州南华纪古天然气渗漏沉积成矿理论和找矿预测方法,已在遵义锰矿国家整装勘查区取得重大进展。说明"内生外成"的古天然气渗漏沉积型锰矿成矿理论和找矿预测方法,在相似的成矿地质背景条件下,具有普适性和推广意义。 相似文献
10.
为实现萨尔朔克金多金属矿床深、边部找矿突破,2016—2022年对矿区开展了大量综合研究和找矿探索工作,取得一些新进展。本文介绍了萨尔朔克金多金属矿床发现史及勘查史、区域地质概况、矿床地质特征,阐述了2016—2022年综合研究和找矿探索工作中取得的新成果、新进展及对矿床的重新认识。认为综合研究工作、物化探工作及地质勘查新理论、新技术方法在矿区深、边部找矿与成矿预测方面具重要作用;投资风险理念意识对找矿是否能够突破具有重大影响。研究成果有助于探索基层地勘行业的进步和发展。 相似文献
11.
文中设计了3种类型的基底收缩挤压砂箱实验模型和一种基底无收缩挤压砂箱实验模型，用于研究柴达木盆地北缘新生代构造的变形机制。实验结果表明，基底收缩挤压模型以反冲断层发育为特色。在双侧对称对冲挤压模型中，正冲和反冲断层的发育程度基本处于均衡状态；在双侧不对称对冲挤压模型中，反冲断层更加发育，尤其在挤压速度较快一侧更加显著；单侧挤压模型中，以反冲断层发育、正冲断层很少为特征。由此表明，基底收缩作用和挤压作用的不对称性促使反冲断层的发育。根据实验结果与实际剖面的对比，笔者认为，基底收缩和不对称挤压是导致该区特殊剖面结构的可能原因，该区新生代构造变形是在基底收缩作用参与下、以祁连山为主的侧向不对称挤压作用的结果。 相似文献
12.
新疆库车坳陷逆掩断裂在油气运聚中的作用 总被引：4，自引：0，他引：4
在研究新疆库车坳陷逆掩断裂、源岩和盖层空间发育特征的基础上,研究了逆掩断裂与源岩、盖层的空间匹配关系.认为断穿源岩、盖层的逆掩断裂则是油气散失的通道;勾通源岩,但未断穿盖层的逆掩断裂则是油气聚集的输导通道,它们控制着库车坳陷油气的聚散及其在空间上的分布.在研究库车坳陷逆掩断裂活动史和源岩排烃史、盖层封闭能力形成史的基础上,研究了逆掩断裂与源岩、盖层的时间匹配关系,认为盖层与源岩的时间匹配关系控制着可供运移的油气量;逆掩断裂与源岩的时间匹配关系控制着可供聚集的油气量,盖层与逆掩断裂的时间匹配关系控制着油气的富集量. 相似文献
13.
AbstractThe structure of the Pyrenean pre-Hercynian rocks involved in the “Axial Zone” antiformal stack, results from the association of Hercynian cleavage-related folds and Hercynian and Alpine thrusts. Some of these Alpine and Hercynian thrusts separate thrust sheets in which Upper Paleozoic rocks, Devonian and pre-Hercynian Carboniferous, exhibit different lithostratigraphy and internal structure.In order to know both, the original Devonian facies distribution and the structural characteristics, the effects of the Alpine and the Hercynian thrusts must be considered. If a conceptual restored cross-section is constructed taking into account both the Alpine and Hercynian thrusts, a different Devonian facies distribution is achieved. Devonian carbonatic successions were originally located in a northernmost position, whereas sequences made by alternations of slates and limestones lie in southernmost areas. Moreover, a N-S variation of the Hercynian structural style appears. In the northern units thrusts are synchronous to folding development and they are the most conspicuous structures. In the intermediate units, thrust postdate cleavage-related folds, and in the southernmost units several folding episodes, previous to the thrusts, are well developed.We present some examples which enable us to discuss the importance of the Hercynian and Alpine thrusts in the reconstruction of the Pyrenean pre-Alpine geology. 相似文献
14.
This paper deciphers the late stress systems involved in the development of kink bands in the perspective of thrust regime.
In kink bands, the correlation coefficient for α–β plots is positive near thrusts and negative away from thrusts. The plots show nearly linear relationship near thrusts and
non-linear relationship away from thrusts. The rotation was prominent mechanism of kink band formation near thrusts and rotation
coupled with shearing, along the kink planes away from thrusts. Along thrusts σ
1 is horizontal E–W trend and it rotates to horizontal N–S trend away from the thrust. The proposed model establishes that
(1) the shearing along kink planes led to angular relationship, β < α and (2) the kink planes of conjugate kinks could be used for paleostress analysis even in those cases where shearing along
these planes has occurred. 相似文献
15.
The Siwaliks in the foothills of the Himalayas, containing molasse sediments derived from the rising mountain front, represent
a foreland fold-thrust belt which was deformed during the continued northward convergence of the Indian plate following the
continent-continent collision. In this contribution we present balanced and restored cross sections along a line from Adampur
through Jawalamukhi to Palampur in the foothills of the Punjab and Himachal Himalayas using published surface/subsurface data.
The cross section incorporates all the rock units of the Sub-Himalaya Zone as well as that of the northern Lesser Himalaya
Zone. The structural geometry of the fold-thrust belt in this section is largely controlled by three buried thrusts within
the Sundernagar Formation of the Lesser Himalaya Zone. Two of these buried thrusts splay from the basal detachment and delineate
a buried horse. Three thrusts towards foreland, including the Main Frontal Thrust (inferred to be a blind thrust in this sector),
splay from these buried thrusts. In the hinterland, an anticlinal fault-bend fold was breached by a sequence of break-back
thrusts, one of which is the Main Boundary Thrust. A foreland propagating thrust system is inadequate to explain the evolution
of the fold-thrust-belt in this section. We show that a “synchronous thrusting” model in whichin-sequence initiation of thrusts at depth combined with continued motion on all the thrusts leading toout-of-sequence imbrication at the upper structural levels better explains the evolution of the fold-thrust belt in the Jawalamukhi section.
The estimated shortening between the two chosen pin lines is about 36% (about 72 km). 相似文献
16.
岩石强度对冲断层形成特征影响的砂箱实验研究 总被引：5，自引：0，他引：5
实验通过地形变化的砂箱模型模拟了两盘岩石强度差异对冲断层形成特征的影响作用。模型设计为在基底收缩参与的情况下 ,变形前地面坡度递增的单侧挤压系列。实验结果显示 ,当变形前地形水平乃至初始地面坡度很小 (<7°)时 ,挤压作用形成两组倾向相反的冲断层。若初始地面坡度显著 (>7°) ,则只形成倾向与挤压方向相反的一组冲断层。结合应力分析认为 ,若两盘岩石强度均一或相近 ,挤压作用形成两组对冲断层 ;当强度明显差异的两盘发生碰撞时 ,强度大的一盘优先向能量弱的方向释放能量 ,形成向另一盘仰冲的一组冲断层。实验结果与陆陆碰撞带剖面断层形态上有较好的相似性。 相似文献
17.
基底收缩对挤压构造变形特征影响——来自砂箱实验的启示 总被引：9，自引：2，他引：9
进行了 4个砂箱模型的模拟实验。其中基底收缩单侧挤压剖面模型以形成后冲叠瓦式断层为特征 ,基底无收缩单侧挤压剖面模型则以发育前冲叠瓦断层为特征。基底收缩斜向双侧挤压平面模型形成两组不同走向的逆断层 ,一组为与挤压带边界基本平行的主控断层 ,另一组为与挤压方向近于垂直的雁列断层。而基底无收缩斜向双侧挤压平面模型仅形成一组与挤压带边界基本平行的逆断层。这些模型的实验结果表明 ,基底收缩对挤压构造变形特征具有重要的影响。后冲 (或向陆冲向 )叠瓦式这种较为罕见挤压构造、以及与挤压方向近垂直的雁列断层的形成与基底的收缩作用有关。对于类似于焉耆盆地这种通常认为是压剪形成的挤压构造组合 ,笔者认为用“基底收缩条件下的斜向挤压作用”可更加贴切地加以解释。 相似文献
18.
Orogens and rift zones have a finite number of regional faults. The accretionary prisms analysed here have a number of thrusts < 50, whereas extensional areas have a number of normal faults ranging between six and 44. The average spacing of thrusts is between 5 and 25 km; spacing of normal faults is more restricted into two peaks, at 25–29 km and 4–6 km, in which the latter is the most common. The number and spacing of faults appear to be mainly controlled by the depth of the decollement plane, which seems to be more variable in compressive settings with respect to rift zones. Basement‐involved orogens present fewer and more spaced thrusts; by contrast, a greater number of thrusts with shorter spacing characterize thin‐skinned thrust belts. The shallower the decollement is, the stronger it appears to control the palaeogeography, in the sense of rheological lateral variations in the sedimentary cover. 相似文献
19.
We have used analogue experiments to investigate the effects of surface topography on the curvature of fold-and-thrust belts, under conditions of (1) initial relief, but no erosion, and (2) no initial relief, but differential erosion, sedimentation and transport.In experiments where a 2-layer model lithosphere shortened and thickened in front of an advancing straight piston, the geometry of the developing thrust wedge was very sensitive to variations in surface topography. In models with an initially flat, horizontal surface, and in the absence of erosion and sedimentation, thrusts were straight, propagated forwards, and nucleated at buckle folds far in front of an advancing piston. Around an initial topographic high (plateau or cone), thrusts tended to be arcuate, forming salients towards the foreland. Initial plateaux and cones tended to behave rigidly, while arcuate thrust slices formed around them. To accommodate differential slip, transfer zones developed on both sides of initial highs. Fault blocks rotated about vertical axes and thrusts moved in oblique slip within transfer zones. In models with initially horizontal surfaces, which were subject to differential erosion, sedimentation and transport, thrusts initially were straight, but then progressively rotated around non-eroded, thickened and stronger areas. These worked as indenters, in front of which new thrusts nucleated at curved buckle folds. These thrusts were also curved, their apices being in front of the thickened, non-eroded areas.In nature, arcuate structural patterns are to be found around the Altiplano of the Central Andes and around the Tromen volcanic ridge in the Neuquén Basin of northern Patagonia. We infer that these areas behaved in quasi-rigid fashion, protected as they were by their high elevations, and that differential erosion at the scale of the entire Andes may have contributed to oroclinal bending. 相似文献
20.
This paper investigates the evolution of thrust wedges with concomitant surface erosion, and its bearing on the exhumation
processes in orogenic belts. We performed sandbox experiments, simulating syn-orogenic erosion on forelandward sloping surfaces
(∼4°). Experiments show that the erosion process has a significant control on the progression of frontal thrusts. In case
of no-erosion condition, wedges with high basal friction develop frontal thrusts with strongly increasing spacing. In contrast,
for the same basal friction the thrusts show uniform spacing as the wedge development involves concomitant surface erosion.
On the other hand, the erosion promotes reactivation of hinterland thrusts in wedges with low basal friction. We show that
erosion-assisted thrust reactivation is the principal mechanism for exhumation of deeper level materials in orogens. Efficiency
of this mechanism is largely controlled by basal friction. The exhumation of deeper level materials is limited, and occurs
within a narrow, sub-vertical zone in the extreme hinterland when the basal friction is high (μb = 0.46). In contrast, the process is quite effective in wedges with low basal friction (μb =0.36), resulting in exhumation along gently dipping foreland-vergent thrusts as well as along thrusts, subsequently rotated
into steep attitude. The zone of exhumation also shifts in the foreland direction in the course of horizontal movement. Consequently,
deeper level materials cover a large area of the elevated part of the wedge. 相似文献