川中地区上三叠统须四段砂体成因及对油气运移影响分析

川中地区上三叠统须四段砂体沉积过程中,由于构造活动强弱的变化,导致物源供应速率与可容纳空间增长之间关系的变化,须四段厚层砂体自下而上由水退式、加积式和水进式3种不同成因类型的砂组纵向叠合而成.水退式砂组主要由高能削截式河道、削截式河口坝和远砂坝组成,加积式砂组主要包括冲蚀下切式河道和高能削截式河道,水进式砂组主要包括低能河道、低能削截式河道、完整式河口坝和下缺式河口坝.不同砂组中砂体类型不同,颗粒大小分异不同,水动力强弱的差异,不同成因砂体间形成了不同的成岩相和储集相,加积式砂组以绿泥石衬边和溶蚀成岩相为主,物性好,为好的储集体;水进式砂组由压实和胶结相为主,物性较差;水退式砂组中溶蚀相和胶结相发育,物性较好,为中等的储集体.须四段三种成因砂组中,加积式砂组中发育高能削截式河道,形成了在平面上广泛分布的高能水道,砂体厚度大,延伸长,发育有利的成岩相,物性较好,为油气的富集提供了足够的空间;同时加积式砂组与水退式砂组呈沉积不整合相接触,呈现相嵌关系,对天然气的运移起到通道作用,加积砂组向上的水进式砂组容易发生储层致密化,形成有利的盖层,使加积式砂组发育区成为川中天然气富集的有利部位.     

西拉木伦河断裂在松辽盆地下部的延伸

西拉木伦河断裂作为华北板块与西伯利亚板块的最终缝合线,其西段的展布较为明确,但其东段尤其是在松辽盆地下部的延伸一直没有定论.本文通过对松辽盆地西部边界嫩江-八里罕断裂、中央断裂构造性质的研究,证实它们都具有左行走滑剪切的特征,据此初步提出了西拉木伦河断裂在松辽盆地下部被嫩江-八里罕断裂和中央断裂左行错移的认识.结合已报道的松辽盆地基底高精度锆石年龄数据,松辽盆地南部重力异常特征、MT剖面以及地壳和岩石圈厚度特征,认为西拉木伦河断裂在松辽盆地下部沿开鲁-通辽-科尔沁左翼中旗-长春-线展布.     

贵州务川瓦厂坪铝土矿床地球化学特征

务川瓦厂坪铝土矿床是近年探明的大型矿床,332+333资源量4397万吨.地球化学研究显示,矿床中Al_2O_3与TiO_2含量成正相关关系,与SiO_2含量成负相关关系;硫同位素组成属于沉积岩范畴,总体显示出变化范围大(-29.20‰～+12.40‰),反映出复杂的成矿环境和轻重硫同位素的多次分离;不同岩、矿石的稀土总量(∑REE)含量变化大,LREE/HREE均大于1,显示轻稀土较富集;铝土矿层中,土状铝土矿稀土元素含量相对高,致密块状铝土矿含量相对低,稀土元素含量与矿石质量总体呈正相关关系.铝土矿层及志留系韩家店组的稀土总量含量较接近.矿床成因属古风化壳沉积型.     

矿产资源评价与矿山环境监测中高光谱遥感技术方法应用的实例

近20年来,高光谱遥感技术（Hyperspectral Remote Sensing）发展迅速,已成为遥感技术的前沿,而矿产资源评价与矿山环境监测是高光谱遥感应用中最成功的领域。高光谱遥感技术具有分辨率高的特点,通过对矿物种类、丰度和成分的识别,特别是对与成矿作用、矿山污染源密切相关的蚀变矿物的识别,可以有效地圈定热液矿化蚀变带,定量或半定量地估计相对蚀变强度和蚀变矿物含量,从而进行岩石矿物的分类和填图,并为矿产资源评价与矿山环境监测提供靶区,指导进一步找矿勘探和环境监测工作的开展。介绍了高光谱遥感技术在矿产资源评价与矿山环境监测中的应用原理和成像光谱学的逐步完善,并详细列举了高光谱遥感技术在斑岩铜矿、热液型金矿、地浸砂岩型铀矿、油气、金刚石等矿种的找矿方面,以及在矿山废弃物中生成酸和缓冲酸分布的监测等方面的具体案例,以期为中国矿产资源评价与矿山环境监测中高光谱遥感技术的应用提供借鉴。     

“嫦娥一号”第一幅月面遥感影像撞击坑特征

撞击坑是月表的主要地貌形态,按普通碗状型、中心隆起型、平底型及同心圆型4种类型描述"第一幅月面图像"上月表撞击坑的形态特征.应用遥感专业图像处理软件,结合白赛尔大地主题反算法,实现撞击坑分布及直径信息提取.研究发现,研究区域的撞击坑直径主要集中在300～700 m.而且撞击坑空间分布不均匀,直径越小,分布越密集.     

清江中游隔河岩库区偏山滑坡形成机制及稳定性分析

偏山滑坡位于清江中游隔河岩库区,距隔河岩大坝54 km,是该库区的大型滑坡之一,其稳定性直接关系到50多户200多人的生命安全及隔河岩水库的正常运行.通过野外调查,采用工程地质测绘、钻探、物探、槽探等工程勘查手段,分析该滑坡的形成机制,查明除地形地貌、地层岩性、物质结构外,滑坡稳定性主要受暴雨、水库水位涨落等外动力因素的影响;从深部位移及地表位移、地表裂缝的监测结果分析,滑坡局部产生变形及位移,正处于蠕变阶段;通过滑坡稳定性计算,结合滑坡形成机制及影响因素分析,滑坡整体稳定性较好,但滑坡在暴雨加库水位骤降条件下,稳定系数有所降低,局部存在滑塌的可能.     

从矿物学角度探讨芝罘岛黄土状黄土成因及古气候变化

沉积矿物是记录物源信息和古气候变迁的良好载体。通过显微镜碎屑矿物鉴定和黏土矿物X射线衍射峰能谱分析对芝罘岛黄土状黄土2 个剖面13 个样品进行处理, 并对数据进行数学统计分析。结果表明, 芝罘岛黄土状黄土矿物种类、矿物形态特征、磁铁矿和岩屑的高含量等都揭示了黄土来源的多源性和近源性, 末次冰期时的海底平原沉积物以及洪积、残积物是芝罘岛黄土状黄土的重要物源, 而西北内陆沙漠吹来的细颗粒物质相对较少。普通角闪石、绿帘石含量较高的黄土堆积后期是以远源沉积为主, 且以风力搬运为主; 磁铁矿、岩屑含量较高的早、中期是以近源沉积为主, 搬运动力较复杂。根据黄土状黄土的剖面层序特征, 碎屑矿物以及黏土矿物垂相变化特征, 说明黄土堆积的早期, 气候是相对温暖湿润的, 之后变得寒冷干燥, 后来又逐渐回暖, 然后再转冷, 呈现出末次冰期该地冷暖交替的气候旋回。     

谭庄-沈丘凹陷油气形成条件分析及勘探思路

谭庄-沈丘凹陷位于周口坳陷中部凹陷带,是一个中、新生代两期断陷叠合的次级构造单元,面积近2800km^2。勘探证实凹陷内沉积了巨厚的中生代早白垩纪地层（分布面积2000km^2）,其中暗色泥岩平均厚达1250m,在多口探井中见到级别不同、层数不一、厚度不等的油气显示,并在周参10、周11、12、19等多口井见到油气流,显示了该凹陷良好的勘探前景;但至今仍未取得实质性的突破,表明它具有一定的复杂性。究其原因,除了生油岩类型不太理想外,后期改造强烈导致保存条件较差及所采用的技术方法不过关也是非常重要的因素。如何寻找改造弱、破坏小、保存好的构造,是下一步勘探突破的重点,而先进适用的技术方法是关键因素。     

Structural Evolution of the Eastern Qiulitagh Fold and Thrust Belt,Northern Tarim Basin,China

The eastern Qiulitagh fold and thrust belt (EQFTB) is part of the active Kuqa fold and thrust belts of the northern Tarim Basin. Seismic reflection profiles have been integrated with surface geologic and drill data to examine the deformation and structure style of the EQFTB, particularly the deformational history of the Dina 2 gas field. Seismic interpretations suggest that Dongqiu 8 is overall a duplex structure developed beneath a passive roof thrust, which generated from a tipline in the Miocene Jidike Formation, and the sole thrust was initiated from the same Jidike Formation evaporite zone that extends westward beneath the Kuqatawu anticline. Dongqiu 5 is a pop-up structure at the western part of the EQFTB, also developed beneath the Jidike Formation evaporite. Very gentle basement dip and steep dipping topographic slope in the EQFTB suggest that the Jidike Formation salt provides effective decoupling. The strong deformation in the EQFTB appears to have developed further south, in an area where evaporite may be lacking. Since the Pliocene, the EQFTB has moved farther south over the evaporite and reached the Yaken area. Restoring a balanced cross-section suggests that the minimum shortening across the EQFTB is more than 7800 m. Assuming that this shortening occurred during the 5.3 Ma timespan, the shortening rate is approximately 1.47 mm/year.     

Permian High Ba-Sr Granitoids: Geochemistry, Age and Tectonic Implications of Erlangshan Pluton, Urad Zhongqi, Inner Mongolia

Abstract: Erlangshan Pluton from Urad Zhongqi, central Inner Mongolia, is located in the middle segment of the northern margin of the North China Plate. The rocks consist mainly of diorites with gneissic structure. Petrochemical characteristics reveal that the diorites belong to metaluminous, high-potassium calc-alkaline series, with chemical signatures of I-type granites. They are characterized by low SiO2 contents (56.63%–58.53%) and A/CNK (0.90–0.96), high Al2O3 contents (17.30%–17.96%) and Na2O/K2O ratios (1.20–1.70), enrichment in large ion lithophile elements (LILE, e.g., Ba=556–915 ppm, Sr=463–595 ppm), and relative depletion in high field strength elements (HFSE, e.g., Nb, Ta, Ti) in primitive mantle-normalized spidergram, and right-declined rare earth element patterns with slightly negative Eu anomalies (d?Eu=0.72–0.90). They have Sr/Y ratios (20–25) evidently less than Kebu Pluton (49–75) to its east. Sensitive high resolution ion micro-probe U-Pb zircon dating of the diorites has yielded an intrusive age of 270±8?Ma. This leads us to conclude that Erlangshan diorites were formed by mixing between the middle or lower crustal-derived magma and minor mantle-derived mafic magma, followed by fractional crystallization, which was trigged by crustal extension and fault activity in post-collisional setting.