陆相残余盆地的主要类型、特点及研究方法

根据我国中生代陆相盆地演化特征，认为陆相盆地不存在原始沉积盆地。陆相残余盆地的基本特征，具有空间上盆地面积大为缩小，地层遭受明显剥蚀，受后期改造而成。提出了两种基本类型和它们的沉积特点以及追踪物质来源、去改造层是恢复残余盆地的基本方法，并以古鄱阳湖中生代盆地为例。     

Chemostratigraphy of Flood Basalts in the Garze-Litang Region and Zongza Block: Implications for Western Extension of the Emeishan Large Igneous Province, SW China

The Late Permian Emeishan Large Igneous Province (ELIP) is commonly regarded as being located in the western part of the Yangtze craton, SW China, with an asymmetrical shape and a small area. This area, however, is just a maximum estimation because some parts of the ELIP were not recognized or dismembered and destroyed during the Triassic to Cenozoic tectonism. In this paper, the chemostratigraphical data of the Zongza block, the Garze-Litang belt and the Songpan-Garze block suggest that the Late Permian basalts in these areas have remarkable similarities to the ELIP basalts in petrography and geochemistry. Flood basalts in the Sanjiangkou area are composed of the lower part of the low-Ti (LT) tholeiite and the upper part of the high-Ti (HT) tholeiite, which is the same as the flood basalts on the western margin of the Yangtze craton. Flood basalts in the Zongza and Songpan-Garze areas, which are far from the Yangtze craton, consist of HT tholeiite only. This is the same as the flood basalts within the Y     

油气充注对成岩作用的影响

油气充注对成岩作用的影响有三个方面 :抑制石英和伊利石的胶结作用、油气中所有机酸对深部孔隙的溶蚀改造作用、油气超压对压实的缓冲作用。英国北海Miller油气藏等的资料显示 ,油气充注较早时 ,油区的石英胶结速率比水区的明显要低 ,石英的胶结丰度比一般预测值低 ,而孔隙度比一般的预测值要高。我国渤海湾盆地东营凹陷油田资料显示 ,无论浅部或深部 ,凡是含油砂岩 ,其长石类及碳酸盐类矿物的溶解都十分强烈 ,次生孔隙很发育 ,而不含油的砂岩 ,其矿物溶解及次生孔隙发育一般较差 ;油层的方解石、白云石含量一般比水层低 ,深层尤为明显。干酪根生成油气时的流体体积增加 ,可大大增加孔隙流体压力 ,产生超压 ,并可传递到储集层 ,因而大大增加对压实作用的抵抗能力。上述三方面实质上都为深部油气成藏改善了储层基础 ,对深部油气勘探具有非常现实的意义。     

鄂东南铜山口、殷祖埃达克质（adakitic）侵入岩的地球化学特征对比：（拆沉）下地壳熔融与斑岩铜矿的成因

鄂东南地区铜山口花岗闪长斑岩体是与斑岩铜钼矿床共生的岩体,但殷祖花岗闪长岩体是与金属成矿无关的岩体。铜山口和殷祖侵入岩的元素地球化学特征与埃达克岩的地球化学特征非常类似,如高Al2O3、Sr含量与La/Yb、Sr/Y比值,富Na2O(Na2O/K2O>1.0),亏损Y与Yb,极弱负Eu异常-正Eu异常以及正Sr异常等。但是铜山口和殷祖侵入岩也存在 明显的差别:前者比后者更偏酸性,但具有较高的K2O,MgO,Cr,Ni和Sr含量,较低的Y和Yb含量,轻重稀土元素分异更明显,并主要显示出正铕异常,区别于后者的极弱负Eu异常-不明显Eu异常。这表明铜山口埃达克质侵入岩的岩浆来源可能比殷祖埃达克质侵入岩的岩浆来源更深:前者可能由拆沉的下地壳熔融形成,残留物主要含石榴子石;而后者可能由增厚的下地壳熔融形成,残留物可能为石榴子石±斜长石±角闪石。另外,热的地幔上涌,底辟(diapir)进入下地壳,导致含角闪石的榴辉岩发生熔融也可形成铜山口埃达克质岩浆。铜山口埃达克质岩浆在穿过地幔的过程中,将会与地幔橄榄岩发生交换反应:一方面由于受橄榄岩的混染而使得岩浆的MgO,Cr和Ni增高;另一方面岩浆中的Fe2O3不断加入到地幔中,导致地幔的氧逸度(fo2)增高,地幔中金属硫化物被氧化并进入岩浆中,富含Cu-Mo等成矿物质的岩浆上升很容易形成斑岩铜钼矿     

青藏高原东缘古近纪粗碎屑岩沉积学及其构造意义

青藏高原东缘古近纪盆地的填图和沉积学研究表明,在青藏高原东缘区域性走滑-挤压构造背景下形成的古近纪盆地内广泛发育厚层—巨厚层状的紫红色粗碎屑岩系。其沉积特征指示为一种近源快速堆积的泥石流和辫状河道沉积体,形成于干旱炎热气候条件下的典型陆内冲积扇环境。盆地充填序列、粗碎屑岩层序、动植物化石和盆地内岩浆岩~(40)Ar-~(39)Ar年代学等综合研究结果表明,古近纪盆地内粗碎屑岩大约形成于38～29 Ma。该时期与青藏高原东缘北段(横断山地区)古近纪盆地的形成和南段(兰坪—思茅地区)大盆地的裂解时间基本一致,这很可能预示着青藏高原在晚始新世—早渐新世期间曾发生过整体的快速构造隆升。     

三套管(NQ3)取心钻进工艺原理及在60°斜孔施工中的应用

为矿产勘察开发提出完整可靠的选矿验证,资源量验证及岩土力学原始资料,引进三套管(NQ3)取心工艺并进行了应用试验,重点介绍了该工艺的原理以及在金矿勘查60°斜孔施工中的应用.     

Partial Melting and Its Implications for Understanding the Seismic Velocity Structure within the Southern Tibetan Crust

In order to constrain the crustal wave velocity structure in the southern Tibetan crust and provide insight into the contribution of crustal composition, geothermal gradient and partial melting to the velocity structure, which is characterized by low average crustal velocities and widespread presence of low-velocity zone(s), the authors model the crustal velocity and density as functions of depth corresponding to various heat flow values in light of velocity measurements at high temperature and high pressure. The modeled velocity and density are regarded as comparison standards. The comparison of the standards with seismic observations in southern Tibet implies that the predominantly felsic composition at high heat flow cannot explain the observed velocity structure there. Hence, the authors are in favor of attributing low average crustal velocities and low-velocity zone(s) observed in southern Tibet mainly to partial melting. Modeling based on the experimental results suggests that a melting percentage     

鄂东地区上泥盆统五通组砂岩沉积相及其古地理特征

对鄂东地区上泥盆统五通组砂岩的成因，一直存在河流相和滨海相的不同认识。野外研究和室内分析表明：该组主要为一套成熟度较好纯净的石英砂岩和含海绿石石英砂岩。概率累积曲线斜率较大，以跳跃组分为主，悬浮组分和滚动组分含量低，有的砂岩跳跃组分具两段式，粒度参数属于分选好的滨海砂范围。微相和粒度分析都表明其具有明显的高能碎屑海岸的滨海沉积特征。砂岩中发育大型冲洗交错层理、大型不对称浪成波痕、不规则的坑凹面等典型的海滩沉积构造。纵向上为临滨下部一临滨上部一临滨下部一临滨上部一前滨一后滨沉积特征，上部为一个完整的退积型海滩沉积序列。区域古地理分析反映下扬子的鄂东地区晚泥盆世时期处于滨浅海环境，其北部可能与秦岭古海洋相通。     

宜昌老林沟石榴石矿床地质特征

老林沟石榴石矿产于黄陵背斜北部类孔兹岩系中一套富铝铁质正常沉积的泥质粉砂岩、泥质岩中,在区域热动力变质作用下,铁铝榴石与夕线石共生,属于巴罗变质系列中夕线石带产物,根据矿物共生组合、指相特征矿物得出形成该矿产的区域变质的温压条件为:t为7 00℃,P为7 30MPa,变质相属低角闪岩相至高角闪岩相。     

Polyphase Deformation of the Weihai-Rongcheng UHP Unit Rocks, NE Sulu： Insights into the Tectonic Evolution of the Dabie-Sulu UHP and HP Belts, China

Different scales of structural data reveal a complex deformation history of ultrahigh- pressure （UHP） rocks exposed in the Weihai-Rongcbeng area, NE Sulu （northern Jiangsu-eastern Shandong）, eastern China. Excluding pre-UHP deformations, at least five major sequential deformational stages （D1-Ds） are recognized. The first deformation （DO produced a weak foliation and lineation in massive eclogites. The foliated eclogite with a dominant foliation containing a stretching and mineral lineation was developed during the I）2 deformation. Both the D1 and D2 deformations occurred under UHP metamorphic conditions, and are well preserved in the eclogite bodies. D3 structures which developed shortly after the formation of granulite/amphibolite facies symplectites are characterized by imbricated associations marked by a regional, steeply dipping foliation, compositional layering, eclogite boudinage, isoclinal folds and reverse ductile shear zones. The D3 deformation was accompanied by decompressional partial melting. A regional, gently dipping amphibolite facies foliation and stretching lineation, low-angle detachments, and dome- and arc-shaped structures formed during the D4 deformation stage dominate to some degree the map pattern of the Weihai-Rongcbeng UHP domain. The last stage of deformation （Ds） gave rise to the final exhumation of the UHP rocks. Ds is characterized by development of brittle-dominated high-angle faulting associated with emplacement of large volmnes of undeformed granite plutons and dykes dated at 134-100 Ma. The deformational and metamorphic sequence followed by the UHP rocks in the Weihai-Rongcheng area is similar to that studied in the entire Dabie-Sulu UHP and HP metamorphic belts from microscopic to mapping scale. Based on structural data, combined with available petrographic, metamorphic and geochronological data, a speculative tectonic evolutionary model for the Dabie-Sulu UHP and IIP belts is proposed, involving continental subduction/collision between the Sino-Korean and Yangtze cratons and subsequent polyphase exhumation histories of the UHP and IIP metamorphic rocks.