Tectonic controls on metamorphism, partial melting, and intrusion: timing and duration of regional metamorphism and magmatism in the Ni de Massif, Turkey     

Donna L. Whitney  Christian Teyssier  Annia K. Fayon  Michael A. Hamilton  Matt Heizler 《Tectonophysics》2003,376(1-2):37-60

Mafic high-pressure granulite, eclogite and pyroxenite xenoliths have been collected from a Mesozoic volcaniclastic diatreme in Xinyang, near south margin of the Sino-Korean Craton (SKC). The high-pressure granulite xenoliths are mainly composed of fine-grained granoblasts of Grt+Cpx+Pl+Hbl±Kfs±Q±Ilm with relict porphyritic mineral assemblage of Grt+Cpx±Pl±Rt. P–T estimation indicates that the granoblastic assemblage crystallized at 765–890 °C and 1.25–1.59 GPa, corresponding to crustal depths of ca. 41–52 km with a geotherm of 75–80 mW/m². Calculated seismic velocities (V_p) of high-pressure granulites range from 7.04 to 7.56 km/s and densities (D) from 3.05 to 3.30 g/cm³. These high-pressure granulite xenoliths have different petrographic and geochemical features from the Archean mafic granulites. Elevated geotherm and petrographic evidence imply that the lithosphere of this craton was thermally disturbed in the Mesozoic prior to eruption of the host diatreme. These samples have sub-alkaline basaltic compositions, equivalent to olivine– and quartz–tholeiite. REE patterns are flat to variably LREE-enriched (La_N/Yb_N=0.98–9.47) without Eu anomaly (Eu/Eu*=0.95–1.11). They possess 48–127 ppm Ni and 2–20 ppm Nb with Nb/U and La/Nb ratios of 13–54 and 0.93–4.75, respectively, suggesting that these high-pressure granulites may be products of mantle-derived magma underplated and contaminated at the base of the lower crust. This study also implies that up to 10 km Mesozoic lowermost crust was delaminated prior to eruption of the Cenozoic basalts on the craton.  相似文献   

Cenozoic Plate interaction of the Australia and Philippine Sea Plates: “hit-and-run” tectonics     

Manuel Pubellier  Jason Ali  Christophe Monnier 《Tectonophysics》2003,363(3-4):181-199

Recent studies in northwest New Guinea have shown the presence of at least two marginal basins of different age, both of which formed in back-arc settings. The older basin opened between the Middle Jurassic and Early Cretaceous, a remnant of which is now preserved as the New Guinea Ophiolite. Its obduction started at 40 Ma and it was finally emplaced on the Australian margin at 30 Ma. The younger basin was active during the Oligocene to Middle Miocene and was obducted in the Early Pliocene. Studies of the western edge of the Philippine Sea also reveal an important deformation of the Philippine arc in the Oligocene, which hitherto has remained unexplained. Using information from these systems, paleomagnetic results, kinematic reconstructions and geochemistry of the supra-subduction ophiolite, we present a plate model to explain the region's Eo–Oligocene development. We suggest that an extensive portion of oceanic crust extended the Australian Plate a considerable distance north of the Australian Craton. As Australia began its steady 7–8 cm/year northward drift in the Early Eocene, this lithosphere was subducted. Thus, the portion of the Philippine Sea Plate carrying the Taiwan–Philippine Arc to its present site may have actually been in contact with the ophiolite now in New Guinea and obduction led to deformation of the Philippine Sea Plate itself. Neogene Plate kinematics transported the deformed belt in contact with the Sunda block in the Late Miocene and Pliocene. This interpretation has implications for the origin for the Philippine Sea Plate and the potential incorporation of continental fragments against its boundaries.  相似文献   

渤海湾盆地区燕山期构造特征与原型盆地   总被引：11，自引：7，他引：11  

周立宏  李三忠  刘建忠  高振平 《地球物理学进展》2003,18(4):692-699

结合近几年来渤海湾盆地区深层地震勘探与解释的成果，重点论述了渤海湾盆地区燕山期构造特征与盆地原型，提出燕山期构造变形样式总体在纵向上可分为三个构造层，分别称为上部、中部和下部；横向上总体可分为三个构造带，西部为向西逆冲的薄皮逆冲带，中部为冲断—走滑带，东部为厚皮褶皱—冲断带，主体由两期挤压方向皆为NW—SE向的褶皱—逆冲变形形成；并将其演化分为三个阶段：燕山早期、燕山中期和燕山晚期。但是，渤海湾盆地区燕山期的构造变形特征和原型盆地有所变化，其空间上的差异是基底构造格局及其空间差异叠合的结果。综合其它研究结果还表明，渤海湾盆地区燕山期构造是在西太平洋大陆边缘弧的挤压构造背景下，陆内壳下拆沉和壳内挤出逃逸构造的综合动力作用下形成的。  相似文献   

塔里木盆地新生代地质地貌特征及其演化     

李江海  吴桐雯  雷雨婷 《高校地质学报》1997,25(3):466

塔里木盆地是亚洲大陆腹地独特的巨型地质地貌单元，是研究新生代地球系统的天然实验室。新生代以来，它经历 了古近纪海湾、新近纪湖泊—三角洲平原、河流—湖泊—沙漠、沙漠—河流的地质演化过程，古地理格局变化的主要因素 是远程碰撞造山作用，造成盆地的封闭、气候干旱。古近纪以来，海湾盆地西低东高，构造挤压造成周缘山脉隆升和盆地 逐渐封闭，这是盆地演化最主要的动力因素。新近纪南高北低，随着青藏高原隆升，周围山脉持续隆升，早先形成的河湖 等地质地貌单元不断被周边山脉所封闭，形成塔里木盆地，发育大湖泊。第四纪以来，盆地西高东低，经历了最快速的地 球系统演化，形成中国较大的内流水系以及最大沙漠。内、外动力的耦合作用及其相互作用，控制了塔里木盆地新生代地 球系统演化，塔里木盆地周缘新构造活跃，在巨型盆地内发育了河流、湖泊、沙漠、戈壁、雅丹、干盐湖等多种第四纪的 地貌类型。不同地质因素时空上相互作用，塑造着巨型盆地地球系统演化，塔里木盆地展示了极干旱地区地球系统第四纪 快速的演化过程。  相似文献   

中国东部中新生代盆地成因及其地球动力学   总被引：9，自引：1，他引：9  

孙加鹏  杨宝俊 《世界地质》1997,16(3):1-6

中国东部大兴安岭－太行山－武陵山重力梯度带一线以东至太平洋西岩，大陆连缘中新生代盆地系的形成，中生代岩浆活动，盆地基本特征同Ｍｏｈｏ、岩石圈和软流圈及上地幔基本特征的内在联系等都表明，它们在时空和成因上有一定联系，可以纳入同一地球动力学过程之中，这种动力学机制可能与岩石圈界，地壳底界的拆离作用有关。  相似文献   

Late Mesozoic Intracontinental Rifting and Basin Formation in Eastern China   总被引：1，自引：0，他引：1  

Ren Jianye Li SitianFaculty of Earth Resources  China University of Geosciences  Wuhan Lin ChangsongDepartment of Energy Resources  China University of Geosciences  Beijing  《中国地质大学学报(英文版)》1997,(1)

ＬａｔｅＭｅｓｏｚｏｉｃＩｎｔｒａｃｏｎｔｉｎｅｎｔａｌＲｉｆｔｉｎｇａｎｄＢａｓｉｎＦｏｒｍａｔｉｏｎｉｎＥａｓｔｅｒｎＣｈｉｎａ＊ＲｅｎＪｉａｎｙｅＬｉＳｉｔｉａｎＦａｃｕｌｔｙｏｆＥａｒｔｈＲｅｓｏｕｒｃｅｓ，ＣｈｉｎａＵｎｉｖｅｒｓｉｔｙｏｆ...  相似文献   

Lithospheric Stretching,Subsidence and Thermal History Modeling: Application to Yinggehai,Qiongdongnan and Songliao Basins in East China   总被引：3，自引：0，他引：3  

Lin ChangsongDepartment of Energy Resources  China University of Geosciences  Beijing Li SitianFaculty of Earth Resources  China University of Geosciences  Wuhan Zhang QiminWest Nanhai Oil Company  Zhanjiang Zhang 《中国地质大学学报(英文版)》1997,(1)

ＬｉｔｈｏｓｐｈｅｒｉｃＳｔｒｅｔｃｈｉｎｇ，ＳｕｂｓｉｄｅｎｃｅａｎｄＴｈｅｒｍａｌＨｉｓｔｏｒｙＭｏｄｅｌｉｎｇ：ＡｐｐｌｉｃａｔｉｏｎｔｏＹｉｎｇｇｅｈａｉ，ＱｉｏｎｇｄｏｎｇｎａｎａｎｄＳｏｎｇｌｉａｏＢａｓｉｎｓｉｎＥａｓｔＣｈｉｎａ＊Ｌｉ...  相似文献   

Periodicity of magnetic intensities in magnetic anomaly profiles: the Cenozoic of the South Atlantic     

B. D'Argenio  M. Iorio  D. H. Tarling 《Geophysical Journal International》1996,127(1):141-155

Spectral analyses of several published magnetic anomaly profiles from Candé & Kent (1992a) were undertaken prior to analysing, in the same way, raw magnetic anomaly data from similar parts of the South Atlantic. It was found that similar and distinct medium and short wavelengths were present in both the published and raw data. When these are converted into the time domain using the average rate of spreading for each profile, these periodicities appear similar, possibly identical, to those expected from the long-term eccentricity orbital parameters (Fischer, DeBoer & Premoli Silva 1990). While such correlations are not necessarily causative, they suggest that magnetohydro-dynamical processes near the core-mantle boundary may be affected by gravitational changes due to planetary orbital perturbations.  相似文献   

柴达木盆地西部新生代气候与地形演变   总被引：24，自引：0，他引：24  

王建  刘泽纯 《地质论评》1996,42(2):166-173

从孢粉植物分异及演变，干旱碎屑及膏盐沉积分布等方面，对柴达木盆地西部新生代气候与地形的演变进行了探讨。结果表明，盆地西部新生代两个极端干燥气候期（膏盐发育期）分别出现在始新世至渐新世及上新世至第四纪。前者与老第三纪行星环流控制下的副热带干燥带有关，而后者与青藏高原的隆升有关。早第三纪盆地西部及周围地区的地势不象以前所认为的那么低平。在第三纪，昆仑山比祁连山低。晚新生代盆地向北推移了７－１１个纬距。  相似文献   

山东中生代橄榄安粗岩系火山岩的地质、地球化学特征及岩石成因   总被引：44，自引：0，他引：44  

邱检生  王德滋  周金城  曾家湖 《地球科学》1996,(5)

山东中生代橄榄安粗岩系火山岩主要分布在沂沭断裂带及其两侧的断陷型陆相火山盆地中，为早白垩世火山活动的产物．Ｒｂ－Ｓｒ全岩等时年龄变化于１１１．４～１１９．６Ｍａ．岩石组合主要为粗面玄武岩－橄榄安粗岩－安粗岩－粗面岩．这套岩石在化学上具有富碱富钾、富铝贫钛、高氧化系数及富轻稀土和大离子亲石元素的特点，并具有较高的ＩＳｒ值和明显偏低εＮｄ值．根据对岩石地质、地球化学特征和产出构造环境的详细分析，表明这套岩石的成因应主要是富集型地幔的部分熔融  相似文献