早前寒武纪克拉通内的叠瓦拼贴构造     

杨书桐  胡受奚 《国土资源》1993,(2)

从早期地幔热对流的动力学特点出发,针对早前寒武纪克拉通内的一些有争议的问题进行了解释;认为不少绿岩地块或地体之间,绿岩与花岗片麻岩之间并非是因垂直运动造成的原地不整合接触,而是因大规模水平运动产生的叠瓦拼贴,这一思想将会帮助我们重新认识克拉通区早前寒武纪地壳演化,并进一步指导填图和地层划分以及找矿工作。  相似文献   

大别山北部的变质复理石推覆体     

刘贻灿  徐树桐  江来利  苏文  吴维平 《地质通报》1998,(2)

大别山北部的变质复理石推覆体属华北大陆板块南部的盖层推覆体,主要包括佛子岭群和卢镇关群。其时代主要为震旦纪—早古生代至泥盆纪。变质作用主要为角闪岩相—绿片岩相,在靠近变质蛇绿混杂岩带附近的部分（佛子岭群）可能曾经因卷入变质蛇绿混杂岩带而有过麻粒岩相或榴辉岩相（？）变质作用。变质复理石推覆体中岩石变形强烈,但不同地段变形程度不等。  相似文献   

Occurrence State of Soluble Organic Matter in Shale Oil Reservoirs from the Upper Triassic Yanchang Formation in the Ordos Basin,China: Insights from Multipolarity Sequential Extraction     

Li  Shutong  Li  Shixiang  Guo  Ruiliang  Zhou  Xinping  Wang  Yang  Chen  Junlin  Zhang  Jiaqiang  Hao  Lewei  Ma  Xiaofeng  Qiu  Junli 《Natural Resources Research》2021,30(6):4379-4402

Natural Resources Research - Quantitative characterization of different occurrence states of soluble organic matter is the basis and key for shale oil resource evaluation and movable oil and...  相似文献   

Architecture and Kinematics of the Dabie Orogen,Central Eastern China   总被引：3，自引：0，他引：3  

XU Shutong  LIU Yican  CHEN Guanbao  WU Weiping Anhui Institute of Geology  Hefei  Anhui  Laboratory of Continental Dynamics of the Ministry of Land  Resources  Beijing 《《地质学报》英文版》2005,79(3):356-371

The geometry of the Dabie Mountains is manifested in terms of the distribution of petro-tectonic units in three dimensions. It is identified into three segments from east to west, four horizons in vertical profiles and eight petrotectonic units from north to south. Three segments are the east, middle and west segments. Four horizons, from top to bottom, are two different meta-tectonic melange in the uppermost part, underthrust basement and cover below them, and mantle at the bottom of the profiles. Eight petro-tectonic units from north to south are: (1) the hinterland basin, (2) the meta-flysch, (3) the ultramafic rock belt (UM) Sujiahe eclogite belt (SH), (4) eclogite belt 2 (Ec2) with most eclogites of continental affinity, (5) eclogite belt 1 (Ecl1) with some eclogite of oceanic affinity, (6) the Dabie complex or underthrust basement of the Yangtze continent, (7) the Susong and Zhangbaling Groups or underthrust cover of the Yangtze continent and (8) the foreland belt. The (3), (4) and (5) units belong to meta-tectonic melange. Some ultrahigh pressure metamorphic minerals such as coesite and micro-diamonds have been found in (3) and (4) units; a possible ultrahigh pressure mineral,clinozoisite aggregate pseudomorph after lawsonite, was found in unit (5). The three tectonic units are speculated to be coherent initially; the UM and SH units are suggested to be the root belt in the east, middle and west segments respectively.The kinematics of the Dabie orogen is divided into three stages: top-to-south thrusting during the eclogite-granulite facies metamorphism, top-to-north extension during the amphibolite metamorphic stage, and faults or shear bands of brittle deformation and greenschist facies metamorphism were formed in the post-orogenic stage since the Late Jurassic and the movement pictures of these faults is different from each other.  相似文献   

安徽省主要构造地质要素的变形   总被引：1，自引：0，他引：1       下载免费PDF全文

徐树桐  周海渊  董树文  陈冠宝  张维明 《地质科学》1986,(4):311-322

安徽省在中国东部的中心部位,跨越不同的构造地质单元。前寒武纪变质岩出露面积约占基岩出露面积的三分之一。变质岩包括太古宙、元古宙及少部分古生代地层;变质相包括麻粒岩相到低级绿片岩相。其中发育有多期褶皱变形和同变质期的断层作用,这些断层在后继变形过程中被改造和复活,形成十分复杂的构造地质图案。  相似文献   

大别山超高压变质带面理化榴辉岩中变形石榴石的几何学和运动学特征及其大地构造意义   总被引：12，自引：4，他引：8  

Xu Shutong  Liu Yican  Su Wen  Wu Weiping  Jiang Laili  Wang Rucheng. 《岩石学报》1999,15(3):321-337

大别山东部双河附近面理化榴辉岩中, 所有榴辉岩相矿物包括石榴石、绿辉石乃至金红石都受到强烈拉伸。用透射电镜可以观察到石榴石晶体中塑性变形的显微构造, 包括自由位错、位错环、位错壁和位错网。拉伸石榴石的应变轴比表现为 Ｘ＞ Ｙ＞ Ｚ。运动学标志如石榴石的不对称碎斑和旋转的金红石颗粒, 表明有旋转应变的作用。石榴石和金红石的福林系数分别为１１８ 和０９８。所有这些都表明石榴石是在接近于平面应变的条件下形成。由于石榴石颗粒在应变前后体积未变,因此也是在简单剪切作用条件下形成的。根据石榴石韧性变形要求的温度条件, 此种变形应在榴辉岩相条件下发生, 代表一次向南的逆冲作用, 经过展开后, 逆冲的方向为南西。根据石榴石的流变律, 其韧性变形的最低温度估计约为 ８００℃。石榴石中普遍有一组透入性破劈理, 它产生于面理化榴辉石折返后的角闪岩相早期, 形成于石榴石韧性变形之后。破劈理及其中反Ｓ形破劈理的运动指向表明有向北的滑动, 发生在主簿源复背斜形成之前; 主簿源复背斜使面理化榴辉岩的产状由倾向北改变为倾向南。根据面理化榴辉岩及其围岩的同位素年龄, 估算出面理化榴辉岩在２００～１９０ Ｍａ 期间的平均垂直折返速率为９ｍ ｍ ／ａ。此外, 还  相似文献   

皖南井潭组变质火山岩Sm-Nd同位素年龄及其大地构造意义   总被引：4，自引：0，他引：4  

陈冠宝  徐树桐 《现代地质》1998,12(4):548-554

皖南地区井潭组变质火山岩原划归新元古界历口群,层位在中元古界上溪群之上。通过重新认识本区的地质条件后,发现它是一套生成于岛弧环境的钙碱性火山岩组合,而原上溪群中部分地层则是与之有关的火山沉积,其层位应在井潭组变质火山岩之上。本次对井潭组变质火山岩Ｓｍ Ｎｄ同位素年龄的研究获得以下信息：一是井潭组的等时线年龄为９９０Ｍａ,指示其形成时代为新元古代;二是其模式年龄平均为１８０７Ｍａ,结合上溪群中已有的Ｓｍ Ｎｄ模式年龄和其他地质资料,进一步证明它是原上溪群的物源供给区;三是以井潭组变质火山岩为主体的构造岩石单位可以与浙江的双溪坞群和江西的双桥山群部分层位对比。这些信息为认识本区乃至整个“江南古陆”的构造格局和演化提供了重要的佐证。  相似文献   

Dating of prograde metamorphic events deciphered from episodic zircon growth in rocks of the Dabie–Sulu UHP complex, China     

Dunyi Liu  Ping Jian  Alfred Krner  Shutong Xu 《Earth and Planetary Science Letters》2006,250(3-4):650-666

The timing of ultra-high pressure (UHP) metamorphism has been difficult to determine because of a lack of age constraints on crucial events, especially those occurring on the prograde path. New Sensitive High-Resolution Ion Microprobe (SHRIMP) U–Pb age and rare-earth element (REE) data of zircon are presented for UHP metamorphic rocks (eclogite, garnet peridotite, garnet pyroxenite, jadeite quartzite and garnet gneiss) along the Dabie–Sulu UHP complex of China. With multiphase metamorphic textures and index mineral inclusions within zircon, the Dabie data define three episodes of eclogite-facies metamorphism, best estimated at 242.1 ± 0.4 Ma, 227.2 ± 0.8 Ma and 219.8 ± 0.8 Ma. Eclogite-facies zircons of the Sulu UHP complex grew during two major episodes at 242.7 ± 1.2 and 227.5 ± 1.3 Ma, which are indistinguishable from corresponding events in the Dabie UHP complex. A pre-eclogite metamorphic phase at 244.0 ± 2.6 Ma was obtained from two Sulu zircon samples which contain low pressure–temperature (plagioclase, stable below the quartz/Ab transformation) and hydrous (e.g., amphibole, stable below  2.5 Gpa) mineral inclusions. In terms of Fe–Mg exchange of trapped garnet–clinopyroxene pairs within zircon domains, we are able to determine the Pressure–Temperature (PT) conditions for a specific episode of metamorphic zircon growth. We suggest that mineral phase transformations and associated dehydration led to episodic eclogite-facies zircon growth during UHP metamorphism ( 2.7 Gpa) began at 242.2 ± 0.4 Ma (n = 74, pooling the Dabie–Sulu data), followed by peak UHP metamorphism (>  4 Gpa) at 227.3 ± 0.7 Ma (n = 72), before exhumation (<  220 Ma) to quartz stability (~ 1.8 Gpa). The Dabie–Sulu UHP metamorphism lasted for about 15 Ma, equivalent to a minimum subduction rate of 6 mm/year for the descending continental crust.  相似文献   

Retrogressive Microstructures of the Eclogites from the Northern Dabie Mountains, Central China： Evidence for Rapid Exhumation     

LiuYican LiShuguang XuShutong ChenGuanbao 《中国地质大学学报(英文版)》2004,15(4):349-354

The ultrahigh-pressure eclogites from the northern Dabie Mountains in central China occurred as tectonic lens or blocks within granitic gneisses or meta-peridotites. Petrologic studies suggest that the studied eclogites experienced strongly retrogressive metamorphism and produced a series of characteristic retrogressive microstructures. The retrograde structures mainly include: (1) oriented needle mineral exsolution, e. g. , quartz needles in Na-clinopyroxene and rotile, clinopyroxene and apatite exsolution in garnet formed under decreasing pressure conditions during exhumation; (2) symplectite, especially, two generations of symplectites developed outside the garnet grains, which are called ““double symplectite““ here; (3) compositional zoning of minerals such as garnet and clinopyroxene; (4) minerals with a reaction rim or retrograde rim, e.g. , omphacite with a diopside rim, diopside with an amphibole rim and rutile with a rim of ilmenite. These retrograde textures, especially mineral zoning and symplectite, provide important petrologic evidence for the exhumation process and uplift of high-grade metamorphic rocks such as eclogite in the northern Dabie Mountains, indicating a rapid exhumation process.  相似文献   

蓝田构造窗   总被引：11，自引：0，他引：11       下载免费PDF全文

徐树桐  孙枢 《地质科学》1993,28(2):105-116

蓝田构造窗位于安徽省南部上溪辟(相当于板溪群)中。组成构造窗的地层为震旦系和部分下古生界,它们以断层与周围浅变质岩接触。浅变质岩包括构造混杂岩、复理石浊积岩、钙碱性火山岩和相应的沉积岩以及前震旦纪碎屑岩四种岩石单位,它们是不同构造背景下的产物,在扬子板块与华南板块碰撞造山过程中聚集到一起的。据此可识别出,以往所说的蓝田盆地实际上是一个构造窗。  相似文献