| 178 | 27 | 156 |
| 下载次数 | 被引频次 | 阅读次数 |
通过对查查香卡地区晚三叠世火山岩岩石学特征、空间分布、形态、火山机构、火山岩与构造关系的研究,确定该套火山岩时代为晚三叠世。岩石地层单位为鄂拉山组,为一套陆相喷发火山岩,呈NW向展布于大海滩-都库隆瓦地区。以中-高钾、高钙、低钛为特征,属钙碱性系列。火山喷发活动由强到弱,岩性由中性向中酸性渐变,岩浆活动由喷发型向侵入型递进。表明岩石构造环境为陆内消减带火山岩中的造山区。是来自地壳下部的火山岩浆经分异结晶并在上涌过程中混入有上地壳物质而喷发形成。喷出时的大地构造环境为陆内造山环境,该火山岩最初可能形成于大陆边缘环境,由于A型俯冲构造活动,测区乃至鄂拉山地区产生一系列右旋走滑断裂带,受NW向右旋走滑断裂的影响,岩石孔隙加大,并出现强烈的热流活动,导致岩浆沿这些断裂带喷出地表。
Abstract:By studying the petrology, the space distribution, the volcanic mechanism, the relationship between the volcanic rock and the intrusive rock of late Triassic Epoch, and the structural zone around Chachaxiangka,the age of the volcanic rock is late Triassic Epoch.The rock stratum unit is Ngoloshan Group. It is a suit of continental eruption volcanic rock, distributing toward NW direction in Dahaitan-Dukulongwa area. Medial-high potassium, high calcium, low titanium, subordinating tocalc-alkaline series.Volcanic eruption acted from strong to weak as medium rocks became gradually into medium-acid rocks in Lithology, and extrusion changed into intrusion in magma activity. The volcanic rocks of Caidamu basin.And being a part of Dulan-Elashan moutain volcanic eraption belt in eastern Kunlun volcanic belt of late Triassic Epoch. This indicates the tectonic environment is orogenic belt region in consume zone. It is formed when magma of the lower Earth's crust streams up,while mingled with the material of the upper Earth's crust, and erupted finally. Tectonic environment belongs to orogenic environment. The volcanic rocks may be formed in continental marginal environment, as a result of A-type subduction,brought a series of dextral rotation strick-slip fault zone,apetuer of rocks became larger, and emerged intense hot fluid,caused magma erupted to the earth's surface from these fault zone.
[1] 高延林,吴向农,左国朝 东昆仑山清山泉蛇绿岩特征及其大地构造意义[J] 中国地质科学院西安地质矿产研究所所刊,1988,(21):8~9
[2] 姜春发,杨经绥,冯秉贵,等 昆仑开合构造[A] 地质矿产部地质专报第(五)12号[C] 1992.37~40
[3] 孙延贵 鄂拉山造山带中段哇洪拉分盆地的充填机制[J] 青海地质,1999,(1):32~35
[4] 殷鸿福,张克信 中国西部造山带1:250000填图方法研究论文集[C] 中国地质大学(武汉),1999.224~268
[5] 许强,潘桂堂,李兴振 秦祁昆交界区地质构造特征及演化模式[M] 北京:中国经济出版社,1996.102~106
[6] P 亨德森,田丰,施良,等译 稀土元素地球化学[M] 北京:地质出版社,1989.109~121
[7] 李昌年 火成岩微量元素岩石学[M] 北京:中国地质大学出版社,1992.183~186
[8] 殷鸿福,张克信 中央造山带的演化及其特点[J] 地球科学—中国地质大学学报,1996,23(5):10~12
[9] PearceJA,TraceelementCharacteristicsoflavasfromdestructiveplateboundaries[J] lnAndesites,ed 1982byThorps R S ,Chichester,Wiley.101~109
[10]张国伟,董云鹏,等 秦岭造山带基本组成与结构及其构造演化[J] 陕西地质,1997,22(2):56~60
基本信息:
中图分类号:P588.1
引用信息:
[1]童海奎,王树林,宋生春,谈生祥,马秀兰,黄青华.青海省查查香卡地区晚三叠世火山岩岩石学及其构造环境[J].高原地震,2004(02):38-48.
2004-06-30
2004-06-30