Redefinition of the Lower Permian Qudi Formation in Yadan area, Rongma Town, northern Tibet, and its tectonic significance
-
摘要:
西藏羌塘中部增生杂岩的不断解体对于该区古生代—三叠纪地层格架的厘定及特提斯洋演化研究具有重要的指示意义。对西藏荣玛乡亚丹地区的增生杂岩进行实测剖面时，发现一段早二叠世大陆斜坡相深水重力流形成的海底扇细碎屑岩沉积，北侧被新生代康托组红层覆盖，南侧与玄武岩等基性岩块呈断层接触，沉积序列不完整，主体为一套海底扇中扇-外扇厚层粉砂岩夹水道砂岩透镜体。碎屑岩层中垮塌沉积的生屑灰岩夹层含Parafusulina，Pseudofusulina，Schwagerina，Chalaroschwa-gerina parampla共4属10种（䗴）类化石，指示地层时代为早二叠世亚丁斯克期。1:25万日干配错幅区域地质调查将该地层归为吞龙共巴组，主要为混积陆棚相沉积。依据岩石地层及化石组合时代，厘定本套海底扇沉积为下二叠统曲地组。结合前人报道的早—中二叠世含（䗴）灰岩建造，以及羌塘中部晚石炭世—早二叠世基性岩的大陆裂谷背景，认为羌塘中部早二叠世沉积代表了中特提斯洋演化的初始阶段，并推测在空谷阶之后发育小规模洋盆。
Abstract:The continuous separation of accretionary complex in central Qiangtang of Tibet is significant for defining the framework of strata from Paleozoic to Triassic and studying the evolution of Tethys. The authors measured a section of the accretionary complex in Yadan area, Rongma Town, Nyima County, Tibet, and discovered a sequence of submarine fan clasolites formed by deep-water gravity flow on the continental slope in Early Permian. The north of the strata is covered by Cenozoic red Kangtuo Formation, and the south is in faulted contact with basalt blocks. It is intercalated with sandstone lenses from the outer part to the middle fan. The intercalated layer of bioclastic limestone formed by collapse deposition contains a fusuline fauna and consists of ten species in four genera such as Parafusulina, Pseudofusulina, Schwagerina, Chalaroschwagerina, suggesting Artinskian period. The 1:250000 geological map of Rigan Peicuo defined the strata as Tunlong Gongba Formation which was mainly formed by diamictite continental shelf deposits. Based on the lithostratigraphy and the time of the fossil assemblage, The authors redefined the submarine fan strata as Qudi Formation. In combination with previous widely reported limestone formation containing fusuline and the continental rift background of basic dikes in central Qiangtrang from Late Carboniferous to Early Permian, the authors hold that the early Permian sedimentary formation represented the initial evolution of the Meso-Tethys Ocean and there existed a small ocean basin after the Kungurian Stage.
-
Key words:
- Rongma Town, Tibet /
- Qudi Formation /
- fusuline fauna /
- Early Permian /
- submarine fan /
- accretionary complex
-
-
图 图版Ⅰ 1.Pseudofusulina japonica Guembel，轴切面，野外编号：D0528-HB1-1；2. Chalaroschwagerina parampla Zhang et Dong，轴切面，野外编号：D0528-HB1-2；3. Parafusulina densa Reichel，轴切面，野外编号：D0528-HB1-3；4. Parafusulina splendens Dunbar et Skinner，轴切面，野外编号：D0528-HB1-4；5. Pseudofusulina huagonensis Zhang，轴切面，野外编号：D0528-HB2-1；6. Parafusulina splendens Dunbar et Skinner，轴切面，野外编号：D0528-HB2-2；7. Pseudofusulina japonica Guembel，轴切面，野外编号：D0528-HB2-3；8. Parafusulina undulate Chen，轴切面，野外编号：D0528-HB2-4；9. Parafusulina sp.，轴切面，野外编号：D0528-HB2-5；10. Parafusulina decora Han.，轴切面，野外编号：D0528-HB3-1；11. Parafusulina sp.，轴切面，野外编号：D0528-HB3-2；12. Parafusulina sp.，轴切面，野外编号：D0528-HB4-1；13. Parafusulina sp.，轴切面，野外编号：D0528-HB4-2；14. Schwagerina callosa Han.，轴切面，野外编号：D0528-HB5-1；15. Parafusulina hexigtenensis Han.，轴切面，野外编号：D0528-HB5-2
-
[1] 李才.龙木错-双湖-澜沧江板块缝合带与石炭二叠纪冈瓦纳北界[J].长春地质学院学报, 1987, 17(2): 156-162. http://www.cnki.com.cn/Article/CJFDTOTAL-CCDZ198702003.htm
[2] 李才, 程立人, 胡克, 等.西藏龙木错-双湖古特提斯缝合带研究[M].北京:地质出版社, 1995: 1-131.
[3] 李才, 翟刚毅, 王立全, 等.认识青藏高原的重要窗口——羌塘地区近年来研究进展评述 (代序)[J].地质通报, 2009, 28(9): 1170-1175. http://dzhtb.cgs.cn/ch/reader/view_abstract.aspx?flag=1&file_no=20090901&journal_id=gbc
[4] 刘本培, 冯庆来, Chonglakmani C, 等.滇西古特提斯多岛洋的结构及其南北延伸[J].地学前缘, 2002, 9(3): 163-164. http://www.cnki.com.cn/Article/CJFDTOTAL-DXQY200203027.htm
[5] 王根厚, 韩芳林, 杨运军, 等.藏北羌塘中部晩古生代增生杂岩的发现及其地质意义[J].地质通报, 2009, 28(9): 1182-1187. http://dzhtb.cgs.cn/ch/reader/view_abstract.aspx?file_no=20090903&flag=1
[6] 耿全如, 潘桂棠, 王立全, 等.班公湖-怒江带、羌塘地块特提斯演化与成矿地质背景[J].地质通报, 2011, 30(8): 1261-1263. http://dzhtb.cgs.cn/ch/reader/view_abstract.aspx?file_no=20110813&flag=1
[7] Zhai Q G, Zhang R Y, Jahn B M, et al. Triassic eclogites from central Qiangtang, northern Tibet, China: Petrology, geochronology and metamorphic P-T path[J]. Lithos, 2011, 125: 173-176. doi: 10.1016/j.lithos.2011.02.004
[8] Liang X, Wang G H, Yuan G L, et al. Structural sequence and geochronology of the Qomo Ri accretionary complex, Central Qiangtang, Tibet: Implications for the Late Triassic subduction of the Paleo-Tethys Ocean[J]. Gondwana Research, 2012, 22: 470-481. doi: 10.1016/j.gr.2011.11.012
[9] 赵政璋, 李永铁, 叶和飞, 等.青藏高原羌塘盆地石油地质[M].北京:科学出版社, 2001.
[10] 王成善, 伊海生.羌塘盆地地质演化与油气远景评价[M].北京:地质出版社, 2001.
[11] 王剑, 谭富文, 李亚林, 等.青藏高原重点沉积盆地油气资源潜力分析[M].北京:地质出版社, 2004.
[12] 吴瑞忠, 胡承祖, 王成善, 等. 藏北羌塘地区地层系统[C]//青藏高原地质文集 (9). 北京: 地质出版社, 1986: 1-32.
[13] 王成善, 胡承祖, 吴瑞忠, 等.西藏北部查桑-茶布裂谷的发现及其地质意义[J].成都地质学院学报, 1987, 14(2): 296-301. http://www.cnki.com.cn/Article/CJFDTOTAL-CDLG198702003.htm
[14] 黄继钧.羌塘盆地基地构造特征[J].地质学报, 2001, 75(3): 333-337. http://www.cnki.com.cn/Article/CJFDTOTAL-DZXE200103009.htm
[15] 王国芝, 王成善.西藏羌塘基底变质岩系的解体和时代厘定[J].中国科学 (D辑), 2001, 31: 77-81. http://www.cnki.com.cn/Article/CJFDTOTAL-JDXK2001S1011.htm
[16] 李才, 郑安柱.西藏羌塘地区古生界划分及其与构造关系讨论[J].西藏地质, 1990, 1: 1-18.
[17] 李才, 王天武, 杨德明, 等.西藏羌塘中央隆起区物质组成与构造演化[J].长春科技大学学报, 2001, 31(1): 25-31. http://www.cnki.com.cn/Article/CJFDTOTAL-CCDZ200101004.htm
[18] 梁定益, 聂泽同, 郭铁鹰, 等.西藏阿里喀喇昆仑南部的冈瓦纳——特提斯相石炭二叠系[J].地球科学, 1983, 19(1): 1-27. http://www.cnki.com.cn/Article/CJFDTOTAL-DQKX198301001.htm
[19] 李曰俊, 吴浩若, 李红生.藏北阿木岗群、查桑群和鲁谷组放射虫的发现及有关问题讨论[J].地质论评, 1997, 43(3): 250-256. http://www.cnki.com.cn/Article/CJFDTOTAL-DZLP199703004.htm
[20] 邓万明, 尹集祥, 吊中平.羌塘茶布-双湖地区基性超基性岩和火山岩研究[J].中国科学 (D辑), 1996, 26(4): 296-301. http://www.cnki.com.cn/Article/CJFDTOTAL-JDXK199604001.htm
[21] 朱同兴, 张启跃, 董瀚, 等.藏北双湖地区才多茶卡一带构造混杂岩中发现晚泥盆世和晚二叠世放射虫硅质岩[J].地质通报, 2006, 25(12): 1413-1417. http://dzhtb.cgs.cn/ch/reader/view_abstract.aspx?flag=1&file_no=2006012263&journal_id=gbc
[22] 耿全如, 彭智敏, 张璋.青藏高原羌塘地区果干加年山-荣玛乡一带石炭纪-二叠纪古生物研究新进展[J].地质通报, 2012, 31(4): 510-520. http://dzhtb.cgs.cn/ch/reader/view_abstract.aspx?file_no=20120403&flag=1
[23] 王泉. 西藏羌塘荣玛地区亚丹片岩变形变质特征及地质意义[D]. 中国地质大学 (北京) 硕士学位论文, 2015: 22.
[24] 黄志勋, 时言, 魏沐潮.二叠系一个新的地层单位——隆林阶[J].成都地质学院学报, 1982, 4: 63-75. http://www.cnki.com.cn/Article/CJFDTOTAL-CDLG198204006.htm
[25] 黄志勋, 曾学鲁.广西隆林地区早二叠世早期 (隆林阶) 的 (䗴) 类动物群[J].地球科学-武汉地质学院学报, 1984, 26: 11-26. http://www.cnki.com.cn/Article/CJFDTotal-DQKX198403002.htm
[26] 盛金章.中国的类[M].北京:科学出版社, 1962: 128-135.
[27] 颜铁增.浙江省船山组的划分和对比[J].地层学杂志, 2003, 27(4): 318-324. http://www.cnki.com.cn/Article/CJFDTOTAL-DCXZ200304008.htm
[28] 张祖圻.华南的二叠系[J].中南矿冶学院学报, 1985, 43: 19-27. http://www.cnki.com.cn/Article/CJFDTOTAL-ZNGD198501002.htm
[29] 曾学鲁, 朱伟元, 何心一, 等.西秦岭石炭纪、二叠纪生物地层及沉积环境[M].北京:地质出版社, 1996: 17-33.
[30] 周铁明, 盛金章, 王玉净.云南广南小独山石炭-二叠系界线地层及类分带[J].微体古生物学报, 1987, 4(2): 123-157. http://www.cnki.com.cn/Article/CJFDTOTAL-WSGT198702000.htm
[31] 史宇坤, 杨湘宁, 刘家润, 等.贵州省紫云县宗地乡下二叠统隆林阶地层初步研究[J].地层学杂志, 2004, 28(4): 326-330. http://www.cnki.com.cn/Article/CJFDTOTAL-DCXZ200404009.htm
[32] Zhang Y C, Wang Y, Zhang Y J, et al. Artinskian (Early Permian) fusuline fauna from the Rongma area in northern Tibet: palaeoclimatic and palaeobiogeographic implications[J]. Alcheringa, 2012, 37: 529-546.
[33] 熊兴国, 徐安全, 岳龙, 等.羌塘才玛尔错晚三叠世地层的厘定及其意义[J].贵州地质, 2006, 23(1): 29-31. http://www.cnki.com.cn/Article/CJFDTOTAL-GZDZ200601007.htm
[34] 翟庆国, 李才, 程立人, 等.西藏羌塘角木日地区二叠纪蛇绿岩的地质特征及意义[J].地质通报, 2004, 23(12): 1228-1230. http://dzhtb.cgs.cn/ch/reader/view_abstract.aspx?flag=1&file_no=2004012221&journal_id=gbc
[35] 翟庆国, 李才, 黄小鹏.西藏羌塘中部角木日地区二叠纪玄武岩的地球化学特征及其构造意义[J].地质通报, 2006, 25(12): 1419-1427. http://dzhtb.cgs.cn/ch/reader/view_abstract.aspx?flag=1&file_no=2006012264&journal_id=gbc
[36] 鲁庆伟, 王根厚.藏北冈塘错地区OIB型和E-MORB型玄武岩组合及大地构造意义[J].新疆地质, 2011, 29(3): 332-336. http://www.cnki.com.cn/Article/CJFDTOTAL-XJDI201103020.htm
[37] Li C S, Arndt N T, Tang Q, et al. Trace element indiscrimination diagrams[J]. Lithos, 2015, 232: 76-83. doi: 10.1016/j.lithos.2015.06.022
[38] Pearce J A. Immobile element fingerprinting of ophiolites[J]. Elements, 2014, 10: 101-108. doi: 10.2113/gselements.10.2.101
[39] 李才, 和钟铧, 李惠民.青藏高原南羌塘基性岩墙群U-Pb和Sm-Nd同位素定年及构造意义[J].中国地质, 2004, 31(4): 384-389. http://www.cnki.com.cn/Article/CJFDTOTAL-DIZI200404006.htm
[40] Zhai Q G, Jahn B M, Su L, et al. SHRIMP zircon U-Pb geochronology, geochemistry and Sr-Nd-Hf isotopic compositions of a mafic dyke swarm in the Qiangtang terrane, northern Tibet and geodynamic implications[J]. Lithos, 2013, 174: 28-43. doi: 10.1016/j.lithos.2012.10.018
[41] 王明, 李才, 翟庆国.青藏高原羌塘南部晚古生代地幔柱?——来自基性-超基性岩的地球化学证据[J].地质通报, 2010, 29(12): 1754-1772. http://dzhtb.cgs.cn/ch/reader/view_abstract.aspx?flag=1&file_no=20101204&journal_id=gbc
[42] Metcalfe I. Palaeozoic and Mesozoic tectonic evolution and palaeogeography of East Asian crustal fragments: The Korean Peninsula in context[J]. Gondwana Research, 2006, 9: 24-25, 30, 35-43. doi: 10.1016/j.gr.2005.04.002
[43] Metcalfe I. Palaeozoic-Mesozoic history of SE Asia[J]. The Geological Society, London, Special Publications, 2011, 355(1): 7-35. doi: 10.1144/SP355.2
-
下载:
图(6)
计量
- 文章访问数: 359
- PDF下载数: 5
- 施引文献: 0