| Preliminary study on the pre-Mesozoic tectonic unit division of the Xing-Meng Orogenic Belt (XMOB) | |
| Alternative Title | Preliminary study on the pre-Mesozoic tectonic unit division of the Xing-Meng Orogenic Belt (XMOB) |
| Xu Bei1; Zhao Pan1; Bao QingZhong2; Zhou YongHeng2; Wang YanYang1; Luo ZhiWen1 | |
| 2014 | |
| Source Publication | ACTA PETROLOGICA SINICA
 |
| ISSN | 1000-0569 |
| Volume | 30Issue:7Pages:1841-1857 |
| Abstract | According to the viewpoint that the paleo-Asian ocean closed by the end of Early Paleozoic and extended during the Late Paleozoic, a pre-Mesozoic tectonic unit division has been suggested. Five blocks and four sutures have been recognized in the pre-Devonia stage, the five blocks are called Erguna (EB), Xing' an (XB), Airgin Sum-Xilinhot (AXB), Songliao-Hunshandak (SHB) and Jiamusi (JB) blocks and four sutures, Xinlin-Xiguitu (XXS), Airgin Sum-Xilinhot-Heihe (AXHS), Ondor Sum-Jizhong-Yanji (OJYS) and Mudanjiang (MS) sutures. The EB contains the Precambrian basement with the ages of 720 similar to 850Ma and epsilon(Hf)(t) = +2.5 to +8.1. The XB is characterized by the Paleoproterozoic granitic gneiss with epsilon(Hf)(t) = -3.9 to 8.9. Several ages from 1150Ma to 1500Ma have been acquired in the AXB, proving presence of old block that links with Hutag Uul block in Mongolia to the west. The Paleoproterozoic (1.8 similar to 1.9Ga) and Neoproterozoic (750 similar to 850Ma) ages have been reported from southern and eastern parts of the SHB, respectively, which suggests occurrence of a Precambrian block. As a small block in east margin of the XMOB, the JB outcrops magmatite and granitic gneiss bases with ages of 800 similar to 1000Ma. The XXS is marked by blueschists with zircon ages of 490 similar to 500Ma in Toudaoqiao village, ophiolites in Xiguitu County and granite with ages of about 500Ma along the northern segment of XXS. The AXHS is characterized by the Early Paleozoic arc magmatic rocks with ages from 430Ma to 490Ma, melange and the Late Devonia molass basins, which indicates a northward subduction of the SHB beneath the AXB during the Early-Middle Paleozoic. The OJYS is composed of the Early Paleozoic volcanic rocks, diorites and granites with ages of 425 similar to 475Ma, blueschists, ophiolitic melange, the Late Silurian flysch and Early-Middle Devonian molasses in western segment, granites (420 similar to 450Ma) in middle segment, and plagiogranites (443Ma) and the Late Silurian molasses in eastern segment. This suture was caused by a southward subduction of the SHB beneath the North China block. The MS is between the SHB and JB, marked by the three phase granites of 485Ma, 450Ma and 425Ma in the SHB. Tectonic units of the Middle Devonian-Carboniferous tectonic stage are recognized based on plant fossils, continental and paralic facies, biomodal volcanic rocks, granites and ophiolites. These units include the Middle-Late Devonian continental basin filled by molasses with plant fossils called the Seribayanaobao Formation in western Inner Mongolia, Carboniferious continental and epeiric sea basin containing terrigenous elastic rocks and carbonate sequence, intrusive and irruptive igneous rock belt with ages from 300Ma to 330Ma containing granites, diorites, gabbros and biomodal volcanic rocks, and Early Carboniferious ophiolites of 330 similar to 350Ma in Hegenshan and Erenhot. These ophiolites are located on the Middle-Late Devonian continental crust base, which suggests a continental rift environment for them. The Permian tectonic units can be divided into passive rift belt, active rift basin, ophiolite belt, and alkaline rock belt, which indicates a continuous extension environment during the Permian. The passive rift belt is composed of thick continental sedimentary rocks containing plant fossils called the Baoligaomiao or Gegentingaobao Formation and biomodal volcanic rocks (270 similar to 290Ma) called the Dashizhai Formation in Inner Mongolia. The alkaline rocks can be divided into north and south belts by their distribution. |
| Keyword | U-PB GEOCHRONOLOGY PALEO-ASIAN OCEAN INNER-MONGOLIA NORTH CHINA NE CHINA GEOLOGICAL SIGNIFICANCE ZIRCON GEOCHRONOLOGY NORTHEASTERN CHINA GRANITIC PLUTONS INTRUSIVE ROCKS Tectonic unit The Xing-Meng Orogenic Belt North China Pre-Mesozoic |
| Indexed By | CSCD |
| Language | 英语 |
| CSCD ID | CSCD:5188618 |
| Citation statistics |
Cited Times:187[CSCD]
[CSCD Record]
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| Document Type | 期刊论文 |
| Identifier | http://ir.imr.ac.cn/handle/321006/143858 |
| Collection | 中国科学院金属研究所 |
| Affiliation | 1.北京大学 2.中国科学院金属研究所 |
| Recommended Citation GB/T 7714 | Xu Bei,Zhao Pan,Bao QingZhong,et al. Preliminary study on the pre-Mesozoic tectonic unit division of the Xing-Meng Orogenic Belt (XMOB)[J]. ACTA PETROLOGICA SINICA,2014,30(7):1841-1857. |
| APA | Xu Bei,Zhao Pan,Bao QingZhong,Zhou YongHeng,Wang YanYang,&Luo ZhiWen.(2014).Preliminary study on the pre-Mesozoic tectonic unit division of the Xing-Meng Orogenic Belt (XMOB).ACTA PETROLOGICA SINICA,30(7),1841-1857. |
| MLA | Xu Bei,et al."Preliminary study on the pre-Mesozoic tectonic unit division of the Xing-Meng Orogenic Belt (XMOB)".ACTA PETROLOGICA SINICA 30.7(2014):1841-1857. |
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