The Boundary Between Sino-Korea Craton and Yangtze Craton and Its Extension to the Korean Peninsula
The Boundary Between Sino-Korea Craton and Yangtze Craton and Its Extension to the Korean Peninsula
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中朝克拉通与扬子克拉通边界及其向朝鲜半岛的延伸
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发表时间：
1998
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影响因子：
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通讯作者：
L. Wenjun
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作者：
Zhai Mingguo;L. Wenjun
大别-苏鲁超高压变质带通常被认为是中朝克拉通（华北克拉通）与扬子克拉通之间的碰撞带（翟和丛，1996）。在研究东北亚构造演化过程中，有两个重要问题：（1）山东半岛的超高压变质带与中朝克拉通的边界问题;（2）中国超高压变质带向朝鲜半岛的延伸问题。关于山东半岛超高压变质带与中朝克拉通的界线问题，一直存在不同的认识。例如，边界被认为是Tan-Lu断层（Bai等人，1993; Wang和Cong，1996），或五莲-荣成断裂（Cao等人，1990年）。最近的研究发现了新的证据，表明可能的边界是沿着五莲-牟平断裂的昆玉山花岗岩杂岩带。我们的新证据是：（1）昆嵛山花岗岩带以西的基性岩为高压麻粒岩而非榴辉岩（翟，1996），其Sm-Nd同位素年龄分别为1750 Ma和2788 Ma，代表其退变质和成岩年龄（李等，（1997年b）;（2）昆玉山花岗岩带以西的正片麻岩测得2600-2900 Ma锆石年龄和1600-2020 Ma Rb-Sr和U-Th-总Pb化学年龄，但没有更年轻的数据（Enami等，1993; Ishizaka等人，（3）昆玉山花岗岩带以东的正片麻岩同位素年龄为110-320 Ma，峰值为180-230 Ma，具有典型的超高压变质带变质岩特征;（4）昆嵛山花岗岩带由大量花岗岩体、岩株和脉组成，年龄为1900-2000 Ma，610-710 Ma和124-180 Ma的同位素年龄表明该花岗岩带的演化历史漫长而复杂。昆嵛山花岗岩带中存在着中朝克拉通和苏鲁超高压变质带中的许多变质岩透镜体和包体。翟伟等（1998）将昆嵛山花岗岩带界定为胶东边界杂岩带。一些地质学家认为，超高压变质带向东延伸至朝鲜半岛（Yin和Nie，1993年; Wang和Cong，1996年），并可能延伸至临津江带（Chang，1994年; Ree等人，1996年）。遗憾的是，目前还没有确凿的证据表明朝鲜半岛存在超高压变质岩石。在这方面，将山东半岛的变质岩与朝鲜半岛北方和南部的变质岩进行比较就显得更为重要。
The Dabie-Sulu ultra-high pressure metamorphic (UHPM) zone is commonly suggested to be a collisional belt between the Sino-Korea craton (North China craton) and Yangtze craton (Zhai and Cong, 1996). Two important questions in formulating the tectonic evolution of the northeast Asia are : (1) the boundary between the UHPM zone and the Sino-Korea craton in the Shandong peninsula and (2) the extension of this Chinese UHPM zone into the Korean peninsula. There have been different opinions on the boundary between UHPM zone and the Sino-Korea craton in the Shandong peninsula. For example, the boundary has been suggested to be the Tan-Lu fault (Bai et al., 1993; Wang and Cong, 1996), or Wulian-Rongcheng fault (Cao et al., 1990). Our recent study finds out new evidences, indicating that the possible boundary is the Kunyushan granitoid complex zone, which occurs along the Wulian-Muping fault. Our new evidences are : (1) the basic rocks west to the Kunyushan granitoid zone are high-pressure granulites rather than eclogites (Zhai, 1996) with their Sm-Nd isotopic ages of 1750 Ma and 2788 Ma, representing their retrograde metamorphic and petrogenetic ages, respectively (Li et al., 1997b); (2) the orthogneisses west to the Kunyushan granitoid zone yield 2600-2900 Ma zircon ages and 1600-2020 Ma Rb-Sr and chemical U-Th-total Pb ages, with no younger data (Enami et al., 1993; Ishizaka et al., 1994), having a typical characteristic for the early Precambrian rocks in the Sino-Korea craton; (3) the orthogneisses east to the Kunyushan granitoid zone have 110-320 Ma isotopic ages with a peak value of 180-230 Ma, showing a typical characteristic of metamorphic rocks in the UHPM zone; (4) the Kunyushan granitoid zone consists of numerous granitic bodies, stocks and veins, which have 1900-2000 Ma, 610-710 Ma and 124-180 Ma istotopic ages indicating a long and complicated evolution history of this granitoid zone. There are many lenses and enclosures of metamorphic rocks from the Sino-Korea craton and Sulu UHPM belt in the Kunyushan granitoid zone. Zhai et al. (1998) have defined the Kunyushan granitoid zone as the Jiaodong Boundary complex zone. Some geologists suggested that the UHPM zone extend eastward to the Korea peninsula (Yin and Nie, 1993; Wang and Cong, 1996) and possibly to the Imjingang belt (Chang, 1994; Ree et al., 1996). Unfortunately, there has not been a conclusive evidence indicating that UHPM rocks occur in the Korea peninsula. In this regard, it becomes more important to compare metamorphic rocks in the Shandong peninsula with those in northern and southern Korea peninsula.