Mesozoic tectonic regime and regional metallogenic background in Northeast China from the temporal and spatial variation of the Mesozoic volcanic rock combination

The northeastern region is located in the eastern part of the Central Asian orogenic belt. During the Paleozoic period, the area experienced the evolution of the paleo-Asian ocean tectonic system, with multiple micro-continental blocks (from the west to the east including the Erguna block, the Xing'an block, and the pine The combination between the Nen-Zhangguangcailing block, the Jiamusi block and the Xingkai block, and the final closure of the Paleozoic early Paleozoic in the late Paleozoic (Senggrand Natalin, 1996; Li, 2006; Tangeta/., 2013) (a ). During the Mesozoic period, the Northeast region not only experienced the superposition and transformation of the Pacific Rim tectonic system, but also the superposition and transformation of the Mongolian-Okhotsk tectonic system (Xueta/., 2009; Wuet a/., 2011; Meng En et al. , 2011). In recent years, major breakthroughs have been made in regional prospecting in the Northeast, especially the discovery of large-super large porphyry molybdenum deposits, which has made the Northeast an important non-ferrous and precious metal resource base in China (Chen Yanjing et al., 2012). At present, most of the understanding of the Mesozoic regional metallogenic background in Northeast China emphasizes the influence of the Pacific Rim tectonic system (Geeta/., 2007), while ignoring the impact of the Mongolian-Okhotsk tectonic system on the Northeast (b) (Bang) En et al., 2011). Even in the study of the Pacific Rim tectonic system, there are still some key scientific issues that have not been resolved. For example, there is still debate about the beginning of the Pacific Rim tectonic system (the Late Triassic or the Early Middle Jurassic) ( Jilin Province Bureau of Geology and Mineral Resources, 1988; Heilongjiang Provincial Bureau of Geology and Mineral Resources, 1993; Zhao Yue et al., 1994; Zhao Chunjing et al., 1996; Sun Deyou et al., 2005; Wueta/., 2007; Yu Fuping et al., 2008; Zhoueta/. , 2009), the evolutionary history of the Mesozoic in the Pacific Rim tectonic system is not yet clear, such as the spatial extent of the influence of the Pacific Rim tectonic system on several subduction events in the Mesozoic. Compared with the study of the Pacific Rim tectonic system, there are fewer studies on the influence of the Mongolian-Okhotsk tectonic system on China. At present, most of the emphasis is on the northward subduction of the oceanic plate, and whether there is a southward subduction and evolution of the Mesozoic. History knows less. Although breakthroughs have been made in the study of the age, genesis and continental crust growth of granite in Northeast China in recent years (Wueta/., 2011), due to the diversity of genetic types of granite and the nature of magma source areas, In terms of component polarity variation, it is difficult to get a good performance. In contrast, volcanic rocks have better compositional polarity, which is more important to reveal the subduction history of the oceanic plate. In view of this, this paper systematically summarizes the chronology of Mesozoic volcanism in Northeast China and the spatiotemporal variation of volcanic rock combinations in different periods, in order to reveal the Mesozoic dynasty in the northeastern region: the Mesozoic tectonic regime and regional metallogenic background in Northeast China: from the Mesozoic volcanic rocks The combination of spatiotemporal changes constrains the tectonic zoning of the Northeast (a, according to Wuetal., 2011) and the main geographic unit of the Northeast (b, according to Meng, 2003). The evolutionary history of the tectonic system and the spatial extent of its effects, this comprehensive understanding It is of great significance to reveal the metallogenic background of the Mesozoic and to guide the regional prospecting in the Northeast.

2 Time Limit of the End of the Paleo-Asian Ocean Tectonic System in Northeast China Before discussing the Mesozoic tectonic system in the Northeast, the understanding of the Paleozoic tectonic regime affecting the area, the evolution history of the Paleo-Asian ocean tectonic system and the end of the tectonic system. At present, most scholars believe that the process of flattening multiple micro-land masses in Northeast China is mainly completed in the Caledonian period. For example, the combination of Erguna and Xing'an blocks has been completed in the early Paleozoic (Gewen Chun et al., 2007). The combination of the Nenchang Guangcailing block and the Jiamusi block has been assembled in the late Caledonian period (Wang et al., 2012), and the combination of the Xing'an block and the Songnen Zhangguangcailing block was completed in the Early Carboniferous (Heilongjiang Provincial Bureau of Geology and Mineral Resources) , 1993). These micro-blocks as a whole (known as the Amur block, Senggr and Natalin, 1996; or Jiameng block, Wang et al., 2009) and the North China block and the final closure time of the ancient Asian Ocean can be from the North China block The evolution history of the Late Paleozoic-Early Mesozoic in the northern margin was answered.

Firstly, from the history of the Late Paleozoic magmatism in the central part of the northern margin of the North China block, it can be seen that in the Devonian, the area developed a set of alkaline complexes and basic-ultrabasic complexes. The former is based on A-type granites. The Lord, together they form a bimodal igneous rock combination, revealing the existence of an extended tectonic setting in the northern margin of the North China block (Zhang et al., 2009).

Secondly, the existence of the Late Carboniferous-Early Permian calc-alkaline igneous rock combination in the northern margin of the North China block reveals the subduction of the Paleo-Asian Ocean southward in the North China block (Zhang et al., 2009), Central Jilin Province. - The existence of the Early Permian calc-alkaline volcanic rocks in the Yanji area further demonstrates the southward subduction of the Paleo-Asian Ocean during the Early Permian (Cao Huahua et al., 2012).

Thirdly, the emergence of the Late Permian, the eastern margin of the Songnen-Changguangcailing block and the western margin of the Jiamusi block and the bimodal igneous rock combination in the northern margin of the North China Craton indicate that the area is in a stretched environment (Liuetal. , 2010; Wang Zijin, 2013; Yuetal., 2013), which is compatible with the stretching environment after the collision of the Middle Permian aluminum garnet gems (Caoetal., 2013).

Fourth, in the early Middle Triassic, the collision of the southern margin of the Xingmeng orogenic belt marked the final closure of the ancient Asian Ocean (Sun Deyou et al., 2004; Li Jinxi integrated the above research results, it can be seen that In the northeastern region, the final closure time of the ancient Asian Ocean may occur at the Middle Triassic. Since then, the area has entered the evolutionary stage of the Pacific Rim tectonic system and the Mongolian-Okhotsk tectonic system.

3 Mesozoic volcanism in the northeastern region According to the statistics of the zircon U->b dating of the Mesozoic volcanic rocks in the Northeast, the Mesozoic volcanism in the Northeast can be divided into six phases (), Late Triassic (200~228Ma) Early Middle Jurassic (173 ~ 190Ma), Late Jurassic (158~166Ma), Early Cretaceous (138~145Ma), Early Cretaceous (106~133Ma), Late Cretaceous (88~97Ma) The distribution of these six volcanic rocks is shown in () (Xuetal., 2013).

~228Ma): The volcanic rocks in this period are mainly distributed in the eastern Jihei and Xiaoxing'anling-Changguangcailing areas. The former is mainly a type A rhyolite combination (Xuetal., 2009), and the latter is a set of bimodal volcanic rock combinations ( Wangetal., 2011a).

~190Ma): The volcanic rocks in this period are mainly distributed in the eastern part of Jihei, Xiaoxing'anling-Changguangcailing and Erguna. The zircon IMPb age frequency map of the Mesozoic volcanic rocks in the eastern part of Jihei, eastern China, U)-Yihei eastern area; (b) i Songliao Basin and Xiaoxing'anling 4 Changguangcailing; (C) Sozhouli area; (d) Northeast area . The histogram part is the Mesozoic granite in the northeastern region, which is derived from Zhang de aL LXZR, Xing'anling Changguangcai LingFig. (Southeast of Dun-Ming fault) and the early-age Jurassic volcanic rocks in Erguna area are mainly calc-alkaline Volcanic rock series (Xu Wenliang et al., 2008; Qi Fuping et al., 2009; Xu, 2013), while Xiaoxing'anling is a set of bimodal igneous rocks ~166Ma): From the current dating results, the volcanic rocks are only distributed. In the west of the Songliao Basin, it is mainly a transitional type of subalkaline. The rock combination is: Xuanwu Ryan Anyan Anyan “small ~145Ma”: The distribution of volcanic rocks in this period is similar to that of the Late Jurassic volcanic rocks. It is not found in the east of the Songliao Basin, mainly a set of A-type rhyolite. In some areas, it is alkaline rhyolite (there is a large amount of sodium iron amphibole) (Mengen et al., 2011; Xu Meijun et al., 2011; Wang Jian~133Ma): this period of volcanic rocks is not only widely distributed in the Greater Xing'an Mountains and the eastern part of Jihei ( Wang, 2010; Meng En et al., 2011; Xu Meijun et al., 2011), and also widely produced in the bottom of the Songliao Basin (裴福萍 et al., 2008; Zhang Fengqi et al., ~97Ma): the volcanic rocks in this period are mainly distributed in Jihei In the east (Ji 7., 2007; Zhang Lei et al., 2009; Zhang7., 2012; Yu Jiejiang et al., 2013), this period of magmatism was also found in the Songliao Basin (Wang Yuxi et al., 2009). In addition, the discovery of volcanic rocks in this period has also been carried out in Fuxin (Xu Wenliang et al., 1999) and Liaonan Qujiayu (Wang Wei et al., 2006).

4 Evolution history and regional mineralization of the Mesozoic Pacific Rim tectonic system in Northeast China 4.1 Determination of the start time of the subtropical tectonic system subduction in Eurasia The evolution history of the Mesozoic tectonic system in the northeast and even the eastern China is not very clear. First of all, the beginning of the subduction of the Paleo-Pacific plate has been a controversial issue. There are two main viewpoints at present. The species are considered to be the Late Triassic (Peng Yu Whale and Chen Yuejun, 2007), while the other species are considered to be early Jurassic (Xud, 2009; Wi丨, 2011). The existence of the Late Triassic A-type rhyolite in eastern Jihe (Xu i., 2009) and the existence of the Late Triassic bimodal volcanic rocks in Zhangguangcailing (Wang i., 2011a), and the late Triassic alkali in Zhang Guangcailing The combination of long granites (Wu, 2011) indicates that the area was in an extended environment during the Late Triassic and did not represent the beginning of the subduction of the Paleo-Pacific structural system.

The existence of calc-alkaline volcanic rock combination can be used as an effective marker to determine the occurrence of paleo-subduction. In recent years, the discovery of the early rushing of the Jurassic (173~190Ma) calc-alkaline volcanic rock combination in eastern Jihei (Dongning in Qingdunchun) provided credible evidence for determining the time for the paleo-Pacific structural system to begin subduction ( Xu Wenliang et al., 2008; Qi Fuping et al., 2009), and the existence of the simultaneous bimodal igneous rock combination in the Changguangcailing area of ​​Xiaoxing'anling (Tang Jie et al., 2011; Yui., 2012; Xu Meijun et al., 2013), revealing the Polarity of the volcanic rocks in the marginal volcanic rocks (a) S Sf volcanic review b) Songliao Basin and Xiaojiu Lingling - Zhang T Cai Ling Yu Xingling Ridge - 4. 2 Middle Jurassic - Early White Early in the world: Intermittent period of subduction of the Paleo-Pacific plate First, from the dating results of existing volcanic rocks, 140~165Ma volcanic rocks have not been found in eastern Jihe, and the volcanic rocks in this stage are mainly distributed in the west of the Songliao Basin. This suggests that the magma event at this stage has nothing to do with the subduction of the Paleo-Pacific plate.

Secondly, there are volcanic rocks and gabbro in the late Middle Jurassic (about 166 Ma) in the Nadanhada terraney ophiolites in the eastern part of the Northeast (Zhao Hailing et al., 1996; Cheng Ruiyu et al., 2006), indicating that Eurasia On the east side of the continental margin is a basin in a stretched environment, and the terrane collage takes place between the Late Jurassic and Early Cretaceous. This is evidenced by the serpentine melange being cut by the Early Cretaceous granite. (Cheng Ruiyu et al., 2006).

In summary, in the late Middle Jurassic-early Cretaceous, the Paleo-Pacific plate did not have a subduction effect on the Eurasian continent.

4.3 Early Cretaceous and Late Cretaceous: Two subductions of the ancient Pacific plate to the Eurasian continent ~133Ma) In the northeastern region, the volcanic activity is extensive and intense, however, in the different regions of the northeastern region, the volcanic rocks The composition has significant variation. In the eastern part of Jihei (including the northeastern margin of the North China block), representative strata include: from the north to the south including the Pikeshan Formation, the Suide Formation, the Dongshan Formation, the Jingouling Formation, the Quanshui Village Formation, and the second dice group. Some samples on the Jiamusi block have relatively high alkaline components. The volcanic rocks are mainly composed of a set of calc-alkaline volcanic rocks (Yu, 2009), which represents the existence of the subduction of the ancient Pacific plate (Izanagi). . The contemporary volcanic rocks are mainly composed of bimodal volcanic rocks in the Songliao Basin and the Daxinganling area (Ge Wenchun et al., or alkali feldspar granite (Wuai., 2011). From the continental margin to the inland, the alkaline group in the volcanic rocks. The fraction has an increased compositional polarity change, indicating the occurrence of subduction from the eastern plate.

~97Ma) Late Cretaceous volcanic rocks are mainly distributed in the eastern part of the Northeast. In the representative volcanic strata of the continental margin (Dongning 4 Junchun 1st line), there are distribution maps of the Early Mesozoic porphyry deposits in the northeastern part of Suifen (According to Bai Ling'an et al., 2012; Sun Jinggui et al., 2012; Chen Yanjing et al., 2012 revision) Names of deposits: 1-Unuug Tushan; 2 Hongshan; 3 Manji River; 4 Ridge; 5 pains; 641 Anbao; 7 per Deyi; 8 - Daheishan; 9 毛倒木;10-Liu Shengdian; lHi Jiazhangzi; 12-Ba Daguan; 13- Taipingchuan consists of a set of calc-alkaline volcanic rocks, and in the new land of Liaoxi in the west, Qujiayu in southern Liaoning, contemporaries The volcanic rocks are mainly a set of alkaline basalt (Xu Wenliang et al., 1999; Yan i., 2003; Wang Wei et al., 2006). On the Jiamusi block, the contemporaneous intrusive rocks are alkaline gabbro (Zhang Lei et al. , 2009). The increase in alkaline components from the continental margin to the intracontinental volcanic rocks indicates the occurrence of subduction from the east.

4. The subduction of the Mesozoic Era in the Paleo-European plate and the age and mineralization of the Mesozoic volcanism from the eastern Jiji area, the subduction of the Paleo-Pacific plate to the Eurasian continent during the Mesozoic period. It occurs in three stages: the Early Fighting Jurassic, the Early Cretaceous and the Late Cretaceous.

In these three stages, the continental margin of the northeastern part of Eurasia is at the tectonic setting of the active continental margin, and it is a favorable place for finding porphyry copper-molybdenum deposits and shallow hydrothermal gold-copper deposits in the eastern part of Northeast China. In recent years, the Early Jurassic porphyry molybdenum deposit in the eastern Jihei is the product of the subduction of the Paleo-Pacific plate (Ge忒, 2007; Sun Jinggui et al., 2012; Chen Yanjing et al., 2012). Compared with early Jurassic, in the eastern Jihei, the intensity of the early Cretaceous and Late Cretaceous magmatism was significantly weakened, especially in the latter, near the outer edge of the continental margin (such as the Dongning 4 Junchun line), mainly Looking for rich gold porphyry copper deposits and high sulfurized gold deposits (Hani., 2013), and entering the inner side of the continental margin, mainly represented by Xu Wenliang et al.: Mesozoic tectonic regime and regional mineralization in Northeast China BACKGROUND: The distribution of the Early Cretaceous shallow hydrothermal deposits in the Northeast China from the temporal and spatial variation of the Mesozoic volcanic rocks (according to Bai Ling'an et al., 2012; Sun Jinggui et al., 2012; Han buckle', 2013; Chen Yanjing et al., 2012) Mineral deposit name: 1 - Wulander; 2, Donggou; 3-敖仑花; 4-Taipinggou; 5-Xinga; 6-Sandaowanzi; 7-Dongan; 8" Dingshan; 9. Pingshan; 10- Dawangzizi; 11 cold field ditch; 124 Yuyuangou; 13-Jiuyugou;: UM, southwestern 岔; 154 soil wilderness; 16. branch; 17-Tianbaoshan; 184 temple; 19 test furnace bowl like arc The stretching environment, the corresponding minerals are mainly based on epithermal gold deposits () Sun Jinggui et al. 2009).

5 Mongolia, the evolutionary history and regional mineralization of the Mesozoic tectonic system. 1. Mongolia, P. Hotkske suture zone evolution history overview Mongolian 415 Hotzke suture zone extends from the Hangai Mountains of Mongolia to Ehotz The Uda Bay of Kehai is about 3000km long and 300km wide. It was located between the Siberian plate, the North China plate and the ancient Pacific plate during the Paleozoic and Early Mesozoic. It is an orogenic belt with a long geological history in northern Asia. It occupies an extremely important position in the history of the formation and evolution of the East Asian continent (Li Jinwei et al., 2009). Since the orogenic belt is mainly located in Russia and Mongolia, the research on its evolution history, especially the impact of the structural belt on China's territory, is less. At present, the main understanding is that the Mongolian 415 Hotsky ocean was relatively broad at the end of the Late Paleozoic (CogniSai., 205), and there was already local subduction (Tomurtogooai., 2005; Mazukabzovai., 2010), and continued to the Permian; due to the Siberian plate relative The rotation of the Zhongmeng block caused the scissors closure of the Okhotsk plate from west to east, the western Late Triassic began to close, and the east closed in the late Siluo (Zonenshainetal., 1990; Zorin, 1999; Sorokinetal , 2004), it is also believed that the collision in the eastern section can last until the late Jurassic-Early Cretaceous (Kravchinsky et al., 2002). As far as the subduction direction of the Mongolia-Okhotsk ocean is concerned, most scholars believe that the oceanic plate subducts northward (Zorin, 1999), and whether there is a southward subduction has been controversial (Wuetal., 2011). In recent years, although the genesis of the Early Mesozoic granites in the Erguna block and the genesis of porphyry deposits have always emphasized the influence of this tectonic belt (Qin Kezhang et al., 1999; Chen Zhiguang et al., 2010; Wuedal., 2011; Wang Wei et al. , 2012; Zhai Hongquan et al., 2012), however, the evolutionary history of the Mongolian-Okhotsk suture zone and its temporal and spatial scope of influence on China are not clear. The rock combination and its spatial and temporal distribution of the Mesozoic volcanic rocks in the Daxing'anling and Yanliao areas, combined with the temporal and spatial distribution characteristics of the Mesozoic volcanic rocks in eastern Jihe, can define the evolution history of the Mesozoic in the Mongolia-Okhotsk suture zone.

5. 2 Triassic: Determination of the southward subduction of the Mongolian-Okhotsk ocean plate In the existing research, the evolution of the Mesozoic early Mongolian-Okhotsk ocean mainly emphasized the northward subduction, and in recent years in Mongolia The study of the Early Mesozoic granitoids and mineralization of the Erguna block in China and China reveals the tectonic evolution history of the southward subduction of the oceanic plate in the early Mesozoic. For example, the intrusive complex of the island arc environment was developed in Erdente, Mongolia, and a large porphyry copper-molybdenum deposit was formed. The ore-forming diagenetic age was about 240 Ma (Jiang Sihong et al., 2010); the Hangayn rock foundation formed in Central Mongolia (255 ~ 230Ma), belonging to the Andean continental marginal arc environment (Tomurtogooetal., 2005; Orolmaaetal., 2008); in addition, the Taipingchuan porphyry copper-molybdenum deposit in the Erguna block in China is formed in the late third The Elevation (Zircon U-Pb age is 202±6 Ma), the deposit is formed in the active continental margin arc environment of the Okhotsk ocean plate subduction to the Erguna block (Chen Zhiguang et al., 2010); Wueta 1. 2011) The study of the Early Mesozoic granites in the northern segment of the Erguna block also suggests that their formation is also related to the evolution of the Mongolian-Okhotsk belt. Based on the above research results, it can be concluded that in the early Mesozoic era, the territory of China has been affected by the Mongolian-Okhotsk suture zone, and mainly represented by the Mongolian-Okhotsk plate to the Erguna block and Central Mongolia. Subduction under the plot. The formation of the Middle Triassic high-magnesium adakitic andesite located in the Linxi, Inner Mongolia Autonomous Region, should be the remote effect of the subduction of the northern Okhotsk ocean plate to the Erguna-Mongolian block, ie the early subduction plate melting in the extended environment. Results of the reaction between the melt and the mantle lava. 5.3 Early Jurassic (180~185Ma): The subduction of the Mongolian-Okhotsk plate on the Erguna block. Zorin (1999) believes that early During the period of Luo Shi, the Mongolian-Okhotsk ocean plate mainly showed subduction to the north, and some scholars believed that the closure of the Mongolian-Okhotsk ocean had occurred in the west (Metelkinetal., 2007). Then, whether there is a Mongolian-Okhotsk plate in the period to the subduction of the Erguna block, the magmatic effect of this period on the Erguna block is answered. First, a set of Early Jurassic basalt-Xuanwu Andesite calc-alkaline volcanic rock combination was established in the Ergun-Genhe area on the Erguna block (Zhang et al., 2008a; Xuetal., 2013). The volcanic rock combination reflects the tectonic setting of the active continental margin; secondly, the formation of granite and mineralized altered granite, which is closely related to the Wunugetugshan porphyry copper-molybdenum deposit in Manzhouli, is also the Early Jurassic (180). ~183Ma, Wang Wei et al., 2012), and the Re-Os isotopic age reflecting the metallogenic age is 178 Ma (佘宏全, 2012). Based on the above characteristics, it can be determined that during the Early Jurassic, the western margin of the Erguna block was in the tectonic setting of the active continental margin. At this time, there existed the bimodal igneous rocks of the Xiaoxing'anling-Changguangcai Ridge, which can rule out that the Early Jurassic calc-alkaline volcanic rocks developed on the Erguna block are not the products of the subduction of the Paleo-Pacific plate. It should be the result of the subduction of the Mongolian-Okhotsk ocean plate to the Erguna block.

5.4 Middle Jurassic (165~170Ma): the closure of the Mongolian-Okhotsk ocean and the regional continental crust thickening event. It is known from the existing research results that during the Mesozoic period, the closure of the Mongolia-Okhotsk ocean from west to east has The characteristics of the scissors closure, the eastern closure time may last until the Late Jurassic-Early Cretaceous (Kravchinsky et al., 2002; Sorokinetal., 2010). For the Erguna block, the closure time of the northwestern Mongolia-Okhotsk ocean should occur in the Middle Jurassic. The evidence is: 1) Located in the Xing'an block and the Songnen-Changguangcailing block. The muscovite granite with the geochemical properties of the "S" type granite was discovered in the Heihe-Xiawu area, and its formation age was 168±2Ma. We believe that the muscovite granite is formed on the background of the continental crust thickening. ), which coincides with the formation of the two mica granites found in the area (Wuetal., 2011); 2) in the northern Hebei-Liaoxi region, there is a widespread regional unconformity - that is, in the Haifanggou Formation The existence of the north-south thrust structure below indicates the existence of the continental crust thickening process (Zhao Yue et al., 1994, 2004; Zhang et al., 2008b), which can occur from the blue above the Haifanggou Formation. The formation age of volcanic rocks of the Qiqi and Lushan Formations (155~158Ma) is restricted (Gaoetal., 2004; Liu Jian et al., 2006; Yangand Li, 2008); 3) a set of alkaline has been formed in the Manguna area of ​​Manzhouli. - subalkaline transition properties of volcanic rocks The combination is represented by the Xumulangou Formation Xuanwu Rough Rock-Guananyan-Ground Rock, while in the western Liaoning Province, the Lanqi Formation and the Lushan Formation are represented, and the former is formed between 158~166Ma (the Peak 2013), the latter formed between 155 and 158 Ma, they are all formed in the extended environment corresponding to the thickened continental crust collapse stage (Xuetal., 2013); 4) the volcanic rocks (155~166Ma) are only distributed in this period. The western part of the Songliao Basin reflects that its formation should be related to the evolution of the Mongolia-Okhotsk suture zone, but not to the Pacific Rim tectonic system, and the volcanic rocks in this period change from the north to the south (Zhang et al., 2008a, 2010) once again proved that their formation should be the product of the evolution of the Mongolian-Okhotsk suture zone.

Based on the above characteristics, it can be concluded that during the Middle Jurassic period, the sub-basic thickening process of the continental crust was carried out in the western slope of the Daxing'anling, and the process of closure of the Mongolian-Okhotsk suture zone was The widely developed Middle-Late Jurassic volcanic rocks should be the product of the thickened continental crust collapse or demolition stage. Xu Wenliang et al.: Mesozoic tectonic regime and regional metallogenic background in Northeast China: Constraints on the temporal and spatial variation of the Mesozoic volcanic rock combination 5.5 Early Early Cretaceous (138~145Ma): Regional extension events and formation of A-type rhyolites The distribution of volcanic rocks in the early Cretaceous was similar to that of the Middle-Jurassic volcanic rocks - only distributed in the west of the Songliao Basin ( Including the western slope of Daxing'anling and the Weibei-Liaoxi area, the representative strata include the Jixiangfeng Formation in the northern section of the Daxing'anling and the Manitou Formation in the southern section and the Zhangjiakou Formation in the northern part of the western Liaoning. The former mainly forms between ~136Ma. Et al, 2003; Zhang Hong et al., 2005). From north to south, the time of formation of volcanic rocks in this period has a new trend (Xuetal., 2013). In terms of geochemical properties, this period of volcanic rocks is characterized by type A rhyolite. In the southern section of the Greater Xing'an Mountains, the volcanic rocks (142Ma) are unconformably covered on the Manketou Ebo Formation (162Ma) and are rich in sodium iron. Alkaline rhyolite of amphibole (Wang Jianguo et al., 2013). The above rock combination revealed that the area was in an extended environment in the early Cretaceous. From the distribution of volcanic rocks in the northeastern part of western Liaoning and western Liaoning, they are not integrated and produced on the Tucheng subgroup, and the regional unconformity developed above the Tucheng subgroup represents another north-south napping event (Zhangetal., 2008b), this period of volcanic rock was formed after this overthrust event, which indicates that the formation of volcanic rocks in this period should correspond to the collapse or demolition stage of the continental crust thickening time - that is, the extended tectonic setting Zhongliang et al., 2008).

5.6 Late Early Cretaceous (110~131Ma): regional extension and bimodal volcanic rock formation Early volcanic volcanic rocks were widely distributed in the northeastern region, especially in the Greater Xing'an Mountains, in the north of the Ku Li Formation rhyolite and Yilikde The group is represented by basalt, which is represented by the Baiyingao Formation rhyolite and the Melutu group basalt in the south. They are formed between 114~131Ma (the peak age is 125Ma; Lin Qiang et al., 1999; Ge Wenchun et al., 2001). ; Wang et al., 2006; Zhang et al., 2008a, 2010; Ying et al., 2010; Meng En et al, 2011; Xu Meijun et al, 2011). In the Weibei-Liaoxi area, the volcanic rocks in this period are represented by the Yixian Formation, which is formed at 120~126Ma (Wei Zhongliang et al., 2008). This volcanic event is characterized by a typical bimodal volcanic rock combination, revealing the existence of a regional extensional environment, which is also supported by metamorphic core complexes, A-type granites and rift basins that were extensively developed in the late Early Cretaceous (Davisetal). . 2001; Wueral., 2002; Wang et al., 2011b). This volcanic event can be linked to the post-arc stretching environment of the ancient Pacific plate submerged under the Eurasian continent, and to the sinking process of the thickened continental crust after the closure of the Mongolia-Okhotsk suture zone. The formation of the Early Cretaceous double-peak volcanic rock combination in the Daxing'anling area should be related to the latter. 5.7 The tectonic evolution and regional mineralization of the Mesozoic in the Mongolia-Ekhutsk suture zone from the northern and southern sections of the Greater Xing'an Mountains in China and the northern and western Liaoning The Mesozoic magmatism time-space frame and rock combination characteristics can be seen that the influence of the Mongolian-Okhotsk suture zone on China during the Mesozoic period is strong, which can be roughly divided into the following stages: ~180Ma) Mongolia-Ehhot The subduction stage of the Tukke plate to the Erguna block: based on the magmatism stage and nature of the granite in the area and its metallogenic characteristics (Qin Kezhang et al., 1998; Chen Zhiguang et al., 2010; Wuedal., 2011; Wang Wei et al., 2012; Qi Hongquan et al., 2012), can be roughly divided into three subduction events (245Ma± and 185Ma±), and the corresponding mineralization is mainly represented by the active continental margin background. Formation of porphyry (copper) molybdenum and copper-lead-zinc polymetallic deposits ().

~120Ma) This stage is mainly characterized by two continental crust thickening processes (around 170Ma and 145Ma) and the corresponding continental crust extension environment (162Ma, 142 ~ 120Ma). The mineralization in this period is mainly characterized by stretching background. The formation of shallow hydrothermal gold deposits, polymetallic deposits and rare and rare earth metal deposits (Bai Lingan et al., 2012; Wang Jianguo et al., 2013).

Reactivation of the 6 ancient suture zone and regional mineralization in the northeastern part of the Central Asian orogenic belt. The Paleozoic period is mainly characterized by the process of flattening between multiple micro-blocks and the arc-land fusion of multi-island arcs. In the early days, the area experienced the final closure of the ancient Asian Ocean, completed the evolution of the Central Asian orogenic belt, and then entered the superimposed evolutionary stage of the Mongolian-Okhotsk tectonic system and the Pacific Rim tectonic system. What is the significance of the paleo-subduction zone (suture zone) formed during the Paleo-Asian ocean tectonic system? What is the indication of regional mineralization? This can be answered from the discovery of different types of deposits in Northeast China in recent years.

6.1 The influence of the Pacific Rim tectonic system on the paleo-subduction zone (or suture zone) and metallogenesis based on the study of the Mesozoic volcanic rocks in eastern Jihe, it is known that the Mesozoic evolution of the Pacific Rim tectonic system in the northeastern margin of the Eurasian continent is mainly represented by three important subduction events. : Early Middle Jurassic (173~190Ma), Early Cretaceous (106~133Ma) and Late Cretaceous (88~97Ma). The ancient subduction zone in the eastern part of the northeastern region mainly includes the Caledonian suture zone (Wang et al., 2012) distributed between the Songnen-Zhangguangcailing block and the Jiamusi block, and the east-west distribution of the northern margin of the North China block. Late Paleozoic sutures (Zhang et al., 2009; Cao Huahua et al., 2012). During the subduction of the Paleo-Pacific plate beneath Eurasia, these ancient subduction zones were revived again, forming a porphyry-type deposit with molybdenum-based active continental marginal structures, such as Xiaoxing'anling-Zhangguangcailing Early Jurassic. Porphyry deposits (Huojihe molybdenum deposit, 184Ma, Chen Jing et al., 2012; Luming porphyry molybdenum deposit, 176Ma, Yang Yanchen et al., 2012; Cuiling molybdenum deposit, 178Ma, Yang Yanchen et al., 2012), North China Early-Middle Jurassic porphyry deposits in the northern margin of the block (Daheishan porphyry molybdenum deposit, 168Ma, Wang Chenghui et al., 2009; Fu'anbao porphyry molybdenum deposit, 167Ma, Li Lixing et al., 2009) should be formed with the ancient Pacific The activation of the ancient suture zone under the plate subduction is related (). From the current statistics on the age of ore-forming in Northeast China, it can be seen that the mineralization in these ancient subduction zones occurred mainly in the Early Middle Jurassic, and in the late Early Cretaceous (106 ~ 133 Ma) and Late Cretaceous (88 ~ 97 Ma). The two subductions have little effect on the paleo-subduction zone. The continental inland of the eastern continental margin mainly exhibits an extensional environment similar to the arc, while the corresponding mineralization mainly consists of gold-rich porphyry copper deposits and epithermal fluids. Type gold deposits mainly () (Hanetal., 6.2 Mongolian Okhotsk tectonic system on the ancient subduction zone (or suture zone) and metallogenesis 6.2.1 Mesozoic early subduction period from the Mesozoic volcanic rock spatial distribution can It is determined that the influence of the Mongolian-Okhotsk tectonic system on China is mainly in the west of the Songliao Basin (including the Weibei-I West area). In the early Mesozoic, the Mongolian-Okhotsk plate subducted the Erguna Under the block, its influence space can reach the northern margin of the North China block, and its east-west distribution of the Early Jurassic Southern Daling Formation basalt (Zhao Yue et al., 2006) should be the remote effect of this subduction. Mainly for North China The influence of the Late Paleozoic suture zone on the northern margin of the block. In addition, the formation of molybdenum-based porphyry deposits in the Early Jurassic in the northeastern margin of the North China block (eg Xintaimen Molybdenum, 183Ma, Zhang Zunzhong, etc., 2009) ;Lanjiagou Molybdenum Mine, 187Ma, Huang Dianhao et al., 1996; Yangjiazhangzi Molybdenum Mine, 187Ma, Huang Dianhao et al., 1996) may also have a remote effect on the subduction of the Mongolian-Okhotsk ocean plate to the Erguna block. Regarding (), the resurrection of the Paleo-Asian Ocean plate beneath the North China block may be the main dynamic background for the formation of these porphyry deposits.

6. 2.2 Late Mesozoic Mongolian-Okhotsk closed collision and extension stage in the Middle Jurassic (unconformity under the Haifanggou Formation) and early Early Cretaceous (unconformity above the Tucheng subgroup) The effects of the two-stage tectonic overthrust events (Zhang et al., 2008b) on the paleo-subduction zone are mainly the occurrence of the continental crust thickening process and the reactivation of the paleo-subduction zone. The former is mainly characterized by the formation of adakitic volcanic rocks (YangandLi, 2008). The latter is mainly manifested in the formation of the Middle-free Jurassic skarn type deposit in the northern margin of the North China block (such as Xiaojiayingzi Molybdenum Mine, 170Ma, Daijunzhi, etc., 2008; Yaojiagou Molybdenum Mine, 169Ma, Fang Junqin Etc., 2012). The regional mineralization mainly occurs in the background of the thickened continental crust collapse or disintegration stage, mainly in the epithermal gold deposit, and the formation of rare-rare earth deposits in the parts of the ancient subduction oceanic plate. For example, the formation of rare earth minerals associated with the A-type rhyolite or alkaline granite of the Jixiangfeng Formation (or Manitou Formation) should be an ancient subduction oceanic plate that has undergone fine-corner porphyry, in a stretched environment. Partially melted product (Wang Jianguo et al., 2013).

7 Conclusion Based on the study of the chronology of the Mesozoic volcanic rocks in Northeast China and the temporal and spatial variation of rock combinations, the following conclusions are drawn: (1) Mesozoic volcanism in Northeast China can be divided into six phases: Late Triassic ~ 166 Ma), Early Cretaceous In the early period (138~145Ma), in the late Early Cretaceous (106(2), the subduction of the Pacific Rim tectonic system to the Eurasian continent began in the Early Jurassic and existed three times during the Mesozoic (early Jurassic, Early Cretaceous and The Late Cretaceous subduction event, its mineralization is mainly characterized by the porphyry deposit in the subduction stage and the epithermal deposit in the background of the intracontinental extension, and the transformation of the ancient subduction zone in the early Jurassic subduction stage. And activation is also the main area for finding porphyry deposits.

(3) The Mesozoic evolution of the Mongolian-Okhotsk tectonic system experienced the subduction of the Early Mesozoic (245-180 Ma) and the important continental crust thickening process of the late Mesozoic (~170Ma and ~145Ma) and corresponding to it. Two regional stretching events (early early Cretaceous: ~142Ma and late: ~125Ma). The northern part of the Erguna and Xing'an blocks is the main area for finding porphyry deposits related to subduction time, while the northern margin of the North China block and the southern section of the Greater Xing'an Mountains are looking for epithermal deposits in the extended background. And key areas of polymetallic deposits.

(4) The spatial extent of the influence of Mesozoic on the Northeast Asian continent in the Central Taiping tectonic system is mainly in the Songliao Basin and the east of the Songliao Basin; and the spatial extent of the Mongolian-Okhotsk tectonic system is mainly in the west of the Songliao Basin (possibly including Songliao) The western slope of the basin) and the northern margin of the North China block.

Acknowledgements In the research and writing process of this article, he has worked with Professor Sun Jinggui, Professor Ge Wenchun, Professor Sun Fengyue, Professor Yang Yanchen, Professor Sun Deyou, etc. to discuss postdoctoral, Yu Yang, Cao Huahua, Zhang Han, Wang Jin, Lu Siming and other graduate students. I have participated in some field work, and I would like to express my heartfelt thanks to them.

Xu Wenliang et al. Mesozoic tectonic regime and regional metallogenic background in Northeast China: Constraints on the temporal and spatial variation of the Mesozoic volcanic rock combination

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