1.3. 1 Archaean strata
Archaean stratigraphic units and their names are based on Hebei regional geology. See table 1.3. 1 for the comparison of Archaean new and old strata (rocks) unit names.
1.3. 1. 1 Lower Archaean Qianxi Group
Qianxi Group is mainly distributed in Yanshan area south of Shangyi-Pingquan deep fault, and is divided into four communities: Huai 'an in the west of Hebei, Miyun in Beijing, Chengde in the north of Hebei and Qianxi in the east of Hebei. It consists of various pyroxene granulites and pyroxene-bearing gneiss with magnetite and quartzite. From bottom to top, it is divided into 2 subgroups and 4 rock groups.
(1) subgroup
Distributed in Millennium community and Huai 'an community. It is divided into two rock groups from bottom to top.
A. Shangchuan Formation, distributed in Taipingzhai and Yangheyu areas in western Guizhou. Mainly pyroxene granulite, migmatization is strong, forming biotite perilla homogeneous migmatite.
B. Santunying Formation, distributed in the east of Gaojiadian to Santunying in Qianxi and on both sides of Shangchuan Formation in the west of Wuzhong 'an in Qian 'an. The lower part is dominated by plagioclase amphibole and plagioclase siltstone; There are more gneiss in the upper part, with magnetite and quartzite.
In addition, the original names of Wayaokou Formation, Mashikou Formation, Yousuobao Formation and Xiabaiyao Formation in Huai 'an community are similar to this subgroup.
(2) Upper subgroups
Distributed in 4 communities in Yanshan area. In the Millennium community, it is divided into Lamagou Group and Machang Group from bottom to top. The original Chongli Formation or Guzuizi Formation in Huai 'an area is equivalent to this subgroup.
A. Lamagou Formation, distributed in Malanyu-Mengheqiao-Qinglong Badaohe area, mainly amphibole plagioclase.
Machang Formation B is distributed in Malanyu, west of Qian 'an Waterworks, near Qinglong and southeast of Kuancheng. Mainly amphibole plagioclase gneiss, garnet is common.
1.3. 1.2 Upper Archaean Fuping Group or Dantazi Group
The upper Archean strata are called Fuping Group in Taihang Mountain area and Dantazi Group in Yanshan Mountain area. Both belong to the same geological age.
(1) Fuping Group
It is divided into two communities: the south and the north. To the north is Fuping community, including Pingshan, Lingshou, Tangxian, Yixian and Laishui. Zanhuang community in the south, including Luquan and Jingxing. It is divided into 9 rock groups from bottom to top.
Table 1.3. 1 Archaean-Proterozoic lithostratigraphic division and correlation table of Hebei province
A. Suojiazhuang Formation, only found in Fuping community, is distributed in Daliushu, Duanjiazhuang, Li Chuan, Tangxian flowerpot, Laiyuan Mazhuang, Zoumayi, Jidaoling and Yinfang in Fuping. Mainly biotite (or amphibole) plagioclase gneiss, locally mixed with marble or magnetite quartzite; The upper part is serpentine (or diopside, phlogopite) marble and amphibole.
B Tuanbokou Formation, distributed in Fuping Community and Zanhuang Community. In Fuping community, it is located in the east of Fuping Yu, Jiuying and Tuanpokou, and in the north of Lingshou Chen Zhuang and Xingtangkou. Formerly known as Fangjiapu Formation in Zanhuang Community, it is distributed in Neiqiu Liulin, Xingtai Fangjiapu, Huang Xi Village and Shahe Zen House.
Tuanbokou Formation consists of migmatite and biotite plagioclase gneiss mixed with amphibole in the lower part and K-feldspar granulite mixed with gneiss in the upper part. Upper rocks: marble and amphibole in the north of Fuping Community, and marble mixed with metamorphic rocks and tremolite in the south.
C. Nanying Formation, distributed in Fuping Community and Zanhuang Community. Formerly known as Beisai Formation, the stratum in Zanhuang residential area is dominated by biotite plagioclase gneiss with magnetite and quartzite. There are garnet amphibole schists in Zanhuang community. There are marble and amphibole on the top.
D. Manshan Formation, mainly distributed in the southwest of Fuping community. The lower part is dominated by biotite plagioclase gneiss with sillimanite granulite; The upper part is marble and amphibole. In some areas, this group was once called "Wanzi Formation" and "Songjiakou Formation".
E. Muchang Formation, mainly distributed in Fuping community. The lower part is mainly biotite (amphibole) plagioclase gneiss mixed with amphibole; The upper part is marble, plagioclase amphibole and diaspore. This group was once called "Wanzi Formation" and "Songjiakou Formation".
F Sidaohe Formation, distributed in Heping Mountain, Fuping. Mainly biotite plagioclase gneiss and granulite, with marble, gneiss and diopside granulite in the upper part.
G. Hongshanpo Formation is only found in Hongshanpo of Pingshan, Yetanqing and Shihuyan of Fuping. It is mainly composed of extremely thick granulite, and the upper part is marble.
H. Paoquanchang Formation, dominated by biotite plagioclase gneiss with biotite granulite and marble; There is often peridotite in the lower part.
1. The elm bay Formation is dominated by amphibole biotite plagioclase gneiss mixed with biotite granulite and marble.
Paoquanchang Formation and elm bay Formation, formerly known as Longquan Guan Formation, are distributed in the southwest of Fuping Community.
(2) Single tower subgroup
It is distributed in Zhangjiakou and Chengde areas north of Shangyi-Pingquan deep fault, and Luanxian, Funing and Lulong are exposed sporadically. Divided into three groups from bottom to top.
A. The Yanwobao Formation, located in the Yanwobao area of Chengde City, consists of strongly altered amphibolite gneiss and amphibolite, with garnet amphibolite (translucent) granulite in between.
B. Baimiao Formation, widely distributed. Mainly biotite granulite, metamorphic rock and biotite (or potash feldspar) gneiss. The migmatization is strong, forming banded and eyeball migmatite. The main body of the former Hongqiying subgroup in Zhangjiakou is basically the same as that of Baimiao Formation.
C. Fenghuangzui Formation, distributed in the south of Damiao-Niangniangmiao deep fault and Fengning area. It is mainly composed of amphibole, amphibole (or black cloud) granulite, and there are many layers of marble. The migmatization is strong, and the migmatization is mainly infiltration and injection.
1.3. 1.3 Upper Archean Wutai Group or Shuang Shan Group
The upper Archean strata are called Wutai Group in Taihang Mountain area and Shuangshanzi Group in Yanshan Mountain area, both of which belong to the same era.
(1) Wutai Group
Distributed in Fuping Community and Zanhuang Community, overlapping Fuping Group. Divided into three groups from bottom to top.
A. Banyukou Formation in Zanhuang County, formerly known as Honghe Formation, consists of quartzite, quartz schist and marble.
B shangbao formation in zanhuang county, formerly known as "shijialan formation", is a set of biotite granulite containing magnetite quartzite.
C. Longjiazhuang Formation, found in Longjiazhuang, is mainly derived from amphibole schist mixed with quartz schist.
(2) Shuangshan subgroup
Sporadic exposure in Yanshan area. Divided into two groups from bottom to top.
A. Ciyushan Formation, exposed in Qianxi community and Chengde community. Formerly known as Jiang Ying Formation, Nandianzi Formation and Taipingzhuang Formation. The lower part is biotite granulite mixed with metamorphic rock; The upper part is biotite garnet schist and amphibole magnet quartzite.
B. Luzhangzi Formation is located on the east bank of qinglong river, a residential area in Qianxi, and consists of plagioclase amphibolite and plagioclase granulite with metamorphic volcanic structure, and sedimentary metamorphic granulite and schist.
Strata of other times will be introduced in relevant chapters, and will not be repeated here.
1.3.2 magmatic rocks
1.3.2. 1 Archaean main magmatic rocks
(1) Early-Middle Archean magmatic rocks
The original rocks of Qianxi Group are mainly basic, neutral, moderately acidic to acidic volcanic rocks.
The ultrabasic rocks emplaced at the same time as volcanic activity are mainly distributed in Huai 'an, passing through Miyun and Zunhua, and moving westward to Qinglong, Chengde and Pingquan. There are mainly rock masses or rock groups in Maojiachang, Yanwangtai, Wudaohe, Sangou and Cigou in Zunhua. The rock mass is very small, only a few meters to several hundred meters long. Rock types are mainly strong serpentine peridotite, lherzolite, serpentine, tremolite and so on.
At Xiba and Damiao in Pingquan, pyroxene syenite intruded into Qianxi Group.
(2) Neoarchean magmatic rocks
There was a strong eruption of intermediate-basic to intermediate-acid volcanic rocks in Wutai period. Afterwards, diorite, granite and syenite intruded. It is mainly distributed in the west section of Shangyi-Pingquan deep fault and south of Fengning-Longhua deep fault, forming an east-west tectonic magmatic belt that starts from Shangyi in the west, passes through Chongli, Fengning, Chengde and Longhua, and reaches Pingquan in the east. In Funing and Qinglong areas, there are Liugezhuang diorite and Sanhedian granite. Laiyuan Shangbao has quartz diorite and granite, and Zanhuang has Xu Ting granite. Others are diorite, granite and other rocks along the structural parts of Shuangshanzi Group.
1.3.2. Proterozoic main magmatic rocks.
(1) Early Proterozoic magmatic rocks
Volcanic rocks are produced in Gantaohe Group and distributed in Luquan-Neiqiu area in Taihang Mountain area. They are mainly metamorphic basalts and a small amount of basaltic andesite. Intrusive rocks are distributed in qinglong river, Fuping and Zanhuang, mainly including serpentine, serpentine olivine pyroxenite, pyroxenite, gabbro and diabase.
(2) Mesoproterozoic magmatic rocks
Volcanic rocks in the Great Wall period occurred in the strata below Dahongyu Formation, mainly distributed in Pinggu, Jixian, Zunhua and Luanxian. The rock type is trachyte, purplish red and brick red, containing 65% ~ 90% potassium feldspar. The intrusive rocks include Chengde Damiao, Tougou plagioclase and Guangtoushan alkaline granite in Pingquan.
1.3.2.3 Paleozoic main magmatic rocks
(1) Early Paleozoic Caledonian magmatic rocks
Only three wells in Kangbao are gneiss quartz diorite and Xiaoying Picture gneiss granite.
(2) Late Paleozoic Variscan magmatic rocks.
Volcanic rocks are distributed in Kangbao and Weichang areas. Formation of andesite in early Permian Sanbianjing Formation.
The intrusive rocks of basic and ultrabasic rocks fracture along the east-west direction, forming four rock zones:
Kangbao-paddock belt: there are mainly Gejiacun gabbro and Dalancheng pyroxenite.
Chongli-Chengde Belt: There are mainly more than 20 rock bodies such as Chongli Shuiquangou aegirine syenite, Xiaojiakouyan, Pteridium aquilinum, Matie amphibolite, Hongshilai, Niangniangmiaotouhui, Gaositai serpentine peridotite and Diaowo gabbro.
Yaojiazhuang-Fanshan-Gushan Belt: There are mainly many rock masses 10, such as Yangyuan Xiangshuigou, Aoyukou nepheline syenite, Yangyuan Yaojiazhuang, Huailai Fanshan pyroxenite, Zhengchang pyroxenite and Gushan pyroxenite.
Yixian-Laishui belt: there are mainly Shuanghezhuang, Dongdugang, Gaozituo gabbro, pyroxene, pyroxene amphibole and other rock bodies.
Granitic intrusive rocks intrude along the uplift between deep faults and are divided into three zones. The paddocks mainly include Kangbao, Mandetang, Daqinggou and Laowopu, and there are Chongli Liutu and Chaozishan granite bodies in the paddock.
1.3.2.4 Main Mesozoic magmatic rocks
Mesozoic magmatism, mainly Yanshan cycle. Yanshan cycle is divided into four stages:
The first phase of Yanshan cycle in early Jurassic: including basalt and andesite of Nandaling Formation, distributed in the volcanic belt from Dashipeng in Luanping to Wujiachang in Chengde in Yanshan Platform Fold Belt (the volcanic cycle from Late Triassic to Early Jurassic is called Nandaling cycle); The intermediate plutonic intrusive rocks are mainly quartz diorite and granite or granodiorite, including Kuancheng Tangdaohe granodiorite, Xinglong Wangpingshi Granite, Zunhua Maoshan Granite, Qinglong Bangchui Cliff Gabbro and so on 10.
The second phase of Yanshan cycle in Middle Jurassic: volcanic activity is strong, mainly composed of andesite, dacite and a small amount of rhyolite (cascade volcanic cycle). Intrusive rocks, including syenite, diorite (porphyrite), granodiorite or granite. There are mainly more than 90 rock bodies in Shexian, such as Xinglong Yuerya and Fushan.
The third stage of Yanshan cycle in late Jurassic is the strongest magmatic activity in Yanshan cycle. The Late Jurassic strata are almost entirely composed of volcanic rocks, including andesite, rhyolite, quartz trachyte and pyroclastic rocks (Zhangjiakou volcanic cycle) with the same composition. The intrusions are hypabyssal and ultrahypabyssal intrusions, such as syenite porphyry, syenite porphyry and quartz porphyry, followed by medium-deep intrusions, such as diorite or quartz diorite, granodiorite or quartz monzonite, monzonite and fine-grained granite. Such as Houshihushan, Shouwangfen, Majiagou, Dahenan, Wang 'an Town, Chiwawu, Ma Peng, Wu 'an Mine, Wu 'an Hongshan, etc.
The fourth stage of early Cretaceous Yanshan cycle: Dabeigou Formation and Huajiying Formation formed intermediate-acid volcanic rocks (Dabeigou volcanic cycle) and shallow small intrusions. There are mainly Fengning Shimengou syenite porphyry, Weichang Shijianfang granite porphyry, Chengde Wudaochuan granite porphyry, Yantongshan granite porphyry, Pingquan Shidongzi granite porphyry and Fujiawan syenite porphyry.
1.3.2.5 Cenozoic main magmatic rocks
The Cenozoic Himalayan cycle is divided into three volcanic cycles: Early Tertiary, Late Tertiary and Quaternary. Volcanic rocks formed by volcanic cycles in the late Tertiary include Hannuoba basalt and Qipanshan basalt.
1.3.3 fault structure
1.3.3. 1 deep fault
A deep fault is a fault that passes through the silicon-aluminum layer and reaches the silicon-magnesium layer or the upper mantle. Some scholars call it crustal fault, lithospheric fault and supralithospheric fault. There are 10 deep faults in Hebei province (Figure 1.3. 1), which are divided into 4 deep fault zones.
The (1) deep fault zone on the northern edge of the Inner Mongolia Earth Axis.
Among them, the Kangbao-Weichang deep fault (No.1, referring toNo. 1.3. 1 in the figure, the same below) passes through the northern part of this area along the 42 N line.
(2) The deep fault zone on the southern edge of the Inner Mongolia Earth axis.
There are three deep faults, namely Fengning-Longhua deep fault (No.2), Damiao-Niangniangmiao deep fault (No.3) and Shangyi-Pingquan deep fault (No.4).
(3) Taihang Mountain deep fault zone
Divided into western belt and eastern belt:
Western belt (Zijingguan deep fault zone), including Upper Huang Qi-Wulonggou deep fault (No.5) and Zijingguan-Lingshan deep fault (No.6);
The eastern belt (Taihang piedmont deep fault zone) includes Huairou-Laishui deep fault (No.7), Dingxing-Shijiazhuang deep fault (No.8), Xingtai-Anyang deep fault (No.9) and Cangzhou-Daming deep fault (10).
1.3.3.2 large fracture
A large fault is a first-class fault between a deep fault and a general fault, with a long length, some of which can reach more than 100 km, but generally does not go deep into the Si-Mg layer. There are 9 large faults in the area, as shown in figure 1.3. 1.
1.3.4 division of structural units
There are two class I tectonic units in Hebei Province and Beijing-Tianjin area: the Sino-Korean paraplatform and the Inner Mongolia-Daxing 'anling geosyncline fold system, which are bounded by the Kangbao-Weichang deep fault (1).
1.3.4.1Ⅱ tectonic unit of Daxinganling geosyncline fold system in Inner Mongolia.
In this area, the secondary structural unit of the Daxinganling geosyncline fold system in Inner Mongolia is the late Hualixi fold belt in Inner Mongolia. Among them, the structural unit Ⅳ is Kangbao fold bundle in Kangbao area and the central depression of Qipanshan in the north of the paddock.
1.3.4.2 Sino-Korean paraplatform Ⅱ structural unit
The Sino-Korean paraplatform has four secondary structural units.
(1) Inner Mongolia Earth Axis
Located in the northern edge of the quasi-territory of China and North Korea. The northern boundary of the earth axis is Kangbao-Weichang deep fault; The southern boundary is the western section of Shangyi-Pingquan deep fault (Shangyi-Chicheng section), and it is connected with Fengning-Longhua deep fault to the east.
(2) Yanshan platform fold belt
The northern boundary of Yanshan platform fold belt is Inner Mongolia axis; The southern boundary generally follows the Gu 'an-Changli fault (No.6) to the west, passes through the northeast fault near Langfang, turns to Miyun near Jixian, then turns to the south from Huairou-Laishui deep fault (No.7) and Dingxing-Shijiazhuang deep fault (No.8), and then turns to the northwest from Wuji-Hengshui fault (No.7). The northern section is bounded by Mashikou-Songzhikou fault (No.2) in the west, connected to the western belt of Taihang Mountain deep fault (No.5) in the south, and then crossed by Zijingguan-Lingshan deep fault (No.6) and Wuji-Hengshui fault (No.7).
(3) Shanxi fault uplift
East boundary, along the west boundary of Yanshan platform fold belt, south to Xingtai-Anyang deep fault (No.9). Shanxi fault uplift entered Shanxi territory westward.
(4) North China fault depression
This area is located in Yanshan platform fold belt, southeast of Shanxi fault uplift.
Figure 1.3. 1 Schematic diagram of deep faults in Hebei, Beijing and Tianjin.