Is there basalt in Azuo Banner, Inner Mongolia?

Alashan Zuo Qi is located in the east of Xinjiang sub-plate, squeezed by North China and Qinghai-Tibet sub-plate, with complex geological structure and frequent magmatic activities.

First class

I. Stratigraphic area

According to the characteristics of sediments, sequences, minerals, paleontology, paleogeographic conditions, magmatic activity and metamorphism, the Zuo Qi Strata in Alashan can be divided into three areas: Tianshan-Xing 'an Strata; Stratigraphic area of North China; Qilian mountain stratigraphic area.

1. Stratigraphic division in Tianshan-Xing 'an area

The northern part is along the south of China-Mongolia border and north of Wuliji and Tukemu lines (about 3910 ′ ~ 40 50 ′ north latitude), belonging to Tianshan-Xing 'an Stratigraphic Area and "Inner Mongolia Grassland Division and Badain Jilin Community". The exposed stratum in this area is pre-Great Wall gneiss. Sinian marine carbonate-clastic rock formation: complete in Paleozoic, composed of clastic rock, carbonate rock and hard sandstone, with marine, continental and land-sea interaction. Mesozoic strata developed, and basic volcanic rocks were built for clastic rocks of foothills-rivers and lakes; The Cenozoic Quaternary is mainly composed of aeolian deposits, alluvial deposits, diluvial deposits and lacustrine deposits, which are rich in minerals, such as lake salt, trona, arsenic nitrate and magnesium salt.

2. Stratigraphic area in North China

To the south of the first line of Wuliji and Tukemu (about 40 50' north latitude), it starts from Erkehashha and Chagan Prague in the west, passes through Xianggendalai, and turns southeast to the north of the first line of Ningxia (about 38 20' ~ 38 30' north latitude), which is a stratigraphic area in North China and belongs to "Jaboulay-Jilantai Community in the East of Alashan Subdivision". The exposed stratum in this area is platform type. The basement is composed of Precambrian metamorphic gneiss, schist, migmatite and early Proterozoic granite, containing iron, graphite and gold. The caprock is Sinian submarine shallow metamorphic marine clastic rock-carbonate rock, which is rich in stromatolites, manganese ores and dolomite. Paleozoic was marine deposit, lacking Silurian, Devonian and Lower Carboniferous, and the middle and late Carboniferous to Permian was acidic volcanic rock with alternating land and sea. Continental sediments contain coal, siderite and clay minerals; The Mesozoic strata are scattered, and the volcanic rocks are clastic rocks from inland foothills-rivers and lakes. Cenozoic strata are widely distributed, and tertiary continental red clastic rocks contain gypsum and uranium. The Quaternary is dominated by aeolian sand, followed by flood, alluvial and lake deposits, which are rich in salt minerals such as lake salt, trona, arsenic, magnesium salt and potassium salt.

3. Stratigraphic area of Qilian Mountain

The southern part of Qi (south of 38 20 ′ ~ 38 30 ′ north latitude) belongs to Qilian Mountain Stratigraphic Area and "Wuwei-Zhongning Community". The oldest exposed strata in this area are the thick marine Loufulishi Formation of Lower Paleozoic and the basic volcanic rocks of clastic carbonate formation. The upper Paleozoic strata are well developed, including continental red clastic-molasse formation, lagoon formation and coal-bearing formation on land and sea. Mesozoic and Cenozoic strata are continental clastic rocks, containing multiple layers of bituminous coal and gypsum.

Second, the stratigraphic description

The strata in Alashan Zuo Qi are developing from the old to the new.

1. Pre-Great Wall System (3 1.03 ~ 1.95 million years ago)

It is distributed in Helan Mountain, Bayanwula Mountain and Harunai Mountain and belongs to amphibole granulite facies-greenschist facies metamorphic complex. The main rock assemblages are biotite amphibole gneiss, schist, granulite, various types of migmatite and dacite. Vein rocks are developed in the strata, mainly diabase, pegmatite, fine-grained rock and chronological veins.

2. Sinian (19.50 ~ 6 15 million years ago)

It is distributed in Helan Mountain, Bayannuorigongliang, Hanwula, Harunai Mountain and other places, and is divided into Great Wall System, Jixian System, Qingbaikou System and Sinian System according to stratigraphic lithologic characteristics.

The Great Wall system distributed in Helan Mountain is called "Huangqikou Group". Distributed in Bayan Xibe, Shalataohai and Haishenghala, they are called "Shabugeng Formation" and "Taklimakan Aobao Formation". It is distributed in Hanwula, Harunai and Tukemu, and is called "Zhaertai Group" and "Langshan System". The Great Wall system consists of metamorphic sandstone, quartzite, slate, phyllite, marble, granulite, schist and gneiss, and the original rocks are carbonate rocks, volcanic rocks and clastic rocks deposited in coastal and shallow seas. The total thickness of this layer is 60 1 ~ 6722 meters, which is unconformity contact with the underlying stratum.

The Jixian series distributed in Helan Mountain is called "Quan Wang Mouth Group". Maodao, which is distributed in Bayanxibo Mountain, marine hala, halaula and Zhulazaga, is called "Bayanxibo Formation", and the Jixian system is low greenschist facies dolomite, sandstone with a small amount of quartzite. It belongs to coastal-shallow sea continental shelf deposits. Rich in many kinds of stromatolites. The total stratum thickness is1331~ 3 842m, which is in fault contact with the underlying stratum.

Qingbaikou system is distributed in the marine hala, Wulan dam and Jurazagamaodao in Bayanxi, and is called "Marine hala Formation" and "Jurazagamaodao Formation". The distribution in Menggenwula and Hanwula is called "Tongchangkou Group", also known as "Great Huoluoshan Group". Qingbaikou system consists of variegated slate, metamorphic siltstone, dolomite, quartzite mixed with argillaceous limestone, including microfossils and stromatolites. The total thickness of this layer is greater than 1.48 1 m, and it is in pseudo-integrated contact with the underlying stratum.

The Sinian system is distributed in Helan Mountain and is called Zhengmuguan Formation or luoquan Formation. It consists of variegated moraine conglomerate, mudstone conglomerate, slate, dolomite limestone and siltstone. It belongs to coastal sediments, containing microscopic plants and spongy spicules. The total thickness of this layer is 56 ~ 287 meters, which is unconformity contact with the underlying stratum.

3. CAMBRIAN (615 ~ 520 million years ago)

It is distributed in Helan Mountain, Agatanwusu, Haoru, Hanwula and Yemaozi Mountain. It is a set of detrital rocks, clay rocks and carbonate rocks in greenschist facies with shallow metamorphism. It is in pseudo-integrated contact with the underlying strata and is divided into lower, middle and upper layers: the lower layer is distributed in Helan Mountain and is called "Suyukou Formation" and "Wudaotang Formation". The lithology is gravelly phosphorite, sandy calcareous phosphorite, phosphorus-bearing sandstone, feldspar sandstone, dolomite and dolomitic limestone, containing trilobites, brachiopods and algae, and the maximum thickness of the stratum is 126 m. The Middle Series is distributed in Helan Mountain and is called Maozhuang Formation, Xuzhuang Formation and Zhangxia Formation. Distributed in Agatanwusu, it is called "Xiangshan Group". Its lithology is variegated shale, limestone, argillaceous banded limestone and scaly limestone. The total stratum thickness is15 ~ 2383m; The Upper Series is distributed in Helan Mountain and is called Gushan Formation, Changshan Formation and Fengshan Formation. The lithology is argillaceous limestone, dolomite, dolomitic limestone, siliceous rock and crystalline bromolimestone, containing trilobites and brachiopod fossils, with a total stratum thickness of126 ~ 353 m.

4. Ordovician (520 ~ 440 million years ago)

It is distributed in Helan Mountain, Tengger Eris, Agatanwusu, Hanwula and other places, and is in integrated contact with the underlying strata, and can be divided into lower series and middle series: the lower series is called Zhongliangzi Formation in the northern part of Helan Mountain, Tianjingshan Formation in the southern part, Hanwula Formation and Woboer Formation. The lithology is limestone, dolomite, dolomitic limestone and argillaceous reticulated limestone. It belongs to shallow sea-coastal sedimentary clastic rock-carbonate rock formation, including cephalopods, brachiopods, gastropods and trilobites, with a total stratum thickness of 205 ~ 1, 065,438+02m. The Middle Series distributed in the central part of Helan Mountain is called Yingtaogou Formation and Pingliang Formation, and the southern part is called Miboshan Formation. The lithology is sandy slate, siltstone, sandstone, sandy limestone mixed with siliceous conglomerate and gravelly limestone, including gastropods, brachiopods, graptolites, bryozoa, corals and trilobites, and the stratum thickness is11~1246m.

5. Silurian (440-400 million years ago)

It is distributed in Hanwula, Haoru and Hanwula, and is in fault contact with the underlying strata. It is divided into three series: the lower series is distributed in Hanwula, which is called "banded Tolgoi Formation" and "Aershangde Formation", and there are sporadic outcrops in Hanwula area. The lithology is mainly siliceous slate, argillaceous slate, siltstone mixed with carbonaceous slate and a small amount of quartzite, including graptolite, brachiopod and gastropod fossils, and the stratum thickness is139.3 ~ 3 096m.. The Middle Series is also exposed in Alshande, Haoru, Jusileng and other places, mainly consisting of intermediate-basic acidic volcanic rocks, pyroclastic rocks and carbonate rocks, belonging to shallow-sea facies deposits, including corals, brachiopods, bryozoa and sea lilies, with a stratum thickness of 1, 865,438+02 ~ 2075m. The Upper Series, which is exposed in the area of Zhusileng, is calcareous sandstone mixed with sandy limestone, containing trilobites, cephalopods, brachiopods, bryozoa and coral fossils, and the stratum thickness is 265,438+08 ~ 442 meters. 6. Devonian (400-330 million years ago)

It is distributed in Badain Jaran community, Tengger Eris, Bayanchaogetu and other places, and it is unconformity contact with the underlying stratum. It can be divided into lower, middle and upper series. The lower series is distributed in Biyushan and Hebulamayin Arige, and is called "Qinghegou Formation". Its lithology is conglomerate, calcareous sandstone, sandy limestone, seasonal sandstone mixed with basic and intermediate acid lava, limestone and slate. It contains brachiopods, gastropods, trilobites, cephalopods and coral fossils, and the stratum thickness is 405.9 meters; Middle China is located in Tengger, Gegen, Dabaishi, Tonghushan and Heitanziliang, and is called "Shixiagou Formation". Its lithology is andesite, dacite, plagioclase, pyroxene basalt, conglomerate, gravelly sandstone, sandstone containing siliceous slate, biolimestone and fossils of plants, brachiopods, corals and trilobites. The formation thickness is 1. The upper reaches of Tonghushan Mountain, Niushoushan Mountain and Heitanziliang Mountain are collectively called "Shaliushui Group", and those in Bayanchaogetu area are called "Zhongning Formation". The lithology is conglomerate, glutenite, sandstone mudstone mixed with sandy limestone, neutral-intermediate acid volcanic rocks, and contains fragments of gymnosperms, corals, brachiopods and fish fossils. The maximum thickness of the stratum is 2595 meters.

7. Carboniferous Period (330-285 million years ago)

It is distributed in Badain Jaran Community, Helan Mountain, Tengger Eris and other places, and it is unconformity contact with the underlying stratum. It can be divided into lower, middle and upper series: the lower series is distributed in Tengger Eris, Tonghushan and Jianwozijing, and is called "Qianheishan Formation" and "Sniffing Niugou Formation". The lithology is sandstone, siltstone, mudstone, shale with limestone, marl and gypsum layer. It contains corals, brachiopods, branchiopods, gastropods, bryozoa and plant fossils, and the stratum thickness is174 ~ 2297m; The Middle China is called "benxi formation" in Helan Mountain and "Yanghugou Formation" and "Jing Yun Formation" in Tengger. The lithology is mainly sandstone, siltstone, shale mixed with limestone and thin coal seam, which belongs to marine and terrestrial sedimentary facies, and contains corals, brachiopods, dragonflies, gills and plant fossils. The stratum thickness is126 ~ 3253m; The Upper Series is distributed in Helan Mountain, Tengger Eris is called "Taiyuan Formation", and it is distributed in Badain Jilin Community as "Amushan Formation". The lithology is shale, sandy shale, sandstone with limestone, coal seam, oil shale, intermediate-basic pyroclastic rock, slate, limestone and conglomerate. It is rich in plants, Odonata, Brachiopoda, Gastropoda, Cladocera and coral fossils, and the stratum thickness is 444 ~ 6 000 meters.

8. Permian (285-250 million years ago)

It is distributed in Lai-Jilantai Community, Badain Jilin Community, Helan Mountain and the southern edge of Qi in Ya Bu. In conformity or unconformity contact with the underlying strata, it is divided into lower series and upper series: the lower series is called Shanxi Formation and Xiashihezi Formation in Helan Mountain area, and the buried Hanhada Formation and Akide Formation in Hanwula, Yachenke and Wulanbaixing. Located in the south of Qi, it is called Dahuanggou Group, but there is no distinction between them. Lithology: Shanxi Formation consists of shale, sandy shale, sandstone with carbonaceous shale and coal seam; The Xiashihezi Formation consists of sandy mudstone, mudstone, sandstone mixed with siltstone and coal seam. Dahuanggou Formation consists of timely sandstone with gravel, silty shale with gravel and glutenite. The buried Hanhada Formation is composed of conglomerate, sandstone, siltstone, biolimestone mixed with siliceous rocks, including plants, corals, brachiopods, cladocera, bryozoa and ammonites, and the stratum thickness is132 ~1545m. The Upper Series is called Shangshihe Formation and Shiqianfeng Formation in Helan Mountain, Halsuhai Group in Halsuhai, Wula, Meng Gen and the border areas between China and Mongolia, and Yaogou Group in the south of the banner area. Lithology: Shangshihe Formation and Shiqianfeng Formation are interbedded with sandy mudstone, mudstone and sandstone; Halsuhai Group consists of conglomerate, hard sandstone, siltstone, shale, dacite, andesite and tuff. Yaogou Formation consists of sandstone, siltstone mixed with mudstone and sandstone. It belongs to the fluvial and lacustrine facies, and only the Hal Sea Group belongs to the marine facies and land-sea facies. Contains plants, gastropods and bryozoa fossils. The stratum thickness is 46 ~ 7000m.

9. Triassic (250 ~ 65438+95 million years ago)

It is distributed in Helan Mountain, Wula, Meng Gen, Wendur Le Tu and other places, and it is in false conformity contact with the underlying stratum. The middle and lower levels are collectively called Zhifang Group of Helan Mountain and Xidagou Group of Letu Wendur. The lithology is mainly calcareous feldspathic sandstone mixed with fine sandstone, sandy mudstone and conglomerate, which belongs to fluvial and lacustrine deposits and contains a small amount of plant fossils. The Upper Series is widely distributed in Helan Mountain, which is called "Yanchang Group", and Wendur Le Tu is called "Nanyinger Group". It is mainly composed of gravelly feldspathic sandstone with mud shale, sandy mudstone, feldspathic fine sandstone, conglomerate, shale with marl, inferior coal seam and coal line. It belongs to fluvial and lacustrine deposits, containing plant fossils, and the stratum thickness is 324 ~ 2525 meters.

10. Jurassic (1.90 ~ 65438+40 million years ago)

Gulaben, Baxingtu, Hariaoribuge, Hongge Rierleng and Bayanwula Mountains in the north of Helan Mountain are unconformity contact with the underlying strata. The Middle-Lower Series is distributed in Gulaban and Baxingtu areas, which is called "Yan 'an Formation", and Bayanwula Mountain and Baoluoxiangwula area, which is called "Haerhan Group". Lithology: Yan 'an Formation consists of sandstone, conglomerate with shale, mudstone and coal seam, while Haerhan Formation consists of conglomerate, sandstone, siltstone, shale, British-An Ning gray conglomerate, sandstone and local coal seam. It belongs to river, lake and swamp facies deposits, and contains fossils of plants, branchiopods and gastropods. The stratum thickness is136 ~ 843m; The Middle Series distributed in Helan Mountain is called Zhiluo Formation. The lithology is mainly sandstone, siltstone and sandy mudstone interbedded, which belongs to fluvial-lacustrine facies and piedmont facies, rich in plant fossils, and the stratum thickness is 97 ~ 750 meters. The Upper Series is distributed in Helan Mountain and is called "Anding Formation". It is composed of conglomerate, sandstone mixed with siltstone and shale, belonging to fluvial facies, and some areas belong to piedmont-fluvial facies. The maximum stratum thickness is 2746 meters.

1 1. Cretaceous (1.4 ~ 700 million years ago)

Widely distributed in Badain Jaran Community, Laijilantai Community in Ya Bu, flat area in front of Helan Mountain and foothills, and unconformity with the underlying stratum. They are divided into lower series and upper series. The lower series is distributed in the middle and north, and is called Bayan Gobi Formation, Su Hong Figure Formation, Guyang Formation, Dashuigou Formation and Urta Formation, while in the south. The lithology is mainly conglomerate, sandstone mixed with siltstone, mudstone and marl. There are oil shale and carbonaceous shale in Wuliji area, and alkaline basalt, basaltic trachyandesite, andesite, trachyandesite, sandstone and mudstone in Su Hong area, including poda, cladocera, ostracod, fish, insects, ostracods, plants and sporopollen fossils, and the stratum thickness is 18 ~ 650. The distribution area of the upper series is related to the unification of the lower series. The north-central part is called "Wulanhushao Formation" and the south part is called "Miaoshanhu Formation". The lithology is mainly gravelly sandstone, sandstone, siltstone, mudstone, local gypsum layer and coal line, including reptiles, gills, gastropods, ostracods, spiders and plant fossils, belonging to river-lake facies, with formation thickness of14 ~ 749m.

12. Tertiary (700-300 million years ago)

Except Palaeocene, other tertiary systems are exposed. It is distributed in the vast area of central and southern China, and is built of continental red clastic rocks with salt layers in some areas. It is deposited in intermountain basin and piedmont basin, belonging to foothill facies, river facies and lake facies. In unconformity contact with the underlying stratum. Eocene is distributed in Suhaitu, Jilong Tonggu, engler, Chalasibe, Naomuhong and other places, containing gastropod fossils, and the stratum thickness is 24 ~1752m. Oligocene is distributed in Hausbudu, Chagan Prague, Hanwula, Orenburg, Tulantai and other places, and is called "Chagan Prague Formation". Distributed in Xianggendalai and Gargler in Sai Han, it is called "Qingshuiying Formation". It contains vertebrates, ostracods, gastropods, branchiopods, charophytes and plant fossils, and the stratum thickness is135 ~ 980m. Miocene distributed in Xinjing, Luanjing, south of Jilantai Lake, Chahan Aobao, Hausbudu, Indri Map, Xilintiebuge and other places, containing mammals, reptiles, ostracods and Charophyta fossils, with a stratum thickness of 36 ~1256m. The Pliocene distributed in Luanjing, Mafuxiazi, Xianggendalai, Hanwula, Aolun Prague and other places on the west side of the southern section of Helan Mountain, and was called "Hegou Formation", which contained fossils such as mammals, gastropods, ostracods, birds, Charophyta and sporopollen. The stratum thickness is147 ~ 805m.

13. Quaternary (03 million years ago to modern times)

Quaternary is widely distributed, concentrated in Badain Jaran, Tengger Eris, Wulanbu and Gobi areas. It is divided into four series: the Lower Pleistocene is distributed in the foothills, and the landform is mostly platform roof, which is composed of diluvial conglomerate, glutenite and gravel layer. Bayanhaote, Shajing and Chahar wells are ice water accumulation. Formation thickness? 0.5~75? Rice; Middle Pleistocene is distributed in Jilantai Basin, Yaobatan, the lower part of intermontane depression in Helan Mountain and the top of terrace in Bayanhaote area. This is a flood alluvium, which consists of alluvial sand and gravel mixed with clay sand and sandy clay. The alluvial lake is composed of fine sand, clayey sand and clay, including vertebrates, gastropods and tortoise fossils, and the stratum thickness is 0. 1 ~ 63m. Upper Pleistocene is distributed in piedmont diluvial platform, inclined plain, lower part of intermountain depression, Gobi desert and loess hilly region. It is composed of alluvial layer, alluvial layer, lacustrine layer and aeolian layer, composed of sand, gravel, pebbles, gravel mixed with silt and sandy clay, and loess mixed with humus silt locally. It contains gill, gastropod, mammal, sporopollen and other fossils. The formation thickness is 0.1~150m; Holocene is widely distributed in desert, Gobi, piedmont diluvial fan, piedmont inclined plain, intermountain depression, Yellow River, modern intermountain valley, modern freshwater lake, alkali lake and saline-alkali beach, and it is aeolian deposit, alluvial deposit, lake deposit, chemical deposit and swamp deposit. The stratum thickness is 0.3 ~ 1.00 m.

Magmatic rocks in the second quarter

In addition to sedimentary rocks and a small amount of metamorphic rocks, magmatic rocks in Zuo Qi, Alashan mainly include intrusive rocks and volcanic eruption rocks. Magmatic rocks are mainly exposed in the northern part of the banner, concentrated in the northern section of Helan Mountain, Harunai Mountain and Bayan Norrigongliang. Due to the strong magmatic activity and the multi-stage characteristics of intrusion and eruption, magmatic activity occurred in almost all geological periods, especially in Variscan and Indosinian granites. Rock types include ultrabasic rock-basic rock-intermediate rock-acid rock-alkaline rock, all of which are exposed and become bedrock, rock plant, rock cover, rock branch, rock tumor, dike and rock neck.

I. intrusive rocks

Intrusive rocks are widely distributed in the northern and southern parts of Qi and Helan Mountains. According to the intrusive stages, it can be divided into Fuping-Jinning stage, Caledonian stage, Variscan stage and Indosinian stage, in which the intrusive rocks are the most widely distributed.

1. Fuping-Jinning period

Fuping-Jinning intrusive rocks are distributed in Baiyanggou in the middle section of Helan Mountain and south of Bayan Aobao in the northern section. Baiyanggou rock mass has an exposed area of 2.75 square kilometers, and its rock composition is plagiogranite composed of plagioclase, quartz and mica, belonging to early Proterozoic intrusions. The granite body in the south of Bayan Aobao is generally exposed for several square kilometers, with the maximum exposure of 124 square kilometers. Magmatic rocks are grayish white and medium-fine-grained, and consist of potash feldspar, plagioclase, syenite, biotite, sillimanite and garnet, with ore-bearing muscovite and sillimanite mineralized.

2. Caledonian period

Caledonian intrusive rocks can be divided into early, middle and late stages: in the early stage, they were scattered in Yemaozishan and Mafuxiazishan, and the rock mass interbedded with diabase and diabase of Xiangshan Group, and the geological age was Middle Cambrian Xuzhuang Formation; In the middle stage, it is distributed in Bayannuorigongliang, Burihanwula, Harunai Mountain and other places. The rocks are mainly pyroxenite, gabbro, diabase and diorite in Lan Gang, mostly in the form of small rock clusters and branches, or in the form of rock nodules and rock caps remaining in the upper part of the Variscan and Indosinian rock masses. The exposed area is generally less than 2 square kilometers, and the maximum is 6. 1 square kilometer. In the late stage, it is scattered in the middle of Qi and Helan mountain areas and divided into basic-ultrabasic rock bodies and acidic rock bodies. Basic-ultrabasic rocks are mainly exposed in Xiaosongshan, Aodun Gerile and other places, mainly gabbro, gabbro-bearing pure gabbro, plagioclase gabbro, lherzolite and pegmatite, followed by gabbro and amphibole gabbro. There are few acid rocks exposed, and the distribution area of xenoliths in Variscan and Indosinian rocks in Bayannuorigong area is several square kilometers. There is a big battlefield in Huduge Township, the southern section of Bayanwula Mountain, and a big battlefield in the southern section of Helan Mountain, with an exposed area of 50 square kilometers and 0.42 square kilometers respectively, consisting of adamellite and plagiogranite. Caledonian intrusive rocks contain minerals limonite, hematite and plagioclase.

3. Wali West District

Variscan intrusive rocks can be divided into early, middle and late stages: in the early stage, they are scattered in Duleji and Ehuhujili. The former is an irregular strip-shaped small rock foundation with an exposed area of 103 square kilometers, and its edge is granodiorite, while the latter is a rock plant with an exposed area of 5 square kilometers, consisting of meat-red adamellite and biotite granite; In the middle stage, it is mainly distributed in Shariza Mountain, Hongge Ri 'erlan area and Tengger Eris. The rock mass is relatively small, mainly intermediate rock, followed by basic, ultrabasic and acidic rocks. The intermediate rocks are composed of quartz diorite, biotite, amphibole-diorite, amphibole-biotite plagiogranite and granodiorite. The basic rocks are composed of hornblende gabbro, gabbro, gabbro and diorite. Ultrabasic rocks are composed of gray-green gabbro, gabbro, lherzolite, pyroxenite and pure gabbro containing gabbro. Acid rocks are composed of adamellite and granite. In the late stage, it is widely distributed in the west of Bayanwula-Paolo Xiangwula, and there are also exposed mafuxiazi. Among them, Sharizha Mountain and Bayannuorigong, the largest areas, are the main magmatic rocks in Alashan region, which are composed of syenite, potash feldspar, plagioclase, biotite and amphibole, and are biotite granite, adamellite, granite, plagiogranite, potash granite and granodiorite. Variscan intrusive rocks are mineralized by ferrochrome, nickel, iron-bearing copper, crystal and fluorite.

4. Indosinian period

Indosinian intrusive rocks are mainly distributed in Shariza Mountain, Baoluoxiangwula Mountain, Diebusk Mountain, Hanwula Mountain, Bayannuorigong Liangshan Mountain and Bayanwula Mountain in the north of the banner, and the scale is second only to that of late Variscan intrusive rocks, mostly in the form of rocks, branches and dikes, with a small amount of bedrock. The lithology is mainly granite, followed by ultrabasic rocks, basic rocks and alkaline rocks. The exposed area of ultrabasic rocks is 0.24 square kilometers, which consists of amphibole, Gan Lan pyroxene, pyroxene amphibole, amphibole and amphibole gabbro. The intermediate rock is exposed about 0.3 square kilometers and consists of dark green diorite. The exposed area of moderately acidic rocks is generally 1 ~ 20 square kilometers, with a maximum of 200 square kilometers. It is composed of adamellite, potash feldspar granite and biotite granite, and the main mineral components are syenite, potash microcrystal, plagioclase, amphibole and biotite. The distribution area of alkaline rocks is 0. 18 ~ 3.5 square kilometers, which is flesh red and light red granite. The mineral composition is mainly syenite, followed by alkaline syenite, aegirine syenite and nepheline syenite. Indosinian intrusive rocks contain iron-bearing copper mineralization, crystals and hibiscus; Red-purple medium-fine grained granite is the raw material of Youliang "Wang Fuhong" decorative board. 〖HT3H〗HJ * 4/5]

Second, erupting rocks

Eruptive rocks are widely distributed and concentrated in the northern part of this banner. According to the eruption stages, it can be divided into Fuping-Lvliang stage, Caledonian stage, Variscan stage, Yanshan stage and Himalayan stage. Eruptive rocks are most widely distributed in the late Variscan period, with the largest thickness of rock mass, and eruptive rocks are less exposed in other periods.

1. Fuping-Lvliang period.

Fuping-Lvliang eruptive rocks are mainly distributed in Diebure, Hanwula, Boudal Gan, Gashun Taolai and other places. Eruptive rocks include granulite, gneiss, granulite, amphibole, schist and various mixed rocks, all of which are basic volcanic rocks and are the products of many volcanic eruptions in early Proterozoic.

2. Caledonian period

Caledonian eruptive rocks, interbedded with diabase and diabase, were found in Yemaozi Mountain and Mafuxiazi in the south of the banner. The almond-shaped altered basalt was found in Bayanchaogetu, the southern section of Helan Mountain, which is the product of homology with diabase and the eruption of marine basic volcano in the early Caledonian. The eruptive rock mass in this period occurred in Xuzhuang Formation in the late Middle Cambrian.

3. Wali West District

Variscan eruptive rocks can be divided into middle and late stages. In the middle stage, it is mainly distributed on both sides of Shariza Mountain, and it is an intermediate-acid pyroclastic rock, consisting of dacite tuff, dacite volcanic breccia and a small amount of basalt, which is produced in Amershan Formation of Upper Carboniferous. In the late stage, it is mainly distributed in Bayannuorigong granite foundation, mostly lava and pyroclastic rocks, and the lithology is mainly acidic intermediate rocks, followed by alkaline alkaline rocks. Rhyolitic lava is distributed in the northeast of Bayannuorigong granite base, with basalt in the south and rhyolitic dissolved rock, porphyry and quartz porphyry in the southwest, all of which are products of late Triassic.