The lower member is purplish red and grayish red massive conglomerate, with gravelly coarse sandstone mixed with grayish purple and purplish red sandstone, and purplish red layered tuffaceous sandstone can be seen at the top; There is a layer of gray and gray-green massive conglomerate at the bottom, and the gravel is mostly angular and subangular, mainly volcanic rocks, which is consistent with the lithology of the underlying Shangshu Formation and has the characteristics of bottom conglomerate. Discontinuous oblique bedding, parallel bedding and massive bedding are developed in this section, and scouring and undercutting structures are developed at the lower part, with occasional wave marks (Figure 1-2). 309.3 meters thick.
Figure 1-2 Scouring surface and bedding structure of the lower member of Tang Zhi Formation (continued)
The upper member is grayish green, gray and grayish white silty mudstone, siliceous shale, siliceous siltstone, tuff and tuffaceous sandstone. Continuous transition with the lower section. Horizontal stripes are generally developed, with occasional wavy, veined bedding, bamboo-leaf structure and sliding deformation structure, with a thickness of 392.8 meters.
This group is mainly distributed in Xintangwu, Shangyu, Sidu and Zu Feng, and there are sporadic outcrops in Xishan and Xujiang Park in Jiangshan Chengguan. This group is in angular unconformity contact with the underlying Shangshu group. In Zhejiang province, the phase transition of this formation is not great, but the thickness decreases from east to west.
(2) Leigongwu Formation (Z 1l). Founded by Liu Hongchong and Sha Qing 'an (1959), it is named Leigongwu, west of Sanli Pavilion in Changshan County.
This group of rocks is a set of rocks with glaciers soaked in water. Yellowish gray and purplish red gravelly mudstone and gravelly silty mudstone. Gravel size varies, with a diameter of 0.2 ~ 30 cm and a gravel content of 5% ~ 15%. Gravels are irregular, angular, pie-shaped, oval and so on. Some gravels, especially blue-gray jasper gravels, often have multiple groups of ice scratches and extrusion pits on their surfaces. Gravel sorting is poor, with no directional arrangement and no bedding. Gravel composition is complex, mainly including carnelian, limestone, manganese-bearing limestone, jasper, veined quartz, siliceous rock, quartzite, quartz sandstone, silty slate and mudstone. 8.5~49.4 meters thick. From east to west, the thickness increases.
This group is mainly distributed in Xintangwu and Huangnitang areas, with sporadic outcrops in the western hills of Chengguan. It is in integral contact with the underlying Zhitang Formation, with obvious characteristics, stable horizon and wide distribution. It is one of the marker beds for the division and correlation of Sinian system, which is roughly equivalent to Nantuo Formation in eastern Xia Dong, and belongs to the late Early Sinian deposit.
(3) Xifengsi Formation (Z2x) evolved from the siliceous limestone of Xifengsi in Shengshenfu (195 1) and was named Xifengsi in the west of Changshan County. Xifengsi Formation can be divided into two sections according to lithology.
The lower part of the lower member is bluish-gray limestone dolomite, which contains dolomite, flint agglomerate microcrystalline limestone and grayish-black silty shale, sometimes irregularly interbedded. The middle part is a layer of purplish red muddy dolomite mixed with dolomite lentil layer, which is small in thickness, but stable in horizon with horizontal stripes, and can be used as a marker layer for division and correlation of the lower member. The upper part is light gray, weathered yellow dolomite, occasionally mixed with black shale. In this section, we can see micro-plant fossils such as Protophyta and hexamask. , the thickness is about 78.1m. ..
The upper part is light gray and grayish white, yellow gray dolomite and massive stromatolite dolomite, and sometimes flint lumps can be seen in the upper part. Horizontal stripe development. The stromatolites Conophyton (cone stromatolite), Baicalia (Baikal stromatolite), Gymnosolen (naked stromatolite), Leiosphaeridia (Chlorophyta), protosphaeridia (Prosphaerococcus) and Brocholaminaria (six masks) were produced, with a thickness of 79.2 meters. ..
This group is mainly exposed in Chen Da and Xintangwu, with sporadic exposure in the western hills of Chengguan. It is in false conformity contact with the underlying Leigongwu Formation.
(4) Tanghe Formation (1h) was founded by Lu He Mu Enzhi (1955) and named in Jiangshan County. The lithology of this group is mainly gray, grayish yellow shale and siliceous shale, and the bottom is stony coal seam, dolomite containing collophanite gravel and nodular phosphorite. Trilobite fossils Hunanocephalus (Hunan cephalopod), Shabaella (sand bar worm) and sponge spicule Proto-spongia (primitive sponge spicule) are produced, and small shell fossils Anabarites (Anabar snail) are also seen at the bottom. Thickness 19. 1 m
This group is mainly distributed in Tanghe and Bianbian areas, and it is in pseudo-integrated contact with the underlying Xifengsi Formation. The stony coal seams at the bottom of this group are all over western Zhejiang, which is an important coal and phosphorus horizon in Zhejiang.
(5) edge group1-o1d). It is a newly revised stratum in this book, which is formed by merging the thin limestone in the lower part of the original Dachenling Formation, Yangliugang Formation, Huayansi Formation, Xiyangshan Formation and Yinzhubu Formation. The lithology of this formation is mainly gray-black thin-layer microcrystalline limestone, argillaceous microcrystalline limestone with calcareous shale bands, dolomite bands at the bottom and increased argillaceous content at the top. Horizontal stripes are developed, and bird's eye structure can be seen at the bottom.
This group is rich in trilobite fossils, which are: Arthricocephalus (arthropod) and Changaspis (Zhang Shi) from bottom to top (equivalent to the original Dachenling Formation); Fuchouia (Fuzhouworm), Lejopyge (bare-tailed catcher), Ptychagnostus (wrinkled-ball catcher), Hypagnostus (hidden-ball catcher), Goniagnostus (prismatic catcher), Triplagnostus (three-point catcher), Pseudophalacroma (fake bald-ball catcher), Doryp. Diplagnostus (dichotomous ball connector), Phalacroma (bald ball connector), Oidalagnostus (swollen ball connector), Linguagnostus (tongue ball connector), sponge bone needle (equivalent to the original Yangliugang group); Glyptagnostus, Pseudoglyptognostus, Proceratopyge, Pseudagnostus, agnostus and brachiopod fossils (equivalent to the original Huayansi Formation); Lotagnostus (flower bud), hedinaspis (hedgeworm), Chekiangaspis (Zhejiang worm), Geragnostus (old bud), Charchaqia (Chaerchak worm), Homagnostus (equal to bulblet), Westergaardites (Wechsler worm), Olenus (oil comb worm) and cephalopods. Hysterolenus (Bactrocera gigantea), Symphysurus (Myxomycetes), Macropyge (Macrocauda), Diceratopyge (Diptera), Staurograptus (Crossgraptolite), Anisograptus (Inverted Graptolite), Bryograptus (Bryograptolite), etc. (equivalent to the bottom of the original silver bead cloth group). It is 329.9 meters thick.
This group is mainly exposed in Bianbian, Dachenling, Yangliugang and Huangnitang, with sporadic exposure in Xishan, Jiangshan City. This group has little lateral change and is in contact with the underlying Tanghe group as a whole. Bianbian Formation is an important horizon of lime burning in western Zhejiang.
Cambrian limestone is most exposed in the Qibianyi belt about 0/0 km north of Jiangshan City, and has a clear boundary with the Ordovician (between the Lotus Hedini belt (Hedinghuaqiu sub-belt) and the Hysterolenus asiaticus belt (Asian post-oil absorption belt)). After years of research, it has become the standard section of the Cambrian-Ordovician boundary in the stratigraphic division of the south of the Yangtze River. 1985, Zhejiang provincial people's government established the CAMBRIAN-Ordovician boundary standard profile protection zone in Bian Xia.
(6) Yinzhubu Formation (O 1y) was developed from Yinzhubu System founded by Zhu Tinghu (1923), formerly known as Yinzhubu, south of Yuqian County, Zhejiang Province. This book revised its bottom boundary and moved the bottom boundary of Yinzhubu Formation to a place where a large number of yellow shale appeared. The lithology of this formation is yellow-green shale, with a small amount of calcareous shale and nodular marl, and purple shale can be seen at the top. Shale looks like a matchstick after weathering. A large number of fossils have been produced, including trilobites Euloma (Lepidoptera elegans), Shumardia (Schumader), Geragnostus (old ball receiver), Niobella (little daughter worm), Inkouia (sewer worm), Ampyx (Nematoda), Asaphopsis (Ctenopharyngodon) and Corrugatagnostus. Graptolites are Adelograptus (hidden graptolites), Clonograptus (branched graptolites), and double graptolites (opposite graptolites). Small ligulate shells and ostracods of brachiopods. It is 57.9 meters thick.
This group is distributed in Bianxia, Huangnigang and the bottom of Jiangshan. The bottom is mostly exposed due to faults, and only in Bian Xia area is it in integrated contact with the underlying Bianxia Group.
(7) Ningguo Formation (O 1n) was founded by Xu Jie (1934) and was named Hulusi in Ningguo County, Anhui Province. 1955, Lu and others introduced a section of Ningguo Formation in western Zhejiang, representing the upper part of the original Indosinian-Zhubu system.
The lithology of this formation is gray-black shale, mixed with thin siltstone and siliceous rocks, with horizontal stripes at the bottom and sometimes microcrystalline limestone. The trilobites produced by this group are Euloma (Lepidoptera elegans), Niobella (little daughter worm), Geragnostus (old ball grafting) and Shumadia (Shu Madia worm). Graptolites include: Didymograptus, Azygograptus, Phyllograptus, Tetragraptus, Glyptograptus, Pseudotrigonograptus, Isograptus, etc. Paracardiograptus (pseudo-heart Graptos), Yushan Graptos (Yushan Graptos), cardiograptus (heart Graptos), Glossograptus (tongue graptos), pseudo-lithograptos (pseudo-moss graptos), Loganograptus (Lloyd's graptos) and so on. Brachiopoda: rotifer, mimicry, tongue; Gastropoda and Ostracoda fossils produce conodonts in limestone at the bottom. It is 40.6 meters thick.
This group is distributed in Jiangshan bottom and Huangnigang in the border area, and also distributed sporadically in Xishan and Hehuatang. This group is in integral contact with the underlying Yinzhubu group.
It is worth noting that there is no limestone in the naming place of Ningguo Formation, so it is named after black graptolite shale. However, there is a limestone lens at the bottom of Ningguo Formation in Jiangshan area, which is not a single graptolite shale. It is different from Ningguo section and closer to Dawan Formation in central and southern China. In addition, the bottom of Ningguo Formation in Jiangshan belongs to Azygographus Suecicus belt (Swedish graptolite belt), and there are three graptolite belts under the Azygographus Suecicus belt of Standard Ningguo Formation in southern Anhui. Considering that Ningguo Formation in Jiangshan area is in contact with the underlying Yinzhubu Formation as a whole, it can be considered that the graptolite shale in Jiangshan area is equivalent to three graptolite belts in the lower part of the standard Ningguo Formation, and turns into yellow-green and purple-red shale at the top of Yinzhubu Formation.
(8) Hulu Formation (O 1-2h) was founded by Xu Jie (1934) and named Hulu Temple in Ningguo County, southern Anhui Province. Lu, Mu Enzhi and others (1955) adopted the name of Le Hu Formation in stratigraphic research in this area. The bottom of the Le Hu Formation mentioned in this book includes the protoniushang Formation, that is, the thin siliceous rocks in the Sargassum fusiforme belt and the beautiful rosewood belt.
The lithology of this group is gray-black thin-bedded siliceous rocks, shales, siltstones and carbonaceous shales, which are yellowish brown to light yellow after weathering. Graptolite: grip graptolite (surrounding graptolite), wing graptolite (wing graptolite), wing graptolite (opposite graptolite), tongue graptolite (tongue graptolite), Nicholsono graptolite (Nishi graptolite), climate graptolite (grid graptolite), carving graptolite (carving graptolite), sword graptolite (sword graptolite) and false lip graptolite. And water-repairing graptolites (water-repairing graptolites Abrograptus, Dicellograptus, Dicranograptus, Nemagraptus, Lasiograptus, Leptograptus and Orthograptotus). Brachiopoda ligulate suborder (Lepidoptera). It is 29.8 meters thick.
This group is distributed in Jiangshan bottom, Huangnigang, the border area, and there are sporadic outcrops in lotus pond and other places. Topographically, it is mostly lowland and is often covered by Quaternary. This group is in integrated contact with the underlying Ningguo Group.
(9) Yanwashan Formation (O2y) was developed from Yanwashan Mountain System founded by Liu He and Zhao Yaceng (1927), and it was named Yanwashan Mountain in Jiangshan.
The lower part of this formation is gray-black microcrystalline limestone mixed with calcareous shale and gray-green nodular marl, the middle part is purple nodular marl, and the upper part is gray nodular marl and gray gravelly limestone mixed with calcareous shale. Trilobite-producing larvae (Lepidoptera), Nileus (Geminid Insect), Jiangxi Tritumor Insect (Jiangxi Tritumor Insect), Birmanites (Burmese Insect), Ampyxinella (Leptospira), Corrugatagnostus (Ancylostomatidae), Calymenesun (Cryptomeria), etc. Cephalopods: Trionyx sinensis (Sinian hornstone), Trionyx Michelia (Miqilin hornstone), Trionyx yanwashan (Yanwashan hornstone), etc. In addition, there are corals, sea lilies, ostracods, brachiopods and gastropods. The thickness is155.2m.. This group has been exposed in Yanwa Mountain, Li Antang, Huangnigang, Jin Mu dock and other places, and there are sporadic exposures in Wu Jia Lane. This group is in integrated contact with the underlying Hule group.
(10) Huangnigang Formation (O3h) was founded by Lu and Mu Enzhi (1955) and named in Huangnigang Village, Jiangshan City.
The lithology of this group is brick red shale, mudstone and silty shale, and the lower part contains more calcareous and siliceous calcareous nodules. Among them, the calcareous tuberculosis center is generally a well-preserved fossil, but not in siliceous calcareous tuberculosis. This group is rich in fossils: trilobite Nankinolithus (Nanjing Trilobite), Nileus (Dicotyledonous Insect), Remopleurides (Lepidoptera), Cyclopyge (Roundtail Insect), Geragnostus (Old Ball Grafting), Corrugatagnostus (Frog Ball Grafting), Telephina (Telephina), Basilicus (Imperial Insect), Ptychopyge (Sideoptera), Birmanites (Burmese Insect), Calymenesum (Cryptocephalus), Atractopyge (Arrow-tailed Insect), Pliomerina (Small Multi-stranded Insect), Encrinurella Cephalopod Michelinoceras (Mickey Hornstone), Fengzuerac (Hornstone). Gastropoda Maclurites (Malpighian snail), Lophospira (Spirogyra) and so on. Coral Agetolites (Aggett coral); Brachiopod Trimerella (three decibels), Sinotrimerella (three decibels in China), Fengzuella (rich shellfish), sponges, ostracods and other fossils. It is 22.4 meters thick.
This formation is widely distributed in Jiangshan, mainly exposed in Da Qiao, Zhengjiawu, Huangnigang, Nongli, Niutangdian, Dalongtou and the bottom of Jiangshan, with northeast distribution and integrated contact with the underlying Yanwashan Formation. This formation is widely distributed, with small thickness, stable lithology and lithofacies, obvious characteristics and abundant fossils, and is a good indicator layer in this area.
(1 1) Changwu Formation (O3c) was founded by Lu He Mu Enzhi (1955) and named in Jiangshan Changwu Village.
The lithology of this group is gray-green, gray-yellow-green shale, calcareous shale mixed with siltstone and fine sandstone, which constitutes the rhythmic layer. Oblique bedding, horizontal bedding, cyclotron bedding, lenticular bedding, corrugated and grooved development. This group of fossils is relatively rare, mainly occurring in the non-rhythmic layer, producing trilobites Ampyxinella (Angle), Ptychopyge (Hemiptera), Calymenesun (Cryptozoa), Birmanites (Burma worm), Corrugatagnostus (Rugosa coccidia), Nileus (Gemworm), telephana(telephana) and Dio. Graptolites, such as Dicellograptus, Climacograptus, Glyptograptus, Pseudoclimacograptus brachiopods, such as Zygospira, Leptellina, Plectambonites, etc. Gastropods, cephalopods, bivalves, cones, mosses and ostracods. It is 320 meters thick.
This formation is the most widely exposed stratum in Jiangshan area, mainly distributed in Shiyangwei, Xuekengjian, Zhujiawu, Wujianong and Changwu. The thickness of Changwu Formation changes greatly, and it thickens from east to west, reaching more than 2000 meters in Chun 'an area. From Sanqu Mountain in Quzhou to Toutou Mountain in Yushan, Jiangxi Province, this stratum has become thick limestone, and benthic organisms such as corals and brachiopods have developed. It is in integral contact with the underlying Huangnigang Formation.