Cambrian typical stratigraphic profile

The Cambrian strata in Zhang Xia, Gushan and Mantoushan, Shandong Province are well developed, well exposed, close to the Jinpu Railway and convenient in transportation, which has attracted the attention of geologists at home and abroad as early as the end of 19. 1903, American geologists B. Willis and E. Blackwell investigated profiles in Zhang Xia, Gushan and Laiwu Jiulongshan, collected fossils and preliminarily divided the Cambrian strata. Their research results were officially published in 1907. The Cambrian strata in Zhang Xia and Gushan are divided into steamed bread shale, Zhang Xia limestone and limestone from bottom to top. Then American paleontologist Bi Ke Tuo (19 13), Japanese Endo Ryuji (1939) and Kobayashi Yizhen (194 1, 1942,/kloc-0). Professor Yuntao Sun, a famous geologist in China, has studied the Cambrian in Zhang Xia and Gushan areas for more than 20 years since 1923, and divided the Cambrian strata.

1953, the standard profile of CAMBRIAN was re-observed in Hegu Mountain by Lu and Dongnanting. The most important thing is to divide the steamed bread shale of B. Willis and E. Blackwell into steamed bread formation, Maozhuang formation and Xuzhuang formation from bottom to top, and put the first two formations in the lower CAMBRIAN, the latter in the middle CAMBRIAN and the fried Midian limestone in Fengshan formation and Changshan formation. Since then, Beijing Institute of Geology, Shandong Geological Bureau and other related geological colleges have successively conducted a large number of field observation, profile measurement, indoor identification and special research on the Cambrian stratigraphic profile in Zhang Xia, and obtained rich practical data, which supplemented and improved the basic data of the profile from different angles and further improved the research level of the profile.

During the period of 1959, the Cambrian stratigraphic section in Zhangxia, located on the north side of Mount Tai, was officially designated as the standard section of Cambrian in North China at the National Stratigraphic Conference. 1958- 196 1 year, Beijing Institute of Geology conducted a regional survey of1:200,000 in Taishan area, and named Taishan metamorphic rocks as Archean Taishan Group, which was divided into Wanshanzhuang Formation, Yanlingguan Formation and Shancaoyu Formation from bottom to top. 1960- 1962, Team 805 of Shandong Geological Bureau conducted 231∶ 50,000 regional surveys, including the remaining area in southern Tai 'an. 1963- 1965, Team 805 of Shandong Geological Bureau adjusted the area of1∶ 50,000 Tai 'an Sheet, which was called Taishan metamorphic rock Taishan complex, and it was divided into five rock formations: Wang Fushan, Fushiyu, Tangjiazhuang, Yujiazhuang and Fengjiayu. At the same time, Cheng of the Academy of Geological Sciences and Zheng Liangzhi and Zhang of Team 805 of Shandong Geological Bureau carried out special research on metamorphic rocks, established the sequences of Yanlingguan Formation and Shancaoyu Formation, restored the original rocks, and conducted petrological research on metamorphic rocks.

After 1978, the geological research of Mount Tai has entered a stage of in-depth development with special research as the mainstay. The protection, management, development and construction of Mount Tai have been greatly strengthened, and the face of Mount Tai has undergone great changes. From 65438 to 0980, Ying researcher made a special study on Taishan metamorphic rocks and published a monograph "Taishan Complex". 198 1- 1984, Professor Lu of Shandong Institute of Mining and Technology made a special study on the formation of Mount Tai and published the article "The Formation and Times of Mount Tai". 1982- 1985, Zheng Liangzhi, Wang Shijin, etc. Shandong Dispatching Team made a special study on Taishan Group in western Shandong, and established Liuhang Formation, which was placed on Yanlingguan Formation and Shancaoyu Formation. 1982- 1987, Ma Yunshun and Zhai Yingchuan, the first geological team of Shandong Bureau of Geology and Mineral Resources, made a special study on the ore-bearing property of Archean greenstone belt in western Shandong. 1982- 1984, Zhao Shiying and others made a special study on the "barrel structure" in Hong Men, Taishan, and published a paper "Discussion on the Causes of the" barrel structure "in Hong Men, Taishan". 1982- 1985, Master Zhu Zhenhua of the Academy of Geological Sciences filled in the geological map of1∶ 25,000 in front of Mount Tai, completed his master's thesis and published the paper "Petrochemical and Geochemical Characteristics of Archean Magmatic Complex in Mount Tai".

1983- 1986, Jiang Boming of Rennes University, Shen of Academy of Geological Sciences and Dong of Shandong Bureau of Geology and Minerals made a special study on the Archean crustal evolution of China, and considered that most of the Taishan complex was metamorphic intrusive rock (gray gneiss), which was called gneiss, and obtained a lot of geochemical and isotopic age data. 1986- 1987 Xie Ning Middle School of Peking University conducted a comprehensive investigation, evaluation, protection and utilization of Taishan scenic resources. 1986- 1990, Wang Shijin of Shandong Dispatching Team conducted1:200,000 Taian and Xintai surveys. At the same time, Xu Huifen of the Academy of Geological Sciences and Dong of Shandong Geological Team 1 made a special study on Archean greenstone belts and Archean strata in western Shandong, systematically summarized the distribution, sequence and metamorphism of Taishan Group, and published a monograph.

1987 UNESCO listed Mount Tai as a world natural and cultural heritage, and its status and influence have undergone historic changes. 1989- 1990 Professor Lu of Shandong Institute of Mining and Technology made a special study on the gravity sliding structure around Mount Tai, and published the paper "Discovery of the sliding structure on the unconformity surface between Archean and Paleozoic around Mount Tai". 65438-0990 Dong, the First Geological Brigade of Shandong Bureau of Geology and Mineral Resources, published a paper entitled Geochemical Characteristics of Archean Complex in Taishan Area. 1990- 1993, Cao et al. of Shandong Bureau of Geology and Mineral Resources published the monograph "Early Precambrian Geology in Luxi". 1993- 1996, Institute of Geology, Ministry of Geology and Mineral Resources, Shandong No.1 Institute of Geology and Mineral Exploration conducted a1:50,000 regional geological survey in Tai 'an City.

1994- 1995 Professor Lu made a special study on the neotectonic movement of Mount Tai, published the article Neotectonic Movement and the Formation and Geomorphology of Mount Tai at Present, summarized the geology and geomorphology of Mount Tai, and wrote the Complete Works of Geology and Geomorphology of Mount Tai. 1995 The First Geological Brigade of Zhuang and Shandong Bureau of Geology and Mineral Resources of the Academy of Geological Sciences published a paper "New Progress in the Study of Neoarchean-Proterozoic Crustal Evolution in Taishan Area". 1997 Zhuang of the Academy of Geological Sciences, Ren Zhikang of the First Geological Brigade of Shandong Bureau of Geology and Mineral Resources and others published a paper entitled "Major Geological Events and Crustal Evolution of Early Precambrian in Taishan Area" in the Journal of Petrology. During the period of 1998, Lu Fatang and others from the Geological Survey Institute of Shandong Geological Survey Bureau published a paper entitled "Geological Characteristics and Rare Earth Geochemical Evolution of Late Archean" Frame Intrusive Rocks in Taishan Area "based on their research results.

1999 Wang Xinshe of Geological Research Institute and Ren Zhikang of the First Geological Brigade of Shandong Bureau of Geology and Mineral Resources published a paper "Significance of Late Archean ductile shear in continental crust evolution in Taishan area". In 2000, Zhang Mingli, Institute of Geomechanics, Academy of Geological Sciences, published a paper entitled Cenozoic Tectonic Movement and the Formation of Mount Tai. In 2002-2003, Professor Lu of Shandong University of Science and Technology and Professor of Taishan Scenic Area Management Committee conducted a special study on the geological and geomorphological characteristics and geological value evaluation of Taishan, and published a paper entitled "Geological Value and Significance of Taishan". In September 2004, China Geo University made a two-week investigation on the construction conditions, geological relics and resources of the proposed Taishan World Geopark in China.

The Cambrian stratigraphic section in Zhang Xia divides the Cambrian into seven stratigraphic units in the lower, middle and upper series, namely, Xiamantou Formation, Zhongmaozhuang Formation, Xuzhuang Formation and Zhangxia Formation, and Shanggushan Formation, Changshan Formation and Fengshan Formation. Now, from the old to the new, it is briefly as follows:

The mantou Formation is mainly composed of variegated shales such as purplish red and yellow green, and argillaceous and dolomitic limestone. The bottom is unconformity on the fleshy red gneiss granite of Taishan complex. The lower limestone contains magnetite nodules and bands, the upper shale contains fine horizontal bedding, and the middle shale contains trilobite fossils ~ Ledley beetles in China. The thickness is119m.

Maozhuang Formation is mainly composed of purple mica shale and limestone. Contains trilobites, brachiopods and algae fossils. The thickness is 39 meters.

Xuzhuang Formation is mainly composed of purple-gray shale and oolitic limestone, in which the lower limestone and gray siltstone often have oblique bedding or cross bedding. Contains trilobite fossils such as Xu Zhuangchong and brachiopod fossils. The thickness is 73 meters.

Zhangxia Formation is mainly composed of oolitic limestone and algal limestone with colored shale. Contains trilobite fossils, such as Dermatidae. The thickness is 198m.

Gushan Formation is mainly composed of bamboo-leaf limestone, massive limestone and yellow-green shale. Contains trilobite fossils such as butterflies and bats. Thickness: 51m.

Changshan Formation is mainly composed of layered limestone, bamboo-leaf limestone with red oxidation ring and purple shale. Contains trilobite fossils such as Castanopsis fargesii and Haoshan. The thickness is 70 meters.

Fengshan Formation is mainly composed of argillaceous limestone and bamboo-leaf limestone. It contains trilobite fossils such as Jinan worm and Fangtou worm, as well as stems and brachiopods of sea lilies. The thickness is 130m.

The standard sections of CAMBRIAN strata in Zhang Xia are located in Shantoushan, Hutouya, Huangcaoding, Tangwangzhai, Fan Zhuang and other places around Zhang Xia and Gushan. Mantoushan is the profile of Xuzhuang Formation, Maozhuang Formation and Mantou Formation, Hutouya-Huangcaoding is the profile of Zhangxia Formation, Tangwangzhai is the profile of Gushan Formation and Changshan Formation, and Fanzhuang is the profile of Fengshan Formation.

Shantoushan is located 2km south of Zhang Xia Town and on the west side of 104 National Road. Named after the shape of steamed bread. There are two small villages at the northern foot of the mountain, named Xuzhuang and Maozhuang respectively. It is the establishment and life-saving place of Shantou Formation, Maozhuang Formation and Xuzhuang Formation in the standard stratigraphic profile of Cambrian in Zhang Xia.

The Cambrian stratigraphic section in Zhang Xia is located in the north of the main peak of Mount Tai and on both sides of the main traffic road from Tai 'an to Jinan, with convenient transportation, simple structure and complete exposure, which is very beneficial to field observation and research. It is one of the stratigraphic sections with the longest history and the highest degree of stratigraphy and paleontology research in China, and occupies a very important position in China's geological history. 1959 After the National Stratigraphic Conference, it was officially determined as the standard stratigraphic section of Cambrian in northern China, which played an important role in the Cambrian stratigraphic correlation in different regions of China and the international Cambrian stratigraphic correlation. At the same time, it is also the place where the type specimens of many Cambrian paleontological species and genera (Kaolizhania, Redichia Chinensis, Ptychopariamantoensis, Shantungia and Sunasp-is Lavevis, Sun Shi) are named or originated. Therefore, this standard stratigraphic profile is very famous at home and abroad, and many domestic and foreign geologists have come here for a long time. At the same time, it has become an important geoscience practice base in Chinese universities, which has high scientific value in geological science, production practice and geological education.