Quaternary strata in East China-South China region

This stratigraphic area includes Hubei, Hunan, Jiangxi, Zhejiang, Anhui, Fujian, Guangdong, Guangxi and Hainan provinces, and is a hilly area of China. Its northern part belongs to subtropical humid climate, and its southern part belongs to tropical rainy climate, with strong chemical weathering, so the sediment in this area is red in color and is the main distribution area of red soil in China. Quaternary strata in this area can be roughly divided into three types: one is the river and lake strata distributed in the Yangtze River basin; Second, it is distributed in the strata containing volcanic rocks and marine deposits in the south; The third is cave accumulation layer, which is mainly distributed in the west. 1. River and lake strata

Figure 10- 19 near Andemen, Nanjing (according to Derijin and Yang, 1935).

Lower Pleistocene Yuhuatai Gravel Layer (Qp 1) Yuhuatai Gravel Layer is named after Nanjing Yuhuatai and distributed along the banks of the Yangtze River. From Nanjing to Yichang, the third terrace of the Yangtze River is composed of a set of grayish white and grayish red gravel layers containing agate (Figure 10- 19), from which the famous "Rain Flower Stone" is produced. Gravel has good roundness and sorting, and is considered as the riverbed sediment of the ancient Yangtze River. Some people think it belongs to the early Pleistocene, while others think it belongs to Pliocene to early Pleistocene. The names of contemporary classes are different in different regions. They are called Luyanchong Formation in Jianghan Plain, Anting Formation in Hangjiahu Area and Taoyuan Formation in Huaibei Plain respectively (Table 10-6).

Table 10-6 Quaternary stratigraphic correlation in East China and South China

Meso-Pleistocene reticulated laterite (Qp2) is distributed along the Yangtze River, Pearl River and its tributaries, river valleys and hilly areas, and is characterized by reticulated (worm-like) laterite, red gravel or red gravel layer (Figure 10-20), with a thickness ranging from several meters to more than 30 meters. The reticular structure is some white vertical secondary bands, which develop in sediments and meander like worms. Its size, density and occurrence have changed and can be formed in sediments or residues of different origins. Some people think that the formation of the network is formed by weathering in a hot and humid climate, while others think that the roots of plants are replaced. In different areas, the Middle Pleistocene has been given different group names. For example, Jinxian Formation in Jiangxi Province is a set of brownish-red gravel layers and gravel layers with reticulation; Qidong Formation is called Qidong Formation in the Yangtze River Delta, which is a set of gray, gray-green clay layers and fine sand layers of river facies and delta plain facies. The lower part of this formation is sandwiched with marine strata and belongs to Shanghai transgression.

Figure 10-20 River sediments and reticulated red soil profile of the fourth terrace in Nalai, Baise, Guangxi (according to Cheng Jie, 2007).

Upper Pleistocene Xia Shu Formation (Qp3) is located in plain, hilly or lake areas. Xia Shu Formation is a set of soil accumulation, which contains yellow clay and sandy clay, iron, manganese and calcium nodules, vertical joints are developed, and 1 ~ 2 layers of ancient soil are developed, which has loess properties. In the valley area, it has a dual structure, and the lower part of Xia Shu Formation is a riverbed gravel layer with a thickness of more than 20m. The Xia Shu Formation was formed when the loess spread southward and accumulated in the Yangtze River basin in the last glacial period, so it can be compared with Malan loess in the loess plateau. According to recent studies, the age of Xia Shu Formation can be extended to the late Middle Pleistocene. In Huaibei Plain, Huangkou Formation and Yingshang Formation are a set of brown or grayish brown or grayish yellow clay layers, loamy layers, clayey silt and paleosol layers. Contemporary strata include Chengdu Clay (Sichuan Basin), Yunmeng Formation (Jianghan Plain), Quantang Formation and Jiashan Formation (Hangjiahu area).

Holocene (Qh) is mainly composed of alluvial gravel layer, sand layer and clay layer, lacustrine clay layer and sandy clay layer. For example, there are Zhenru Formation, Wusong Formation, Pudong Formation and Waibaiduqiao Formation in Shanghai, Hemudu Site in Yuyao, Zhejiang, and Pingyuan Formation in Jianghan Plain.

2. Volcanic rocks and marine sedimentary strata

This layer is mainly distributed in southern Guangdong and Hainan Island. The Lower Pleistocene Zhanjiang Formation (Qp 1) is mainly distributed in Leizhou Peninsula and Hepu, Guangxi. It is a set of white, gray or variegated gravel layer, sand layer and clay layer, and the lower part is volcanic rock, with the thickness ranging from 2m to 250m. The Middle Pleistocene Beihai Formation (Qp2) is unconformity with Zhanjiang Formation, which is brownish red, brownish yellow, grayish white clay and gravel layer, containing microcrystalline meteorites and volcanic rocks. The Upper Pleistocene Lufeng Formation (Qp3) is a fine sand layer of coastal facies. Holocene (Qh) is mainly composed of river sediments, coastal silt and volcanic ejecta.

3. Cave accumulation layer

Under the update system (1) (Qp 1)

The Lower Pleistocene in this area is most developed in the Three Gorges area of the Yangtze River and Guangxi, such as the Great Ape Cave in Liucheng, Guangxi, the Longgupo in Wushan, Chongqing, and the Longgudong Cave in Jianshi, Hubei.

The Dayuandong deposit in Liucheng, Guangxi, has a layer of calcium on the surface and red-yellow and yellow sandy clay mixed with limestone breccia under it, with a thickness of about1m. This stratum is rich in mammal fossils and great ape fossils, such as Bubi great ape, giant panda species, little pig badger, Sangshi giant hyena, former Oriental saber-toothed elephant, Shi Pei tapir, Chiji Lake, pig, Guangxi giant sheep, etc., reaching 37 species. In the early early Pleistocene, it was accumulated near the Longgupo of Wushan, which was a set of gravel layers and sandy clay layers, producing "Wushan Man" fossils and abundant mammalian fossils.

Figure 10-2 1 Profile of Gulong Cave in Jianshi, Hubei Province (according to Cheng Jie et al., 2004)

The deposit of Gaoping Longgu Cave in Jianshi County, Hubei Province is a set of light reddish brown, grayish yellow clay, loam and sandy clay with calcareous lamellae, with a thickness of about 5m (Figure 10-2 1), which is called Gaoping Formation, and its age is earlier than the Aoduwei sub-era. Abundant mammal fossils, such as giant panda, saber-toothed elephant, tapir, Chinese rhinoceros, etc. In addition, there are Jianshi Zokor, Red-backed Zokor, Giant Zokor, etc. Found apes, "pioneer" fossils and stone tools. There are Wushan Longgupo and Guangxi Liucheng Great Ape Cave accumulations earlier than the Longgudong era.

The location of Bijiashan Mountain in Liuzhou, Guangxi is later than the accumulation of Gulong Cave. The cave is 60m above the water surface of Liujiang River, and its lithology is a set of yellow sandy clay layers and clay layers with a thickness of 8. 2m。 Including black-bellied saber teeth, thick leather saber teeth, fine-toothed saber teeth, front saber teeth, oriental saber teeth, China tapir, china rhino, Zhu Xiao pig and Bijiashan pig.

(2) Middle Pleistocene Series (Qp2)

Representatives of cave accumulation in the Middle Pleistocene include Hulu Cave in Tangshan, Nanjing, Longtan Cave in Hexian County, Anhui Province, Yanjinggou in Wanzhou, Chongqing, Xinglong Cave in Fengjie, etc. The sediments in Huludong, Tangshan, Nanjing are light reddish brown, reddish brown, taupe clay layer and sandy clay layer, with the thickness of 1. 1 ~ 4.9m, starting from 637 ~ 500 kab.p and ending at10 kab.p. This stratum produces "Nanjing Man" fossils and is rich. Such as root vole (Microtus oeconomus), mutant hamster (Cricetinus varians), China hyena (Pachycrocuta sinensis), double-headed monitor lizard (Dicerorhinus mercki), swollen bone deer (Megalo- ceros pachyosteus) and Koch's. The age of "Nanjing people" is about 500 kab.p

The research on Yanjinggou site has a long history, and the mammal fauna produced is considered to be typical of the giant panda-saber-toothed elephant fauna in southern China. Yanjinggou deposit is a fractured deposit with red and dark yellow clay layers and falling limestone breccia. The fossil site of "Changyang Man" (early Homo sapiens) in Xiajiawan, Changyang, Hubei Province belongs to the late Middle Pleistocene stratum (195 kab.p.), and the sediments are dark yellow sandy clay and limestone breccia. Giant panda. China Crocodile, Oriental Saber-toothed Elephant, Augusta monitor lizard and china rhino. In addition, the sediments near Longtan in Taodian Town, Hexian County, Anhui Province also belong to this period (150 ~190 kab.p.), containing "Hexian people" (Homo erectus).

The Daxin black hole in Guangxi is 80 ~ 90m higher than the modern valley bottom, and the sediment in the hole is 3. 4m thick, purple sandy clay layer at the bottom, yellow sandy soil layer at the top and calcium plate layer at the top. These deposits are rich in mammalian fossils, up to 38 species. There are mainly black giant apes, giant pandas, civet cats, saber-toothed tigers and China tapirs. China rhino, Bijiashan pig, etc. Therefore, the age of black hole sediments should be early Middle Pleistocene.

(3) Upper Pleistocene Series (Qp3)

The late Pleistocene caves in this area are well developed, such as Maba Lion Rock in Guangdong, Wugui Cave in Jiande, Zhejiang, and Lotus Cave in Dantu, Jiangsu. The sediments in the lion cave of Maba are divided into three layers, the lithology is yellow-brown clay, travertine and sand layer, and the thickness is about 5 m. ), giant panda (Ailuropoda sp.), Xiong Ke, Ultimate Crocodile, Oriental Saber-toothed Elephant, Ancient Giant Tooth Elephant, china rhino and other fossils have produced "Maba Man" (Early Homo sapiens) fossil age129 kab.p. ..

The sediments in Guidong, Jiande, Zhejiang Province are red, brown-yellow-red clay with a thickness of 1. 45m。 Mammalian fossils include macaques (Macaca sp. ), giant panda, ultimate crocodile, saber-toothed elephant. China rhino, wild boar and buffalo. The sediments in Tian Tong Cave of Xinxing Farm in Liuzhou, Guangxi are grayish yellow and reddish yellow sandy clay, mixed with limestone and flint breccia, with a thickness of 65438±0.5m, including giant panda, saber-toothed elephant and china rhino.

(4) Holocene series (Qh)

Holocene caves include Wannian Fairy Cave in Jiangxi and Lishui Shenxian Cave in Jiangsu. Xianren Cave is a grayish yellow sandy soil layer and sandy clay with a thickness of 8. There are abundant fossils of mammals and late Homo sapiens, such as macaques, rabbits, civet cats and muntjac. Shenxian Cave is reddish brown, brownish red clay and sandy clay, about 7m thick, containing mammalian fossils.