Misplaced Pages

#413586

21-813: The Li River originates in the Mao'er Mountains in Xing'an County and flows in the general southern direction through Guilin , Yangshuo and Pingle . In Pingle, the Li merges with the Lipu and Gongcheng , becoming the Gui, and in turn falls into the Xijiang , the western tributary of the Pearl River . The upper course of the Li River is connected by an ancient Lingqu canal with

42-668: A mountain or hill in China is a stub . You can help Misplaced Pages by expanding it . Neoproterozoic Gradstein et al., 2012 Ediacaran Period, 630–541.0 Ma The Neoproterozoic Era is the last of the three geologic eras of the Proterozoic eon , spanning from 1 billion to 538.8 million years ago, and is the last era of the Precambrian "supereon". It is preceded by the Mesoproterozoic era and succeeded by

63-528: Is a National Level Nature Reserve. On August 31, 1944, a Consolidated B-24 Liberator aircraft of the United States Army Air Corps crashed on Kitten Mountain following a bombing raid on Japanese warships off the coast of Taiwan . The ten man crew were listed as missing in action for 52 years until the remains of the aircraft were discovered in 1996 by two local youths searching for medicinal herbs. This article related to

84-411: Is currently dated at 538.8  million years ago ). A few of the early animals appear possibly to be ancestors of modern animals. Most fall into ambiguous groups of frond-like organisms; discoids that might be holdfasts for stalked organisms ("medusoids"); mattress-like forms; small calcareous tubes; and armored animals of unknown provenance. These were most commonly known as Vendian biota until

105-663: The Grenville orogeny makes the Neoproterozoic the period of Earth's history that has produced most continental crust. At the onset of the Neoproterozoic the supercontinent Rodinia , which had assembled during the late Mesoproterozoic, straddled the equator. During the Tonian, rifting commenced which broke Rodinia into a number of individual land masses. Possibly as a consequence of the low-latitude position of most continents, several large-scale glacial events occurred during

126-676: The Paleozoic era of the Phanerozoic eon, and is further subdivided into three periods , the Tonian , Cryogenian and Ediacaran . One of the most severe glaciation event known in the geologic record occurred during the Cryogenian period of the Neoproterozoic, when global ice sheets may have reached the equator and created a " Snowball Earth " lasting about 100 million years. The earliest fossils of complex life are found in

147-741: The Vendian , while Chinese geologists referred to it as the Sinian , and most Australians and North Americans used the name Ediacaran. However, in 2004, the International Union of Geological Sciences ratified the Ediacaran Period to be a geological age of the Neoproterozoic, ranging from 635 to 538.8 (at the time to 542) million years ago. The Ediacaran Period boundaries are the only Precambrian boundaries defined by biologic Global Boundary Stratotype Section and Points , rather than

168-723: The Xiang River , which flows north into the Yangtze ; this in the past made the Li and Gui Rivers part of a highly important waterway connecting the Yangtze valley with the Pearl delta. The 439-kilometre (273 mi) course of the Li and Gui Rivers is flanked by green hills. Cormorant fishing is often associated with the Lijiang. Cruises on the Li are famous, attracting millions of visitors per year. The Li and its tributaries drain

189-415: The 20 yuan note. 24°37′48″N 110°38′24″E  /  24.6301°N 110.64°E  / 24.6301; 110.64 Mao%27er Mountains Kitten Mountain (also Mao'er Mountains ; Chinese : 猫儿山 ; pinyin : Māo'ér Shān ) is a 2,142 metres (7,028 ft) mountain located on the border between Ziyuan County and Xing'an County , Guangxi Zhuang Autonomous Region (GZAR) in

210-657: The Guilin basin, that gives the area a dramatic landscape. Two distinctive types of karst are found, Fengcong, and Fenglin, which have evolved for the past 10-20 million years, within the Cenozoic . Fengcong karst dominates the course of the Li River and is defined as a group of limestone hills with a common limestone base, with deep depressions (or dolines ) between the peaks, and sometimes described as peak cluster depression karst. Hundreds of caves are present in this terrain, with 23 having passages longer than -1 km alongside

231-610: The Li River gorge. The longest is the Guanyan Cave System which extends from Caoping to Nanxu. Fenglin dominates the area around Yangshuo and south of Guilin and is defined as isolated limestone hills separated by a flat limestone surface generally covered by loose sediments, and sometimes described as a peak forest plain. The best-known fenglin is the tower karst around Yangshuo. These towers consist of strong and massive limestone forming near vertical sides with base diameters less than 1.5 times their height. The heights of

SECTION 10

#1732766227414

252-471: The Neoproterozoic (early Tonian), but physical evidence for such animal life is lacking. Possible keratose sponge fossils have been reported in reefs dated to c. 890 million years before the present, but remain unconfirmed. The nomenclature for the terminal period of the Neoproterozoic Era has been unstable. Russian and Nordic geologists referred to the last period of the Neoproterozoic as

273-537: The Neoproterozoic Era including the Sturtian and Marinoan glaciations of the Cryogenian Period. These glaciations are believed to have been so severe that there were ice sheets at the equator—a state known as the " Snowball Earth ". Neoproterozoic time is subdivided into the Tonian (1000–720 Ma), Cryogenian (720–635 Ma) and Ediacaran (635–538.8 Ma) periods. In the regional timescale of Russia,

294-710: The People's Republic of China that lies about 80 kilometres (50 mi) from the prefecture-level city of Guilin . The peak lies in the Yuecheng Mountains , part of the Nan Mountains and dates to the Neoproterozoic Era from 1,000 to 539 million years ago. Kitten Mountain is the highest peak in Guangxi, with a prominence of 1,861.5 metres (6,107 ft) above the surrounding area, and it

315-692: The Tonian and Cryogenian correspond to the Late Riphean ; the Ediacaran corresponds to the Early to middle Vendian. Russian geologists divide the Neoproterozoic of Siberia into the Mayanian (from 1000 to 850 Ma) followed by the Baikalian (from 850 to 650 Ma). The idea of the Neoproterozoic Era was introduced in the 1960s. Nineteenth-century paleontologists set the start of multicellular life at

336-463: The Tonian period in the form of Otavia , a primitive sponge , and the earliest fossil evidence of metazoan radiation are found in the Ediacaran period, which included the namesaked Ediacaran biota as well as the oldest definitive cnidarians and bilaterians in the fossil record. According to Rino and co-workers, the sum of the continental crust formed in the Pan-African orogeny and

357-425: The area from Guilin to Yangshuo, descending from 141-metre (463 ft) at Guilin to 103-metre (338 ft) at Yangshuo. Mean flow past Guilin is 215 cubic meters per second, and alluvium sediments consisting of well-sorted gravels covered by silty sand, forming floodplains and terraces along its route. Yet, it is the 2,600-metre (8,500 ft) of Devonian and Carboniferous limestones and karst terrain within

378-668: The first appearance of hard-shelled arthropods called trilobites and archeocyathid sponges at the beginning of the Cambrian Period. In the early 20th century, paleontologists started finding fossils of multicellular animals that predated the Cambrian. A complex fauna was found in South West Africa in the 1920s but was inaccurately dated. Another fauna was found in South Australia in the 1940s, but it

399-802: The formal naming of the Period, and are currently known as Ediacaran Period biota. Most were soft bodied. The relationships, if any, to modern forms are obscure. Some paleontologists relate many or most of these forms to modern animals. Others acknowledge a few possible or even likely relationships but feel that most of the Ediacaran forms are representatives of unknown animal types. In addition to Ediacaran biota, two other types of biota were discovered in China. The Doushantuo Formation (of Ediacaran age) preserves fossils of microscopic marine organisms in great detail. The Huainan biota (of late Tonian age) consists of small worm-shaped organisms. Molecular phylogeny suggests that animals may have emerged even earlier in

420-690: The towers range from 30 to 80 m in the central basin but can be as high as 300 m near the Fengcong. Fenglin evolves from Fengcong by slow and continuous tectonic uplift , associated with the Himalayan orogenic zone , and even slower erosion of the towers. Famous show caves in the Guilin area include the Qixing Dong and the Luti Dong . The imagery of the Li River is featured in the fifth series of

441-479: Was not thoroughly examined until the late 1950s. Other possible early animal fossils were found in Russia, England, Canada, and elsewhere (see Ediacaran biota ). Some were determined to be pseudofossils , but others were revealed to be members of rather complex biotas that remain poorly understood. At least 25 regions worldwide have yielded metazoan fossils older than the classical Precambrian–Cambrian boundary (which

SECTION 20

#1732766227414
#413586