Paibi (), a village in

Paibi Township Paibi (), a village in Paibi Township (), Huayuan County, Xiangxi Tujia and Miao Autonomous Prefecture Hunan, China, is the location of the Global Boundary Stratotype Section and Point (GSSP) which marks the boundary between the third and Furongia ...

(),

Huayuan County Huayuan County () is a county of Hunan Province, China, it is under the administration of Xiangxi Autonomous Prefecture. Located on the western margin of the province and the south western Xiangxi, it is immediately adjacent to the borders of Gu ...

Xiangxi Tujia and Miao Autonomous Prefecture Xiangxi Tujia and Miao Autonomous Prefecture (; Tujia: Xianxxix bifzivkar befkar zifzifzoux; Miao: Xangdxid tutjadcul maolcul zibzhibzhoud) is an autonomous prefecture of the People's Republic of China. It is located in northwestern Hunan provin ...

Hunan Hunan (, ; ) is a landlocked province of the People's Republic of China, part of the South Central China region. Located in the middle reaches of the Yangtze watershed, it borders the province-level divisions of Hubei to the north, Jiangxi to ...

, China, is the location of the

Global Boundary Stratotype Section and Point A Global Boundary Stratotype Section and Point (GSSP) is an internationally agreed upon reference point on a stratigraphic section which defines the lower boundary of a stage on the geologic time scale. The effort to define GSSPs is conducted b ...

(GSSP) which marks the boundary between the third and

Furongian The Furongian is the fourth and final epoch and series of the Cambrian. It lasted from to million years ago. It succeeds the Miaolingian series of the Cambrian and precedes the Lower Ordovician Tremadocian Stage. It is subdivided into three sta ...

epochs of the

Cambrian The Cambrian Period ( ; sometimes symbolized C with bar, Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million ...

Period on the

geologic time scale The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochrono ...

. Paibi was selected over the Kyrshabakty River section, Malyi Karatau,

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...

, and the GSSP was ratified by the

International Union of Geological Sciences The International Union of Geological Sciences (IUGS) is an international non-governmental organization devoted to international cooperation in the field of geology. About The IUGS was founded in 1961 and is a Scientific Union member of the Inte ...

in late 2003. It established the first formally agreed upon subdivision of the Cambrian. The village gives its name to the

Paibian The Paibian is the lowest stage of Furongian series of the Cambrian. It follows the Guzhangian ( 3rd series of the Cambrian) and is succeeded by the Jiangshanian Stage. The base is defined as the first appearance of the trilobite ''Glyptagnostus r ...

Age in the Cambrian Period. The Paibi section occurs within the

Huaqiao Formation Huaqiao may refer to: *Overseas Chinese (华侨), or Huaqiao in pinyin *Huaqiao University (华侨大学), in Quanzhou, Fujian *Huaqiao railway station (花桥站), station of the Shanghai-Nanjing Intercity High-Speed Railway in Shanghai *Huaqiao s ...

, which consists of a thick succession of carbonate beds deposited in the outer part of the Jiangnan Slope Belt, and extends from the middle Cambrian through the Lower

Ordovician The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start ...

. It satisfies all the

geological Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Eart ...

and

biostratigraphic Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock strata by using the fossil assemblages contained within them.Hine, Robert. “Biostratigraphy.” ''Oxford Reference: Dictionary of Bio ...

requirements for a GSSP, is readily accessible, and includes chemostratigraphic, palaeogeographic,

facies In geology, a facies ( , ; same pronunciation and spelling in the plural) is a body of rock with specified characteristics, which can be any observable attribute of rocks (such as their overall appearance, composition, or condition of formatio ...

-relationship, and sequence-

stratigraphic Stratigraphy is a branch of geology concerned with the study of rock layers (strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithostrati ...

information. The section lies at an elevation of 774 metres. The evolution of ''

Glyptagnostus reticulatus ''Glyptagnostus reticulatus'' is a species of agnostid trilobite belonging to the genus '' Glyptagnostus''. It existed during the Paibian Age ( million years ago) of the Cambrian. It has a cosmopolitan distribution and is an important index fossi ...

'' (an agnostoid

trilobite Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the At ...

) from more basal species of the genus ''Glyptagnostus'' marks the boundary. Other markers which occur near the boundary include the first appearance of the conodont ''

Westergaardodina proligula ''Westergaardodina'' is a species-rich genus of spine, U or W-shaped paraconodont known from Middle Cambrian to Lower Ordovician strata. Use in stratigraphy Paibi, a village in Hunan, China, is the location of the Global Boundary Stratoty ...

'' and the

Steptoean positive carbon isotope excursion The Steptoean Positive Carbon Isotope Excursion (SPICE) was a geological event which occurred about 494.6 million years ago near the beginning of the International Furongian Epoch of the Cambrian Period. The SPICE event was a positive shift in car ...

, a large positive shift in

carbon-13 Carbon-13 (13C) is a natural, stable isotope of carbon with a nucleus containing six protons and seven neutrons. As one of the environmental isotopes, it makes up about 1.1% of all natural carbon on Earth. Detection by mass spectrometry A mass ...

isotope Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers (mass numbers) ...

References

* * {{cite web, url=http://www.iugs.org/iugs/news/china_paibian_gspike.htm , title=Another "Golden Spike" in China , publisher=International Union of Geological Sciences , date=28 November 2003 , accessdate=2006-06-30 , url-status=dead , archiveurl=https://web.archive.org/web/20041115220416/http://www.iugs.org/iugs/news/china_paibian_gspike.htm , archivedate=November 15, 2004 Villages in China Stratigraphy of Asia