Jiangshanian

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Second age of the Furongian epoch

title: "Jiangshanian" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["jiangshanian", "cambrian-geochronology", "geological-ages"] description: "Second age of the Furongian epoch" topic_path: "philosophy" source: "https://en.wikipedia.org/wiki/Jiangshanian" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Second age of the Furongian epoch ::

::data[format=table title="Infobox geologic timespan"]

FieldValue
nameJiangshanian
colorJiangshanian
time_start494.2
time_start_prefix~
time_end491
time_end_prefix~
timelineCambrian
name_formalityFormal
name_accept_date2011
former_namesCambrian Stage 9
celestial_bodyearth
usageGlobal (ICS)
timescales_usedICS Time Scale
chrono_unitAge
strat_unitStage
timespan_formalityFormal
lower_boundary_defFAD of the Trilobite Agnostotes orientalis
lower_gssp_locationDuibian B Section, Duibian, Zhejiang, China
lower_gssp_coords
lower_gssp_accept_date2011
upper_boundary_defNot formally defined
upper_def_candidatesFAD of the Trilobite Lotagnostus americanus
upper_gssp_candidatesDuibian, Zhejiang, China
::

| name = Jiangshanian | color = Jiangshanian | time_start = 494.2 | time_start_prefix = ~ | time_end = 491 | time_end_prefix = ~ | image_map = | caption_map = | image_outcrop = | caption_outcrop = | image_art = | caption_art = | timeline = Cambrian | partially_contained_in = | partially_contains = | name_formality = Formal | name_accept_date = 2011 | alternate_spellings = | synonym1 = | synonym1_coined = | synonym2 = | synonym2_coined = | synonym3 = | synonym3_coined = | nicknames = | former_names = Cambrian Stage 9 | proposed_names = | celestial_body = earth | usage = Global (ICS) | timescales_used = ICS Time Scale | formerly_used_by = | not_used_by = | chrono_unit = Age | strat_unit = Stage | proposed_by = | timespan_formality = Formal | lower_boundary_def = FAD of the Trilobite Agnostotes orientalis | lower_gssp_location = Duibian B Section, Duibian, Zhejiang, China | lower_gssp_coords = | lower_gssp_accept_date = 2011 | upper_boundary_def = Not formally defined | upper_def_candidates = FAD of the Trilobite Lotagnostus americanus | upper_gssp_candidates = Duibian, Zhejiang, China | o2 = | co2 = | temp = | sea_level = The Jiangshanian is the middle stage of the Furongian series. It follows the Paibian Stage and is succeeded by the still unnamed Stage 10 of the Cambrian. The base is defined as the first appearance of the trilobite Agnostotes orientalis which is estimated to be million years ago. The Jiangshanian lasted until approximately million years ago.

The Jiangshanian stage was named after Jiangshan, a city in China's Zhejiang province, where its GSSP was defined.

Stratigraphy

The Global boundary Stratotype Section and Point (GSSP) of the Jiangshanian is the "Duibian B Section" (), west of the village of Duibian (碓边), and 10 km north of Jiangshan. The outcrop belongs to the Huayansi Formation (华严寺组). The upper boundary (the base of the Stage 10) is not formally defined by ICS, but there is a proposal to set the first appearance of an agnostoid Lotagnostus americanus as its marker.

In 2012, international research group proposed the Kyrshabakty section in the Malyi Karatau Range, southern Kazakhstan, as a candidate for the Auxiliary boundary Stratotype Section and Point (ASSP) of the Jiangshanian. The proposal was approved by an overwhelming majority of votes by the International Subcommission on Cambrian Stratigraphy (ISCS). The section is situated near Kyrshabakty River, about 28 km north-east of the Zhanatas town. The first appearance datum (FAD) of Agnostotes orientalis is located at an altitude of 259 m above the base of the section, in the Zhumabay Formation, also known as Bestogai Formation. In 2021, the International Union of Geological Sciences (IUGS) proposed to deny the use of specific points and replace them by Standard Auxiliary Boundary Stratotypes (SABS) for more "flexible" correlations with GSSPs.

Major events

At the beginning of the Jiangshanian, there was a peak in species diversity, comparable to that observed in the middle Guzhangian, before the Guzhangian–Paibian extinction. Jiangshanian extinction, which lasted approximately from 493.9 to 491.3 Ma, reduced species diversity by 55.2%. It was followed by an interval of relatively small fluctuations in species richness, which ended shortly after the beginning of the Ordovician.

Paleontology

Nearly 50 fossil genera were found in the Jiangshanian deposits of the Sandu Formation in Guangxi, South China. Organisms presented by the algae, graptolites, the cnidarian Sphenothallus, one species of Palaeoscolecida, and arthropods, which include aglaspidid, mollisoniid, and "bivalved" forms. Rare hurdiids were discovered in the Jiangshanian strata in Sandu Formation and Wiśniówka Sandstone Formation in Poland. Trilobites Parabolina, Hedinaspis, Eugonocare and Cermatops, with agnostoid genera including Pseudagnostus and Rhaptagnostus, were collected from the Jiangshanian sediments of western Tasmania. Trilobite genera Monocheilus, Ptychaspis and Wilbernia are known from the Jiangshanian Honey Creek Formation in the Wichita Mountains, Oklahoma, USA.

References

References

  1. (December 2012). "Global Standard Stratotype-Section and Point (GSSP) for the Base of the Jiangshanian Stage (Cambrian: Furongian) at Duibian, Jiangshan, Zhejiang, Southeast China". Episodes.
  2. "Latest version of international chronostratigraphic chart". [[International Commission on Stratigraphy]].
  3. "GSSP for Jiangshanian".
  4. "ISCS Working Groups: Working Group on the Stage 10 GSSP". International Subcommission on Cambrian Stratigraphy.
  5. Gappar Kh. Ergaliev, Vyacheslav (Slava) G. Zhemchuzhnikov, Leonid E. Popov, Michael G. Bassett, Farkhat G. Ergaliev. (2014). "The Auxiliary boundary Stratotype Section and Point (ASSP) of the Jiangshanian Stage (Cambrian: Furongian Series) in the Kyrshabakty section". Episodes.
  6. Martin J. Head, Marie-Pierre Aubry, Werner E. Piller, Mike Walker. (2023). "The Standard Auxiliary Boundary Stratotype: a proposed replacement for the Auxiliary Stratotype Point in supporting a Global boundary Stratotype Section and Point (GSSP)". Episodes.
  7. Yiying Deng, Junxuan Fan, Shengchao Yang, Yukun Shi, Zhengbo Lu, Huiqing Xu, Zongyuan Sun, Fangqi Zhao, Zhangshuai Hou. (2023). "No Furongian Biodiversity Gap: Evidence from South China". Palaeogeography, Palaeoclimatology, Palaeoecology.
  8. Xuejian Zhu, Rudy Lerosey-Aubril, Javier Ortega-Hernández. (2021). "Furongian (Jiangshanian) occurrences of radiodonts in Poland and South China and the fossil record of the Hurdiidae". [[PeerJ]].
  9. Gaëtan J-M Potin, Allison C. Daley. (2023). "The significance of ''Anomalocaris'' and other Radiodonta for understanding paleoecology and evolution during the Cambrian explosion". [[Frontiers in Earth Science]].
  10. Christopher J. Bentley, James B. Jago, Keith Corbett. (2020). "Late Cambrian (Iverian, Jiangshanian) fossils from the Professor Range area, Western Tasmania". [[Alcheringa (journal).
  11. Sean R. Blackwell, Stephen R. Westrop. (2023). "A new Cambrian (Jiangshanian, Sunwaptan) trilobite fauna from Oklahoma and its biostratigraphic significance". Journal of Paleontology.

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jiangshaniancambrian-geochronologygeological-ages