Xiaowa Formation

Xiaowa Formation
Stratigraphic range: Carnian
TypeGeological formation
UnderliesLaishike Formation
OverliesZhuganpo Formation
Lithology
Primarylimestone, marl
Location
CountryChina
ExtentYunnan–Guizhou Plateau

The Xiaowa Formation is a Carnian-age geological formation found in southern China. It is a sequence of limestone and marls from the Carnian stage of the Triassic. Its lower section was previously known as the Wayao Formation or Wayao Member of the Falang Formation (a nomenclature still used by some authors). In 2002, the Wayao Member was renamed and raised to the Xiaowa Formation to prevent confusion with an Eocene unit of the same name.[1] Crinoids and marine reptiles are abundant in the Xiaowa Formation, forming a lagerstätte known as the Guanling biota. Ammonoids and conodonts found in the formation constrain its age to the early Carnian.[2][1][3][4][5] Reptiles of the Guanling biota include ichthyosaurs, thalattosaurs, placodonts, and Odontochelys (an early relative of turtles).[4] Sedimentary events within this formation have been tied to the Carnian Pluvial Event.[6][7]

  1. ^ a b Cite error: The named reference :1 was invoked but never defined (see the help page).
  2. ^ Hao Weicheng, Sun Yuanlin, Jiang Dayong, Yang Shouren, Wang Xinping (2003). "Cephalopods of the "Falang Formation" (Triassic) from Guanling and Zhenfeng Counties, Guizhou Province, China". Acta Geologica Sinica - English Edition. 77 (4): 430–439. Bibcode:2003AcGlS..77..430H. doi:10.1111/j.1755-6724.2003.tb00124.x. ISSN 1755-6724. S2CID 129859010.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  3. ^ Yan Li, Zuoyu Sun, Yuan-Lin Sun, Dayong Jiang, Weicheng Hao (May 2013). "Carnian (Late Triassic) ammonoid biostratigraphy in Luoping County, eastern Yunnan Province, China". Acta Scientiarum Naturalium Universitatis Pekinensis (in Chinese and English). 49 (3): 471–479.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  4. ^ a b Benton, Michael J.; Zhang, Qiyue; Hu, Shixue; Chen, Zhong-Qiang; Wen, Wen; Liu, Jun; Huang, Jinyuan; Zhou, Changyong; Xie, Tao; Tong, Jinnan; Choo, Brian (2013-10-01). "Exceptional vertebrate biotas from the Triassic of China, and the expansion of marine ecosystems after the Permo-Triassic mass extinction". Earth-Science Reviews. 125: 199–243. Bibcode:2013ESRv..125..199B. doi:10.1016/j.earscirev.2013.05.014. ISSN 0012-8252.
  5. ^ Sun, Zuoyu; Jiang, Dayong; Ji, Cheng; Hao, Weicheng (2016-03-15). "Integrated biochronology for Triassic marine vertebrate faunas of Guizhou Province, South China". Journal of Asian Earth Sciences. 118: 101–110. Bibcode:2016JAESc.118..101S. doi:10.1016/j.jseaes.2016.01.004. ISSN 1367-9120.
  6. ^ Sun, Y. D.; Wignall, P. B.; Joachimski, M. M.; Bond, D. P. G.; Grasby, S. E.; Lai, X. L.; Wang, L. N.; Zhang, Z. T.; Sun, S. (2016-06-15). "Climate warming, euxinia and carbon isotope perturbations during the Carnian (Triassic) Crisis in South China". Earth and Planetary Science Letters. 444: 88–100. Bibcode:2016E&PSL.444...88S. doi:10.1016/j.epsl.2016.03.037. ISSN 0012-821X.
  7. ^ Zhang, Yang; Li, Mingsong; Ogg, James G.; Montgomery, Paul; Huang, Chunju; Chen, Zhong-Qiang; Shi, Zhiqiang; Enos, Paul; Lehrmann, Daniel J. (2015-10-15). "Cycle-calibrated magnetostratigraphy of middle Carnian from South China: Implications for Late Triassic time scale and termination of the Yangtze Platform". Palaeogeography, Palaeoclimatology, Palaeoecology. 436: 135–166. Bibcode:2015PPP...436..135Z. doi:10.1016/j.palaeo.2015.05.033. ISSN 0031-0182.