Core XK-1, bottom of the Xisha carbonate platform, Shidao Island, Xuande Atoll (Oligocene of China)

Also known as Reef 891

Where: China (16.8° N, 112.3° E: paleocoordinates 17.6° N, 112.9° E)

• coordinate stated in text

• outcrop-level geographic resolution

When: Sanya Formation, Chattian (28.1 - 23.0 Ma)

• formation-level stratigraphic resolution

Environment/lithology: reef, buildup or bioherm; limestone and reef rocks

• The Sanya Fm (1258–1032 m) contains a thick dolomitic reef with some bioclastic limestone in the upper part, alternating reefal and bioclastic limestone in the middle, and brownish breccia and coral reefs in the bottom. Fossils of Actinacis and Spiroclypeus were found at 1245 m and 1255 m in core XK-1, respectively, supporting the estimate that these biogenic reefs date back to the late Oligocene. Besides the two fossils, red algae, including Lithoporella melobesioides, Lithoporella minus, Neogoniolithon, and Mesophyllum, and benthic foraminifera, including Amphistegina lessonii, Amphistegina lobifera, and Spiroclypeus were also found in the lower part of the Fm.

Size classes: macrofossils, mesofossils

Primary reference: Y. Li, X. Liu, W. and L. Yi. 2021. Magnetic Properties and Initiation of Biogenic Reefs in Xisha Islands, South China Sea, at the Oligo–Miocene Boundary. Journal of Marine Science and Engineering [W. Kiessling/M. Krause]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 223349: authorized by Wolfgang Kiessling, entered by Mihaela Krause on 09.11.2021

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Anthozoa
 Scleractinia - Actinacididae
Actinacis sp.
Actinacis sp. d'Orbigny 1849 stony coral
Foraminifera
 Nummulitacea - Nummulitidae
Spiroclypeus sp.
 Asterigerinacea - Amphisteginidae
Amphistegina lobifera, Amphistegina lessonii
Amphistegina lessonii d'Orbigny 1826
Florideophyceae
  - Corallinophycidae
Neogoniolithon sp., Lithoporella melobesioides, Lithoporella minus, Mesophyllum sp.
Neogoniolithon sp. Setchell and Mason 1943
Lithoporella minus Johnson 1964
Mesophyllum sp. Lemoine 1930