"Siaohopa Formation" (Upper Unit) at Rongxi, Xiushan County, SE Sichuan Province: Telychian, China

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Rhynchonellata - Orthida - Dalmanellidae
Isorthis sp. Kozlowski 1929
Rhynchonellata - Atrypida - Atrypinidae
Nalivkinia sp.
Rhynchonellata - Athyridida - Nucleospiridae
Nucleospira cf. calypta
Pterobranchia - Cyclograptidae
Galeograptus sinensis
Pterobranchia - Graptoloidea - Monograptidae
Pristiograptus xiushanensis
Pristiograptus sp.
see common names

Geography
Country:China State/province:Sichuan County:Xiushan
Coordinates: 28.6° North, 108.9° East (view map)
Paleocoordinates:6.2° North, 126.6° East
Basis of coordinate:based on political unit
Geographic resolution:local area
Time
Period:Silurian Epoch:Llandovery
Stage:Telychian 10 m.y. bin:Silurian 1
Key time interval:Telychian
Age range of interval:438.50000 - 433.40000 m.y. ago
Stratigraphy
Formation:"Siaohopa"
Stratigraphic resolution:member
Stratigraphy comments: Except where otherwise stated, ref. 7624 uses Lower Silurian as equivalent to Llandovery, Middle Silurian as equivalent to Wenlock, and Upper Silurian as equivalent to Ludlow plus Pridoli. "The lower unit may be correltaed with the Siaohopa Formation. The upper unit was previously assigned to the Shamao Fm., but the typical Shamao Fm. has a lithology that is different..." "The presence of Pristiograptus xiushanensis and Petalolithus in the lower part of the formation indicates a correlation with the Leijiatun Fm. of early Upper Llandovery age. The presence of Monograptus enshiensis, which is close to M. undulatus of the British section, in the upper part of the formation suggests that this part is also of Upper Llandovery age. Therefore both lithologic and paleontologic evidence indicates that the "S. Fm." should be correlated with the Leijiatun and Majiaochong Fms. of Upper Llandovery age."
Lithology and environment
Primary lithology: siltstone
Secondary lithology: calcareous "shale"
Lithology description: Formation at Rongxi "consists of a lower unit of sandstone and silty sandstone overlain by an upper uhnit of siltstone, calcareous shale, and thin-bedded sandstone...The lower unit [has] a thickness of 182 m. The upper part...has a thickness of 161 m."
Environment:marine indet.
Geology comments: Correlation chart indicates BA3 based on shelly fauna for this formation at this locality.
Taphonomy
Collection methods and comments
Reason for describing collection:biostratigraphic analysis
Metadata
Database number:27843
Authorizer:M. Foote Enterer:M. Foote
Modifier:M. Foote Research group:marine invertebrate
Created:2003-01-14 11:29:23 Last modified:2006-09-13 14:01:03
Access level:the public Released:2003-01-14 11:29:23
Creative Commons license:CC BY
Reference information

Primary reference:
7624. E.-z. Mu, A. J. Boucot, X. Chen and J.-y. Rong. 1986. Correlation of the Silurian rocks of China. In A. J. Boucot and W. B. N. Berry (eds.), Geological Society of America Special Paper 202:1-80 [M. Foote/M. Foote/P. Wagner]