Also known as 35 km east of the town of Ayaguz.
Where: Kazakhstan (48.0° N, 80.9° E: paleocoordinates 10.2° S, 74.0° E)
When: Diplograptus foliaceus graptolite zone, Unit 3 Member (Karagach Formation), Sandbian (458.4 - 453.0 Ma)
• According to Nikitin (1972, p. 206, text-fig. 69), the Karagach Formation overlies a discontinuous sequence of fine siliciclastic rocks belonging to the Middle Ordovician Naiman Formation, and underlies the Upper Ordovician Zhartas Formation, which comprises andesitic volcanic rocks and tuffs with units of volcaniclastic sandstones and argillites. Tsai (1976) estimated the thickness of the Karagach Formation to be over 1200 m, and subdivided it into four informal units (see Figs 2–3) which in ascending order are: (1) limestones about 10 m thick; (2) dark grey siltstones with a few beds of fine-grained sandstones about 200 m thick; (3) alternating sandstones and siltstones about 130 m thick; (4) siltstones about 675 m thick with a few beds of sandstones and calcareous siltstones in the uppermost 30 m of the unit.
• bed-level stratigraphic resolution
Environment/lithology: sandstone and siltstone
Size class: macrofossils
Preservation: cast
Collected by M. Apollonov
• Some illustrated and referred type specimens are deposited in the F. N. Chernyshev Central Geological Scientific Research and Exploration Museum (CNIGR), St Petersburg.
Primary reference: M. Ghobadi Pour, L. M. E. McCobb, R. M. Owens and L. E. Popov. 2011. Late Ordovician trilobites from the Karagach Formation of the western Tarbagatai Range, Kazakhstan. Earth and Environmental Science Transactions of the Royal Society of Edinburgh 101:161-187 [P. Wagner/P. Wagner]more details
Purpose of describing collection: taxonomic analysis
PaleoDB collection 162196: authorized by Pete Wagner, entered by Pete Wagner on 19.09.2014
Creative Commons license: CC BY (attribution)
Taxonomic list
Trilobita | |
Shumardia aff. extensa Weir 1959 trilobite | |
Microparia (Heterocyclopyge) sp. Marek 1961 trilobite
Symphysops cf. djebaglensis Kolova 1936 trilobite
Cyclopyge cf. tereki trilobite | |
Kimakaspis kovalevskyi Ghobadi Pour et al. 2011 trilobite | |
Aethedionide sp. Zhou and Ju 1983 trilobite
Dionide sp. Barrande 1847 trilobite | |
Dindymene aff. longicaudata Kielan 1960 trilobite
Dindymene brevicaudata Kolobova 1972 trilobite | |
Dulanaspis karagachensis Ghobadi Pour et al. 2011 trilobite | |
Pterobranchia | |
Pseudoclimacograptus scharenbergi Lapworth 1976 climacograptid |