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 2 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 162194: authorized by Pete Wagner, entered by Pete Wagner on 19.09.2014

Creative Commons license: CC BY (attribution)