Also known as Verkhoyansk Region, northeast of Yakutsk

Where: Verkhoyansk, Russian Federation (62.0° N, 129.7° E: paleocoordinates 55.8° N, 18.2° E)

• coordinate based on political unit

• small collection-level geographic resolution

When: Lower Member (Solonchan Formation), Bashkirian (323.2 - 315.2 Ma)

• This formation is composed of inequigranular banded siltstones 20-60 m thick alternating with equally thick beds (lenses) of medium- and fine-grained sandstones. The total thickness of the formation is 1250-1300 m. The studied sequence represents the sediments of the frontal part of the thick rock complex contaning the repeated members of banded siltstones interpreted as prodeltaic deposits. They usually contain preserved marine fauna. The number and thickness of the siltstone beds deposited at the base of the paleodelta and bearing the sliding structures are larger in the lower part of the formation, whereas the upper part mostly contains more coarsely-grained sandy members with interbeds of the intraformational conglomerate and rare lenes and laminae of clayish siltstones. Hence, the Solonchan Formation represents the sediments of the transgressive-regressive sedimentary stage. The lower mudstone-siltstone part of the formationindicates the transgressive stage, whereas the regressive stage is represented by the upper siltstone-sandstone part. Based on the lithology, the formation is subdivided into the Lower and Upper subformations

• bed-level stratigraphic resolution

Environment/lithology: prodelta; lithified, fine-grained, calcareous siltstone and lithified, concretionary, calcareous mudstone

Size class: macrofossils

Primary reference: E. S. Sobolev, I. V. Budnikov, A. G. Klets and V. S. Grinenko. 1998. Late Bashkirian Amminoids and Nautiloids from Western Verkhoyansk Region. Paleontological Journal 32(5):13-25 [J. Alroy/C. Simpson/C. Simpson]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 44263: authorized by John Alroy, entered by Carl Simpson on 07.09.2004

Creative Commons license: CC BY (attribution)