Kråkeholmen, 4d (Ordovician of Norway)

Where: Oslo-Asker, Norway (59.9° N, 10.6° E: paleocoordinates 29.3° S, 9.1° W)

• coordinate estimated from map

When: Skogerholmen Formation, Pirgu (449.5 - 445.6 Ma)

• "4d α-γ", in Henningsmoen, 1953

• formation-level stratigraphic resolution

Environment/lithology: marine; limestone and shale

• In the type area, the base of this formation marks an abrupt change from a shale dominated succession to rubbly limestones up to 10cm thick passing upwards into nodular limestones (up to 10cm) and shales (up to 35cm). The rubbly limestone is not developed in Ringerike. The uppermost 2 3m of the formation comprises bedded limestones (5 10cm) and shales (5 30cm)

Size classes: macrofossils, mesofossils

Primary reference: G. Henningsmoen. 1953. Upper Ordovician Ostracods from the Oslo region, Norway. Norsk Geologisk Tidsskrift 33(8):69-108 [B. Kröger/B. Kröger]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 190057: authorized by Björn Kröger, entered by Björn Kröger on 27.11.2017

Creative Commons license: CC BY (attribution)

Taxonomic list

 Beyrichiacea - Eurychilinidae
Opikella umbilicata Kummerow 1924 ostracod