Probable Voorstehoek Formation (2nd Shale), Gamka Poort (Devonian of South Africa)

Where: South Africa (33.3° S, 21.6° E: paleocoordinates 64.4° S, 157.9° W)

• coordinate stated in text

• local area-level geographic resolution

When: Voorstehoek Formation (Bokkeveld Group), Eifelian (393.3 - 387.7 Ma)

• Lowest Eifelilan. Age call from ref. 9618. Oosthuizen states that this is "probable Voorstehoek Formation".

• formation-level stratigraphic resolution

Environment/lithology: marine; bioturbated siltstone and bioturbated, silty mudstone

• Ref. 9618 gives interpretation of Bokkeveld Group as a series of shallowing-upward packages, with argillaceous unit below and arenaceous unit above. Voorstehoek Formation is the "second shale", i.e. the second argillaceous unit. The shallowing upward sequence is interpreted as representing environments from the shelf up to deltaic systems. Most fossils come from lower mudstones, often in lenses.
• Ref. 9616 refers only to "shale". Ref. 9617, for formation as a whole, cites "Siltstone, silty mudstone, parallel-laminated, massive, horizontal, ripple- and micro cross laminated, abundant ripple-marks, bioturbation, fossiliferous lenses."

Primary reference: R. D. F. Oosthuizen. 1984. Preliminary catalogue and report on the biostratigraphy and palaeogeographic distribution of the Bokkeveld fauna. Transactions of the Geological Society of South Africa 87:125-140 [M. Foote/M. Foote/M. Foote]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 35594: authorized by Michael Foote, entered by Michael Foote on 30.12.2003

Creative Commons license: CC BY (attribution)

Taxonomic list

Trilobita
 Phacopida - Calmoniidae
Bainella baini trilobite
 Phacopida - Homalonotidae
Gastropoda
 Euomphalina - Platyceratidae
""Diaphorostoma" sp." = Platyceras (Platyostoma)
""Diaphorostoma" sp." = Platyceras (Platyostoma) Conrad 1842 snail
Crinoidea
  -
Crinoidea indet. Miller 1821 Sea lily
Strophomenata
 Productida - Chonetidae
Lingulata
 Lingulida - Disciniidae