Gydo Formation equivalent, KL 1/65 borehole (Devonian of South Africa)

Where: South Africa (32.4° S, 20.7° E: paleocoordinates 60.7° S, 150.9° W)

• coordinate based on political unit

• outcrop-level geographic resolution

When: Gydo Formation (Bokkeveld Group), Emsian (407.6 - 393.3 Ma)

• Strictly speaking the rocks are not formally named, but authors state that "The sequence can in all respects be correlated with the Gydo Formation". Age call from ref. 9618. Fossils are from between 2721 and 2804 meters in the borehole.

• formation-level stratigraphic resolution

Environment/lithology: marine; ferruginous, micaceous, pyritic, black, gray shale and siltstone

• Ref. 9618 gives interpretation of Bokkeveld Group as a series of shallowing-upward packages, with argillaceous unit below and arenaceous unit above. 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.
• Sequence overall consists of alternating sandstone, siltstone, and shale. The part of the borehole from which the fossils come is characterized by "Shale with minor siltstone lenticles, grey to black, micaceous, massive, numerous fossils and occasional rare pyrite traces and limonite nodules"

Collection methods: core

Primary reference: A. J. Boucot, N. Eldredge, J. Gray, J. A. Pojeta, and J. N. Theron. 1986. Devonian invertebrates from the Bokkeveld Group below the Karoo succession near Sutherland. Annals of the Geological Survey of South Africa 20:119-128 [M. Foote/M. Foote/M. Foote]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 35604: authorized by Michael Foote, entered by Michael Foote on 30.12.2003

Creative Commons license: CC BY (attribution)

Taxonomic list

unclassified
  -
Trilobita
 Phacopida - Calmoniidae
Calmoniidae indet. Delo 1935 trilobite
 Phacopida - Homalonotidae
Homalonotidae indet. Chapman 1890 trilobite
Burmeisteria sp. Salter 1865 trilobite
Bivalvia
  -
"Pelecypoda indet." = Bivalvia
"Pelecypoda indet." = Bivalvia Linnaeus 1758 clam
 Cardiiformii -
"Modiomorphoida indet." = Modiomorphida
"Modiomorphoida indet." = Modiomorphida Newell 1969 clam
 Protobranchia - Malletiidae
Gastropoda
  -
Gastropoda indet. Cuvier 1797 snail
 Euomphalina - Platyceratidae
Platyceratidae indet. Hall 1859 snail
 Bellerophontida - Bellerophontidae
Bellerophontidae indet. M'Coy 1851 snail
 Bellerophontida - Plectonotidae
? Plectonotus sp. Clarke 1899 snail
Bryozoa
  -
Bryozoa indet. Ehrenberg 1831
Crinoidea
  -
Crinoidea indet. Miller 1821 Sea lily
 Lophophorata -
Tentaculitida indet. Ljaschenko 1955
Brachiopoda
  -
Brachiopoda indet. Cuvier 1805
Strophomenata
 Productida - Chonetidae
Rhynchonellata
 Terebratulida - Meganterididae
 Spiriferida - Hysterolitidae
 Rhynchonellida - Leptocoeliidae