JBH-B23 Jebel Boulahoujeb, Lansarine Chain (Cretaceous of Tunisia)

Where: Tunisia (36.8° N, 9.6° E: paleocoordinates 22.6° N, 14.3° E)

• coordinate estimated from map

When: Lyticoceras nodosoplicatum ammonoid zone, H2 Member (El Mergueb Formation), Early/Lower Hauterivian (136.4 - 130.0 Ma)

• The section JBH-B starts after a lateral displacement of 10m to north–west from the top of section JBH-A. About 20m of limestone–marl alternations of the upper Valanginian are exposed at the base of the succession. The Hauterivian is represented by 783m of thickness, including a 65m gap of observation.

Environment/lithology: marine; lithified, calcareous limestone

• The Jebel Boulahouajeb section belongs the Tunisian trough a strongly subsiding basin from the Jurassic to Cretaceous time span. It corresponds to a deep marine palaeoenvironment characterized by pelagic-deep deposits.
• About 20m of limestone–marl alternations of the upper Valanginian are exposed at the base of the succession. The Hauterivian is represented by 783m of thickness, including a 65m gap of observation. The succession is characterized by calcareous bundles that are limestone-dominated intervals (thick calcareous beds and reduction of marl-bed thickness); they are separated by thick marl-dominated intervals. Starting by a sandstone bed (JBH-B3; 3 m, ochre's colour), the lower part of the section JBH-B is composed by two calcareous bundles named H1 (JBH-B5 to B20; 34 m)

Size class: macrofossils

Preservation: cast, mold/impression, original aragonite, original calcite

Primary reference: S. Melliti, S. Reboulet, N. Ben Haj Ali, M. S. Arfaoui, F. Zargouni and L. Memmi. 2019. Ammonoid and foraminiferal biostratigraphy from uppermost Valanginian to lowermost Barremian of the Jebel Boulahouajeb section (northern Tunisia). Journal of African Earth Sciences 151:438-460 [A. Kocsis/M. Gomez Correa]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 205689: authorized by Adam Kocsis, entered by Monica Alejandra Gomez Correa on 18.10.2019

Creative Commons license: CC BY (attribution)

Taxonomic list

Cephalopoda
 Ammonitida - Desmoceratidae
Plesiospitidiscus sp. ammonite
categories based on specimen counts
 Ammonitida - Lytoceratidae
Lytoceras sp. Suess 1865 ammonite
categories based on specimen counts
 Ammonitida - Olcostephanidae
Olcostephanus sp. Neumayr 1875 ammonite
categories based on specimen counts
 Phylloceratida - Phylloceratidae
"Phylloceras (Hypophylloceras) tethys" = Euphylloceras thetys, Phyllopachyceras winkleri
"Phylloceras (Hypophylloceras) tethys" = Euphylloceras thetys d'Orbigny 1841 ammonite
categories based on specimen counts
Phyllopachyceras winkleri Uhlig 1882 ammonite
categories based on specimen counts