Bajocian (Middle Jurassic) ammonites of stratigraphical and palaeobiogeographical importance from Mombasa, Kenya, East Africa

Collections of Middle Jurassic ammonites made at the Mwachi River locality, near Mombasa in the late 1980′s and early 1990′s are described. They support previous research concluding a Late Bajocian age for the major or the upper part of the ‘Posidonia shales’, immediately below and above the dividin...

Full description

Saved in:
Bibliographic Details
Published inGeodiversitas. Vol. 39; no. 4; pp. 717 - 727
Main Author Galácz, András
Format Journal Article
LanguageEnglish
Published National Museum of Natural History 01.12.2017
Subjects
ammonite zones
Bajocian
Bajocien
compositions fauniques
faunal compositions
Jurassique moyen
Kenya
lytoceratids
lytocératidés
Middle Jurassic
palaeogeography
paléogéographie
phylloceratids
phyllocératidés
zones à ammonite
Online AccessGet full text

Cover

More Information
Summary:Collections of Middle Jurassic ammonites made at the Mwachi River locality, near Mombasa in the late 1980′s and early 1990′s are described. They support previous research concluding a Late Bajocian age for the major or the upper part of the ‘Posidonia shales’, immediately below and above the dividing Massive (Coral) Limestone. The ammonite species are figured and briefly described. Two Upper Bajocian ammonite zones are evidenced: a lower assemblage indicates the Strenoceras niortense Zone and a higher one belonging to the Garantiana garantiana Zone. Most of the ammonites are Tethyan forms with abundant phylloceratids and lytoceratids, some indicating connections with coeval Arabian and Sinai faunas. Palaeobiogeographically the assemblages suggest a deep-water position on the East-African Gondwana margin, with strong faunistic influence from the open Tethys and very restricted connections with the Arabian shallow water regions.
ISSN:1280-9659
1638-9395
DOI:10.5252/g2017n4a4