ASHGILLIAN GRAPTOLITES OF THE CHIRFA REGI ON (DJADO, REPUBLIC OF NIGER)

Authors
LEGRAND P
Citation
P. Legrand, ASHGILLIAN GRAPTOLITES OF THE CHIRFA REGI ON (DJADO, REPUBLIC OF NIGER), Bulletin des centres de recherches exploration-production Elf-Aquitaine, 17(2), 1993, pp. 435-442
Citations number
28
Categorie Soggetti
Geology,"Energy & Fuels","Engineering, Petroleum
Journal title
Bulletin des centres de recherches exploration-production Elf-Aquitaine → ACNP
ISSN journal
03962687
Volume
17
Issue
2
Year of publication
1993
Pages
435 - 442
Database
ISI
SICI code
0396-2687(1993)17:2<435:AGOTCR>2.0.ZU;2-I
Abstract
For the first time, Glyptograptus (Glyptograptus ?) ojsuensis KOREN & MIKHAILOVA of Ashgillian age is detected on the African continent in t he Chirfa area (Djado, Republic of Niger). This occurrence allows a pr ecise dating of the Chirfa Formation to be made and underlines the com plexity of the paleogeography near the Ordovician-Silurian boundary of Gondwana, the reconstitution of which should not be influenced by the positions of the existing outcrops.