Open AccessPermian Ages of “Younger Granites” from Mounio Province (Gouré area, Southeastern Niger)
Author(s) -
Mahamane M. S. Chékaraou,
Moussa Konaté
Publication year - 2021
Publication title -
european journal of environment and earth sciences
Language(s) - English
Resource type - Journals
ISSN - 2684-446X
DOI - 10.24018/ejgeo.2021.2.6.220
Subject(s) - geology , carboniferous , radiometric dating , pyroclastic rock , magmatism , permian , rhyolite , geochemistry , volcanic rock , pluton , geochronology , paleontology , volcano , tectonics , structural basin
African formations intruded by the “Younger Granites” ring complex. In the study area, the “Younger Granites” are represented by volcanic to acid plutonic rocks with hyperalkaline trends (pyroclastic rocks, rhyolites, microgranites, granites, syenites), forming in the North, a circular structure called Gouré ring complex. Preliminary geochronological datings of the Mounio granites have yielded Carboniferous ages. However, recent investigations carried out in this province have identified structures similar to Pan-African deformation structures, such as folds and several generations of schistosity/foliation. Analysis of the relationship between deformation and magmatism has removed any ambiguity regarding the relative age of the deformation. This study focuses on the radiometric dating of the “Younger Granites” of Gouré area, in order to update the geochronological data. Thus, three samples (pyroclastitic rock, rhyolite, microgranite) were dated by the K-Ar method on total rock using a mass spectrometertype MI 1201 IG. Radiometric dating results assign a Lower Permian age (293-287 Ma) to the “Younger Granites” Ring Complex of the Mounio Province in Niger, classically considered to be Carboniferous in age.