1. Description: The Chokier Formation is composed of calcareous shales, pyrite-rich Aluniferous shales (‘ampelites’) and silicites (‘cherts’ or ‘phtanites’), with a rich marine fauna, devoid of coal seams or rootlet beds with the exception of the Bois-et-Borsu Member

2. Description: The Chokier Formation is composed of calcareous shales, pyrite-rich Aluniferous shales (‘ampelites’) and silicites (‘cherts’ or ‘phtanites’), with a rich marine fauna, devoid of coal seams or rootlet beds with the exception of the Bois-et-Borsu Member (‘Shales with …