Late Devonian conodonts from the Chah-Riseh area, central Iran

WA Museum Records and Supplements | Updated 9 years ago

Abstract - In order to refine the chronologic framework for the Chah-Riseh area, north-east of Isfahan, limestone samples were collected from a section measured through the most continuous outcrop of limestone thought to span the youngest Late Devonian and/or Early Carboniferous time interval, through an apparent erosional interval into a substantial sequence of dolomitised carbonate. A small Late Devonian (Early expansa Zone) conodont fauna was recovered from the lower half of the section. Above the conodontbearing horizons a red shale and quartz arenite horizon indicative of an erosional interval proved to be unfossiliferous. Above that again, the sequence of dolomitised carbonates is dated as Early Permian on the basis of their fauna of foraminifers. The hiatus between the lower limestone and the upper dolomitised limestones encompasses latest Famennian, the entire Carboniferous and possibly the earliest Permian horizons. Based on chronology and lithology, the lower limestone is referred to the Shishtu Formation, and the upper dolomitised carbonates to the Jamal Formation.