Sequence stratigraphy of Shiranish Formation in Dokan area, Northern Iraq

Abstract

The Late Campanian and Maastrichtian attend closure of the Southern Neo-Tethys and formations intraplate extensional and transextensional basin, in addition to deposition of the Shiranish Formation in the foreland basin (Jassim and Buday 2006). The Shiranish Formation (228 m thick) is exposed on the southwestern limb of the Sarah anticline in the Dokan area. Its consists of dark gray marly limestone, soft bluish gray marl rich in planktonic foraminifera, shales, and thin pelecypodal limestone bed on the top of the formation. The lower contact is unconformable with the underlying Turonian Kometan Formation, while the upper contact is conformable with the overlain Tanjero Formation. Six main facies were distinguishable throughout the formation reflecting the middle shelf to middle bathyal depositional environments of the formation. The alternation of these depositional environments used to interpret three depositional sequences containing three maximum flooding surfaces (MFS 165, MFS 170, and MFS 175 of Sharland et al. 2001 and Aqrawi et al. 2010) show good correlation with those in Iraq and other part of Arabian plate.