oa Structures of the Kirkuk Embayment, Northern Iraq; Foreland Structures Or Zagros Fold Belt Structures?

Several anticlines in northern Iraq and Syria have been studied through the construction of balanced<br>and restored cross sections. Based upon structural analysis each of the studied anticlines is a faultpropagation<br>fold that developed due to Zagros related recent inversion of much older normal faults.<br>Studies on the Iranian part of the Zagros fold belt have suggested that the regional variation in the<br>character of the fold belt is related to weak detachment surfaces in the stratigraphic section, primarily<br>the decollement developed near the top of the Hormuz salt where the salt is present. No evidence for<br>Hormuz salt has been found within the Kirkuk Embayment, and although detachment surfaces<br>contribute the area’s structural character, the prominent folds appear to originate mainly from<br>basement involved faults.<br>Two distinct inversion structural trends exist; an EW system and a NW system of inverted grabens. In<br>Syria, several of the faults associated with the EW trending system cuts the basement on seismic data<br>and have stratigraphic relationships suggesting that their displacement originated in the<br>Neoproterozoic. In Iraq where a thicker sedimentary section is present, the available seismic data does<br>not show the complete sedimentary section or fault systems’ trajectories. While the NW fault system of<br>inverted normal faults could be linked to the Zagros Orogen by a decollement surface in the<br>sedimentary section, regional relationships and potential-field data suggest that this trend also is<br>basement involved and has a Neoproterozoic origin.