Causes of disturbances in the Persian Gulf ‘s Holocene sedimentary sequences

The Persian Gulf is one of the most prominent postglacial landscape changes in the world. The basin has recorded the Holocene climate changes and sea level fluctuations in its sedimentary sequences. Therefore, the study of the Persian Gulf’s Holocene sediments is of great importance. Understanding the postglacial climatic and oceanographic condition requires the discrimination of post-depositional disturbances from syn-depositional processes that are controlled by climatic and oceanographic conditions. In this regard, we used two short sediment cores obtained from the deepest parts of the Persian Gulf (PG) and Strait of Hormuz (SH) using a gravity corer to investigate the most important disruptors of the Holocene sedimentary sequences. Sedimentological studies along with X-ray images and high-resolution photographs were implemented on two well radiocarbon-dated short sediment cores. The radiocarbon results show that the sediments are disturbed in both cores. The SH core shows repeated age reversal and evidence of liquefaction. The PG core, on the other hand shows evidence of age reversal on top and a hiatus at the base. We assumed that the late-Holocene SH sedimentary sequence is more prone to be disturbed by earthquake while gas venting and relatively strong bottom currents are also influential. On the other side, bioturbation is more responsible for sediment disturbances in PG during the Mid to late Holocene. It is suggested that before starting comprehensive studies on the PG sediments, sedimentary structures are investigated to determine any disturbances in the sequence