AMS-dated mollusks in beach ridges and berms document Holocene sea-level and coastal changes in northeastern Kuwait Bay

Abstract

In northeastern Kuwait, ancient beach ridges and associated berms are separated from the present shoreline by a 4-6 km-wide sabkha. A diverse mollusk fauna in the beach ridges attests to a former open marine environment. A total of 21 AMS dates were obtained in this study. Thirteen mollusk samples from beach ridges yielded AMS dates ranging from~6990 cal yr BP in the southeast to~3370 cal yr BP in the northwest, suggesting a southeast to northwest age progression during the Holocene transgression. In contrast, four samples from berms throughout the study area yielded AMS dates of 5195-3350 cal yr BP showing no age progression; these berms consist largely of Conomurex persicus gastropods that aggregated by storms during a highstand at 5000-3500 cal yr BP. The berms are presently at~+ 6 m above sea level, 2-3 m above the beach ridges. Human settlements were common on the ridge crests before and after the highstand. Regression to present-day sea level commenced after the highstand, which is when the sabkha began forming. A landward, marine-built terrace, which yielded AMS dates N43,500 14 C yr BP, probably formed during Marine Oxygen Isotope Stage 5e and hence is not genetically related to the beach ridges.

Review on Late Pleistocene‐Holocene relative sea‐level changes in Kuwait: New evidence from Failaka island

“…T A B L E 3 Dated sea-level indicators and elevation from Kuwait (Gunatilaka, 1986;Al-Asfour, 1982;Reinink-Smith, 2015;Dalongeville, 1990;Dalongeville & Sanlaville, 1987; and this study) below present mean sea-level). A marine high-stand just before the LGM marine regression seems, however, unlikely.…”

“…The data from Dalongeville and Sanlaville (1987) highlight small oscillations between +0.80 and +1.30 m (samples 13-20, Table 3), but this could be explained by measurement approximations on the field and overall, the sea-level seems relatively stabilised for more than a millennium. Regarding the late Holocene, data from the northern part of the Kuwait Bay (Reinink-Smith, 2015) and Enjefa (Tanoli, 2014) present significant elevation for this period (+3 and +3.5 m a.m.s.l. between 5000 and 1800 cal yr BP) and suggest a much higher relative sea-level high-stand, but this level is not documented anywhere in the Gulf so far.…”

“…More recently, Reinink-Smith (2015) carried out a study in the north-eastern part of the Kuwait Bay, around Al-Bahra, Jazirat Dubaij and As-Subiya areas. Overall, 21 radiocarbon datings were performed, and the results were calibrated by the author, using marine reservoir correction.…”

Palaeoenvironmental and sea level changes during the Holocene in eastern Saudi Arabia and their implications for Neolithic populations

“…Farrant et al (2015) suggest that dunes cement rapidly during humid periods due to the meteoric leaching of unstable aragonitic material, which is reprecipitated as intergranular, meniscus vadose cement, along with gypsum. This rapid cementation is confirmed by OSL dating, which indicates the most recent phase of carbonate dune deposition occurring during the Late Holocene, followed by cementation and stabilization (Farrant et al, 2012;2015). While the formation of the Dammam Aeolianite has previously been suggested to be the result of carbonaterich materials deflated from the exposed Gulf basin during low sea level stands (Glennie 1998;Teller et al, 2000), we suggest that this is not the case for the 29 cemented carbonate dunes at Dosariyah due to the 3.0 ka Late Holocene age for this unit and the Early Holocene ages for the underlying quartz-rich sand unit, which is at least 7-8 ka based on OSL dating.…”

Migration of Barchan Dunes in Qatar–Controls of the Shamal, Teleconnections, Sea-Level Changes and Human Impact

“…Rough estimates of 8000-6000 years ago [19,20], 10,000-8000 years ago [21], or even 12,000 years ago [22] can be found in literature, along with the rather precise timing of 4100 years ago [10]. Likewise, a broad range of dates is found for the mid-Holocene sea-level highstand both in Qatar and the wider Gulf region, e.g., 8000-4000 years ago [23], 5 to 6 millennia ago [24], 6000-4500 cal years BP [25], around 6000 BP [18], 5000-3500 cal years BP [26], or "shortly after 5290-4570 cal year BP" [27] (p. 79).…”