Page 198 - Life & Land Use on the Bahrain Islands (Curtis E Larsen)

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Holocene Sea Levels

Marine beach features associated with the Holocene are more readily dated by
radiocarbon methods than their Pleistocene counterparts. Therefore, these more
recent landforms provide a clearer understanding of relative sea level changes in
the gulf over the past 10,000 years. In general, the geological record (based on
Evans et al. 1969) shows a relatively rapid rise in sea level from the Late
Pleistocene low stand that drained the gulf approximately 20,000 years ago. TTie
sea rose rapidly until 7000 B.P., when it continued to rise at a slower rate until
4000 to 5000 B.P. This rise inundated the Gulf of Bahrain and separated Bahrain
from the mainland to form a group of islands. After this period, sea level was
maintained near the present level although it may have fluctuated above or below
its norm at various times due to eustatic changes in the sea or tectonic changes in
the region.
Detailed coastal research over the past decade has improved the Holocene
coastal record for the gulf, but uncertainties in interpretation remain. Debates
arise over the mechanisms of sea level changes, rather than the evidence for such
changes themselves. Thus, scientific arguments revolve around eustatic or tectonic
controls to sea levels. Here, however, we are concerned with relative sea level
changes as an aid in reconstructing past human environments. We can, therefore,
examine the composite record of dated coastal landforms for the relatively stable
Arabian coast in order to develop a perspective of the potential effects of sea level
changes on human systems.
Taylor and Illing (1969) presented a detailed study and a suite of additional
radiocarbon dates between 3930 + 130 and 4340 + 180 B.P. for a series of raised
beaches from 1-2 meters above sea level on the Qatar Peninsula, Tliese dates
showed an apparent rise above the present sea level and correlated temporally with
a 4002 + 200 B.P. date reported by Evans et al. (1969) from similarly elevated beach
deposits near Abu Dhabi. Al-Asfour (1978) has dated a similar set of low terraces
TTiese,
bordering the Bay of Kuwait between 4570 + 70 and 3250 + 60 B.P.
however, have been tectonically deformed.