Rivers of the Hadramawt watershed (Yemen) during the Holocene: Clues of late functioning

A multi-proxy analysis of the Holocene humid phase from the United Arab Emirates and its implications for southeast Arabia's Neolithic populations

“…Farrant et al (2015) suggest that the aeolian record in the Gulf region is preservation limited, recording dune stabilisation and cementation at the onset of humid episodes. Determining why the lower Gulf region appears to have been outof-phase with other areas of Arabia is complicated by the continuing uncertainty surrounding the different climatic systems influencing the Peninsula during the earlyto mid-Holocene (Berger et al, 2012). Most palaeoclimate studies from central and southern Arabia link the arid-humid transition to the steady northwards migration of the ITCZ and associated monsoon rains, a notion well supported by the δ 18 O data from the Omani speleothem records Fleitmann and Matter, 2009).…”

“…Cullen et al, 2000;Brooks, 2006;Staubwasser and Weiss, 2006;Dixit et al 2014a). However, it is important that causal relationships are not based solely on broad, continental-scale changes in climate, but instead assess their impact at a more local level in terms of landscape sensitivity and stability and the availability of environmental resources, such as freshwater and vegetation (Berger et al, 2012).…”

“…Geo-archives have revealed that areas of the presently hyper-arid Arabian subcontinent were transformed into an ameliorated landscape during the early-to midHolocene, with more favourable hydrological conditions leading to the expansion of lakes and vegetation throughout the desert interior Lézine et al, 2010;Berger et al, 2012). This change is thought to have been driven by a northwards shift in the mean latitudinal position of the Intertropical Convergence Zone (ITCZ) and associated monsoon precipitation belt (Overpeck et al, 1996;Fleitmann et al, 2007).…”

“…Whilst these long-term, continuous sedimentary archives have proven invaluable in reconstructing broad climatic trends, they reveal little about the evolution of the terrestrial landscape at the local level. Indeed, a recent synthesis of a range of Arabian geo-archives demonstrated that there is significant regional heterogeneity (sensu throughout the Peninsula during the Holocene (Berger et al, 2012). Fleitmann et al (2007) linked these differences to the time-transgressive migration of the summer ITCZ, with the onset and termination of humid conditions, and whether these transitions were gradual or abrupt, dependent upon the geographical location of a particular site.…”

“…They may have contributed to continued lacustrine sedimentation at some sites north of 24°N during the mid-Holocene, when most palaeolake records from central and southern Arabia had ceased (Parker and Goudie, 2008). Understanding the significance of these differences is complicated further as most Arabian terrestrial geo-archives are prone to erosion, yield little dateable material and are rarely continuous (Berger et al, 2012). Furthermore, highresolution palaeoclimate records reveal a series of millennial-scale, high amplitude, short-term periods of increased aridity superimposed on these long-term trends, further challenging the notion that the early-to mid-Holocene was stable and wholly humid Fleitmann and Matter, 2009).…”