The unexpectedly short Holocene Humid Period in Northern Arabia

The early to middle Holocene Humid Period led to a greening of today's arid Saharo-Arabian desert belt. While this phase is well defined in North Africa and the Southern Arabian Peninsula, robust evidence from Northern Arabia is lacking. Here we fill this gap with unprecedented annually to sub-decadally resolved proxy data from Tayma, the only known varved lake sediments in Northern Arabia. Based on stable isotopes, micro-facies analyses and varve and radiocarbon dating, we distinguish five phases of lake development and show that the wet phase in Northern Arabia from 8800-7900 years BP is considerably shorter than the commonly defined Holocene Humid Period (similar to 11,000-5500 years BP). Moreover, we find a two century-long peak humidity at times when a centennial-scale dry anomaly around 8200 years BP interrupted the Holocene Humid Period in adjacent regions. The short humid phase possibly favoured Neolithic migrations into Northern Arabia representing a strong human response to environmental changes

The Holocene humid period in the Nefud Desert: Hunters and herders in the Jebel Oraf palaeolake basin, Saudi Arabia

Archaeological surveys and excavations in the Jebel Oraf palaeolake basin, north-western Saudi Arabia, have identified a well-preserved early- to mid-Holocene landscape. Two types of occupation site can be distinguished: nine small and ephemeral scatters from single occupation phases on the slopes of sand dunes and three hearth sites indicative of repeated occupation on palaeolake shorelines. In addition, 245 rock art panels, 81 cairns, and 15 stone structures were recorded. This diverse dataset provides an opportunity to reconstruct occupation patterns and changes in landscape use. A particularly important site, Jebel Oraf 2, documents two episodes of lake high stands at ca. 6500 BC and 5300 BC, flooding parts of the locality. Neolithic pastoralists likely occupied the site after the end of the wet season, when the terrain was dry. Earlier sites are located in dune embayments some 7–14 m above the shore of the palaeolake. These locations are consistent with hunting strategies identifiable in the rock art that suggest wildlife was ambushed at watering places. Later rock art at Jebel Oraf also documents the hunting of wild camel in the Iron Age. The lithic industries documented in the Jebel Oraf basin support arguments of repeated contact with Levantine populations