Micromorphology revealsin situMesolithic living floors and archaeological features in multiphase sites in central Sudan

Abstract

In the Khartoum region of central Sudan, Mesolithic sites were established on sandy ridges distributed along the Nile. Most of the excavations carried out in recent decades have revealed limited preserved archaeological structures or layers corresponding to subsequent phases of human presence due to the disturbance of the deposits. Post-depositional processes affecting Mesolithic sites include (1) the excavation of Neolithic to Post-Meroitic cemeteries at the same sites, (2) surface erosion, and (3) pedoturbation leading to the mixing of the stratigraphy. During a recent field operation along the western bank of the White Nile, archaeological contexts that were only partially disturbed were identified. Employing a geoarchaeological approach and the micromorphological study of sediments (supported by 14 C dating), settlements were placed in their paleoenvironmental contexts and differences between in situ Mesolithic layers and those disturbed by later processes were identified. Furthermore, it was possible to interpret the functional aspects of three categories of pits containing Mesolithic pottery (fireplace pits, fireplace pits with shell accumulations, and waste pits) and to discuss their significance within the wider framework of North African archaeology. Finally, this project has demonstrated the importance of integrating the geosciences (especially micromorphology) and archaeology in the study of processes leading to the formation and preservation of openair prehistoric sites in arid landscapes.

Holocene Supra-Regional Environmental Changes as Trigger for Major Socio-Cultural Processes in Northeastern Africa and the Sahara

“…Moreover, geochemical study of stable isotopes (C and O), coupled with paleontological study of molluscs and microfossils, confirm the occurrence of constant freshwater lakes up to a few tens of metres deep. Lake sediments indicate that along the Nile, several ponds were active in this phase; they were limited in extension and interpreted as the result of an increased runoff of the western tributaries of the Nile, which are today inactive (Williams 2009;Williams and Jacobsen 2011;Zerboni 2011;Williams et al 2015). In this phase, the great lakes in the Horn of Africa experienced a general drop in their level after the dry LGM, a high stand, in some cases never reached again later in the Holocene (e.g., Gasse 1977Gasse , 2000Marshall et al 2011).…”

“…Dry phases (8.2 BP event and termination of the AHP) are illustrated by vertical grey bars; the duration of the 8.2 BP climate anomaly is reported according to Thomas et al 2007. (A) Lake-level fluctuations in the SW Fezzan (Zerboni 2006;Zerboni and Cremaschi 2012); (B) calcareous tufa sedimentation in the Tadrart Acacus massif (Cremaschi et al 2010); (C) activity of lake Gureinat (Hoelzmann et al 2010); (D) activity of Nubian lakes (Hoelzmann 2002); (E) activity of palaeolakes fed by sporadic runoff in central Sudan (Williams and Jacobsen 2011;Zerboni 2011); (F) deposition of Sapropel S1 in the eastern Mediterranean (Ariztegui et al 2000;Hennekam et al 2014); (G) lake level changes in the Fayum Depression (Hassan 1986); (H) terrigenous (Ti) input to Lake Tana (Marshall et al 2011); (I) Lake Chad lake-level changes (Servant 1983); (J) Bahr El-Ghazal depression lake-level changes (Servant and Servant-Vildary 1980); (K) Lake Abhé level changes in eastern Africa (Gasse 1977); (L) Sahara dust record off Mauritania (deMenocal et al 2000); (M) the δ 18 O record of the Greenland NGRIP ice core (North Greenland Ice Core Project members 2004); (N) mean summer insolation at 20°N (Berger and Loutre 1991) Africa as consequence of the strengthening of the African monsoon. The expansion of the monsoon domains over North Africa was a consequence of a gradual orbital increase in summer season insolation coupled with strongly non-linear feedback processes (deMenocal et al 2000).…”

The microstratigraphic record of human activities and formation processes at the Mesolithic shell midden of Poças de São Bento (Sado Valley, Portugal)

“…In archaeological contexts, micromorphology has proven to be especially useful for several relevant aspects of the archaeological record interpretation, such as the distinction between anthropogenic and natural processes (Aldeias et al 2014;Mallol et al 2010;Goldberg et al 2003;Karkanas 2002), including the nature and significance of stratigraphic contacts and discontinuities (Mallol and Mentzer 2015). It has been particularly successful in the identification and assessment of the degree of preservation of anthropogenic features, such as combustion features (Mentzer 2014;Aldeias et al 2012) and occupational surfaces-including Mesolithic ones (Zerboni 2011)-and the recognition of human activities such as bedding, trampling (Goldberg et al 2009;Miller et al 2013) or intentional reworking of debris (Shillito et al 2011;Sherwood and Kidder 2011). These types of activities are very often only discernible at this microscopic scale.…”

Discriminating pottery production by image analysis: a case study of Mesolithic and Neolithic pottery from Al Khiday (Khartoum, Sudan)

“…1). Unlike other previously investigated sites in Central Sudan, the Al Khiday sites are unique, because they provide the first well-preserved, quite continuous Mesolithic stratigraphic sequence, overlain by sporadic Neolithic and more recent layers, and graves (Salvatori et al, 2011;Zerboni, 2011). Radiocarbon dating of organic remains from these closed contexts indicates that the area was occupied during the Early and Middle Mesolithic periods (16-D-5, 16-D-4, 16-D-4B) over a period of about 800 years (7000e6200 calibrated BC), Late Mesolithic (10-W-4: second half of 6th millennium cal.…”