2.1. Las Bela (Balochistan)
The fieldwork was conducted by 2–3 persons, walking ca. 6 hours per day for two 2 weeks each season, recording and mapping all the surface finds by a Garmin-GPS device, photographing all sites and concentrations of artefacts and associated shells on the spot. Shell samples for radiocarbon dating were systematically collected whenever available. One adult T. palustris mangrove shell fragment was sampled for dating, though other mangrove (T. telescopium) or marine species were also collected in the case of absence of T. palustris fragments (Table 1).
The scope of the surveys carried out between 2011 and 2014 along the ancient shores of the Siranda Lake was to check the presence of mangrove shells along the eastern side of the sabkha depression which had been reported in the 1960s (Snead 1966, Fig. 15) (Fig. 1, n. 1). The research led to the discovery of 76 sites among which are shell middens and concentrations of knapped stone artefacts often found in association with shells (Biagi and Nisbet 2023). Lake Siranda is located in the southernmost part of the Las Bela Valley, in south-eastern Pakistani Balochistan (Fig. 2). It is oriented in a north-south direction. Its western and southern sides are delimited by mobile sand dunes (Snead 1966, 48) which separate it from the Sonmiāni Lagoon (Miāni Hōr), which is at present surrounded by mangroves, and the Arabian Sea (Naeem et al. 2020).
During the winter and summer monsoon seasons, the depression is fed by sparse rains (Minchin 1907, 18) and the Watto River which flows from the north (Snead 1966, Fig. 13). According to a report written around the beginning of the last century, “when full ..... is 9 miles long and 2 miles broad” (Minchin 1907, 9). So far, 45 Siranda sites have been radiocarbon dated at Groningen University Radiocarbon Laboratory (CIO) mainly by T. palustris or T. telescopium mangrove shells, 1 by Anadara rhombea, 1 by Scylla serrata mangrove crab claw, and 6 by fish otoliths (Table 1).
Most of the Siranda shell middens consist of thin deposits of decoloured fragments of T. telescopium, T. palustris and other shell species. The only exceptions are SRN-28 and SRN-29, which are located along the south-eastern shore of the lake. SRN-28 is a thin, almost circular midden ca 30 m in diameter, which is surrounded by at least 13 heaps of mangrove shells, 2 to 3 m in diameter each (Fig. 3). Most probably it was settled in different periods of the Neolithic: This is confirmed by two radiocarbon dates (SRN-28.10: GrA-62260, 6500 ± 40 uncal BP, and SRN-28: GrA-55819, 5440 ± 40 uncal BP both on T. palustris: see Table 1). SRN-29 is an impressive shell mound surrounded by several smaller shell middens and shell heaps scattered over a very wide area (Fig. 4) from which Neolithic knapped artefacts and one copper vessel have been retrieved (SRN-29Sud: GrM-18731, 7130 ± 35 uncal BP, SRN-29: GrA-54299, 6595 ± 35 uncal BP, and SRN-29.1: GrM-18729, 3272 ± 24 uncal BP, all on T. palustris: see Table 1). None of the Siranda middens has either been excavated or has shown evidence of habitation structures, graves, human and animal bones, hearths or charcoals. Two Neolithic (SRN-19 and 29), four Chalcolithic and one Bronze Age sites have yielded ceramic potsherds.
The percentage and state of fragmentation of the mangrove shells varies site by site, although T. telescopium is always prevailing (Haque and Choudhury 2015; Raw et al. 2017). Other common species are Anadara rhombea and Thais. Three characteristic net weights, obtained from bilaterally notched beach pebbles, have been recorded from the Neolithic shell middens SRN-62, 64 and 73. They suggest that the Siranda Neolithic communities practised some type of small scale fishing.
The radiocarbon results and the techno-typological characteristics of the knapped stone artefacts suggest that the oldest shell middens were settled during the Neolithic, between the last two centuries of the 8th and the entire 7th millennium uncal BP (Fig. 2). The lithic assemblages of this period are represented by microlithic bladelet artefacts obtained almost exclusively from dark reddish-brown Ras Gadani chert, whose sources outcrop ca. 50 km south of the lake (Sarwar 1992; Naseem et al. 1996–1997). The tools consist of prismatic and subconical microlithic cores with one prepared platform from which parallel-sided microbladelets have been detached, microlithic isosceles trapezes, micro-drills, retouched and unretouched microbladelets (Biagi and Nisbet 2023).
The 6th millennium uncal BP Chalcolithic sites have yielded knapped stone artefacts made from Gadani and other varieties of black and whitish chert. Although the location of these sources is currently unknown, we can exclude that they exploited any of the well-known Sindhi sources (Biagi et al. 2018a). At present we know that limestone formations and conglomerate deposits containing knappable cherts do exist in Balochistan (Aubry et al. 1988), although the provenance of our Chalcolithic artefacts cannot be established with certainty.
Most of the Chalcolithic bladelets were detached by pressure to obtain blanks with straight, parallel sides and trapezoidal or triangular cross-section. The tools are represented by semi-abrupt retouched bladelets and truncation and one lunate (Biagi and Nisbet 2023). These artefacts can be compared with those of the Amri phase that flourished in Sindh during this period (Casal 1964; Biagi 2005), and the Chalcolithic layers of Mehrgarh in Balochistan (Lechevallier 2003; Biagi 2022).
Along the Las Bela coast, other groups of shell middens have been discovered and radiocarbon dated at Ras Gadani and Ras Phuari (Biagi et al. 2013b) (Fig. 1, n. 2), and along the small Bay of Daun (Biagi 2011a; Biagi et al. 2013a) (Fig. 1, n. 3). The available data suggest that this part of the northern coast of the Arabian Sea (Hughes 1877, 136) was unpopulated until the last centuries of the 8th millennium uncal BP, as has been suggested for the entire coast of the Arabian Peninsula (Preston and Parker 2013).
Moving farther south, the Bronze Age site of Sonari is the only fishers-gatherers settlement known along the northern coast of the Arabian Sea. The site is located in a well-sheltered saddle that opens at the top of the limestone terrace facing the Hub River mouth at Ras Muari (or Cape Monze, Sindh) (Fig. 1, n. 4). It consists of a few small, rectangular stone structures oriented in an east-west and north-south direction whose floor is covered with hundreds of fragments of Meretrix bivalves. The presence of several net sinkers made from beach pebbles, marine and mangrove shells, shows that fishing and shells gathering were the most important subsistence activities practised by the inhabitants of the site, which has been radiocarbon dated to the 5th millennium uncal BP by mangrove and marine shells (Biagi et al. 2021b).
2.2. Lower Sindh and the Indus Delta
Lower Sindh is one of the provinces of Pakistan whose careful investigation can lead to great improvements in our knowledge of the archaeology of the Indian Subcontinent. The complexity of the Sindhi landscape has been stressed by several authors (Haigh 1894; Pithawalla 1936; Lambrick 1964, Khan 1979; Flam 1993). A seminal volume on the geology of the region has been written by W.T. Blanford (1880) who reported the presence of “rocky outcrops” raising from the Indus alluvium all of which have shown traces of prehistoric settling (Biagi 2023).
Professor A.R. Khan surveyed part of the territory in the 1970s. He was the first to report the discovery of marine shells “60 miles inland and at a high of more than 1,100 feet” (Khan 1979, 18). Many concentrations of knapped stone artefacts, mangrove and marine shells have been discovered and radiocarbon dated in the region during the last two decades (Biagi et al. 2018a, 2021c).
Investigations have been extended to the confluence of the Mol and the Khadeji Rivers, ca. 30 km north of the present coastline (Fig. 1, n. 12), where concentrations of knapped stone artefacts have been found in association with a few marine and mangrove shells (Biagi et al. 2021a). One fragment of a large marine bivalve from the Khadeji Valley site KDJ-1 has been radiocarbon dated to 8275 ± 45 uncal BP (GrA-63862) (Biagi 2019–2020). The result shows that groups of Holocene hunter-gatherers were active in the territory during the second half of the 9th millennium uncal BP, that they exploited the Arabian Sea coastal environment, and moved towards the interior following the terraces of the most important watercourses, the Malir River, in our case (Khan 1979, 18).
T. telescopium Chalcolithic shell middens have been discovered in the Makli Hills and Shah Hussain, south of Thatta (Biagi et al. 2018b; Biagi 2023) (Fig. 1, nn. 9 and 10). However, the only settlement of this period with evidence of intensive exploitation of marine resources is Tharro Hill near Gujo (Majumdar 1934, 20) (Fig. 1, n. 8). The site has been attributed to the Chalcolithic Amri phase (Shaffer 1992) due to the recovery of characteristic painted potsherds with geometric motifs, typical knapped stone artefacts, and two radiocarbon dates obtained from marine and mangrove shells (Biagi 2022). A small concentration of Oyster shells discovered along the southern edge of the Tharro terrace has been radiocarbon dated to 6910 ± 60 uncal BP (GrN-32119). Neolithic mangrove shell fragments have been collected and dated from the Mulri Hills (Fig. 1, n. 5), in the eastern suburbs of Karachi, Rehri (Fig. 1, n. 6), a village facing the Gharo Creek, and the limestone terraces around the village of Gharo (Biagi et al. 2021c) (Fig. 1, n. 7).
Sindh is punctuated by many shallow salt basins, called “dhandhs”, which show “evidence of the former sea communicating the interior..... After a huge inundation of the area, they lose their aloofness from one another and are joined together for the time being. Later on, when the flood waters subside, they regain their individuality and aridity and grow in salinity” (Pithawalla 1936, 310–311). Their archaeological importance has been implemented by the discovery of concentrations of microlithic knapped stone artefacts along the western banks of the Kheenjar Lake (Fig. 1, n. 14) near Jhimpir (Biagi 2011b), and west of the Haleji Lake (Fig. 1, n. 13).
In December 2022, surveys were conducted along and around two low hills located ca 1000–1500 m west of the Haleji freshwater reservoir (Khan et al. 2012). Before the 1930s, Haleji was a dhandh, a “fine sheet of water, also fed by hill torrents, but its size is chiefly regulated by the amount of rainfall” (Hughes 1876, 291). The surveys led to the discovery of many concentrations of knapped stone artefacts often associated with Oyster shells and, in one case, T. telescopium fragments. So far only three Haleji sites have been radiocarbon dated (Fig. 5). The results show that the concentrations with microlithic stone tools and Oyster shells (Fig. 6) discovered on the top of the terrace were settled during the last centuries of the 8th millennium (HLJ-41: GrM-32748, 7215 ± 27 and HLJ-67: GrM-32749, 7237 ± 26 uncal BP), while that with T. telescopium mangrove shell fragments discovered at the north-easternmost foot of the same terrace, belongs to the last centuries of the 7th millennium (HLJ-22: GrM-32746, 6254 ± 24 uncal BP) (Fig. 7).