Multidisciplinary Approach to the Study of Tableware and Common Wares from Early Medieval Tokharistan

Abstract

Between the 5th and 8th centuries AD, several (semi-)nomadic populations invaded ancient Tokharistan (Central Asia), introducing political, socio-economic and cultural changes that also affected pottery production. The study of ceramic materials thereby represents a useful tool for shedding light on the transformations related to such historical events. Unfortunately, no systematic research on ceramics from this region and this period has been conducted to date, and the information available mostly concerns the formal characteristics and imprecise relative chronologies. Aiming to contribute to the knowledge of Early Medieval pottery production in the territory north of the Amu Darya, we present a preliminary investigation on tableware and common wares recovered in the settlements of Khosijat Tepe, Shurob Kurgan, Balalyk Tepe and Dabil Kurgan. This paper provides new data on the vessels’ morphological/stylistic characteristics and relative chronologies, allowing their contextualisation and categorisation. In order to explore the manufacturing processes and their provenance (production areas), a multidisciplinary approach that combines WD-XRF, powder XRD and thin-section optical microscopy was carried out, allowing us to determine the chemical, mineralogical and petrographic compositions, respectively. The results suggest that most vessels consist of local/regional products. The choice and processing of the raw materials are broadly similar. However, slight variations are observed among the ceramics from distinct sites, related to the procurement of clayey sediments from different sources. Although a certain degree of morphological and technological continuity regarding the preceding Kushano-Sasanian pottery tradition is attested for some functional categories, new shapes and decorations appear, confirming the introduction of new practices in the region.

1. Introduction

Tokharistan, or Bactria, as it was called until the end of the 4th c. AD, was a territory corresponding to modern-day south Uzbekistan, south Tajikistan and northern Afghanistan. It was a prosperous region, thanks to its geographical features that allowed the development of agriculture, pastoralism and mining (metals and semi-precious stones). The territory is irrigated by the Amu Darya and its tributaries, and surrounded by steppes to the north, mountain ranges to the north-east and deserts to the west. Its strategic position favoured the interaction between nomadic and sedentary populations and the exchange of resources, goods, ideas and traditions.

With the consolidation of the Kushan Empire in the 1st c. AD, Bactria became one of the most important points of confluence and exchange of products from the Mediterranean area, the Middle East, Central Asia, India and China. The Kushan kings ruled over most of Central Asia and the northern Indian sub-continent between the 1st c. AD and the 3rd c. AD and actively participated in and benefited from the trade routes connecting their domains with China and the Roman and Parthia Empires. In the second half of the 3rd c. AD, Bactria passed under the Persian Sasanian influence and was governed by the Kushano-Sasanian dynasty [1].

The arrival of nomadic Hunnic tribes from Altai around the mid-4th c. AD had a considerable impact on the economy, society and culture, marking the passage of Central Asia from Antiquity to the Early Middle Ages. The Chionites/Kidarites were the first groups to settle Tokharistan, and their long-lasting war with the Sasanians caused the depopulation and impoverishment of the territory [1]. They were followed by another confederation of tribes, the Hephthalites, that occupied a large part of Central Asia in the 5th c. AD. The Hephthalite domination weakened around the 6th c. AD, when the Turks, other nomadic tribes coming from Mongolia, took control of Sogdia and the territories of Tokharistan north of the Amu Darya. Their presence entailed a precarious political equilibrium that resulted in the formation of semi-independent kingdoms and principalities. The territories south of the Amu Darya, still ruled by the Sasanians, were also annexed to the western Turkic khanate in the early 7th c. AD, and a few decades later, the whole region was conquered by the Arabs [1].

Helpful evidence for the comprehension of the social and cultural transformations related to these events is provided by the study of ceramic finds from the settlements inhabited between the 5th and 8th centuries. Regrettably, the investigation of the Early Medieval pottery from Tokharistan is quite limited compared to that carried out on the productions from the Hellenistic, Kushan and Islamic periods, especially from the archaeometric point of view. No comprehensive and systematic study on Early Medieval pottery, evaluating production systems, ceramic technology and use, distribution patterns, and the evolution of forms, decorations and techniques over time, has been conducted so far. In addition, little is known about the location of the pottery workshops active between the 4th and 7th centuries AD. This implies that the provenance and chronology of the ceramic finds (based mainly on coins and comparative studies of ceramic repertoires) are sometimes uncertain.

Solov’ev [2] outlines a general evolution in the morphological and stylistic features of ceramic production in the Early Medieval period, ranging from the late 5th to the mid-8th centuries according to Central Asian historiography. The tableware and common wares dating to the 5th/6th centuries are usually coated with red (or less frequently brown) slips, sometimes decorated with burnished patterns, and exhibit a direct influence of the previous Kushan tradition. Morphological changes become more significant since the mid-6th c. AD, and the manufacturing quality seems to deteriorate during the 7th c. AD, as witnessed by a poorer working of the ceramic pastes, thicker vessel walls and little durable slips, generally applied only onto the rim of jars and storage jars. Tableware and common wares are also handmade; the ornamentation is limited to rims and shoulders and mainly consists of pinches, engravings and carved concentric lines [2].

Aiming to provide new data on the typologies, technologies, production areas and distribution of Early Medieval pottery in Tokharistan, the present study focuses on tableware and common wares from four sites in the Surkhan Darya basin (south Uzbekistan): the fortified towns of Khosijat Tepe, Shurob Kurgan [3,4] and Dabil Kurgan [4], and the castle of Balalyk Tepe [5] (Figure 1). The four settlements were all excavated by Soviet expeditions in the second half of the last century [2,3,6]. Khosijat Tepe and Shurob Kurgan, probably founded by the Late Kushans (3rd c. AD) and inhabited at least until the Islamic period [2,3,7], played a relevant role because of their proximity to commercial routes within the Silk Road network. In particular, Shurob Kurgan was located at a crossing point of the Amu Darya [3]. Balalyk Tepe, well known for its wall paintings, is presumed to have been the residence of a feudal lord and inhabited only during the Early Medieval period [5,8]. Dabil Kurgan, which shows evidence of occupation from the Achaemenid (6th c. BC) to the Modern Age, owes its importance to its geographical location and the presence of ore deposits and salt mines.

This research complements a previous study centred on coarse wares (mainly cooking pots and large storage jars) from Khosijat Tepe and Balalyk Tepe [9]. Here, we examine the morphological and decorative traits of tableware and common wares to broaden the systematisation of the main types recovered in the region; we also investigate the evolution in the formal and stylistic characteristics with respect to the Kushano-Sasanian repertoires, and the influences introduced by the various people who successively occupied the territory. In addition, the analysis of the chemical, mineralogical and petrographic composition of the ceramic pastes by means of wavelength-dispersive X-ray fluorescence (WD-XRF), powder X-ray diffraction (XRD) and thin-section optical microscopy (OM) provides insights into the provenance and the main technological processes involved in their manufacture (choice and working of the raw materials, shaping methods, surface finishing and firing temperature and atmosphere).

2. Materials and Methods

A total of 38 ceramics were sampled and analysed (

Table 1. Inventory of the ceramics from Balalyk Tepe (BT), Dabil Kurgan (DK), Khosijat Tepe (KT) and Shurob Kurgan (SK).

Sample	Description and Presumed Dating	References and Parallels	Earlier Examples	Analysis
BT-Pl1	Plate (6th–7th c.) Wide and shallow conical body, with vertical rim and pointed lip. Red-brown slipped in the inner and outer surfaces.	Balalyk Tepe [5] (p. 89; 60.3) Khosijat Tepe [2] (fig. 9.1) Ajina Tepe [2] (fig. 18.22) Dabil Kurgan [6] (p. 45; 5.13)		OM, XRD, XRF
BT-Pl2	Plate/bowl (6th–7th c.) Deep carinated body, with a convex lower part and a concave, flared upper part; direct rim and round lip. Red-brown slipped rim inside and outside.	Khosijat Tepe (KT-Pl1) Nameless Settlement [2] (fig. 29.25)	Tchingiz Tepe [10] (p. 24) Termez [11] (p. 295, TRZ332) Zar Tepe [12] (p. 166; 79.15) Bishkent Valley [13] (p. 175, XXVII-20)	OM, XRD, XRF
BT-Jr1	Jar (6th–7th c.) Globular body with a short and narrow neck and 4 semi-circular handles placed vertically in the upper body; rim with an internal recess for a lid and external grooves. Red-brown slip on the outer surface.	Balalyk Tepe [2] (p. 91; 64)		OM, XRF
BT-Jg1	Jug (7th c.) Globular body with short, narrow neck; vertical, direct rim incised with external grooves. Non-slipped, with incised, horizontal lines in the upper body.	Shurob Kurgan [14] (p. 108, 14.6)		OM, XRD, XRF
DK-Jr1	Jar (6th–7th c.) Globular body with vertical, semi-circular handles; vertical, thickened rim, externally profiled, with a flat lip. Red-brown slip on the rim and the upper part of the body, with incised, concentric lines in the shoulder.	Dabil Kurgan [6] (p. 46; 6.10)		OM, XRD, XRF
DK-Jg1	Jug/jar (7th c.) Short, narrow neck, with vertical, thickened rim, externally profiled with grooves. Red slip and concentric, parallel incised lines in the shoulder.	Dabil Kurgan [6] (fig. 8.10)		OM, XRD, XRF
KT-Cp1	Cup/bowl (6th–7th c.) Small hemispherical body with a disc-shaped foot; slightly in-curved rim with pointed lip. Traces of dark-brown slip in the inner and outer surfaces.	Khosijat Tepe [2] (fig. 9.10) Dabil Kurgan [6] (p. 45; 5.10) Shurob Kurgan [14] (p. 112, 18.7 or 19)	Dalverzin Tepe [15] (p. 144, 100.6) Termez [16] (p. 543, 3) Tchingiz Tepe [17] (p. 31, 18)	OM, XRD
KT-Cp2	Cup/bowl (6th–7th c.) Oval body, with slightly out-curved rim and pointed lip. Dark-brown slip covering the rim in the inner and outer surfaces and drips of slip in the inner surface.	Khosijat Tepe [2] (fig. 12.12) Shurob Kurgan [14] (p. 104, 10.2)		OM, XRD, XRF
KT-Bw	Bowl (5th–6th c.) Deep, slightly flared body; short, slightly everted rim marked with an inflection and round lip. Red slip in the inner and outer surfaces.	Dabil Kurgan [6] (p. 45; 5.8)	Tchingiz Tepe [17] (p. 62, 21) Zar Tepe [12] (p. 163; 76.5; p. 174; 87.21; p. 188, 101.19)	OM, XRD, XRF
KT-Bw2	Bowl (5th–6th c.) Hemispherical body; thickened, T-shaped rim. Red slip in the inner and outer surfaces.	Kalai Kafirnigan [2] (fig. 32a-1)	Zar Tepe [12] (p. 160, 71.7г and p. 166, 79 17)	OM, XRD
KT-Pl1	Plate/bowl (6th–7th c.) Deep carinated body, with a convex lower part and a concave, flared upper part; slightly everted rim and round lip. Dark brown slipped in the inner and outer surfaces.	Balalyk Tepe (BT-Pl2) Nameless Settlement [2] (fig. 29.25)	Termez [11] (p. 295, TRZ332) Zar Tepe [12] (p. 166, 79.15) Bishkent Valley [13] (p. 175, XXVII-20)	OM, XRD
KT-Pl2	Plate/bowl (6th–7th c.) Very simple hemispherical body; straight rim and pointed lip. Red-orange slipped in the inner and outer surfaces.	Khosijat Tepe [2] (fig. 9.4) Dabil Kurgan [6] (p. 51; 8.2) Shurob Kurgan [14] (p. 112, 18.7; 113, 19.5) Kuchuk Tepe [2] (fig. 6.5) Kafir Kala [2] (fig. 20.9)	Tchingiz Tepe [17] (p. 49, 39)	OM, XRD
KT-Pl3	Plate/bowl (6th–7th c.) Wide conical body; rim turning upward with a pointed lip. Red slipped inside and probably outside. Soot marks in the outer surface.	Khosijat Tepe [2] (fig. 9.1) Kuchuk Tepe [2] (fig. 6.2) Shurob Kurgan [18] (p. 60, 10.6)	Zar Tepe [12] (p. 169, 82.11)	OM, XRD
KT-Pl4	Plate (6th–7th c.) Wide conical body forming a sort of carina in the upper part; direct rim with round lip. Probably non-slipped.	Khosijat Tepe [2] (fig. 8.2) Balalyk Tepe [5] (p. 89, 60.3) Kafir Kala [2] (fig. 20.4) Kalai Mir [2] (fig. 30.21) Kulagly Tepe [2] (fig. 3) Ajina Tepe [2] (fig. 18.22)	Zar Tepe [12] (p. 169, 82.2)	OM, XRD
KT-Pl5	Plate (7th–8th c.) Wide convex body with carinated profile; wavy rim with round lip. Red-brown slipped in the inner and outer surfaces.	Dabil Kurgan [6] (p. 61; 13.11) Shirkent [2] (fig. 38.6)		OM, XRF
KT-Gb1	Handled goblet (6th–7th c.?) Deep, convex body; direct, simple rim; ring-shaped vertical handle attached just under the rim, and decorated with parallel, longitudinal grooves. Non-slipped.	Khosijat Tepe [2] (fig. 9) Balalyk Tepe [5] (p. 89; 60.2b) Dabil Kurgan [6] (p. 45; 5.1) Kulagly Tepe [2] (fig. 3)	Bishkent Valley [13] (p. 173, XXV-10 and 11)	XRD, XRF
KT-Pt1	Platter (6th–7th c.) Deep, conical body with small flat base; everted rim marked with an inflection and round lip. Non-slipped.	Khosijat Tepe [2] (fig. 9.14; 10.2) Kulagly Tepe [2] (fig. 3, 4th row, 4th profile)		OM, XRD, XRF
KT-Pt2	Platter (5th–6th c.) Conical body with flared wall; thickened rim, slightly prolonged downward. Red slip inside and outside, and burnished decoration over the inner surface.	Kuev Kurgan [2] (fig. 5.41) Shurob Kurgan [14] (p. 112, 18.16)	Dalverzin Tepe [15] (p. 157, 110.18) Zar Tepe [12] (p. 187, 100.6)	OM, XRD, XRF
KT-Pt3	Platter/basin (7th–8th c.) Conical body with flared wall; straight rim marked by a protrusion/trim on its outer part, with a round lip. Painted with slip over the upper inner surface.	Dabil Kurgan [6] (p. 54; 9.10)	Aktepe II [19] (p. 185, XXIII-4)	OM, XRD, XRF
KT-Bs1	Basin (7th–8th c.) Flared body, slightly carinated; sub-triangular, vertical hanging rim. Non-slipped. Soot marks on the outer surface.	Shurob Kurgan [18] (p. 57, 7.9)	Kampyr Tepe [20] (p. 62,1) Zar Tepe [12] (p. 161, 73.1б; p. 178, 91.7)	OM, XRD, XRF
KT-Bs2	Basin (7th–8th c.) Flared wall; vertical, thickened rim marked by an inflection, with round lip. Non-slipped.	Shurob Kurgan [18] (p. 60, 10.9)		OM, XRD, XRF
KT-Bs3	Basin (7th–8th c.) Conical body with flared wall; straight rim marked by a protrusion/trim on its outer part decorated by digital impressions, with a round lip. Non-slipped but with a cream-coloured patina.	Khosijat Tepe [2] (fig. 13.25) Shurob Kurgan [18] (p. 57, 7.1) Khayrabad Tepe [2] (fig. 14.85)		OM, XRD, XRF
KT-Bs4	Basin (7th–8th c.) Conical body with flared wall; straight rim marked by a protrusion/trim on its outer part decorated by digital impressions, with a round lip. Non-slipped.	Khosijat Tepe [2] (fig. 13.25) Shurob Kurgan [18] (p. 57, 7.1) Khayrabad Tepe [2] (fig. 14.85)		OM, XRD, XRF
KT-Jg1	Jug (7th–8th c.) Flat base; spherical body. Non-slipped.	Khosijat Tepe [2] (fig. 12.1) Kafir Kala [2] (fig. 22.13) Shirkent [2] (fig. 38.15) Shurob Kurgan [18] (p. 59, 9.6)		OM, XRD, XRF
KT-Jg2	Jug (6th–7th c.) Globular body with narrow, short neck; small mouth with a vertical rim marked with one groove, and round lip. Red slip on the outer surface and mouth inner part.	Balalyk Tepe [5] (p. 67 or 72) Ajina Tepe [2] (fig. 18.10) Shirkent [2] (fig. 38.15)	Tchingiz Tepe [17] (p. 62, 16 or 20) Kobadian [19] (p. 194, XXXII-14)	OM, XRD
KT-Jr1	Jar/pot (7th–8th c.) Hemispherical body; straight, short neck; everted, rounded rim. Neck and upper body are decorated with a wavy motif; soot marks in the outer surface and the upper inner surface.	Kafir Kala [2] (fig. 22.12?)	Ak Tepe II [19] (p. 179, XVII-3)	OM, XRD
KT-Jr2	Jar (6th–7th c.) Relatively wide mouth and short neck; vertical rim with an inner ridge to accommodate a lid and outer trimming, with round lip; incised horizontal line on the shoulder. Non-slipped.	Khosijat Tepe [2] (fig. 7.20) Shurob Kurgan [18] (p. 54, 4.5)	Kara Tepe [21] (p. 39, KT28) Tchingiz Tepe [17] (p. 63, 49)	OM, XRD, XRF
KT-Jr3	Jar/jug (6th–7th c.) Relatively wide mouth and short neck; vertical, thickened rim profiled with a groove and a protrusion, with a round lip; horizontal, parallel lines on the shoulder. Non-slipped.	Khosijat Tepe [2] (fig. 10.19) Shurob Kurgan [14] (p. 113, 197.6 and 7)	Zar Tepe [12] (p. 189, 102.16)	OM, XRD, XRF
KT-Jr4	Jar (6th–7th c.) Relatively wide mouth and very short neck; out-turned, thickened rim with a protrusion above the junction with the neck, and a pointed lip. One or two vertical handles with longitudinal grooves attached to the upper body. It is decorated with two bands of incised horizontal lines and, between them, a band of wavy lines. Non-slipped.	Shurob Kurgan [18] (p. 54, 4.4)	Kara Tepe [21] (p. 39, KT29) Tchingiz Tepe [17] (p. 63, 52) Dalverzin Tepe [15] (p. 44)	OM, XRD, XRF
KT-Jr5	Jar (7th–8th c.) Flat base; almost vertical body; thick, uneven wall. Non-slipped.	Dabil Kurgan [22] (p. 149, 7.15) Kalai Kafirnigan [2] (fig. 31.19)		OM, XRD, XRF
SK-Cp1	Cup/bowl (6th–7th c.) Small, hemispherical body with thick walls; in-turned rim with round lip. Brown-red slip on the inner and outer surfaces.	Balalyk Tepe [5] (p. 89; 60.1b) Khosijat Tepe [2] (fig. 9.10)	Zar Tepe [12] (p. 176, 89.13) Kara Tepe [21] (p. 39, KT1) Termez [11] (p. 175, 7 or 8; 193, 12).	OM
SK-Cp2	Cup/bowl (6th–7th c.) Deep, conical body with thick walls; straight rim with round lip. Red slip inside and outside.	Shurob Kurgan [18] (p. 60, 10-5) Dabil Kurgan [6] (p. 45, 5.13)	Kampyr Tepe [23] (p. 739, 1, KPT9)	OM, XRD, XRF
SK-Pl1	Plate/bowl (6th–7th c.) Tulip-shaped body with thick walls; almost vertical wall, rounded in the lower part; out-turned, rim with two parallel grooves on the outer side. Dark brown slip on the rim.	Shurob Kurgan [14] (p. 112, 18.6)	Bishkent Valley [13] (p. 175, XXVII-18)	OM, XRD, XRF
SK-Bs1	Basin (6th–7th c.) Truncated cone shape with thick walls; straight rim marked by a protrusion/trim on its outer part, with round lip. Non-slipped.	Shurob Kurgan [18] (p. 53, 3.10) Khosijat Tepe [2] (fig. 7.10)	Aktepe II [19] (p. 185, XXIII-4)	XRD, XRF
SK-Jg1	Jug (7th–8th c.) Narrow, long neck; vertical, slightly in-turned rim, trimmed on the outer surface with protrusions and grooves. Dark brown slip outside.	Shurob Kurgan [18] (p. 59, 9.10)	Tchingiz Tepe [11] (p. 384, TRZ166) Zar Tepe [12] (p. 175, 88.12) Aktepe II [19] (p. 178, XVI-13)	OM, XRD, XRF
SK-Jg2	Jug (7th–8th c.) Neck diverging upward; thickened rim profiled with protrusions and a groove on the outer part. Traces of red slip on the external surface.	Dabil Kurgan [22] (p. 147, 5.23)	Zar Tepe [12] (p. 186, 99.3)	OM, XRD, XRF
SK-Jg3	Base of jug or basin (7th–8th c.) Disc-shaped foot and convex body. Non-slipped.	Shurob Kurgan [14] (p. 110, 16.5)		OM, XRD, XRF
SK-Jr1	Jar (7th–8th c.) Wide mouth; very short neck; thickened triangular rim with a pointed lip, marked with an inflection. Traces of red slip on the external surface.	Shurob Kurgan [18] (p. 61, 11.12; p. 58, 8.12) Kafir Kala [2] (fig. 23.17)	Shodmon Kala [19] (p. 192, XXX-2) Aktepe II [19] (p. 182, XX-26)	OM, XRD, XRF

). The 8 vessels from Shurob Kurgan (coded SK) were provided in 2009 by the archaeologists working on the site, while the rest of the materials—24 specimens from Khosijat Tepe (coded KT), 4 from Balalyk Tepe (coded BT) and 2 from Dabil Kurgan (coded DK)—were provided by the Archaeological Museum of Termez in 2013. Sampling was performed under specific restrictions, and only a few of the pieces belonging to the collections stored at the museum were available for analysis; therefore, the number of vessels sampled in some cases was very small. Anyway, the criterion adopted was to ensure the characterisation of as many functional categories and shapes as possible. We are aware that the few sherds from Balalyk Tepe and Dabil Kurgan are not representative of all the remains from the two sites. Notwithstanding, we decided to analyse them because they were not unique examples of specific typologies from those sites, and, at the macroscopic level, their morphologies and ceramic pastes exhibited features similar to other vessels from the same sites; moreover, a comparison with the specimens from Khosijat Tepe and Shurob Kurgan could add information, even if not exhaustive, about Early Medieval pottery from this area.

Photographs of the sherds accompanied, when possible, by the drawings of probable representative prototypes are shown in Figure 2, Figure 3 and Figure 4, following a chrono-functional classification. Despite the fragmented state and/or small dimensions of the samples, the complete shape of the vessels could be determined in most cases using analogies with items from these and other sites in Tokharistan reported in the literature (Table 1). Thus, drawings from previous publications were taken as reference for some vessels, as mentioned in the captions of Figure 2, Figure 3 and Figure 4.

The items were first chronologically contextualised by comparative analysis according to the occupational phases singled out at the four sites and classified based on their shape, size and decoration. Then, they were analysed using different archaeometric techniques to obtain information on composition and technology. Finally, their diffusion at the regional level was approached by identifying morphological parallels with vessels from coeval sites in Tokharistan—mainly reported in the Russian-language literature.

Chemical, mineralogical and petrographic compositions were determined by means of WD-XRF, powder XRD and thin-section OM, respectively. Due to the small size of the sherds, WD-XRF analysis could not be carried out on KT-Cp1, KT-Bw2, KT-Pl1 to KT-Pl4, KT-Jg2, KT-Jr1 and SK-Cp1, XRD could not be carried out on BT-Jr1, KT-Pl5 and SK-Cp1, and OM could not be carried out on KT-Gb1 and SK-Bs1.

WD-XRF and XRD were performed in the CCiTUB laboratory at the University of Barcelona in two different periods (in 2010 and in 2014) with different devices, as specified below.

Fragments of approximately 30 g were extracted from each sherd, powdered and homogenised in a tungsten carbide mill after the removal of the superficial layers. Major and minor elements were determined on glassy pills prepared with 0.3 g of powdered sample in an alkaline fusion with lithium tetraborate at a 1/20 dilution. Trace elements and Na₂O were measured using pressed pills prepared with 5 g of powdered sample. Ceramics from Shurob Kurgan were analysed in 2010 by using a Philips PW 2400 spectrometer, and the rest of the samples were analysed in 2014 by using an Axios-Max advanced Panalytical, both with a Rh anode tube as the excitation. The operating conditions of the two spectrometers are reported in the Supplementary Materials (Tables S1 and S2). The concentrations were quantified by reference to 60 International Geological Standards. Loss on ignition (LOI) was measured by firing 0.3 g of dried specimen at 950 °C for 3 h. Thereafter, the chemical data were statistically treated with the software R to evaluate the compositional similarity or dissimilarity among the examined vessels. Two diffractometers working with the same wavelength (Cu–Kα1 radiation, λ = 1.5406 Å) were used for the XRD analysis; vessels from Shurob Kurgan were examined in 2010 with a Siemens D-500, operating at 40 kV and 30 mA, while the rest of the samples were analysed in 2014 with a PANalytical X’Pert PRO alpha 1, operating at 45 kV and 40 mA. Diffractograms were taken with a 2Θ angle ranging from 4.01° to 79.98° (step size = 0.0170°; scan step time = 51.2383 s) in the Siemens D-500 and from 5.01° to 79.97° (step size = 0.026°; scan step time = 47.474 s) in the PANalytical X’Pert PRO. The mineralogical phases were identified using PANalytical’s X’Pert High Score, enabling an estimate of the firing regime.

The petrographic study was performed on thin sections using an Olympus BX43F polarising microscope. Photomicrographs were acquired with an Olympus D73-WDR digital camera connected to the microscope and Stream Basic image analysis software. The samples were divided into petrographic groups defined through the characteristics of the matrix (colour, optical activity), microstructure, porosity and non-plastic inclusions (frequency, size, shape, distribution and type), both in the fine (<0.125 mm) and coarse (>0.125 mm) fractions [24,25], in order to address provenance and production techniques.

3. Morphological Examination and Chronological Contextualisation

Prototypes and photographs of the vessels analysed are reported in Figure 2, Figure 3 and Figure 4, while a short description of the morphology and decoration of each sherd, as well as the proposed dating, is given in Table 1. The chronological frame is based on parallels and connections/associations with earlier types according to the available bibliography also included in Table 1. Brief comments about the shaping methods deduced from the macroscopic examination of the artefacts and a possible chronological contextualisation are added hereafter.

The vessels from Balalyk Tepe and Dabil Kurgan are wheel-thrown, as inferred from the concentric lines visible on their external surfaces produced by forming and finishing methods. The features of the shape and slipping of the two plates from Balalyk Tepe (BT-Pl1 and BT-Pl2) suggest an evolution from Kushan and Kushano-Sasanian prototypes (Figure 2), largely found in ancient Termez [10]. On the contrary, the globular profile of the jars and jugs from the two sites is characteristic of Early Medieval specimens (Figure 4), and the vertical handles in jars BT-Jr1 and DK-Jr1, the ornamental grooves in BT-Jg1, and the decorative concentric lines on the shoulder and the trimming of the rim of DK-Jg1 are all elements appearing from the 6th c. AD onward [2,6,14].

The vessels from Khosijat Tepe are wheel-thrown, except basin KT-Bs1 (Figure 3) and jars KT-Jr1 and KT-Jr5 (Figure 4). The former may have been moulded, judging from its external characteristics and the fingerprints left by the potter on its inner surface. The shape may derive from a prototype of Hellenistic tradition [20], produced, with some variations, during the Kushan and Kushano-Sasanian periods until the Early Middle Ages [14] (p. 87), [18]. In contrast, the wide-necked jar (or pot) KT-Jr1 was probably made by pinching, as evidenced by the irregularities in the surface, the thickness of the wall and the presence of fingerprints. Analogies with artefacts from Kafir Kala in Sogdiana suggest a dating to the Early Medieval period [2]; however, some morphological features seem to resemble a more ancient kind of jar, slightly larger, found in a Tajik site located in the lower course of the Kafirnigan River, a tributary of the Amu Darya [19]. The flat base KT-Jr5 is characterised by a thick, uneven wall and very rough finishing, indicating that it was presumably made by pinching. Its complete shape cannot be established, but similarities with fragments unearthed in other sites suggest a dating to the 7th/8th centuries [2,22].

Bowls and plates KT-Bw1, KT-Bw2, KT-Pl1, KT-Pl2 and KT-Pl4 (Figure 2), in addition to jug KT-Jg2 and jars KT-Jr2 and KT-Jr3 (Figure 4), recall Kushan and/or Kushano-Sasanian typologies for the shape and the slip, when present [11,12,17,21]. Cup/bowl KT-Cp1 (Figure 2) also resembles prototypes that were widespread in Termez and throughout Bactria between the 1st and the 4th centuries [17]; they probably derive from an earlier tradition, as attested to by artefacts appearing in Greco-Bactrian contexts at Dalverzin Tepe [15] and Termez [16].

The profiles of cup/bowl KT-Cp2 and plate/bowl KT-Pl3 (Figure 2) may also be an evolution of Kushan or Kushano-Sasanian shapes [10]; however, the dark slip that covers only the outer and inner parts of the rim of the former and the shade of the red slip covering the latter suggest a later period. KT-Gb1 is a goblet with a ring-shaped, vertical handle decorated with parallel, longitudinal grooves (Figure 2). This prototype was quite common in the Early Middle Ages, especially in the 6th c. AD [2,5,6]; however, examples of handled goblets were also present in earlier periods (see the Kushan vessels reported by Mandelshtam [13] in the Bishkent Valley).

KT-Pl5 (Figure 2) is a plate with a wavy edge, maybe an imitation of some metal items. According to Solov’ev, it represents a new shape that spread in northern Tokharistan and Sogdia in the 7th c. AD [2,6].

Platter KT-Pt2 (Figure 3) is distinguished by a red slip over the inner surface, embellished with a burnished decoration forming a flower. Similar profiles are not unusual in Kushano-Sasanian and Early Medieval contexts, and such decoration appears in other specimens from Termez [10] (p. 31) and Khosijat Tepe [2] (fig. 12.10).

Fragments KT-Bs2, KT-Bs3 and KT-Bs4 represent new shapes (Figure 3). According to Solov’ev [14], the decorative stripe on the two latter pieces represents a hallmark characterising basins produced at the beginning of the 8th c. AD, which continued to be used during the Islamic period.

The rim of jar KT-Jr4 (Figure 4) is common in the Kushan and Kushano-Sasanian epochs [17,21]; however, the handle profile is typical of Medieval vessels from Tokharistan [18].

Finally, the eight pieces from Shurob Kurgan are all wheel-thrown, and their shapes seem to be an evolution of Kushan or Kushano-Sasanian prototypes [11,12,19,21], except base SK-Jg3 (Figure 4), which presents analogies with some Early Medieval or Islamic wares [14].

4. Archaeometric Results

4.1. Chemical Analysis

Statistical analysis [26] was applied to the chemical concentrations of 29 samples obtained by WD-XRF (

Table 2. Chemical normalised data of the samples analysed by WD-XRDF (major and minor elements from Fe₂O₃ to SiO₂ in %).

Sample	Fe2O3	Al2O3	MnO	P2O5	TiO2	MgO	CaO	Na2O	K2O	SiO2
BT-Pl1	6.01	15.20	0.08	0.16	0.66	3.06	9.71	1.22	3.18	56.31
BT-Pl2	6.25	15.04	0.10	0.20	0.68	3.52	11.68	2.10	2.74	55.79
BT-Jr1	5.96	14.57	0.10	0.20	0.62	3.94	10.83	1.26	3.12	52.80
BT-Jg1	7.04	18.22	0.08	0.20	0.76	3.31	2.78	1.60	4.15	59.71
DK-Jr1	5.52	14.40	0.08	0.24	0.65	3.12	6.57	1.59	4.38	58.92
DK-Jg1	5.77	14.69	0.05	0.12	0.79	2.80	1.24	1.64	3.35	68.61
KT-Cp2	6.29	15.88	0.08	0.22	0.69	3.36	10.04	1.27	3.67	54.34
KT-Bw1	6.43	16.24	0.09	0.24	0.71	3.18	7.99	1.10	3.94	57.07
KT-Pl5	6.63	16.47	0.09	0.21	0.71	3.20	10.26	1.11	3.86	54.28
KT-Gb1	5.64	14.55	0.09	0.21	0.66	2.85	10.54	1.33	3.42	58.45
KT-Pt1	5.69	14.68	0.09	0.34	0.67	2.91	9.80	1.31	3.30	58.88
KT-Pt2	6.40	16.11	0.10	0.26	0.67	4.00	9.39	1.12	3.73	56.82
KT-Pt3	5.39	13.74	0.09	0.25	0.64	2.59	11.26	1.39	3.29	55.51
KT-Bs1	6.57	16.57	0.10	0.23	0.74	3.02	9.54	1.34	3.64	56.76
KT-Bs2	5.58	14.47	0.08	0.19	0.67	2.47	9.92	1.31	3.39	56.74
KT-Bs3	6.46	16.12	0.09	0.47	0.70	3.13	11.28	1.04	3.69	54.50
KT-Bs4	6.00	15.23	0.09	0.29	0.67	3.01	10.55	1.16	3.83	53.35
KT-Jg1	6.22	16.17	0.09	0.31	0.73	2.81	7.86	1.28	3.79	59.22
KT-Jr2	6.15	15.94	0.08	0.24	0.71	3.09	9.37	1.22	3.58	56.57
KT-Jr3	6.18	15.53	0.09	0.22	0.69	3.18	10.96	1.10	3.58	54.47
KT-Jr4	5.97	14.54	0.12	0.25	0.60	4.13	14.55	1.59	3.06	51.22
KT-Jr5	6.09	16.04	0.08	0.31	0.72	2.81	10.98	1.49	3.57	54.84
SK-Cp2	6.28	15.77	0.09	0.42	0.65	3.99	9.14	0.96	3.87	55.04
SK-Pl1	5.99	15.59	0.09	0.22	0.67	3.16	9.49	1.37	3.35	58.29
SK-Bs1	5.69	14.65	0.09	0.22	0.66	3.13	10.06	1.18	3.14	57.03
SK-Jg1	6.22	15.77	0.09	0.30	0.66	3.67	8.33	1.39	3.50	57.97
SK-Jg2	5.40	14.36	0.08	0.31	0.62	3.87	7.47	2.63	3.51	55.20
SK-Jr1	5.84	15.47	0.09	0.28	0.62	3.48	7.81	1.37	3.58	59.40
SK-Jg3	6.30	15.09	0.11	0.18	0.67	3.65	12.30	1.67	2.84	54.95

and

Table 3. Chemical normalised data of the samples analysed by WD-XRDF (trace elements from Ba to Cr in ppm, and LOI in %).

Sample	Ba	Rb	Th	Nb	Pb	Zr	Y	Sr	Ce	Ga	V	Zn	Cu	Ni	Cr	LOI
BT-Pl1	450	119	14	10	21	148	24	238	56	19	118	88	26	40	82	4.27
BT-Pl2	549	104	16	11	9	148	26	288	60	19	116	92	29	46	93	1.74
BT-Jr1	472	110	17	11	23	139	24	328	63	18	112	96	29	43	88	6.41
BT-Jg1	652	142	17	13	33	142	28	197	73	22	131	112	36	50	98	1.96
DK-Jr1	459	115	15	11	25	169	25	230	59	18	106	92	22	37	77	4.36
DK-Jg1	508	112	18	15	23	239	26	149	70	18	104	81	22	43	98	0.77
KT-Cp2	456	125	17	11	23	151	26	417	65	19	104	98	27	43	84	4.00
KT-Bw1	452	125	15	11	23	146	25	365	68	20	115	90	26	42	74	2.85
KT-Pl5	459	129	16	11	26	152	26	263	58	20	118	92	26	42	85	3.04
KT-Gb1	459	109	3	10	8	83	86	268	60	18	1	6	23	36	74	2.13
KT-Pt1	450	111	14	10	12	157	26	247	56	17	96	92	23	36	79	2.19
KT-Pt2	557	124	17	12	24	140	26	365	68	20	129	81	28	50	100	1.23
KT-Pt3	467	109	15	11	21	161	26	303	63	17	95	85	22	34	69	5.70
KT-Bs1	494	124	15	11	19	160	28	235	68	20	117	92	42	42	85	1.32
KT-Bs2	464	112	15	11	22	159	26	234	64	18	104	84	22	35	67	5.05
KT-Bs3	519	128	17	11	22	156	27	511	66	20	108	103	30	45	87	2.34
KT-Bs4	471	115	15	11	23	154	26	341	58	19	114	95	24	41	76	5.66
KT-Jg1	546	127	15	11	22	164	26	256	59	20	95	91	28	40	86	1.36
KT-Jr2	428	131	16	11	22	157	26	422	66	20	119	98	27	41	86	2.90
KT-Jr3	497	124	16	11	23	159	27	301	58	20	106	96	29	42	80	3.84
KT-Jr4	417	75	16	10	20	125	23	516	52	18	107	92	26	42	88	3.81
KT-Jr5	381	125	16	11	18	148	25	343	58	19	119	91	42	34	83	2.93
SK-Cp2	533	144	17	18	24	150	29	473	59	21	110	100	31	56	83	3.61
SK-Pl1	464	143	15	17	12	177	28	286	52	20	91	92	30	45	70	1.63
SK-Bs1	473	134	15	17	23	179	29	385	51	19	95	88	29	44	67	4.00
SK-Jg1	405	139	14	16	17	172	28	386	58	20	101	94	32	51	76	1.93
SK-Jg2	543	131	15	16	24	152	26	449	61	19	99	91	29	41	70	6.37
SK-Jr1	537	141	18	17	20	153	27	326	66	20	97	95	35	50	80	1.88
SK-Jg3	556	120	20	19	20	163	29	270	60	20	91	101	46	59	72	2.07

). The value of the total variation (tv = 1.68) resulting from the calculation of the compositional variation matrix (CVM) is higher than 0.50 and indicates that the ceramic wares do not present a monogenic composition, as it appears evident looking at the chemical data (see samples BT-Jg1, DK-Jg1 and KT-Gb1). Repeating the calculation without goblet KT-Gb1, which differs significantly in most trace elements’ relative amounts, the total variation is much lower (tv = 0.70), but still higher than 0.50. Additional information, such as the total sum of variances in each chemical element (τ_.i value), reveals that most of the variability is introduced by P₂O₅, CaO, Na₂O, Th, Pb, Y, Sr, V and Zn (Figure 5).

The high τ_.i values of P₂O₅, Na₂O and Pb may be partly due to differences in the raw materials employed; however, the relative amounts of these elements may also have been modified by contamination processes that occurred in the burial ground [27]. Thus, the high P₂O₅ values detected in basin KT-Bs3 (0.47%) and cup SK-Cp2 (0.42%) may derive from a post-depositional alteration connected to anthropic activity [28]. As for Na₂O, the high amounts detected in plate BT-Pl2 (2.10%) and jug SK-Jg2 (2.63%) could be associated with secondary processes, probably related to the presence of analcime in the former, and to an enrichment in sodium coming from the soil—crystallised as halite (NaCl)—in the latter; both minerals were identified by XRD. Contamination processes may also have affected lead concentrations in some samples (ranging from 8 ppm in the handled goblet KT-Gb1 to 33 ppm in jug BT-Jg1). The τ_.Zn value is determined by the abnormally low content in the handled goblet KT-Gb1 (6 ppm), compared with the 112 ppm in jug BT-Jg1. The high variability in Th, Y and V is mainly due to the anomalous values of a single specimen, KT-Gb1, which exhibits very low Th (3 ppm) and V (1 ppm), and very high Y (86 ppm).

The relative content of CaO, ranging from 1.24% in DK-Jg1 to 14.55% in KT-Jr4, also exhibits high variability mainly due to the different compositions of the raw materials (e.g., in BT-Jg1 and DK-Jg1), to calcareous inclusions (e.g., in DK-Jr1 and KT-Jg2) and, to a much lesser extent, to the precipitation of secondary calcite (e.g., in KT-Pt1 and KT-Jg1) and maybe gypsum (see Section 4.3). These secondary phases could be partially or totally allochthonous and affect the original calcium amount. Nevertheless, it can be noticed that the alterations/contaminations detected in some specimens are of little relevance (see the features of the groundmass and porosity described in Section 4.3), also considering that, with two exceptions (BT-Jg1 and DK-Jg1), the set of samples consists of calcareous pastes. Moreover, looking at the results of the XRD analysis reported in Section 4.2, secondary calcite, when detected, is associated with firing phases such as gehlenite and diopside, and could derive from an alteration of gehlenite [29]. Given that the calcium contribution due to the secondary phases identified is negligible, CaO, which is one of the main components of ceramic pastes, was included in the subsequent statistical treatment.

Being an alkaline earth metal, Sr, with values ranging from 149 ppm in DK-Jg1 to 516 ppm in KT-Jr4, may also be affected by interferences with other alkaline earth metals such as Ca and Ba [30].

Since the original compositions may have been partly modified by the post-depositional processes outlined above, the CVM was recalculated using the renormalised sub-composition Fe₂O₃, Al₂O₃, TiO₂, MgO, CaO, K₂O, SiO₂, Ba, Rb, Th, Nb, Zr, Y, Ce, Ga, V, Ni and Cr. The new value obtained for the total variation was still high (tv = 1.17). Excluding the samples responsible for most of the variability, BT-Jg1, DK-Jg1 and KT-Gb1, the total variation becomes notably lower (tv = 0.18), pointing to a similar or common geochemical composition. The dataset was treated statistically by log-ratio transformation using Fe₂O₃—the element presenting the least variation—as the divisor [30]. Cluster analysis was applied considering 29 samples, by determining the mean squared Euclidean distance and using the average algorithm. In the resulting dendrogram (Figure 6), most vessels are plotted in the same cluster, while jugs BT-Jg1 and DK-Jg1 and goblet KT-Gb1 appear joined at a higher ultrametric distance.

The cluster comprises 26 vessels characterised by calcareous pastes. Within this cluster, jar KT-Jr4 stands out, having the highest MgO and CaO concentrations and the lowest SiO₂, Rb and Y percentages. Slight differences are also observed in base SK-Jg3, with higher CaO, MnO, Th, Nb and Ni values, and in jar DK-Jr1, with higher K₂O and lower CaO contents. The analysis also highlights a separation in two sub-clusters formed by the vessels from Balalyk Tepe and Khosijat Tepe on the one hand, and by those from Shurob Kurgan on the other, the latter being slightly poorer in Cr and richer in MgO, Rb, Nb, Zr and Ni.

BT-Jg1 and DK-Jg1 are separated from the cluster because of their low-calcareous pastes, as is obvious from Table 2; moreover, the former exhibits high Al₂O₃, Fe₂O₃, K₂O, Ba, V and Zn values, whereas the latter has high SiO₂ and Zr and low MnO.

As is apparent from Table 2 and Table 3, the handled goblet KT-Gb1, with its very low (in some cases anomalous) values of Th, Pb, Zr, V and Zn and high Y content, departs from the rest of the vessels, pointing to a different composition; it may have been manufactured with raw materials from a different area.

The ternary diagram (Figure 7), built with the main components SiO₂, Al₂O₃ and CaO+MgO, also highlights the separation between the cluster richer in calcium and magnesium and the two jugs BT-Jg1 and DK-Jg1, richer in silica and alumina (as expected for low-calcareous samples).

The biplot (Figure 8) obtained by applying principal component analysis (PCA) to the same log-ratio-transformed data, excluding the loners BT-Jg1, DK-Jg1 and KT-Gb1, confirms the separation between the vessels from Shurob Kurgan (on the left) and from Khosijat Tepe (on the right). Two vessels from Balalyk Tepe can be distinguished because of their slightly higher CaO and lower K₂O contents, and specimens KT-Jr4, SK-Jg3 and DK-Jr1 are isolated due to the peculiarities mentioned above.

The first two components justify the 63.45% of the variability.

4.2. X-Ray Diffraction Analysis

It is known that the firing process determines mineralogical and textural changes in ceramic pastes mainly depending on their original composition, temperature reached and firing atmosphere [29,31,32]. In calcareous pastes, calcite begins to react above 750–800 °C, giving origin to new Ca-silicates such as gehlenite and diopside, and disappearing above 900 °C. Gehlenite starts decomposing above 950 °C and is no longer present at 1050–1100 °C, while diopside remains stable. The crystallisation of the two Ca-silicates in oxidising conditions also plays a role in the nucleation of hematite. In low-Ca pastes, the decomposition of the phyllosilicates (illite, muscovite, etc.), around 900 °C, leads to the precipitation of spinel. This mineral transforms into mullite at higher temperatures, disappearing completely between 1000 and 1100 °C. The iron released in these reactions allows the nucleation of hematite that, in reducing conditions, converts into magnetite, replaced by other iron phases above 950 °C.

Bearing these considerations in mind, the identification of the primary and firing phases in the diffractograms obtained by powder XRD, together with the intensity of their peaks, allowed an estimate of the equivalent firing temperature (EFT) and atmosphere of 35 samples (

Table 4. Mineralogical phases detected through powder XRD and corresponding equivalent firing temperature (EFT); Anl: analcime (NaAlSi₂O₆·H₂O); Cal: calcite (CaCO₃); Di: diopside (CaMgSi₂O₆); En: enstatite (MgSiO₃); Gh: gehlenite (Ca₂Al₂SiO₇); Hem: hematite (Fe₂O₃); Hl: halite (NaCl); Ill: illite-muscovite (KAl₂(AlSi₃O₁₀)(OH)₂); Kfs: K-feldspar (KAlSi₃O₈); Pl: plagioclase (NaAlSi₃O₈); Qz: quartz (SiO₂); sec. Cal: secondary calcite; Spl: spinel (MgAl₂O₄).

Samples	Mineralogical Phases	EFT
DK-Jr1, KT-Bs2, KT-Bw1, KT-Pl2	Qz, Pl, Kfs, Ill, Cal, Hem	800–850 °C
BT-Pl1, KT-Jr5, KT-Pt3, KT-Bs4, KT-Jg2, KT-Pl3, KT-Pl4	Qz, Pl, Kfs, Ill, Cal, Hem, Gh, Di, (Hl)	850–900 °C
SK-Cp2, SK-Bs1, SK-Jg1, SK-Jg2	Qz, Pl, Kfs, Ill, Cal, Hem, Gh, Di, (Hl)	900–950 °C
KT-Jr2, KT-Jr3, KT-Jr4, KT-Bw2	Qz, Pl, Kfs, Ill, Cal, Hem, Gh, Di, (Hl)	950–1000 °C
KT-Pt2, KT-Bs1, KT-Bs3, KT-Jr1	Qz, Pl, Kfs, Ill, Hem, Gh, Di, (Hl)	950–1000 °C
KT-Pt1, KT-Jg1, SK-Pl1, SK-Jr1	Qz, Pl, Kfs, Hem, Gh, Di, sec. Cal	≥1000 °C
KT-Cp1, KT-Cp2, KT-Pl1	Qz, Pl, Kfs, Hem, Gh, Di	≥1000 °C
BT-Pl2	Qz, Pl, Kfs, Gh, Di, Anl	≥1000 °C
SK-Jg3	Qz, Pl, Kfs, Hem, Di	≥1000 °C
DK-Jg1	Qz, Pl, Kfs, Ill, Hem, Spl	900–950 °C
BT-Jg1	Qz, Pl, Kfs, Ill, Hem, Spl, En	950–1000 °C
KT-Gb1	Qz, Pl, Kfs, Hem, Gh, Di	≥1000 °C

; Figure 9). In addition, the presence of secondary phases deriving from contamination and alteration processes that occurred during use or in the burial ground was also detected in some specimens and confirmed by petrographic analysis.

Regarding the Ca-rich pastes, jar DK-Jr1, bowl KT-Bw1, plate KT-Pl2 and basin KT-Bs2 are characterised by the presence of primary phases that include quartz, plagioclase, K-feldspar, abundant phyllosilicates and calcite. Since hematite may also constitute a primary phase, the absence of clearly developed firing phases suggests a low firing temperature, probably below 850 °C (Figure 9a). In tableware and common wares BT-Pl1, KT-Pl3, KT-Pl4, KT-Pt3, KT-Bs4, KT-Jg2 and KT-Jr5, besides the same primary phases, firing phases such as incipient diopside and well-developed gehlenite can be observed, which indicates a firing temperature around 850–900 °C. Hematite is especially abundant in KT-Pl2 and KT-Pl4.

The diffractograms of cup SK-Cp2, basin SK-Bs1 and jugs SK-Jg1 and SK-Jg2 exhibit the coexistence of both primary and firing phases; the former include quartz, plagioclase, K-feldspar, phyllosilicates (more abundant in SK-Cp2 and SK-Bs1) and calcite (more abundant in SK-Bs1); the firing phases, such as hematite, diopside and gehlenite, are consistent with a firing temperature around 900–950 °C. Bowl KT-Bw2 and jars KT-Jr2, KT-Jr3 and KT-Jr4 present the same primary and firing phases; however, the decrease in phyllosilicates and calcite, together with the parallel increase in diopside, suggests a higher EFT (950–1000 °C) (Figure 9a). A similar range of temperature can be assumed for samples KT-Pt2, KT-Bs1, KT-Bs3 and KT-Jr1, in which calcite is totally decomposed and gehlenite has almost disappeared, but the phyllosilicates are still present. Judging by the grey colour of the paste in the central part of the sherd, KT-Bs1 may have been fired under a reducing atmosphere and cooled in oxidising conditions or fired under an atmosphere that shifted from reducing to oxidising.

KT-Cp1, KT-Cp2, KT-Pl1, KT-Pt1, KT-Jg1, SK-Pl1 and SK-Jr1, as well as the loner KT-Gb1 (Figure 9c), include quartz, plagioclase and K-feldspar (particularly abundant in KT-Jg1) as primary phases, and hematite, high diopside and low gehlenite as firing phases. The absence of phyllosilicates indicates a firing temperature above 1000 °C, and therefore the calcite in the two specimens KT-Pt1 and KT-Jg1 from Khosijat Tepe and the two specimens from Shurob Kurgan should be considered secondary calcite.

In plate BT-Pl2, the almost complete decomposition of gehlenite and the absence of phyllosilicates and calcite, accompanied by well-developed diopside (Figure 9a), point to a firing temperature around 1000°C. Feldspars are abundant, while iron oxides are not visible since, in high-fired Ca-rich pastes, hematite develops as nanoparticles [33]. The high firing temperature and high amounts of Ca and Na are compatible with the presence of analcime as a secondary phase. This Na-zeolite may derive from the decomposition of gehlenite [31] but might also be related to an enrichment in sodium originating from the soil [34].

Concerning SK-Jg3, the absence of phyllosilicates and gehlenite, together with the well-developed diopside peaks, denotes a firing temperature above 1000 °C.

A secondary phase, visible in many samples (KT-Bs3, KT-Bs4, KT-Jr2, KT-Jr4, SK-Jg2), is halite (Figure 9a). Its deposition is related to the circulation of chloride-rich solutions in a semi-arid environment such as the Surkhan Darya valley, where high concentrations of evaporites are present [21] [23] (p. 747).

In the case of the Ca-poor specimens, jug DK-Jg1 contains quartz, plagioclase, K-feldspar and phyllosilicates as primary phases. However, the appearance of incipient firing phases such as spinel and the low intensity of the phyllosilicates’ peaks indicate an EFT around 900–950 °C. A higher firing temperature (950–1000 °C) can be supposed for jug BT-Jg1, where hematite (quite abundant), spinel and enstatite (a Mg-orthopyroxene) are detected as firing phases (Figure 9b).

4.3. Petrographic Analysis

A total of 36 samples were examined by thin-section optical microscopy and classified, according to their petrographic composition and textural features, into eight petrographic groups, some comprising single individuals (

Table 5. Description of the petrographic groups identified through OM (C.F.: coarse fraction; F.F.: fine fraction; *** predominant to dominant; ** frequent to common; * scarce to rare; Am: amphibole; Cal: calcite; Cpx: clinopyroxene; Ep: epidote; Fsp: feldspar; Grt.: granitoid rock; Kfs: K-feldspar; Mca: Mica; Meta: metamorphic rock; Ol: olivine; Pl: plagioclase; Qz: quartz; Volc: volcanic rock.

Fabric Group	Groundmass	Inclusions	Voids
B1 BT-Pl1, BT-Pl2, BT-Jr1	Brownish, calcareous, moderately homogeneous (more heterogeneous in BT-Pl2), low vitrified to vitrified (in BT-Pl2)	C.F.: common (in BT-Pl1), moderately sorted, sub-angular to sub-rounded, sub-equant to elongated. *** Qz, Kfs, Pl, Grt (≤0.5 mm, finer in BT-Pl1 and BT-Jr1); * semi-decomposed Cal (micrite), Meta, Am, opaque minerals, Mca. F.F.: abundant; predominant Qz and Fsp; other: semi-decomposed carbonates, opaque minerals, Mca.	Few vughs and vesicles
B2 BT-Jg1	Brownish, Fe-rich, homogeneous, semi-vitrified	C.F.: common, moderately sorted, sub-angular to sub-rounded, sub-equant to elongated. *** Qz, altered Kfs, Pl Grt (≤0.8 mm); * Meta, Am, opaque minerals, Mca, sporadic En. F.F.: abundant; predominant Qz and Fsp; other: opaque minerals, Mca.	Few vesicles
D1 DK-Jr1	Brown-orangish, calcareous, moderately homogeneous, low vitrified	C.F.: common, poorly sorted, sub-angular to sub-rounded, sub-equant to elongated. *** Qz, altered Kfs, Pl (≤0.5 mm); ** carbonates (≤1.3 mm); * opaque minerals, Mca, Am, siltstone. F.F.: abundant; dominant Qz, Fsp, carbonates; few opaque minerals, Mca, Am.	Few vughs and vesicles
D2 DK-Jg1	Brown-orangish, Ca-poor, moderately homogeneous, semi-vitrified	C.F.: few, poorly sorted, sub-angular to sub-rounded, sub-equant to elongated. *** Qz, Kfs, Pl, (≤0.8 mm); * opaque minerals, Mca, sedimentary grains. F.F.: very abundant; dominant Qz, Fsp, Mca, Am.	Few vughs and vesicles
K1A KT-Bs1, KT-Jr5	Brownish, Ca-rich, heterogeneous (mix of Fe-rich and Ca-rich clays with different amounts of inclusions), semi-vitrified	C.F.: common, poorly sorted, sub-angular to sub-rounded, mostly elongated. *** Claystone (≤2.4 mm); ** Qz (<0.3 mm), micritic calcite with reaction rims (≤0.8 mm); * opaque minerals, chert. F.F.: common to abundant; silt and fine-sand grain-sized; predominant Qz and Fsp; common semi-decomposed carbonates, opaque minerals, Mca.	Abundant vughs and planar voids, partially filled with secondary minerals (micrite, halite)
K1B KT-Jr1	Brown-reddish, heterogeneous (Fe-rich streaks and Ca-rich spots), semi-vitrified	C.F.: few, moderately sorted, sub-angular to sub-rounded. *** Qz, Kfs, Pl (≤0.4 mm); ** opaque minerals, claystone and siltstone (≤1.7 mm); * Meta. r. and semi-decomposed calcite (micrite) (<0.4 mm). F.F.: common to abundant; silt and fine-sand grain-sized; predominant Qz and Fsp, common opaque minerals, Mca.	Common elongated vughs and vesicles
K2A KT-Bw2	Brown-reddish, heterogeneous with Ca-rich spots, semi-vitrified	C.F.: few to common, moderately sorted, sub-angular to sub-rounded, sub-equant to elongated. *** Qz, Pl, Kfs (≤0.5 mm); ** sandstone and silt aggregates (≤0.8 mm), semi-decomposed calcite (micrite) (≤0.8 mm); * Meta, Mca, Am, Volc, opaque minerals (≤0.5 mm). F.F.: common; predominant Qz and Fsp; other: Mca, micrite, opaque minerals, Am	Few vughs and vesicles
K2B KT-Cp1, KT-Cp2, KT-Bw1, KT-Pl1, KT-Pl2, KT-Pl3, KT-Pl4, KT-Pl5, KT-Pt1, KT-Pt2, KT-Pt3, KT-Bs2, KT-Bs3, KT-Bs4, KT-Jg1, KT-Jg2, KT-Jr2, KT-Jr3	Brown to brown-orangish or brown-reddish, mixing of Fe-rich clay with Ca-rich material, moderately homogeneous, low vitrified (in KT-Cp2, KT-Bw1 and KT-Pl2) to vitrified (in KT-Pt2, KT-Jg1 and KT-Pl4)	C.F.: few to common, moderately sorted, sub-angular to sub-rounded, sub-equant to elongated. *** Qz, Pl, Kfs (≤0.5 mm); ** Meta (≤0.5 mm), semi-decomposed calcite (micrite) (up to 0.8 mm in KT-Jg2); * Mca, Am, Volc and crystals (Cpx, Ep), opaque minerals, chert. F.F.: common; predominant Qz and Fsp; other: Mca, micrite, opaque minerals, Am, Cpx.	Few to common vughs and vesicles, sometimes filled with secondary minerals (micrite and maybe gypsum?) (KT-Bs3, KT-Bs4)
K2C KT-Jr4	Pale brown, Ca-rich, moderately homogeneous, fine, vitrified	C.F.: common, moderately sorted, sub-angular to sub-rounded, sub-equant to elongated. *** Meta and crystals (Qz, Kfs, Pl) (≤0.5 mm); ** claystone (≤1 mm); * Mca, Am, Cpx, carbonates, Volc. F.F.: common; predominant Qz and Fsp; other: Mca, micrite, opaque minerals, Am.	Few vughs and vesicles, sometimes filled with secondary minerals (halite)
S1A SK-Jg2, SK-Jr1	Brownish, Fe-rich with Ca-nodules, fine, moderately homogeneous, semi-vitrified	C.F.: common, poorly sorted, sub-angular to sub-rounded, sub-equant to elongated. *** Qz, Pl, Kfs (≤0.8 mm); ** Meta, semi-decomposed carbonates (micrite); * Mca, Am, Vol, Cpx, opaque minerals, sandstone. F.F.: common; predominant Qz, Fsp, Mca; sporadic Am and opaque minerals.	Few vughs and vesicles
S1B SK-Cp1, SK-Pl1, SK-Jg1	Brownish, Fe-rich with Ca-nodules, fine, moderately homogeneous, semi-vitrified to vitrified	C.F.: common, moderately sorted, sub-angular to sub-rounded, sub-equant. *** Qz, Pl, Kfs (≤0.5 mm); ** Meta; * opaque minerals, Mca, semi-decomposed carbonates (micrite) (up to 1.35 mm in SK-Pl1), Am, sandstone; sporadic Cpx, Ep, Srp and Volc. F.F.: common; predominant Qz, Fsp, semi-decomposed carbonates, opaque minerals, Mca.	Few to common vughs and vesicles
S1C SK-Cp2	Brown-orangish, Fe-rich, fine, heterogeneous, semi-vitrified	C.F.: few, moderately sorted, sub-angular to sub-rounded, sub-equant. *** Qz, Pl, Kfs (≤0.5 mm); ** Meta; * opaque minerals, Mca, semi-decomposed carbonates (micrite); sporadic Cpx, Ep, Srp and Volc. F.F.: common; predominant Qz, Fsp, semi-decomposed carbonates, opaque minerals, Mca.	Few vughs and vesicles
S2 SK-Jg3	Brownish, Ca-rich, very fine, moderately homogeneous, vitrified	C.F.: few, moderately sorted, sub-angular to sub-rounded, sub-equant to elongated. *** Qz, Pl, Kfs and Meta (≤0.4 mm); ** opaque minerals; * Mca, Am, Volc. F.F.: common; predominant Qz, Fsp, Mca, semi-decomposed carbonates; sporadic Am and opaque minerals.	Few vughs, vesicles and channels

).

Two petrographic groups were distinguished among the samples from Balalyk Tepe. A calcareous, finer fabric, B1, comprising plates BT-Pl1 and BT-Pl2 and jar BT-Jr1, exhibits a Ca-rich matrix and inclusions derived from igneous and metamorphic rocks, together with semi-decomposed carbonates (Figure 10a). In particular, in BT-Pl2, heterogeneities in the matrix and reaction rims around some voids may be due to neo-formed calcite. The medium-coarse, low-calcareous fabric B2 is represented by BT-Jg1, characterised by an Fe-rich groundmass mainly containing crystals derived from granitoids (Figure 10b).

The two samples from Dabil Kurgan correspond to different medium-coarse fabrics. Fabric D1, represented by jar DK-Jr1, has a Ca-rich matrix containing coarse calcareous inclusions and crystals of quartz, feldspars and phyllosilicates derived from plutonic rocks, together with a few fragments of fine-grained metamorphic rocks (Figure 10c). Fabric D2, comprising the low-calcareous jug DK-Jg1, exhibits finer inclusions consisting of fragments of granitoids and derived crystals, especially quartz and altered K-feldspar (Figure 10d).

The samples from Khosijat Tepe can be divided into two petrographic groups, K1 and K2, mainly distinguished by the features of the matrix, the frequency of the non-plastic inclusions and the absence/presence of fragments or crystals derived from volcanic rocks. K1, represented by wares KT-Bs1, KT-Jr1 and KT-Jr5, is a rather coarse fabric with a relatively heterogeneous groundmass. The clots and streaks with varying amounts of inclusions (more evident in KT-Bs1) are probably the result of the mixing of Ca-rich and Fe-rich clays (Figure 10e). Slight differences in the inclusion type, frequency, distribution and grain size allow the identification of two sub-groups. Basin KT-Bs1 and jar KT-Jr5 form sub-group K1A, in which the coarse fraction is relatively scarce and mainly consists of fragments of claystone. In contrast, the inclusions in the fine fraction are common to abundant, especially in KT-Bs1, which contains more mica flakes. Relatively abundant secondary minerals, deposited during use or burial, are visible in the voids. Jar KT-Jr1, representing sub-group K1B, exhibits a finer, less porous and more heterogeneous matrix, with streaks of different colours following the orientation of the wall, indicative of a handmade shaping. The inclusions are fewer than in sub-group K1A; among them, small crystals of quartz and feldspars prevail, together with common fragments of fine-grained metamorphic rocks. Sporadic coarser inclusions of sedimentary origin (claystone and siltstone) are also visible.

Most of the fine wares from Khosijat Tepe are associated with group K2 (Figure 10f), although several sub-groups have been recognised based on the calcareous nature of the groundmass, the frequency of the lithologies represented (both in the fine and coarse fractions) and the grain size of the inclusions. The latter consist mainly of crystals derived from igneous rocks, as well as calcareous and metamorphic clasts. Mica laths, amphibole, opaque minerals, some fragments of basalt rock and clinopyroxene crystals were also identified. Sub-group K2A, comprising tableware KT-Bw2, can be distinguished by the presence, in the coarse fraction, of large, rounded sandstones and spots that are lighter than the matrix, probably resulting from the decomposition of carbonates. The fine fabrics of the remaining vessels are broadly similar and can be clustered in one large sub-group, K2B. They exhibit slight differences in the features of their groundmass and porosity. The matrix is Fe-richer in KT-Bw1, KT-Pl5, KT-Pt2, KT-Jg1 and KT-Jg2, while it appears less homogeneous in KT-Cp2, KT-Pl2, KT-Pl5 and KT-Bs3, where the mixing of an Fe-rich clay with a calcareous material is evident. The latter could correspond to a sediment of maritime origin, and thus the small carbonate nodules observed in these samples may derive from the decomposition of calcareous microfossils. Coarser aggregates of micritic calcite (maybe allochthonous calcite precipitated into the pores) are detectable in KT-Bs3. Non-plastic inclusions derived from the same lithologies are less abundant in samples KT-Cp1, KT-Pl5 and KT-Bs3 and have a coarser grain size in sample KT-Jg2. Carbonates are more abundant in samples KT-Pt3, KT-Bs2 and KT-Jg2, micas in KT-Jg1—probably due to the firing temperature—and opaque minerals in KT-Pl3 and KT-Pl4.

Rhomboidal/lenticular aggregates are detected in KT-Cp2, KT-Bs3, KT-Bs4 and KT-Jr2. They partially fill the voids and are more abundant in KT-Cp2 and KT-Bs3, appearing oriented parallel to the vessel margins. These could be secondary gypsum, considering that evaporite minerals are common components of the soil in this area and gypsum is observed in archaeological ceramics from Kampyr Tepe [23]. Anyway, the nature of these aggregates should be ascertained by SEM-EDS analysis, since the presence of gypsum in the mineralogical composition obtained by XRD is not clear.

Voids are also filled by micrite originating from the decomposition and recrystallisation of carbonate clasts.

Jar KT-Jr4, forming the sub-group K2C, can be distinguished by its finer, calcareous, vitrified matrix and the higher frequency of opaque minerals and carbonates (Figure 10f). The presence of aggregates of crystals with an acicular shape, probably of secondary origin (halite?), has also been noticed.

The specimens from Shurob Kurgan, all belonging to the calcareous chemical cluster except SK-Jg3, can be included in the same petrographic group, S1 (Figure 10g). Yet, slight differences in the groundmass and the inclusions’ frequency, size and shape allow three sub-groups to be distinguished. Sub-group S1A, represented by jug SK-Jg2 and jar SK-Jr1, has a medium-coarse fabric (coarser in SK-Jr1). The coarse fraction includes predominant fragments of plutonic and metamorphic rocks and derived crystals (quartz, plagioclase, K-feldspar and phyllosilicates), together with quite abundant semi-decomposed carbonates, sporadic sandstone and volcanic clasts. Sub-group S1B, comprising cup SK-Cp1, plate SK-Pl1 and jug SK-Jg1, is a fine fabric with a more vitrified groundmass (especially in SK-Cp1 and SK-Pl1) and a coarse fraction consisting of more abundant and finer inclusions of the same lithologies, although with lower semi-decomposed carbonates and a higher percentage of mica. Sub-group S1C, represented by cup SK-Cp2, is a fine fabric with a more heterogeneous groundmass containing fewer inclusions.

Base SK-Jg3 is the only specimen in group S2 (Figure 10h). It is characterised by a fine fabric with a very fine, vitrified, calcareous matrix; the coarse inclusions are fewer than in the previous group; and it predominantly comprises quartz and feldspar (mainly potassic), common opaque minerals and some micas and amphiboles, together with sporadic volcanic clasts.

5. Discussion

Most Early Medieval vessels investigated have been categorised based on morphological and stylistic criteria, and considering the analogies (in shape, size, ornamental elements and slipping) with vessels from coeval or earlier sites in south Uzbekistan. They generally exhibit significant differences in body design, rim and decoration related to their specific function, period of production and use. The specimens have also been contextualised in specific chronological frames, although the relative chronologies proposed for the different ceramic types are not precise, and a systematic study including more ceramic assemblages is required to better determine the dating in each case. Nevertheless, the investigation allowed us to trace the evolution of some shapes and decorations, and to associate them with the sedentary and semi-nomadic pre-Islamic cultures present in the region. Vessels such as KT-Cp1, KT-Bw1, KT-Bw2, KT-Pl1, BT-Pl2 and KT-Pt2 represent prototypes clearly deriving from the Kushan and even Greco-Bactrian traditions (see bibliographic references in Table 1) and can be linked to the sedentary populations living in the region. Other vessels, such as KT-Pl5, KT-Pt1, KT-Bs3, KT-Bs4, BT-Jr1 and DK-Jr1, represent prototypes that seem to make their appearance in several settlements in Tokharistan from the 6th century onward (see bibliographic references in Table 1), and could be related to the diffusion/integration of new habits introduced by the (semi-)nomadic populations that occupied that area. The profiles of the pieces dating to the Early Medieval period are less elaborate than in earlier epochs; decoration, when present, is quite simple and consists of engraved and/or embossed motifs (mainly fingerprints, pinches and simple, parallel lines) on the rims and shoulders of jugs, jars and basins. Some wares are covered with a slip (red, orange or brown), generally limited to the rim.

The archaeometric characterisation has certain limitations since we do not know the location and characteristics of the pottery workshops north of the Amu Darya dated in this period, and we do not have archaeometric references for their ceramic products. For this reason, provenance can only be determined at the level of production areas, by considering the compositional similarities between the vessels investigated and ceramic assemblages from production sites dating to earlier and later periods that, according to archaeometric research, were certainly manufactured in the region (i.e., Hellenistic ceramics from Kampyr Tepe, and Kushan, post-Kushan and Islamic ceramics from Termez) [21,23,35,36]. The chemical analysis by WD-XRF provides information on the vessels’ compositional (dis)similarities, which is necessary to determine the distribution patterns of ceramic production. The statistical treatment of the chemical data shows that 26 of the 29 vessels analysed by XRF constitute a fairly homogeneous group characterised by calcareous pastes. This means that calcareous materials were generally more available and probably preferred to produce tableware and common wares. Moreover, the similarities/dissimilarities in the chemical composition indicate that most vessels were manufactured using similar raw materials, albeit from different sources, as confirmed by thin-section optical microscopy. Exceptions are two jugs (BT-Jg1 and DK-Jg1) characterised by Ca-poor pastes, and the Ca-rich, handled goblet KT-Gb1. The employment of Fe-rich/Ca-poor clays is quite rare in tableware and common wares but has been attested to in cooking wares and storage jars at ancient Termez and other Bactrian sites from the Kushan [10] to the Islamic period [35].

The petrographic analysis also allows us to conclude that the raw materials are consistent with the geological environment of the southwestern part of the Surkhan depression, an intramontane basin filled with sedimentary deposits (sheets J-42-19 and J-42-20 of the Soviet geological maps, 1:200,000). In fact, the inclusions of sedimentary origin detected in the thin sections could be derived from claystone, sandstone, siltstone and limestone from the upper Quaternary and Cenozoic levels that outcrop near the four sites, or from terrestrial and marine clays, siltstone, sandstone and dolomite making up the Mesozoic sequences that emerge at the foothills of the Kugitang-Tau mountains. Conversely, the inclusions of igneous and metamorphic origin can be related to the underlying Palaeozoic Hercynian basement. This only outcrops along the orogenic margins [37], but the lithologies from which it is formed are present in the material deposited by the rivers, and an alluvial fan (in the lower Sherabad valley) is not far from the settlements.

Combining the results provided by XRF and OM, a local/regional origin may be supposed for the vessels analysed. The only exception could be the handled goblet KT-Gb1, in which the values of most trace elements differ significantly from those of all the other samples. As a thin section of this item is not available, it is not possible to establish whether the petrographic composition matches the region’s geology. In addition, the lithologies detected in the vessels investigated match those found in earlier and later regional products from nearby sites such as Kampyr Tepe and Termez [21,23,35,36].

The remarkable similarity in the chemical and petrographic composition of almost all the specimens from Khosijat Tepe and Balalyk Tepe (especially BT-Pl1) suggests that they were crafted in the same production area. Considering that Balalyk Tepe was a castle, it is reasonable to presume that the pottery recovered there was manufactured at nearby sites (maybe Khosijat Tepe).

With respect to jars KT-Jr4 from Khosijat Tepe and DK-Jr1 from Dabil Kurgan, the nature of the inclusions is the same as for the other samples, but the different percentages of some major elements point to a slightly different choice in the raw materials.

The petrographic composition of the low-calcareous loners BT-Jg1 from Balalyk Tepe and DK-Jg1 from Dabil Kurgan is compatible with the geology of the region; nevertheless, the values of most elements depart from those of the other specimens, hinting that the two jugs may have been crafted in different production centres.

The vessels from Shurob Kurgan have fabrics analogous to those of the majority of the vessels from Khosijat Tepe, indicating the use of similar recipes; nevertheless, the presence of sporadic minerals such as epidote and serpentinite, together with the slight differences in the values of MgO and some trace elements, point to a different origin of the raw materials.

The fabric of SK-Jg3 is characterised by a calcareous matrix containing very few inclusions (although of the same nature as the other samples from Shurob Kurgan); therefore, the dissimilarities detected in the chemical composition could just be related to the sediment employed rather than a different provenance.

As concerns the processing of the raw materials, thin-section analysis indicates that coarse, poorly worked pastes, obtained by mixing different kinds of clayey sediments, were used in the three handmade wares from Khosijat Tepe; the rest of the vessels were made of generally well-refined pastes.

Considering the modelling process, basin KT-Bs1 was probably shaped by moulding, while jars KT-Jr1 and KT-Jr5 were shaped by pinching. Their thick, often irregular walls and the rough finishing (especially of the inner surface where prints left from the forming process are visible) are evidence of the impoverishment of the manufacturing quality in these categories of objects during the 7th c. AD. All the tableware and the rest of the common wares show evidence of wheel throwing.

Slips are generally applied just to the rim or the upper part of plates, bowls and some platters, jars and jugs. A deterioration in their quality, compared to the red coatings characteristic of the Kushan and Kushano-Sasanian periods, as proposed by Solov’ev [2], seems to be confirmed by the fact that, in many cases, only a few traces of them remain; anyway, a further investigation by SEM-EDS analysis is required to determine their composition.

Information about the firing regime can be deduced from the mineral phases detected by powder XRD. The vessels analysed were fired at temperatures ranging from 800 to 1100 °C, with a predominance of medium or high temperatures, generally under a single oxidising atmosphere. This preference might be related to the mechanical properties acquired by the ceramic material during firing, given that high temperatures increase the vitrification of the matrix and, consequently, the strength of the vessel, i.e., the ability to withstand stress without cracking [38]. There is no apparent relationship between the firing temperature and the shape of the artefact or the characteristics of the paste. This could be consistent with the fact that even in the same firing process, the temperature is not homogeneous within the firing chamber.

The comparative analysis of the vessels’ formal, compositional and technological features at the regional level and over a broad chronology provides interesting results. First, it highlights the occurrence of some changes in Early Medieval repertoires. These changes are not only aesthetic (shape of rims and handles, decorative elements, slipping) but also technological (appearance of handmade vessels among tableware and common wares), and could be related to domestic, social and political transformations. Moreover, the morphological and stylistic diversity detected in pottery from different sites reflects the demise of the standardisation achieved under the Kushans and maintained by the Kushano-Sasanian rulers [10]. This points to the diffusion of new practices, presumably introduced by the nomadic and semi-nomadic populations which occupied the Surkhan Darya basin in pre-Islamic times. Second, this study attests to a certain continuity in the production of specific shapes originating in the Kushan and Kushano-Sasanian or even earlier traditions and the use of specific manufacturing techniques. Evidence is given by the strong analogies between tableware and common wares from the four considered sites and other nearby settlements, when comparing the chemical and petrographic compositions. For example, the composition of the vessels from Shurob Kurgan is similar to that of the Greco-Bactrian tableware from Kampyr Tepe [23]. The two sites lie geographically very close to each other, and the clayey sediments could have likely been procured from the same sources over many centuries. In addition, very similar fabrics and chemical compositions can be observed in jug SK-Jg3 from Shurob Kurgan and jug (or jar) TS16 from Termez dating to the Islamic period [36], as well as in jar KT-Jr1 (and maybe KT-Jr5) from Khosijat Tepe and another jug of the Islamic period, TS17, from Termez [35]. The presence of shapes with strong morphological analogies and the use of very similar recipes in ceramic productions from different periods support the hypothesis that previous pottery traditions were maintained for specific categories of objects and continued in the Islamic age.

This study represents just an initial step in improving our knowledge of Early Medieval pottery production and leaves many questions open. To achieve a better understanding of the evolution of the manufacturing technology and the extent of the commercial and cultural interactions between the social/ethnic groups living in Tokharistan during the period considered, a more precise dating and a broader archaeological/archaeometric study of ceramic materials are needed.

6. Conclusions

The contextualisation and categorisation of 38 tableware and common wares from Khosijat Tepe, Shurob Kurgan, Balalyk Tepe and Dabil Kurgan, together with their morphological analysis, allow us to sketch out the evolution of some shapes and decorations deriving from earlier cultural traditions (Greco-Bactrian and Kushan), and to detect the presence of new shapes and decoration—generally less elaborate than in the previous epochs—especially from the 6th century onward. From a technological point of view, these changes are accompanied, in some cases, by a deterioration in the manufacturing quality (a poorer paste working, a rougher forming and finishing). These elements hint at the introduction of new practices in a deep-rooted crafting tradition, which can be associated with the various socio-cultural entities (semi-nomadic and sedentary) coexisting in the region between the late 4th and the late 7th centuries.

Useful information about the manufacturing processes/choices, possible production areas and distribution dynamics of the ceramic productions can be inferred from the archaeometric characterisation. We observe the following:

• The examined vessels are mostly made of calcareous pastes, which suggests that tableware and common wares were preferentially crafted with calcareous materials.
• With few exceptions, raw materials are very similar, although from different sources.
• Vessels from Khosijat Tepe, Balalyk Tepe and maybe Dabil Kurgan—excluding the handled goblet KT-Gb1 and the low-calcareous jugs BT-Jg1 and DK-Jg1—could have the same provenance; vessels from Shurob Kurgan could be ascribed to a different production centre, as could jug BT-Jg1 and jug DK-Jg1; and the handled goblet KT-Gb1 could be imported.

Regrettably, due to the lack of archaeometric studies about workshops dating to the considered period and geological sampling in the area, it is not possible to attribute the petro-chemical groups defined above to specific crafting centres or identify the sources of the raw materials.