Sickles from the Sosnovaya Maza hoard of the Late Bronze Age from the Lower Volga region: Technological analyses, experiments and chronology

Highlights

• The time of the Sosnovaya Maza hoard falls on the period that follows the period of the ‘metallurgical boom’ in the northern Eurasia steppes linked to the activities of the miners/metal workers of the Srubnaya and Alakul cultures of the Late Bronze Age.

• The ¹⁴C date for pit-house at Alekseyevka where the Sosnovaya Maza type of sickle has been found remains the only chronological benchmark for this type of artifacts based on which the time interval of the Sosnovaya Maza hoard can be narrowed down to 1400–1300 cal BC.

• It is possible that the metal used to produce the Sosnovaya Maza type of sickles was linked to copper pyrite deposits in the southern Urals (the Trans-Urals and the northern periphery of the Urals-Mugodzhary region); Late Permian oxidized ores of the Urals from the Kargaly (Sakmar-Samara region) mining and metallurgical region; and deposits characterized by very radiogenic ²⁰⁸Pb/²⁰⁴Pb, localization of which might be northern Kazakhstan.

Abstract

The Sosnovaya Maza hoard was discovered by chance in the Saratov region in the Lower Volga in 1901 without any archaeological context. Based on the sickle form and the metal composition–copper with an elevated level of iron–so called Sosnovaya Maza type of sickles was singled out. The comparative analysis of the production technology and the alloying and lead isotope composition of the Sosnovaya Maza type of sickles found in the Volga region, in the Urals and the northern Kazakhstan sites helped obtained more data on the metalworking of this period which became a wide spread activity and required search of new deposits and new sources of surplus.

The tracewear study assessed that all sickles were cast in a univalve mold with a flat lid. The ICP-MS analysis determined a rather high heterogeneity of the hoard item elemental composition as well as significant variability in the level of trace elements in the metal. Research experiments through smelting of chalcopyrite raw material and native copper from the Osenneye copper pyrite deposit in Ural melt was conducted, the copper obtained in general correspond to the copper composition of the Sosnovaya Maza tools.

Significant variability of the isotope ratios of lead isotopes of Sosnovaya Maza hoard items confirms our hypothesis that raw material came from several ore sources: copper pyrite deposits in the southern Urals (the Trans-Urals and the northern periphery of the Urals-Mugodzhary region); Late Permian oxidized ores of the Urals from the Kargaly (Sakmar-Samara region) mining; and the metallurgical region and deposits characterized by the very radiogenic ²⁰⁸Pb/²⁰⁴Pb, localization of which at the moment does not seem possible. The analyses of the Alekseyevskoye items imply that it might be northern Kazakhstan.

The ¹⁴C date obtained is used as a chronological marker for the Sosnovaya Maza type sickles and the entire Sosnovaya Maza hoard. This enabled us to narrow down the time interval during which such sickles made from ferrite copper were used and date the hoard to 1400–1300 calBC. The study identified the role of new metalworking provinces located in the eastern part of the Eurasian world.

Introduction

The hoard near the village of Sosnovaya Maza in the Saratov region in the Lower Volga was found in 1901 (Fig. 1). Practically all items of this assemblage are kept in the State Historical Museum in Moscow; several items from the assemblage are now in the Saratov Local Lore Museum (a sickle, a celt and two daggers) and the Khvalynsk Local Lore Museum (a dagger, a sickle and a sickle fragment) (Malov 2019). The total weight of the hoard items is 22.5 kg. Regarding its weight, the hoard ranks second among other Bronze Age hordes of eastern Europe after the Boryslav hoard found in what is now western Ukraine which weighs 30.5 kg. The difference between these two hoards is that the Boryslav hoard mostly consists of fragments of ingots rather than finished goods while the Sosnovaya Maza hoard is largely composed of finished cast items and their fragments (Malov, 2019, Dobrovolsky, 1948). The study of the Sosnovaya Maza hoard will allow us to raise the questions about other late Bronze Age hoard assemblages and also in the future to compare hoarding practices in other regions of Europe and northern Eurasia. The results obtained provide answers to the question as to whether the Sosnovaya Maza hoard and similar hoards can be treated as caches of various materials collected for remelting. The results of the analyses will also help understand the technological tradition of the local Volga and Ural populations, use and re-use of metal in cal2000 BC, and also derive some conclusions about potential linkage of the hoard to metal flows in the eastern area of northern Eurasia in the second half of 2000 BCE.

The studied hoard consists of sickles, several daggers, celts, a chisel and a copper ingot (Fig. 2). The Sosnovaya Maza assemblage is of special historical and cultural value as it reflects the process of amassing metalworking products; metalworking technologies employed; and development of new ore deposits in the eastern part of the Eurasian world. Specific traits of typological and technological standards set for its items were used as a basis for singling out archaeological cultures of the Late Bronze Age in the steppe belt of northern Eurasia (Khvalynsk, Srubnaya and Ivanovka).

The Sosnovaya Maza hoard mostly contains sickles, 44 in total (Golmsten, 1933, Avanesova, 1991: 21; Dergachev and Bochkarev 2002). These sickles are wide tools with a curved back, a prominent backrib running along the back and an almost straight cutting edge of the blade which ends up in a round or pointed tip. In most cases, the sickle base is not emphasized. A peg hole is one of the major characteristics of such tools. The blade of some sickles becomes thinner abruptly towards the base forming a ledge that serves to mark the boundary of the base part that could be gripped and used as a handle (Fig. 3). The first studies of the composition of the metal the hoard items are made from were conducted by D.A. Sabaneyev (Spintsyn 1909: 65–66). These studies demonstrated that the sickles were cast from copper with an elevated level of iron (Chernykh 1966: 127-131; 1970: 17–20). The metal alloying composition does not contain arsenic or tin typical for Bronze Age metal. That is why, E.N. Chernykh referred the metal of the hoard items to the chemical metallurgical group of pure copper. He believed that the elevated level of iron was associated with copper pyrite deposits (Chernykh 1966: 128). Because of absence of data on the level of sulfur and some other elements in the Sosnovaya Maza metal, this assumption was not checked. Based on the spectral analysis, E.N. Chernykh singled out two groups of metal alloys of the Sosnovaya Maza items: (1) alloys with elevated levels of tin, silver and lead (less than0.002%) because of addition tin bronze scrap; (2) alloys without addition of alloying elements. The scholar thought that most hoard items had been cast from two large copper ingots of a rather heterogeneous metal composition; in his view, at least 21 sickles were made from one ingot (Chernykh 1970: 19-20).

Based on the sickle form and the metal composition, so called Sosnovaya Maza type of sickles was singled out (Dergachev and Bochkarev 2002: 47–59). Such sickles found at settlements and in hoards were predominantly distributed across the Volga region and the areas east of the Volga (Kolev 2008: 216). Relative dating of the sickles and the Sosnovaya Maza hoard itself was based on the chronologies of the cultures dating to the final stage of the Bronze Age across the steppe belt of northern Eurasia stretching from the Balkans-Carpathian region to Kazakhstan, the Minusinsk Depression in Siberia and the Tien Shan foothills (Krivtsova-Grakova, 1948, Avanesova, 1991; Dergachev and Bochkarev 2002; Degtyareva et al. 2019). The hoard itself was attributed to the Srubnaya (Timber-grave) culture (Krivtsova-Grakova 1948), the Ivanovka culture (Kolev 2008), the Khvalynsk culture of the cordoned ware culture (named so because a strip of clay was added around the outside of a pot) (Malov 2019), whereas sickles of a similar type were referred to the Alekseyevskoye-Sargary culture (Degtyareva et al. 2019). For this reason, based on general chronology of these cultures, and with practically no ¹⁴C data available for the final stage of the Bronze Age in the eastern areas of the steppe Eurasian belt, the date of the hoard was put within a rather wide interval ranging from 1500 BCE to 1200 calBC and even to a later period (Krivtsova-Grakova 1948) (Table 1).

The objective of this study was to do comparative analysis of the production technology and the alloying composition of the Sosnovaya Maza sickles found in the Volga region and sickles of the Sosnovaya Maza type discovered in the Urals and the northern Kazakhstan sites (Fig. 1); perform radiocarbon dating of the samples retrieved from a closed assemblage (a pit-house at the Alekseyevskoye settlement in Kazakhstan with a Sosnovaya Maza type sickle) and discuss a narrower dating interval of the Sosnovaya Maza hoard. Another important task of the study was to check the hypothesis advanced by E.N. Chernykh regarding the source material of the metal the hoard items are made from which, in his view, are copper pyrite ores from the Urals deposits (Chernykh 1970: 19).

The study included metalworking experiments to examine characteristics of raw material used; methods of ore concentration, technics and copper reduction in heating plants, specific features of casting, hot forging and benchwork of the tools made from copper-based alloys. The experiments conducted helped to check the hypothesis advanced by E.N. Chernykh mentioned earlier.

The study enabled the team to assess similarity and difference in the metal from the Sosnovaya Maza items and the metal from the Urals and northern Kazakhstan items (reference dataset); identify the role of new metalworking provinces located in the eastern part of the Eurasian world; attempt to describe the level of technological attainment of the Bronze Age metalworkers.