Introduction

This paper deals with the chlorite stones obtained from the latest archeological researches at the Konar Sandal site, Jiroft in order to determining the chemical and mineralogical composition and identifying their provenance. The chlorite objects are the most distinctive cultural material from the Jiroft civilization (generally dated back to the third millennium BC). These luxury items have been recognized as an indicator of the connections and interactions in southwest Asia during Bronze Age. Scholars of the ancient Near East have long recognized that the Iranian plateau was a source for these valuable materials. Although the soft green chlorite objects have been found in a wide range from the Indian subcontinent to northern Mesopotamia, these finds were produced in the Halil River Basin for local utilization rather than export. In this paper, some fragments of chlorite vessels recovered from the plundered graveyard of Konar Sandal South are chosen for archaeometric analyses. Also, some samples from newly found mines of the Faryab region (south of the Jiroft plain) have been analyzed for the provenance of the ancient objects of Konar Sandal.



Methods and Results

Petrological and petrographical methods, X-ray diffraction (XRD) and X-ray fluorescence (XRF) and inductively coupled plasma optical emission spectroscopy (ICP-OES) were used to identify the mineralogical and geochemical structure of chlorites and the possible relationship of these materials with the chlorite mines in the Faryab region. Clustering of the results will be interpreted through statistical methods. Polarizd light microscope has been used inorder to characterize the fabrication and texture of the stones in both plane polarized and cross polarized light. For determining the crystalline phase constituents powder patterns of rocks were measured. The characterization of the crystalline phases of the rocks (QXRD), allows the classification of the samples by the different structures. X-ray flouresence has used for the determination of the bulk chemical composition of the rocks. The major, minor and trace elements measured as oxides, and the correlation between the main oxide constituents tend to allow a good classification of the archaeological samples to the stones from the mines. An ICP-MS (inductively coupled plasma mass spectrometry) systems has used to undertake an analytical technique that can be used to measure elements at trace levels in some archaeological and stones from the mines.



Results and Discussion

Iconography, production, provenance, exchange and circulation of chlorite vessels have been topic of many researches in the recent decades. Philip Kohl has deeply studied these studies. Philip Kohl has conducted various studies based on physical and chemical analyses on carved and uncarved samples of chlorite from Tepe Yahya and from outcrops or source samples collected in the mountains immediately north and west of the site and from these vessels found on sites stretching from Mesopotamia into south-western Iran (Susa) and across the Iranian plateau. His studies demonstrated that most of the vessels carved in this distinctive style were indeed made of chlorite and not the related soft stone steatite to which they had been mistakenly attributed. Another archaeometric analysis on the resource of chlorite in the Jiroft region was done by Emami and his colleagues (2017) which resulted in identifying some ancient mines in the western mountains of the Jiroft region which were used by the craftsmen of Konar Sandal. The present research on the chlorite mines of the south of Jiroft region, particularly the Faryab region, introduced new mines which could be used by the craftsmen of the Jiroft civilization in the early Bronze Age. Interestingly, similarities in the mineralogical and geochemical composition of chlorites obtained from Konar Sandal South graveyard and Faryab mines introduce the Faryab mineralogical zone in the south of Kerman as one of the provenances this stone. It seems that further geo-archaeological investigations can identify more ancient mines and mineralogical zones of chlorite in the Kerman Province.



Conclusion

Investigated chlorite objects and stones were examined in order to find any relationship between Konar Sandal and rock samples from Sikhoran mine and Nazari mine in central Faryab orogeny (Mehrouiyeh). On the basis of chemical analysis and measurement of trace elements by XRF and ICP methods, as well as petrology and phase studies, it was determined that Faryab mine played a key role for fabrication of these chlorite stones in the third millennium. Analytical results have approved that the amount of major oxides e.g. MgO and FeO, as well as minor elements e.g. Ca, P, Ti, Sr, were to be an essential factor for clustering of the materials and their origin.

The distinctive features of the quarried stone from Faryab district assumed in good potential correlation with the analyzed samples from south Konar Sandel Cemetery (especially in the M4 and M3 samples). The result is reliable with the results of XRD analysis and thin section petrography of the samples. XRD phase analysis of the rocks from the mines were assumed that the rocks mostly consist of clinochlore, tephrite, spinel and olivine, which have obviously approved the same phase composition within the samples of south Konar Sandal cemetery. Based on petrography, mineralogical and textural observations, the rocks of the region are mainly composed of magnesium-containing olivines, serpentine peridotites and sometimes opaque particles with spinel chemical composition, e.g., magnetite and chromspinel.

The extension of producing and trade of chlorite from southeast to the Punjab valley of Pakistan can be expressed by means of excessive diversity regarding the condition of metamorphism (hydrothermal and proximity) of the chlorite rocks in the southeast of Iranian plateau. In this case, the rock feeding source for the production of chlorite stone artefacts and containers in Halil Rood area is much more diverse than what we know. However, since the Faryab mines are located in an area as cross-cultural bridge between the Persian Gulf to Mesopotamia, the importance of influential economic factors, trade and exchange of chlorite is among the most important case studies in the third millennium BC Iran.