Grid reference: 513300/3878100
Cadastral plan: XXIX/54
Aerial photo: 1993, Run 177, No. 46
SIA: SIA 1 (Agrokipia Kriadhis)
SCY022-1a. Layers of dumping from ore beneficiation
This POSI is located on one of the arteficial terraces in the eastern part of the open cast mine. Here, ancient piles of mining and roasting debris were dissected by bulldozers, and are now visible as vertical sections along 35 m of the northsouth face of the open cast mine. Three sections (Sub-Units SCY022-1a, 1b and 1c) were cleaned back to expose the stratigraphy, and to allow proper recording and sample collection.
Section SCY022-1a contained 43 distinct, stratified layers of material. Although the top layer consists of modern mining debris, which in fact derives from the terrace lying directly above, we are confident that the other layers have maintained their original stratigraphy. We base this statement on the presence of a natural outcrop of pillow lava to the north of the layers, which was unaffected by modern mining and seems to have acted as a protective barrier for the stratified deposits. The bulldozers apparently cut through two ancient spoil heaps that partly overlap. The lower layers cover the full extent of the section. Because of the partial collapse of the section and the overgrowth, we were unable to reach the base of the deposit and therefore do not know its full extent. The spoil heaps consist of a sequence of layers comprised mainly of crushed gossan, which sometimes alternates with layers of crushed calcareous material (limestone, chalky marl) and layers of roasted ore and gossan intermixed with ash and charcoal.
Significant quantities of furnace or roasting conglomerate were found in three layers. Smelting (tap) slag was observed in several layers, but appeared to consist of scattered pieces rather than any consolidated deposit. Layer 38, at least, appears to represent an abandonment, since it consisted of hard-packed, eroded material devoid of ore, flux or any other metallurgical remains.
Approximately 25 m to the south of the two heaps and along the same north-south face of the open cast was another area with 19 stratified layers (SCY022-1b); this too was cleaned and recorded. Like the top layer in SCY022-1a, the same layer in SCY022-1b was made up of material disturbed or redeposited during modern mining activities; however, an outcrop of pillow lava bordering the area to the south served to assure integrity of the stratigraphy. Pieces of furnace or roasting conglomerate.
Over the two years that elapsed since the first SCSP fieldwork in the mine (1995), erosion had exposed in the area between the two sections pieces of furnace conglomerate similar to the ones found in SCY022-1a. We therefore decided to investigate this area (1997), and a section measuring approximately 4 x 2 m was cleaned back and drawn. Judging from the inclination of the layers, this seems to be another heap of mining waste and roasting debris. Since the lower, relatively horizontal Layers 37-43 consist of gossan, bedrock outcrops and the actual bedrock, we may assume that they represent the original surface on which the heap was formed. The presence of charcoal in Layer 39 may be the earliest indicator of some activity on this surface. As in the case of SCY022-1a, there are a number of layers (or lenses) which consist almost entirely of furnace conglomerate, others which consist of crushed gossan frequently mixed with charcoal, and others which contain ash.
The location of SCY022, the nature of the stratified material and the form of the deposits all indicate that we are dealing with a spoil heap consisting of waste that derives from mining, mineral dressing and roasting. Mineral dressing is the essential preparative step to the smelting process, in which the metalliferous minerals are concentrated by removal of most gangue material.
SCSP's work at Agrokipia Kriadhis represents the first systematic investigation of an ore roasting deposit. As stated above, the nature of the Kriadhis deposits indicates that these remains derive from ore beneficiation which, apart from crushing and sorting, included roasting. The material preserved on the piles are those parts of the ore poor in copper, which were therefore dumped with the rest of the gangue. The analysis of this material enables us to draw some important conclusions regarding this rather elusive aspect of the complex processes involved in ancient copper production.
Only three sherds were collected in the vicinity of these sections. One is an imported Greek Black Glaze kylix or skyphos handle, dated to either the 6th or the 5th century BC (see above). Although the dating of this sherd corresponds well with the pottery collected in other nearby POSIs and archaeometallurgical units, we have to bear in mind the extent of disturbance to this area before considering the relevance of this find to the actual mining activities. The same considerations hold true for the other two sherds from SCY022, one of which dates to the Late Roman period and the other to the Medieval-Modern periods. A notable amount of Archaic-Classical pottery was also collected from the surface of the terraces of the modern mine east of SCY022, with a high proportion of decorated, table and imported wares. This pattern suggests some connection with Úlite activities rather than mining and ore processing. The question thus arises whether these finds actually date the mining activities.
To resolve such issues, charcoal samples were collected from all the SCY022 sub-units and four of them were submitted for radiocarbon dating. The calibrated dates indicate that the spoil heaps date to the late Geometric, not to the Archaic-Classical period. We know very little about mining and metallurgical activities during Geometric times, and here we have good evidence that the mines were active and copper was produced, if not exported, at this time. The fact that there is so much Archaic and Classical material (especially of the 6th and 5th centuries BC) in and around the modern mine may indicate a continuation if not an intensification in extracting copper from this ore deposit.