In September 2007 the Prehistory Laboratory of Siena University – Grosseto annex undertook the fourth excavation campaign in the Grotto di Spaccasasso (Alberese, GR), situated in the interior of the Maremma Regional Park. The investigation continued inside the Copper Age funerary chamber that had been excavated in past years. A new area was opened on the south-western edge of the plateau. At what was probably the bottom of the sequence of funerary deposits, along the rock face up against which the funerary chamber had been created, a stony level was observed which appeared to have been deliberately arranged. This may be the base level of the chamber itself. In the remaining sectors of the chamber the presence of bones and pottery fragments continued, though to a lesser degree than in the overlying layers. Among the materials recovered during this campaign only a few quartzite flakes are of note. This raw material was used for making picks and mallets used for the quarrying of cinnabar from the limestone ledge onto which the grotto opened. The evidence brought to light by the opening of the south-western area began with a disturbed layer of soil covering a level of quarry detritus constituted by medium to small clasts with sharp edges. This was concordant with what emerged immediately south of the collapse of boulders delimiting the funerary chamber. The archaeological material from this area was extremely scarce and limited to a few quartzite flakes within the quarrying detritus. During this years campaign a series of surveys were also carried out on the plateau above the Spaccasasso relief. A limestone ridge running in a north-east/south-west direction, apparently semi-submerged by an earth deposit, was identified. In the area in front of the ridge several quartzite implements were recovered, similar to those used for quarrying, found along the fan of detritus formed on the south flank of the relief, although they were smaller than the latter. A preliminary analysis of these finds identified a number of concentrations of artefacts which had not therefore been casually dispersed across the area. Thus, it may be suggested that the quarrying of cinnabar may also have occurred in other points on the Spaccasasso relief. Following these observations and as a preliminary to further stratigraphic investigations, a series of interventions to recover surface finds, as well as a topographical survey of the limestone ridge and the entire Spaccasasso hill, are planned.

Between August and September 2008 excavations continued on the Copper Age funerary chamber which had been investigated in previous campaigns. Together with still abundant pottery fragments numerous fragments of human skeletal remains were found. The repertory of pottery forms remained homogeneous, conforming to the picture that has emerged to date, and can be dated to a full phase, probably late, of the Eneolithic period. The pottery showed all the characteristics of vase productions in funerary contexts known from the natural cavities in southern Tuscany and grouped together under the generic definition “Grossetan group”. Laterza elements were present, probably Gaudo and Conelle, all elements already seen in the analysis of the pottery finds recovered from the disturbed deposit by the Società Naturalistica Speleologica Maremmana. However, mixed with these were elements more specifically attributable to the early and middle Bronze Age, absent in the pottery assemblage from the funerary chamber. According to recently acquired data it is the presence of Laterza elements which seems to give the materials from Spaccasasso a particular connotation, distinguishing it from strictly Grossetan archaeological realities and inserting it into the wider context of the central-southern Tyrrhenian. The cultural associations of the Spaccanasso ceramic assemblage are similar to recently published funerary and dwelling contexts for which a series of radiometric dates are known. In particular the necropolis and settlement of Osteria del Curato – via Cinquefrondi, Rome, if two dates that fall within the 4th millennium B.C. in calibrated chronology are excluded, falls completely within the 3rd millennium B.C., in particular within the first centuries. On the other hand the two dates known for Spaccasasso fall within both these centuries. These were obtained from bones recovered out of context during the first interventions by the Società Naturalistica Speleologica Maremmana (Cavanna e Pellegrini 2007). The strong concentration of archaeological material and the complex depositional model linked to the ritual of secondary burial necessitated an accurate taphonomic study. This was carried out by making a zenithal photographic survey of each stratigraphic unit divided into 50 x 50 cm squares. Each square considered was delimited by numbered markers geo-referenced and leveled. On each photograph, printed in colour at a scale of 1:2, the individual finds were highlighted and given a progressive number, inserted into a table with its three spatial coordinates (x, y, z). This year a 3D scan was made of one of the layers in the funerary chamber. The 3D scanner employed for the acquisition of data used “time of flight” (TOF) technology consenting the measurement of objects at a distance of over 100 m (optimal range 2-100 m, maximum range over 150 m) with millimetric precision. Thanks to the motorised movement it was possible to make scans with an angle of vision of 360° x 36° in a single session, acquiring over 3000 points per second. The same procedure was applied to the entire plateau onto which the funerary chamber opened, the aim being to provide a virtual reconstruction of the archaeological complex. One of the objectives behind this operation was the desire to provide an efficient tool for the future exploitation of the site within a museum project.

In the period between the 24th August and 11th September 2009 an anthropogenic deposit in primary deposition was excavated and recorded according to the methodology put into place during previous campaigns. The archaeological deposit of the Buca di Spaccasasso, dating to the full Copper Age, has been interpreted as a funerary chamber for burials in secondary deposition. The limestone ledge up against which the chamber was created, was used for the extraction of cinnabar, present in veins in the rock, in both prehistory and historical periods. At this moment in the investigations it can be stated with a fair degree of certainty that quarrying of this ledge began prior to the creation of the funerary chamber. Several thin layers of earth were removed which included small to medium stones often with flat surfaces, apparently arranged to form a surface on which archaeological material rested. below were further layers of archaeological material and stones which appeared to be a continuation of the layers above. Among the human remains the prevalence of crania was confirmed (one unit produced an almost entire but fragmentary skull). The decrease in the number of pottery forms was confirmed, these were however preserved in large fragments. Finally, some of the stratigraphic units were characterised by the presence of quartzite and green stone flakes. These were particularly frequent in the layers outside the perimeter of the funerary chamber (US 57) and at its base (US 41). Among the flaked stone finds were a number of arrowheads including some limestone examples. Of note is the find of two plaques made of Sus tusks. Whilst the excavation of the funerary chamber was underway a survey was made of the areas above the Buca di Spaccasasso as the start of investigations into the evidence for cinnabar quarrying. The survey was carried out over a sample area of 53 x 20 m. The morphology was documented by a survey at a scale of 1:100 on which the single finds were positioned. The finds were referable exclusively to flaked stone picks and mallets used for quarrying.

Between 23rd August and the 11th September 2010 the Prehistory Department of Siena University undertook the sixth excavation campaign at Buca di Spaccasasso (Alberese, GR), in the Maremma Regional Park. Work continued on the removal of the fill from the Copper Age funerary chamber. Excavation began of the breccia formed from the fine detritus resulting from limestone quarrying for the extraction of cinnabar from the wall in which the chamber had been created. The white breccia must have constituted the boundary of the funerary area. The situation inside the funerary chamber, towards the west, seemed to relate its earliest phase. The breccia found below US 58 outside of the chamber seemed to enter into the latter and underlie the stones delimiting its southern side (US 70). To the east the situation was more complex. The very narrow area lay between the rock wall and a large boulder situated exactly in the centre of the chamber. Here, human bones were recovered that were less fragmentary with respect to the rest of the chamber; in particular intact arm bones were found in association with a small globular cup, also intact, all preserved in a structure protected by stones along the sides and covering it (US 69-64. The find is distinct from what has been brought to light in the funerary chamber to date, and it will be evaluated whether this evidence relates to the chamber’s “consecration” or may represent an earlier funerary phase. The phase in which the chamber was created was documented by a 3D laser scan carried out by Dr. Paolo Machetti of Studiosette, Florence. Whilst the funerary chamber was excavated the survey on the area above (begun in the previous year) continued and a number of artefacts relating to the quarrying of cinnabar were recovered. The survey was undertaken according to the method established in 2009. Therefore, the morphology of a second sample area of 52 x 20 m was documented at a scale of 1:100 on which the single find spots were positioned. The finds comprised flaked stone picks and mallets used for quarrying activities.

This campaign continued excavating the fill of a “funerary chamber”, dating to the full Copper Age. The funerary remains lay beneath a deposit constituted by rocky detritus resulting from the quarrying of cinnabar, present in veins in the bank of limestone rock along which the Eneolithic funerary chamber had been created. Between the construction of the chamber and the quarrying deposit there appeared to be a shallow sterile level, documenting an interruption in the site’s use. By the end of the excavation season, the chamber was completely emptied of its fill and this exposed a series of new horizontal layers, probably attesting the end of the cinnabar quarrying activities. The roof of the deposit contained little archaeological material with the exception of a number of quarrying tools and a few flakes and small blocks of quartzarenite and green stone. Survey and mapping of the zone above the excavation area continued. Here, the presence of quartzarenite and green stone mallets and picks, as well as blocks of raw materials, suggested that cinnabar was also quarried in correspondence with a small cavity obstructed by collapses from a limestone rock face. A total station was used to set up a polygonal grid, which precisely positioned the excavation area on the geodetic grid of the Tuscany region. The excavation, situated on the hill slope, was also topographically linked to the surface surveys and geophysical surveys undertaken in the zone above the excavation and on the summit of the Spaccasasso hill. A new geophysical survey was carried out during this campaign, in order to test the anomalies, identified last year by geophonic tests, caused by anthropological activity below the floor surface in correspondence with the finds of quarrying tools. Two magnetometer tests were undertaken along the two axes that resulted in the previous year’s tests. The results confirmed the existence of at least two vertical shafts and a spherical subterranean cavity close to the cavity identified in the limestone bank. All of the graphic and photographic documentation from the excavation is being reproduced in 3D using systems such as Bundler, PMVS, Photoscan, Meshlab, and ERDAS software (Leica). This process, tested for the first time on an excavation, means that is possible to produced 3D images without using a laser scanner on site.

Between the 20th August and 12th September, the prehistory department of the University of Siena undertook the eighth excavation campaign at the Buca di Spaccasasso (Alberese, GR), in the Parco Regionale della Maremma. Students from Trømso University (Norway) and Florence University also took part. During the excavation, a survey continued in the area above the Buca di Spaccasasso in correspondence with another possible site for the extraction of cinnabar. The excavation investigated the layout of the Copper Age funerary chamber whose fill was excavated in 2011. This led to the start of excavations on the underlying mine levels whose detritus had clearly been adapted in preparation for the installation of the funerary structure itself. The chamber was installed up against the limestone wall containing cinnabar veins and onto which the “Buca” di Spaccasasso opened, at the point where the detritus from the cinnabar extraction was accumulated, in correspondence with the front of the mine. Here, the wall had been artificially rectified and was characterized by rough, sharp surfaces. In order to house the funerary structure, the mining detritus was removed to create a level surface and an accumulation of material was used to form a cordon around the chosen area. Boulders and stones were arranged so as to act as containment along the western edge of the chamber, opposite the calcareous rock face. There were chips of green stone and a number of spherical heads from small mallets, also made of green stone, as well as limestone chippings smeared with cinnabar dispersed among the mining detritus. A sort of deposit of large blocks of red quartz arenite emerged at the mouth of the “buca”, that appeared unused. The amount of green stone in the detritus and the small mallet heads together with the limestone chips smeared with cinnabar, suggest this level was formed during a phase during which the cinnabar itself was “dressed”. In fact, it is possible to suggest that following the detachment of large limestone blocks, probably carried out using large quartz arenite tools, well attested on the fan descending downhill and to a lesser degree at the foot of the mine front, work continued with the breaking up of the blocks in order to recover the cinnabar minerals within them. The continuation of the survey immediately uphill from the “buca” confirmed the concentration of mining tools in the proximity of what could be a cavity, at present blocked by collapsed material, opening in the limestone bedrock running north-south along the hill. Last year’s survey identified the presence, below a substantial concentration of mining tools, of a number of subterranean cavities with sub-vertical and sub-spherical morphology. These will be investigated during the next campaign.

Nel periodo tra il 19-31 agosto 2013 si sono svolte le indagini stratigrafiche alla Buca di Spaccasasso (Alberese, GR), nel Parco Regionale della Maremma. Hanno partecipato alla campagna studenti dei Corso di Laurea Triennale e Magistrale dell’Università degli Studi di Siena, dottorandi, e specializzandi. La ricerca è stata rivolta alle evidenze risultanti dall’attività estrattiva dei minerali di cinabro presenti nel bancone di calcare massiccio che costituisce il Poggio di Spaccasasso. L’evidenza mineraria al momento si data solo in relazione alla cronologia della camera funeraria. Tra l’impianto della camera e il deposito di cava il livelletto sterile che documenta un'interruzione nella frequentazione del sito non è riconoscibile ovunque. Il deposito archeologico formatosi a seguito dell’attività estrattiva finalizzata al recupero di minerali di Cinabro, ha restituito evidenze che documentano diversi passaggi del ciclo di estrazione del minerale. In particolare sembra possibile riconoscere unità stratigrafiche di accumulo di detrito grossolano frutto delle fasi di “abbattimento” del bancone di calcare massiccio in cui sono presenti le vene di Cinabro. A tale tipo di evidenza sono associati prevalentemente strumenti – mazzuoli o picchi-di grandi dimensioni, ottenuti da blocchi di Quarzarenite rossa. Sono poi riconoscibili accumuli di detrito minuto probabilmente relativi alle fasi di frantumazione dei blocchi di calcare per il raggiungimento delle vene di Cinabro e la sua estrazione. A questo detrito si associano prevalentemente porzioni di mazzuoli di medie e piccole dimensioni ottenuti in pietra verde di una variante non scistosa ma a grani anche quarzosi. L’effettiva associazione dei due diversi tipi di strumento, ottenuti con le due diverse materie prime, con fasi diverse dell’attività estrattiva necessita di dati quantitativi, tipologici e tipometrici ancora non disponibili. L’affermazione sopra riportata si basa al momento su semplici osservazioni effettuate sul campo che necessitano di conferme anche sulla base delle future analisi spaziali e di laboratorio. La campagna si è conclusa mettendo in luce un livello di pietrame di morfologia appiattita e concoide, di dimensione massima tra i 15 e i 20 cm. La morfologia e l’aspetto delle superfici di queste pietre permettono di interpretarle come scaglie di decorticamento della parete di calcare per l’avvio dell’attività di estrazione del Cinabro. Queste scaglie sembrano quindi documentare il primo momento di sfruttamento minerario in questo punto del bancone di calcare. Le lastre di decorticamento in taluni casi presentano la superficie di una delle due facce alterata, non compatta e polverosa. Inoltre il deposito su cui poggiano si presenta a tratti non terroso ma costituito da polvere grigia finissima. Nell’ambito di una tesi triennale del Corso di Laurea in Diagnostica e Materiali per la Conservazione e il Restauro presso la Facoltà di Scienze Matematiche Fisiche e Naturali dell’Università di Firenze sono in corso le analisi per la caratterizzazione del Cinabro di Spaccasasso e la sua eventuale presenza sulle porzioni attive degli strumenti da cava, in particolare sui mazzuoli in pietra verde.

This was the 10th season of excavation and research on the Poggio di Spaccasasso in the Maremma Regional Park. The aim was to investigate the open-air quarry used for working the veins of cinnabar present in the limestone of Poggio di Spaccasasso. The cinnabar quarry lies below the Eneolithic funerary structure excavated during previous seasons. The deposit relating to the mining of the cinnabar veins was sealed at one point by sterile soil that had slipped down from a fissure in the limestone above from which red-orange soil continues to descend today. The excavated evidence seemed to confirm the use of the fire setting technique for demolishing the quarry face. As well as the scars on the rock face seen in the previous campaign, evidence was uncovered that documented the repeated lighting of fires close to the quarry face. Greenstone mallets were found next to a large limestone block with flat horizontal surfaces that suggest this was an area used for breaking up the limestone rocks containing the cinnabar after they had been broken away from the quarry face. The fires had been built both on top of detritus of medium sized clasts slopping steeply towards the quarry face, and directly on the bedrock. The conformation of this rock was the same as the vertical walls of the quarry face and of the “Buca” itself. This may be a “quarry floor” whose conformation again seems linked to the use of fire. While the excavations took place at the Buca di Spaccasasso, work began on the contextualisation of the micro and meso topography of the conoid fan immediately below the Buca. A dry-stone wall interrupted the stratigraphic continuity between the quarry face and the detritus spread lower downhill. The wall was built to contain the material excavated between 2000 and 2004 by the “Gruppo Speleologico Naturalistico Maremmano”. The embankment formed by this terrain completely obliterated the quarry’s original morphology. The area subject of the contextualisation was inserted into a grid of 10 x 10 m and 5 x 5 m squares, aligned with the excavation grid. As well as collecting artefacts, the morphological elements in a part of the area were recorded. The survey of such elements aimed to identify possible factors that may have influenced the distribution of the quarrying tools. The collection highlighted a number of significant concentrations including one in the area surrounding a manmade structure for containing the detritus. A topographical survey of the dispersed material from the quarrying activity and the area’s morphology was carried out in the area uphill from the Buca di Spaccassaso plateau. Here, grond-penetrating radar and seismographic surveys carried out in areas with particularly dense concentrations of tools and particular morphological formations (2011 campaign) had revealed the presence of underground cavities both in the form of vertical “wells” and sub-spherical spaces. This season’s investigations identified two “wells”, one of which perfectly vertical, sub-cylindrical and about 6 m deep (Pozzo 1), and the other with a blocked, sub-horizontal opening (Pozzo 2).

This was the 11th campaign of excavations carried out by the University of Siena’s Laboratory of Prehistoric Archaeology and Interuniversity Research Centre for the Study and Promotion of Prehistoric Cultures, Technologies and Landscapes. During the 2015 campaign, the investigation of the evidence for the open-air mining of cinnabar continued. This began with the removal of a baulk left in to show the stratigraphic sequence existing in the mine. Its removal was necessary as it covered a crucial point for reading the stratigraphy of the entire area. In effect, an inconsistency between the stratigraphic sequence in the north sector and that in the south sector of the excavation area was revealed. The two areas appeared to be separated by a cut in the limestone bedrock constituting the level on which the archaeological deposit in the south sector rested, and which is interpreted as a probably mining surface. The cut, which probably ran along a natural fracture in an east-west direction, met the east wall (East Front) forming a right angle and seemed to correspond with another mine face (South Front) obliterated and filled with detritus and cemented ashy levels (still in course of excavation). The detritus filling this face was very mixed, comprising large to medium gauge crushed stone, without any soil matrix. The fill presented clear gaps and was discontinuous. Over the course of time it suffered settling and collapse, the latter possibly the cause of the stratigraphic discontinuity between the two sectors of the excavation area. Large fragments of carbonised wood were recovered from immediately on top of the gravel fill, below the lenses of charcoal that were perhaps cemented by the calcinated limestone amid the detritus. As things stand, there appear to be quarrying phases that predate the funerary structures in the area in front of the Buca di Spaccasasso, in correspondence with the amphitheatre created in the limestone bedrock. The last of these phases originated the cemented ashy layers, attached to working areas constituted by very fine gravel mixed with black, charcoally soil containing chips and fragments of rachitic green stone hammer stones (East Front). This extraction phase may have come to an end following the collapse of the overhanging rock that the activity itself had created during the course of time. The detachment of stone masses would have rendered the rock face vertical and the collapsed masses themselves were then used to form the border of the funerary structure’s ossuary that was created when the cave went out of use. The face uncovered this season (South Front) represented an earlier extraction phase, filled with mixed and unstable detritus, which formed the floor and work surface in the later mining phases. It remains to be established whether the reclamation and filling of the South Front, the earliest, occurred after the mining undertaken in the shaft known to date as the Buca di Spaccasasso and the small adjacent cave in the southernmost portion of the limestone bedrock. These two cavities, which the evidence indicates were man-made for mining activities, cannot be easily inserted within the sequence of mining phases that are being identified. In fact, both cavities are isolated stratigraphically from the rest of the mining evidence due to clandestine interventions. It is possible that mining in the Buca and adjacent cavity date to an intermediate phase with respect to the South Front, the earliest, and the West Front, the latest. Their chronological collocation in this intermediate phase of mining activity remains, at present, hypothetical. For the important funerary evidence excavated during previous campaigns, the Poggio di Spaccassaso has been inserted into the PRIN MIUR 2010-11 (3 years - prot.2010EL8TXP) Project “EPIC – Eredità biologica e culturale della popolazione italiana centro-meridionale lungo 30 mila anni” (thirty thousand years of the biological and cultural inheritance of the central-southern Italian population), coordinated by Prof. Olga Rickards, for genetic, paleo-nutritional analyses and radiometric dating.

Per sopraggiunti problemi organizzativi la campagna di scavo non ha avuto corso.

This year, two short campaigns took place on the site of Poggio di Spaccasasso. The excavations were carried out by Siena University’s Laboratory of Prehistoric Archaeology and the Interuniversity Research Centre for the Study and Promotion of Prehistoric Cultures Technologies and Landscapes (CRISP). Two sectors were investigated in the western extension of the plateau. In the north-western sector, the area was cleared and the humus and excavated soil (spoil heap) from recent excavations removed. This exposed a dark, almost black, loose soil containing medium to large crushed limestone and quarrying tools in gabbro and quartz–rich sandstone. This level can be interpreted as quarry detritus relating to the phase when the Neolithic quarrying activity was abandoned. In the south-western sector, there was a horizon of loose soil containing minute to medium-large gravel, corresponding with the Neolithic abandonment phase of the quarry, in the quadrants positioned on the same axis as the entrance to the mine shaft. Below this was a layer of light grey dusts and minute and very minute gravel resulting from the demolition of the embedded rock using fire, which also caused the abundant medium to large limestone conchoidal chips present in the same deposit. It seems possible to associate this level with the later phases of Neolithic cinnabar quarrying. To date this deposit had only been partially investigated at the bottom of the quarry’s east face. Part of a small pit was identified at the edge of an old excavation trench. It contained a few very small pottery fragments and human bones. The pit, which had almost entirely been removed by the trench, relates to the funerary phase of the site.

This was the 14th campaign of excavations at Poggio di Spaccasasso, in the Maremma Regional Park (Alberese – GR). Excavation continued in the north-west and south-west sectors of the plateau quarry, which were opened in 2017. Work also continued in the north-east and south-east sectors where the investigations were suspended in 2016. The reopening of the north-east sector aimed to excavate the hearth area, “hearth 1”, characterised by a hardened accumulation of calcinated limestone probably mixed with ash. This accumulation contained a moderate quantity of vegetal charcoal and several gabbro hammerstones (intact and fragmented). The preliminary analysis of the FTIR of the hearth’s hardened deposit presently in progress at the Bioscience Research Center di Fonteblanda (GR) has so far identified high levels of mercury (Hg) while cinnabar (HgS) seems absent. This result appears consistent with the type of structure analysed. When exposed to moderately high temperatures the mercury sulfide that was extracted at the site releases mercury. On the contrary, cinnabar, easily identifiable by its red colour, was present in dense concentrations throughout the earthy deposit and in the debris from the mineral reduction occupying the extraction area in the parts not subject to heat from the fires. As often mentioned, the use of fire in the extraction process is documented at Spaccasasso both in the phases of breaking down the limestone containing the cinnabriferous veins and in the reduction phases, and this due to the extreme hardness of the limestone close to the cinnabar deposits. It is certainly plausible that the use of fire, despite the good level of techniques for its control, could not however prevent the loss of a part of the extracted cinnabar in the form of mercury. The area of this hearth could be interpreted as the place for the separation of the mineral from the rock containing it. Continuing towards the western edge of the plateau, still within the North area, loose brown soil, some very dark, was removed. It contained moderately large limestone blocks and intact and fragmentary mallets made of quarzarenite and occasionally gabbro. The layers removed sloped down towards the valley, contrary to those in the North-east area, all more or less horizontal or sloping towards the extraction front. The almost exclusive presence of quarzarenite tools poses the still unanswered question of the functional or chronological significance to be attributed to the tools made in this material. At present, the area cannot be dated using methods producing an absolute chronology and the archaeological data itself does not provide a clear chronology for this level. In this area of the plateau, the presence of root systems that have clearly disturbed the archaeological deposit continues to be problematical and caution is needed in the reading of the evidence. In the south area, the sector next to the east wall was uncovered, on which the mineshaft opened. There was another scatter of moderately hardened calcinated limestone mixed with fine – very fine debris in which limestone chips and medium-large blocks were dispersed, which bordered the layer to the west. Vegetal charcoal and gabbro chippings were also present here. The type of deposit, its position, and slope towards the shaft opening suggest it can be interpreted as an accumulation of detritus from the digging of the shaft. Several negative layers containing human bones and pottery fragments were also identified in the south area, but towards the west edge of the plateau. As seen last year, this evidence can be associated with later activity, perhaps mining, in the phases post-dating the period when the plateau was used as a cemetery area during the Copper Age.