VIII sobre minería y metalurgia históricas en el sudoeste europeo, Jun 11, 2014
The aim of the research program MineMet 2012-2015 financially supported by ANR (French National A... more The aim of the research program MineMet 2012-2015 financially supported by ANR (French National Agency for Research) is to study and characterise the economic implications of new mining districts on secondary deposits during the Antiquity. Our study is focused on two regions with Au placer deposits, one in Gaul to the Lemovices (Limousin and North Perigord) and another one in Hispania, to the Cerretanes in Cerdagne, and on tin placer deposit in Gaul to the Eduens in Morvan (Burgundy). We present here our results on gold from Cerdagne and tin from Morvan. The project propose to identify and characterise new mining districts which are detectable in the landscape as topographical anomalies of the slopes and show similarities with certified Antique mining sites known from other locations. To accomplish the project’s purposes a new field research approach was initiated with the mapping of the supposed new mining districts and the detailed mapping of several excavated structures showing similarities with channels and water tanks, remnants of an ancient hydraulic network as well as exploitation sites. Their study involving archaeological diggings also allow identifying the dynamic of exploitation and uncovering hidden structures (channels, basins) and artifacts which together prove the presence of mining driven structures and offer clues for chronology. Metal provenance studies (geology, geochemistry/isotopes) are going on in parallel for the alluvial gold from Cerdagne and the colluvial cassiterite from Morvan. EIectrum/gold grains and cassiterite grains sampled in the vicinity of the studied mining structures will be compared with pre-Roman and Roman gold and bronze artifacts discovered in the same two regions. The first research in Cerdagne started in 2008 in the valley of Segre between French and Catalan Cerdagne in a broad partnership between historians, archaeologists and geologists from Toulouse and Barcelona (Olesti et al., forthcoming). About 30 sites presenting deep erosional profiles and being strictly contoured on the slopes have been mapped. These negative anomalies in the landscape are very similar to the trench mining sites as are known in NW Spain or NW Romania for the alluvial gold mining during Antiquity. These deep incisions were considered until now as traces of natural erosion along the slopes. However, several panning campaigns in Cerdagne on the Catalan side around the village of All, and on the French side NE of Sail/agouse confirmed the constant presence of electrum/gold grains in the alluvial deposits. In the frame of the MineMet program the collected electrum grains are currently prepared for geochemical and isotope analyses for traceability purposes. Between 2010 and 2011 several diggings made in Las Guilleteres (All, Catalonia, Spain) revealed a sort of basin or water tank made of two superposed dams of stones situated on the slope upstream of deep trenches cut in alluvial deposits. The presence of common ceramic fragments found in the filling of the basin indicates an Antique occupation of the structure. It is possible to consider this structure as a water reserve for alluvial Au exploitation downstream but for the moment we did not identified any trace of channel connecting the basin with the exploitation sites. New diggings are necessary in Cerdagne to ultimately prove the surface exploitation of the alluvial gold. South and east of Autun (Burgundy, France) BRGM discovered a significant tin anomaly (cassiterite) within secondary deposits (alluvial and arenitic deposits) developed on granite rocks. Furthermore, the forestry slopes from these areas are crosscut by a dense network of up to 4 m deep trenches which downstream pass into large cirques. These lowlands in the landscape were interpreted as surface mines in secondary deposits. These surface works were created by hydraulic mining of secondary cassiterite deposits. Upstream of cirques and trenches it is easily to follow a hydraulic network made of channels and several basins. The source of water is situated in the upper part of the hills, the so-called Montjeau domain, south ofAutun, where several lakes still exists. Archaeological diggings were done in 2005 close to a trench exploitation for tin in the so-called La Montagne (Autun) site. A hidden channel was revealed firstly by geophysical prospection and it was afterwards confirmed during the diggings by the presence of iron hydroxides concentrated along the lowermost part of the channel. The diggings allowed us to discover two hidden channels going towards the exploitation site validating thus the hypothesis of placer mining. The ceramics discovered on the bottom of the channels date its abandon during 1st c. AD. The trenches and cirques are located downstream of the hydraulic system (channels and basins) to which they are connected and altogether are found in a forested area and thus invisible for classical aerial investigations. The difficulty of the field covered by forests…
Alburnus Maior (Rosia Montană, Romania) was an important precious metals mining site during Roman... more Alburnus Maior (Rosia Montană, Romania) was an important precious metals mining site during Roman times. Geological, ore deposit and geochemical studies have been carried out on the ore bodies exploited during the Roman period that have been discovered during archaeological excavations. The primary purpose of the present paper is to demonstrate the importance of the study of geologically and chronologically referenced ores by means of mining archaeology and geology for identifying the sources of precious metals from Roman Antiquity.The geological studies carried out in the Cârnic Massif allowed the identification of four mineralisation phases. Three of these four phases have been exploited by the ancient miners. Each mineralised phase is characterised by a specific precious metals mineral association, and two of them contain rare Te and Ge bearing minerals. As their elemental composition is heterogeneous, the use of lead isotopes represents a good methodology for refining their char...
VIII sobre minería y metalurgia históricas en el sudoeste europeo, Jun 11, 2014
The aim of the research program MineMet 2012-2015 financially supported by ANR (French National A... more The aim of the research program MineMet 2012-2015 financially supported by ANR (French National Agency for Research) is to study and characterise the economic implications of new mining districts on secondary deposits during the Antiquity. Our study is focused on two regions with Au placer deposits, one in Gaul to the Lemovices (Limousin and North Perigord) and another one in Hispania, to the Cerretanes in Cerdagne, and on tin placer deposit in Gaul to the Eduens in Morvan (Burgundy). We present here our results on gold from Cerdagne and tin from Morvan. The project propose to identify and characterise new mining districts which are detectable in the landscape as topographical anomalies of the slopes and show similarities with certified Antique mining sites known from other locations. To accomplish the project’s purposes a new field research approach was initiated with the mapping of the supposed new mining districts and the detailed mapping of several excavated structures showing similarities with channels and water tanks, remnants of an ancient hydraulic network as well as exploitation sites. Their study involving archaeological diggings also allow identifying the dynamic of exploitation and uncovering hidden structures (channels, basins) and artifacts which together prove the presence of mining driven structures and offer clues for chronology. Metal provenance studies (geology, geochemistry/isotopes) are going on in parallel for the alluvial gold from Cerdagne and the colluvial cassiterite from Morvan. EIectrum/gold grains and cassiterite grains sampled in the vicinity of the studied mining structures will be compared with pre-Roman and Roman gold and bronze artifacts discovered in the same two regions. The first research in Cerdagne started in 2008 in the valley of Segre between French and Catalan Cerdagne in a broad partnership between historians, archaeologists and geologists from Toulouse and Barcelona (Olesti et al., forthcoming). About 30 sites presenting deep erosional profiles and being strictly contoured on the slopes have been mapped. These negative anomalies in the landscape are very similar to the trench mining sites as are known in NW Spain or NW Romania for the alluvial gold mining during Antiquity. These deep incisions were considered until now as traces of natural erosion along the slopes. However, several panning campaigns in Cerdagne on the Catalan side around the village of All, and on the French side NE of Sail/agouse confirmed the constant presence of electrum/gold grains in the alluvial deposits. In the frame of the MineMet program the collected electrum grains are currently prepared for geochemical and isotope analyses for traceability purposes. Between 2010 and 2011 several diggings made in Las Guilleteres (All, Catalonia, Spain) revealed a sort of basin or water tank made of two superposed dams of stones situated on the slope upstream of deep trenches cut in alluvial deposits. The presence of common ceramic fragments found in the filling of the basin indicates an Antique occupation of the structure. It is possible to consider this structure as a water reserve for alluvial Au exploitation downstream but for the moment we did not identified any trace of channel connecting the basin with the exploitation sites. New diggings are necessary in Cerdagne to ultimately prove the surface exploitation of the alluvial gold. South and east of Autun (Burgundy, France) BRGM discovered a significant tin anomaly (cassiterite) within secondary deposits (alluvial and arenitic deposits) developed on granite rocks. Furthermore, the forestry slopes from these areas are crosscut by a dense network of up to 4 m deep trenches which downstream pass into large cirques. These lowlands in the landscape were interpreted as surface mines in secondary deposits. These surface works were created by hydraulic mining of secondary cassiterite deposits. Upstream of cirques and trenches it is easily to follow a hydraulic network made of channels and several basins. The source of water is situated in the upper part of the hills, the so-called Montjeau domain, south ofAutun, where several lakes still exists. Archaeological diggings were done in 2005 close to a trench exploitation for tin in the so-called La Montagne (Autun) site. A hidden channel was revealed firstly by geophysical prospection and it was afterwards confirmed during the diggings by the presence of iron hydroxides concentrated along the lowermost part of the channel. The diggings allowed us to discover two hidden channels going towards the exploitation site validating thus the hypothesis of placer mining. The ceramics discovered on the bottom of the channels date its abandon during 1st c. AD. The trenches and cirques are located downstream of the hydraulic system (channels and basins) to which they are connected and altogether are found in a forested area and thus invisible for classical aerial investigations. The difficulty of the field covered by forests…
Alburnus Maior (Rosia Montană, Romania) was an important precious metals mining site during Roman... more Alburnus Maior (Rosia Montană, Romania) was an important precious metals mining site during Roman times. Geological, ore deposit and geochemical studies have been carried out on the ore bodies exploited during the Roman period that have been discovered during archaeological excavations. The primary purpose of the present paper is to demonstrate the importance of the study of geologically and chronologically referenced ores by means of mining archaeology and geology for identifying the sources of precious metals from Roman Antiquity.The geological studies carried out in the Cârnic Massif allowed the identification of four mineralisation phases. Three of these four phases have been exploited by the ancient miners. Each mineralised phase is characterised by a specific precious metals mineral association, and two of them contain rare Te and Ge bearing minerals. As their elemental composition is heterogeneous, the use of lead isotopes represents a good methodology for refining their char...
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