| P number: | P208030 |
|---|---|
| Old photograph number: | A08108 |
| Caption: | South Crofty Mine, Carn Brea, Cornwall. |
| Description: | The mill at South Crofty Mine. James table showing tin concentrate. The head of cassiterite is the narrow light band crossing the table diagonally and passing of the concentrate (near) end about a foot from the left-hand corner. The darker band at the left of this is the midling product consisting of particles of cassiterite adhering to quartz and heavy minerals such as iron oxides, tourmaline etc. Lighter waste materials - quartz etc. - appear as a pale area on the left of the table where they pass to tailings. Cassiterite (tin oxide) has been exploited in Cornwall and Devon since the Bronze Age (1800 B.C.) when the ore was probably obtained from alluvial and eluvial gravel deposits. During the Roman occupation a more extensive development of the ore deposits took place. The hey-day of mining was in the 1800's and from 1880 to the slump in the 1920's there was a steady decline in the industry caused mostly by competition from colonial ore deposits. Since then the fluctuating price of tin has caused rehabilitation of some mines at various periods. The source and areal distribution of the mineralization of the region is generally believed to be related to the intrusion of the Armorican granite. The mineralizing fluids may have been a late-stage product of the consolidating granite or they may have risen through the slowly crystallizing granite from great depths. |
| Date taken: | Wed Aug 01 00:00:00 BST 1945 |
| Photographer: | Rhodes, J. |
| Copyright statement: | Crown |
| X longitude/easting: | 168500 |
| Y latitude/northing: | 41500 |
| Coordinate reference system, ESPG code: | 27700 (OSGB 1936 / British National Grid) |
| Orientation: | Landscape |
| Size: | 249.85 KB; 1000 x 703 pixels; 85 x 60 mm (print at 300 DPI); 265 x 186 mm (screen at 96 DPI); |
| Average Rating: | Not yet rated |
| Categories: | Best of BGS Images/ Images from the archives, Geoscience subjects/ Economic geology/ Metalliferous mining, tin |
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