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Uploaded on:
14/02/2009 04:11:59
Digital Asset
File Size:
324.24 KB
1001 x 789 pixels
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P number: P007083
Old photograph number: L01450
Caption: Penrhyn Quarry, Bethesda, Gwynedd.
Description: Penrhyn Quarry is famed for the production of its purple-red slates. Several beds or veins of slate are worked in the quarry. The purple Penrhyn Slates can be seen on house roofs throughout the UK and were also shipped worldwide, most notably to Australia. The east face shown in this image exposes the 'grey slates' which constitute the major division of the upper part of the slate succession. A prominent green rather sandy band, the 'hard green slate' is being worked in the centre left below the excavator and can be seen to pass into striped slates to the right. In the foreground a dolerite dyke (igneous intrusion) cuts purple slates from lower in the succession. The high quality and relatively light weight of Welsh slates when compared with local stone slates and other roofing materials, led to the rapid expansion of the Welsh slate industry in the 19th century. Slates were needed in large quantities to roof the buildings housing the workforces in the new industrial towns. The success of the Welsh slates caused the rapid demise of many local slate producers particularly, for example in Scotland which no longer produces its many local slates.
Date taken: 01/05/1974
Photographer: Thornton, K.E.
Copyright statement: NERC
Acknowledgment: This image was digitized with grant-in-aid from JIDI the JISC Image Digitization Initiative
X longitude/easting: 261730
Y latitude/northing: 364640
Coordinate reference system, ESPG code: 27700 (OSGB 1936 / British National Grid)
Orientation: Landscape
Size: 324.24 KB; 1001 x 789 pixels; 85 x 67 mm (print at 300 DPI); 265 x 209 mm (screen at 96 DPI);
Average Rating: Not yet rated
Categories: Best of BGS Images/ Geological structures, Geoscience subjects/ Economic geology/ Slates, Geoscience subjects/ Named locality  


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