| P number: | P212398 |
|---|---|
| Old photograph number: | A13302 |
| Caption: | A bentonite horizon, Hunderton Rough, River Wye, Hereford, Hereford & Worcester. |
| Description: | Close-up of bentonite horizon, Raglan Marl, River Wye. Horizontal variegated beds of silty mudstone containing a 0.18 m. calcium smectite bed are exposed beneath a metre-thick coarse sandstone which is not seen in the photograph. The lowest 0.23 m. of the section is a tough blocky silty mudstone, coloured reddish brown in the lower part but greenish grey in the upper part. The bentonite horizon rests with a sharp contact on the mudstone and is ochreous in the basal 3 mm. Above, the bentonite ranges through deep greyish red into pink and at the top is yellowish, greenish grey. A 0.32 m. reddish-brown to purplish-grey mudstone overlies the bentonite but is not well seen in the photograph. Bentonite is a soft, plastic, porous light-coloured rock composed essentially of colloidal silica as clay minerals especially of the montmorillonite group. Bentonite has the ability to swell in water and is used in to thicken oil well drilling muds. The Raglan Marl, now known as the Raglan Mudstone Formation is of Lower Old Red Sandstone age. |
| Date taken: | 01/01/1979 |
| Photographer: | Collins, R.E. |
| Copyright statement: | NERC |
| X longitude/easting: | 348580 |
| Y latitude/northing: | 238740 |
| Coordinate reference system, ESPG code: | 27700 (OSGB 1936 / British National Grid) |
| Orientation: | Landscape |
| Size: | 345.68 KB; 1000 x 790 pixels; 85 x 67 mm (print at 300 DPI); 265 x 209 mm (screen at 96 DPI); |
| Average Rating: | Not yet rated |
| Categories: | Unsorted Images |
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