• 50  of  567
Uploaded on:
14/02/2009 02:58:40
Digital Asset
File Size:
283.61 KB
1001 x 720 pixels
2192 views 4 downloads
P number: P002204
Old photograph number: C01976
Caption: North of Sron Rubha na Gaoithe, south-west of Helmsdale, 0.4 km. south-west of Portgower, Sutherland.
Description: The rocks are white bands of sandy limestone alternating with flaggy sandstones and mudstones of Middle Old Red Sandstone facies and age. It is thought that the boulder bed formed by accumulations of rock-fall breccias at the foot of a submarine escarpment along the line of the Helmsdale Fault in the then Jurassic seas, the higher upthrow landward side of the fault being composed of the Old Red Sandstone. Large chunks of rock would have broken off the steep scarp slopes (possibly due to earthquake activity on the fault) and slid slowly, usually channelled down gullies to spread out fan-like on the deep, flatter sea floor at the bottom of the scarp. The 'fallen stack' is one such huge block. The Helmsdale Boulder Bed (Jurassic, Kimmeridgian age). Near view of part of the famous misnamed gigantic 'fallen stack of Portgower'. A geologist sits on the rocks in the top of the picture.
Date taken: 01/01/1914
Photographer: Lunn, R.
Copyright statement: Crown
Acknowledgment: This image was digitized with grant-in-aid from SCRAN the Scottish Cultural Resources Access Network
X longitude/easting: 199500
Y latitude/northing: 812500
Coordinate reference system, ESPG code: 27700 (OSGB 1936 / British National Grid)
Orientation: Landscape
Size: 283.61 KB; 1001 x 720 pixels; 85 x 61 mm (print at 300 DPI); 265 x 190 mm (screen at 96 DPI);
Average Rating: Not yet rated
Categories: Unsorted Images, Geoscience subjects/ Stratigraphical  


There is currently no feedback