www.Sarsen.org: Finding the Fremington Clay Erratics

I have been studying the original descriptions of the erratics found in the Fremington Clays, which are very different to the nearby Coastal Ice Rafted erratics, and sadly they have been lumped in with them which has caused confusion. Are they also ice rafted glacial erratics or fluvial from Dartmoor?

I think I have found two or three of the original half a dozen, so they could be examined again and the very old descriptions of them could be updated.

The original references are:

Dewey, H. (1910). Notes on some igneous rocks from North Devon. Proceedings of the Geologists' Association, 21(4), 429–434.

Taylor, C.W. (1956) Erratics of the Saunton and Fremington areas. Report and Transactions of the Devonshire Associaton for the Advancement of Science, Literature and Art, 88, 52–64.)

The following photos and text are from Taylor (1956):

A collage of images of a large boulder

AI-generated content may be incorrect.

There are two boulders from this district which are mentioned in the literature, and both of them were found without any difficulty, as they are preserved, and it would appear that enquiries for them are not infrequent. The present owner of Combrew Farm, Mr. Tucker, is aware of their interest, and unnecessary "hammering" is discouraged. The third boulder, which, though mentioned, has not so far been described or figured, came originally from the clay-pit of the old Fishley Pottery, now long disused, while as regards recent finds, two further masses have been obtained from the brown clay of Brannam's pit and are noted below. Although the literature makes no mention of the fact, the boulders Nos. 6 and 7 following are understood from local information to have been found also in the clay of the Fishley pit.

No. 6. A boulder is mentioned by Dewey¹¹ as at Bickington, about a quarter mile east of Combrew Farm, but owing to development, it has recently been moved to the garden on the right of the gateway to the main yard of the Farm. In case any ultra-zealous Glacialist should fit certain scars on portions of this rock, the author hastens to mention that it was dragged in its present position instead of being ruthlessly broken up on site, a consideration which is highly appreciated.

The original measurements and photograph have been given by Dewey, which need not be repeated here; it may be added, however, that the mass shows no distinct striae or wedge-shape, and the boulder measures roughly 40 x 30 x 25 inches high, the longest axis pointing almost E-W. It may be a Crinan spilite, of the pillow-lava type of igneous rock, which occurs in the Menaige district and elsewhere in Cornwall.

No. 7. The next erratic of this group is the hyalopilitic andesite, also previously described with No. 6 above. It is now situated on the right of the gated portion of the driveway to Combrew Farm, and is a glassy, brittle andesite, quite different from any of the foregoing rocks. Well rounded and about sixteen inches across, it contains no augite, but otherwise resembles similar rocks of Dumfries and Loch Craignish, Argyllshire.

No. 8. The rock from the Fishley Pottery clay-pit has hitherto merely been mentioned as "an igneous boulder" which may now be found on the right-hand, inside the gate of the first building (the old disused pottery) on approaching Combrew Farm from the main road. It is well covered with lichen, with flat top and base, and measures 47 x 19 x 16 inches high. Of a light grey colour, it is holocrystalline, with some quartz and much felspar, which appears altered; little mica could be observed. The texture is rather granitic, with a fine, pale coloured base containing the larger phenocrysts of quartz and felspar up to 5 mm. in size, but averaging 3 mm.

The two Combrew Farm erratics, 6 & 7 and maybe 8, appear to still be on the roadside and pictured on Google Streetview.