Some notes on the distribution of erratics over eastern Moray / by W. Mackie.

  • Mackie, William
Date:
[1900]
Catalogue details

Licence: In copyright

Credit: Some notes on the distribution of erratics over eastern Moray / by W. Mackie. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    deserve notice. These are of barytes. Two of these—one a large one—have been observed in the Eothes Burn. Veins of barytes occur in the neighbouring quartz schists and quartzites; but I know of no vein that could possibly have yielded the blocks observed. B. Again, to the south-west of the area there exists an important centre whence boulders have radiated in directions the extreme lines of which would meet at an angle of something more than 140 degrees. The parent rock is a diorite, which is found in place at Netherly about four miles west of Eothes On its eastern side the rock is a quartz-diorite, the quartz grains of which teem with innumerable rutile needles. To the west, in place of hornblende it shows augite, hypersthene, and occasionally, 1 think, a little diallage; and though there is usually still a little free quartz, it contains no needles. In either case the rock is very characteristic, and boulders from this area, many of which have been identified microscopically, have been carried away in great numbers to the north-east, in which direction they are to be found often of large size over the north-eastern slopes of the Brown Muir and Findlay Seat. On their way they must have crossed the hollow of Glen Eothes as if it had no existence. They are particularly plentiful near the northern opening of that glen, and have been met with nearly as far north as Longmorn Station, particularly near the farm of Eashcrook, where, however, they begin to be buried under the post-glacial sand and gravels which from this point seaward become such an important feature in the surface geology of the country. They have gone due north, but in rather sparing numbers, and are seen from time to time along the old road over the Mannoch Hill from Knockando to Birnie. They have gone directly east into the valley of the Spey at Conrock. They have gone round the shoulder—more likely right over the top— of the granite protrusion of Hunt Hill, and one large boulder, ascertained by microscopic examination to belong to the eastern side of the parent area, is found across the Spey built in four pieces—each of which is not much under three feet in diameter —into the dyke by the roadside just west of Craigellachie. Fragments of the same rock have been observed at least 1000 feet up the northern face of Benrinnes, and on the same aspect of the Blue Hill at elevations not much less. That debris from the same area has been carried much further in the same direction we have evidence in the numbers of its characteristic quartz grains that are to be found in the boulder clays and river sands collected in the Fiddich Valley some distance to the south-east. It is to be noted that other diorites occur in this area. These,
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