Sand and gravel resources, Sheet 87W Ellon, Cainozoic of north-east Scotland
|Merritt, J W, Auton, C A, Connell, E R, Hall, A M, and Peacock, J D. 2003. Cainozoic geology and landscape evolution of north-east Scotland. Memoir of the British Geological Survey, sheets 66E, 67, 76E, 77, 86E, 87W, 87E, 95, 96W, 96E and 97 (Scotland).
Contributors: J F Aitken, D F Ball, D Gould, J D Hansom, R Holmes, R M W Musson and M A Paul.
Sheet 87W Ellon
Most of the sand and gravel resources in this district (P915376) form terraced glaciofluvial sheet deposits. Those in the northern portion of the sheet occur within the Ugie Water catchment and were included in the ‘Peterhead’ sand and gravel assessment (MAR 58). Deposits in the southern portion lie within the Ythan catchment and were evaluated as part of the ‘Ellon’ assessment (MAR 76). In the north, sands and gravels underlying discontinuous glaciofluvial terraces flanking the North Ugie Water downstream from Strichen constitute the most important resources; water-saturated gravel is also present beneath the floodplain. Smaller spreads of glaciofluvial sand and gravel flank the floodplain of the South Ugie Water, upstream of Old Deer, which is also built upon a glaciofluvial terrace. Similar terraced deposits extend along the valleys of the southern tributaries of the South Ugie Water, in the vicinity of Fordmouth (NK 012 457) and Stuartfield (NJ 973 457), but much of the latter resource is sterilised by buildings. Most of the readily available resources in this area were exploited during the 1970s and 1980s.
Glaciofluvial terrace deposits also form the most extensive resources in the Ythan catchment. These terraced deposits have been extensively worked downstream of Methlick. Most of the resources consist of coarse gravel (boulders over 1 m in diameter are common) lying above the water table. A less attractive resource of gravel, occurring almost entirely below the water table, underlies the river floodplain; it was formerly dredged at a pit (NJ 922 321) near Ardlethen. Terraced glaciofluvial sand and gravel associated with a former course of the Ythan, between Ellon and its present estuary, also constitute a significant resource of sand and gravel. It has been worked extensively in a pit to the north of Deep Heather (NJ 976 290). An isolated deposit of sand and gravel was worked in a large pit (now filled-in) at Tillybrex (NK 002 348). Moundy deposits in the vicinity of Cross Stone (NJ 954 279) are currently being worked.
The composition of gravels on Sheet 87W is illustrated in P915335, which shows that psammitic clasts predominate, although granitic clasts constitute a significant component. Small amounts of deleterious material are generally present and pebbles of basic igneous rocks are numerous within the water-saturated gravels in the vicinity of Ardlethen. Most of the resources in the Ythan valley contain material suitable for a wide variety of end-uses, but those within the catchments of North Ugie Water and South Ugie Waters possibly suit fewer types of end-use. For example, only a limited amount of material matches the end-use criteria for coarse asphalt aggregate. However, fine aggregate potentially suitable for mortaring and concrete is present in some of the more sandy terraced deposits.