Sand and gravel resources, Sheet 87E Peterhead, 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 87E Peterhead
As on Sheet 87W, most of the sand and gravel deposits in the northern part of this sheet (P915377) were included in the ‘Peterhead’ resource survey; those in the southern portion were evaluated as part of the ‘Ellon’ assessment. The most extensive resources in the northern half of the sheet occur as terraced spreads of glaciofluvial gravel and sand around the confluence of the North and South Ugie Water and along the tributaries of the River Ugie, in the vicinity of Longside. There has been considerable exploitation of the terraced sand and gravel in the valley of the North Ugie Water, but a significant proportion of the resource remains; water-saturated gravel is also present beneath the floodplain. The terraced deposits to the south of Longside are generally more sandy and have not been worked as intensively.
Assessment boreholes sunk in alluvial deposits within the valley of the River Ugie indicated only minor resources of variable thickness and extent. The patchy deposits of sand and gravel that underlie degraded terraces flanking the Burn of Faichfield are probably more attractive resources, as are the glaciofluvial deposits around Blackhills (NK 050 527) and Artlaw (NK 073 501); all have been worked in several places.
The coastal sand dunes north of Peterhead constitute a significant resource of medium-grained sand, with shell fragments locally abundant. Raised beach gravel is known to underlie the sand at several localities. Smaller spreads of blown sand are present inland of the Bay of Cruden and within the Sands of Forvie. The latter lie within a nature reserve, which precludes their exploitation.
In the southern part of Sheet 87E, the main deposits of glaciofluvial sand and gravel occur as relatively thin, discontinuous spreads, forming mounds and ridges on both sides of the boundary between the Logie-Buchan and East Grampian drift groups (P915297). Notable resources within the Logie-Buchan Drift Group occur in the vicinity of Hatton and also between Hillhead (NK 022 340) and Mains of Collieston (NK 032 292). The latter include the Kippet Hills Esker (P219697)), described in Appendix 1 (Site 16 Kippet Hills). Discontinuous resources of glaciofluvial sand and gravel and sandy glaciolacustrine deposits occur beneath clayey overburden between Hatton and Cruden Bay; waste partings of laminated silt and clay are commonly present within the sequences. Similar glaciofluvial–glaciolacustrine successions also extend from Lochlundie Moss to beyond the southern margin of Sheet 87E. Glaciofluvial sands and gravels are less widespread within the East Grampian Drift Group, though they have been worked near Moreseat (NK 054 404), North Aldie (NK 072 409) and Redleas (NK 091 428).
The Palaeogene–Neogene gravels of the Buchan Ridge Gravels Member crop out along the ‘Buchan Ridge’, between the Moss of Cruden and the Hill of Aldie, and beyond the ridge, at Den of Bodham. Unlike the quartzose gravels at Windy Hills, these deposits are primarily composed of flint cobbles in a matrix of kaolinitic clay and quartz sand (largely formed from highly decomposed clasts of igneous and metamorphic rocks). These gravels are regarded as being too coarse and clayey to be a particularly attractive source of aggregate, but they are a source of ornamental cobbles. These deposits are described further in Site 14 Moss of Cruden.
Granite, decomposed to sand, has been exploited quite widely for making tracks and for use in foundations. It was dug on the Hill of Longhaven for bedding oil and gas pipelines.
The sand and gravel in the northern part of Sheet 87E are similar in composition to most of those on Sheet 87W and contain material suitable for fine asphalt aggregate, plastering/mortar sand and fine concrete aggregate. Clasts of psammitic and granitic rocks predominate (P915335) and a notable proportion of flint is present in the glaciofluvial gravels south-east of Longside. Much of the granitic material is probably derived from the Peterhead Granite; the flint is probably reworked from the Buchan Ridge Gravels Member.
In the southern part of the sheet a high proportion of platy clasts of limestone and calcareous siltstone occur within gravels of the Logie-Buchan Drift Group. The deposits were formerly burnt for the local production of lime. The calcareous clasts were probably derived from Mesozoic rocks in the adjacent offshore area. The gravels yield coarse- and fine-grained aggregates that appear to be suitable for most end uses.