Banffshire, a north-eastern county of Scotland, bounded N. by the Moray Firth, E. and S. by Aberdeenshire, and W. by Elgin and Inverness. It has an area of 403,364 acres, or 633&FRAC12; sq. m. The surface is diversified. The northern half is mostly a fine, open, undulating country of rich, highly-cultivated soil. The southern is mountainous, but extensive farms are found in its fertile glens. Some of the mountains are thick with forests, some present a beautiful intermixture of rock and copse, while others are covered with brown heath. The principal mountains are all in the south; among them are Cairngorm, on the confines of the shires of Banff and Inverness (4084 ft.), famous for its amber-coloured quartz crystals, the "cairngorms" of Scots jewelry; Ben Rinnes (2775 ft.); Corryhabbie (2563); Cook's Cairn (2478); Carn an t-Saidhe (2401); and the Buck of Cabrach (2368). No great rivers belong wholly to Banffshire. For a considerable part of their courses the Spey forms the western and the Deveron the eastern boundary of the county. But Banffshire streams are comparatively short, the chief being the Avon, Fiddich, Isla, Buckie, Deskford - with a series of cascades - and Livet. Most of them are stocked with trout and the Spey and Deveron are famous for their salmon.
The great glens are distinguished for their romantic scenery, the chief being Glen Avon, Glen Barry, Glen Fiddich, Glen Isla, Glen Livet, and Glen Rinnes. The largest lochs are in the extreme south: Loch Avon (2300 ft. above the sea), Loch Builg (1586) and Loch Etchachan (3100).
The geology of Banffshire is closely connected with that of the neighbouring counties of Aberdeen and Elgin, from which it is divided by no natural boundaries. The greater portion is occupied by crystalline schists of sedimentary origin belonging to the Eastern Highland sequence. The groups which are typically developed comprise (1) slates, black schists and phyllites with thin black limestone, sometimes containing tremolite, (2) the main limestone, (3) the quartzite (Schiehallion). These form subparallel belts trending north-east and south-west from the seacoast between Cullen and Portsoy southwards by Keith and Dufftown to the head waters of the Avon beyond Tomintoul. Some excellent sections of the phyllites are to be seen on the shore between Sandend, near Portsoy, and Findlater Castle, near Cullen, and in the railway cutting near Mulben, west of Keith. The main limestone has been worked at Fordyce, near Grange east of Keith, and at Keith and Dufftown. The quartzite, which is regarded as probably the highest member of the series, forms prominent ridges due to the more rapid erosion of the phyllites, mica-schists and limestones occupying the intervening hollows.
It appears on the coast between Cullen and Buckie, it forms the Durn Hill near Portsoy, the Binn of Cullen, the Knock Hill, Ben Aigan and various ridges trending southwards from Grange by Glen Fiddich towards Tomintoul. In the north-east part of the county there is a large development of slate with interbedded greywackes and pebbly grits, which occupies the coast section between Macduff and Troup Head except a small part at Gamrie. The slate has been quarried for roofing purposes. No fossils have been found in these strata and their age is uncertain. The metamorphic sediments have been pierced by acid and basic igneous intrusions, partly before and partly after the folding and metamorphism of the strata. The older acid and basic materials appear as sheets injected along the lines of bedding of the sediments and are traceable for considerable distances. They are foliated in places, the planes of schistosity being more or less parallel with the planes of bedding in the schists. The older acid rocks are represented by the sills of granite and augen-gneiss occurring west of Portsoy, south of Fordyce and near Keith, while the older basic rocks are illustrated by the belt of gabbro, epidiorite and hornblende-schist which stretches southwards from the coast at Portsoy, by Rothiemay to Huntly in Aberdeenshire. Veins and bosses of serpentine are associated with these basic intrusions at Portsoy and near Grange, one of the veins being traceable at intervals from the shore southwards in the direction of Knock Hill. The later intrusions are represented by the Ben Rinnes mass of granite and its basic modification, the Netherly diorite, east of Rothes. Various mineral localities occur throughout the county, of which some of the most important occur on the shore at Portsoy, as for example the gabbro masses in Portsoy Bay with enstatite, hypersthene and labradorite, the graphic granite with microcline, muscovite and tourmaline at East Head, the chiastolite-schist west of the marble quarry, the mottled serpentine with strings of chrysotile.
Resting unconformably on these metamorphic rocks, Old Red sandstone strata are met with in a few places. Thus, they cross the Spey and appear in the Tynet Burn east of Fochabers, and extend eastwards to Buckie. Outliers of these beds appear on the shore near Cullen and south of Fordyce, while the largest area extends from Gamrie east by Pennan on the north coast of Aberdeenshire to Aberdeen. The strata consist mainly of conglomerates and red sandstones, which, at Gamrie and at Tynet, are associated with a band of limestone nodules embedded in a clayey matrix, containing fish remains. The more abundant species occurring at Gamrie, as determined by Dr R. H. Traquair, are Diplacanthus striatus, Rhadinacanthus, Cheiracanthus Murchisoni, Pterichthys Milleri, Coccosteus decipiens. In view of the fossil evidence these beds have been referred to the middle or Orcadian division of this formation. In the interior near Tomintoul, another large deposit, composed of conglomerate and sandstone, occurs, which may be of the same age, though no fossils have as yet been obtained from these beds.
There is a widespread covering of boulder clay especially in the northern part bordering the shore, where it contains fragments of shells and includes numerous boulders which have been carried eastwards from the high grounds west of the Moray Firth. In the brickclays at Blackpots to the north-west of Banff, fragments of shells also occur together with Jurassic fossils. Shelly sands have been recorded near the Ord south of Tillynaught near Portsoy, and shells have been found in stratified deposits on the shore near Gamrie.