loch doon rhinns of kells in background
silurian , ordovician rocks important in county; thrown oft-repeated folds axes lying in north-east–south-west direction. ordovician rocks graptolitic black shales , grits of llandeilo , caradoc age. occupy northern part of county north-west of line runs 3 m. north of new galloway , south of rinns of kells. south-east of line graptolitic silurian shales of llandovery age prevail; found around dalry, creetown, new galloway, castle douglas , kirkcudbright.
overlying llandovery beds on south coast strips of wenlock rocks; extend bridgehouse bay auchinleck , exposed in kirkcudbright bay, , can traced farther round coast between granite , younger rocks. carboniferous rocks appear in small faulted tracts, unconformable on silurian, on shores of solway firth. best developed kirkbean, include basal red breccia followed conglomerates, grits , cement stones of calciferous sandstone age.
brick-red sandstones of permian age come within county on w. side of nith @ dumfries. volcanic necks occur in permian , basalt dikes penetrate silurian @ borgue, kirkandrews, etc.
most of highest ground formed masses of granite have been intruded ordovician , silurian rocks; criffel mass lies dalbeattie , bengairn, mass extends east , west between cairnsmore of fleet , loch ken, lies north-west , south-east between loch doon , loch dee , small mass forms cairnsmore of carsphairn. granite quarried kirkmabreck, near creetown dock construction 1830 on.
glacial deposits occupy of low ground; ice, having travelled in southerly or south-easterly direction, has left abundant striae on higher ground indicate course. radiation of ice streams took place heights of merrick, kells, etc.; local moraines found near carsphairn , in deagh , minnoch valleys. glacial drumlins of boulder clay lie in vales of dee, cree , urr.
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