It consists in the main of an Archean block or " coign,"which still occupies nearly the whole of the western half of the continent, outcrops in north-eastern Queensland, forms the foundation of southern New South Wales and eastern Victoria, and is exposed in western Victoria, in Tasmania, and in the western flank of the Southern Alps of New Zealand.
The chief outcrops occur around Biggarsberg and along the upper slopes of the Drakensberg.
The outcrops of these rocks succeed each other in order of age in roughly concentric belts, with the Archaean mass of the island of Anglesey as a centre, but the arrangement in detail is much disturbed and often very irregular.
The well-water was supposed to have percolated underground, through the Blythesdale Braystone, which outcrops in patches on the eastern edge of the Rolling Downs formation.
With the Beaufort series this occupies over twothirds of the western portion of the province and has wide outcrops in Zululand and in the Vryheid districts.
The chief outcrops are in the south-western Transvaal, around Zoutpansberg and in Swaziland.
There are occasional outcrops of rock and low perpendicular cliffs.
This identification has been confirmed by the discovery of a series of boundary inscriptions, apparently marking the limit of the city's lands, which have been found cut in rock - outcrops partly surrounding the site.
Of these the most notable is the Niagara escarpment which extends eastward from Canada, past Lewiston and Lockport, - a downward step from the Erie to the Ontario plain, where the Niagara limestone outcrops, and its resistance to denudation accounts for the steeply rising face at the boundary between the two plains.
The plastic clay, which rests chiefly on chalk, occupies the remainder of the estuary of the Thames, but at several places it is broken through by outcrops of chalk, which in some instances run northwards to the banks of the river.
In the township there are outcrops of good granite and of verde antique, and along a range of hills E.
The Westphalian plain is broken by extensive outcrops of the underlying cretaceous beds, and is not very fertile, except in the Hellweg, a zone between the Haarstrang and the Lippe.
They appear at the surface adjacent to most of the outcrops of the Archean, and in some other places.
It is well exposed in New York, Wisconsin, Missouri and elsewhere, about the outcrops of older rocks.
The outcrops of the system appear for the most part in close association with the outcrops of the Cambrian system, but the system appears in a few places where the Cambrian does not, as in southern Ohio and central Tennessee.
Geology.Germany consists of a floor of folded Palaeozoic rocks upon which rest unconformably the comparatively little disturbed beds of the Mesozoic system, while in the North German plain a covering of modern deposits conceals the whole of the older strata from view, excepting some scattered and isolated outcrops of Cretaceous and Tertiary beds.
In the southeastern part of the island there are also a few very small outcrops of Mesozoic beds.
Deepand Assuan (First Cataract), the course of the river is interrupted by outcrops of granites and other crystalline rocks, which have been uncovered by the, erosion of the overlying sandstone, and to-day form the mass of islands, with numerous small rapids, which are described not very accurately as cataracts; no good evidence exists in support of the view that they are the remains of a massive barrier, broken down and carried away by some sudden convulsion.
The outcrops are largely hidden under laterite.
There are outcrops of lead in Marinduque and Cebu, and in Marinduque considerable silver is associated with the lead.
The' four topographic belts of the state correspond very closely to the outcrops of its geological formations; the rocks of the Appalachian belt being of Palaeozoic age; the formation of the Highlands, Archaean; that of the Triassic Lowland, Triassic; that of the irregular hills of the Coastal Plain, Cretaceous and Tertiary.
On both sides of the arch, east and west, the Coal Measures remain intact, forming outcrops which disappear towards the sea under the more recent strata of Permian or Triassic age.
The group of heights of South Wales, running on the whole from west to east, marks the outcrops of the Old Red Sandstone and Carboniferous strata which lie within a vast syncline of the Silurian rocks.
A few small outcrops occur where still more ancient strata have been raised to the surface, as, for instance, in Charnwood Forest, where the Archaean rocks, with intrusions of granite, create a patch of highland scenery in the very heart of the English plain; and in the Lickey Hills, near Birmingham, where the prominent features are due to volcanic rocks of very ancient date.
The general trend of the outcrops of the various formations is from south-west to north-east; the dip is south-easterly.
Regarding now the outcrops of bed-rock, there are exposures of Algonkian (doubtful, and at most a mere patch on Pilot Knob), Archean, Cambrian, Ordovician, Silurian, Devonian, sub-Carboniferous and Carboniferous.
Eastward of the Inferior Oolite lie the narrow outcrops of the Great Oolite and Cornbrash.
In the Bad Lands there are scanty outcrops of the Chadron formation (known also as " Titanotherium beds "), the oldest of the Tertiary beds.
There are only very scanty outcrops except along the rivers.
There are almost no Cretaceous outcrops except on the streams, especially the Niobrara, Republican and Platte rivers - and in the Bad Lands.
The superficial Miocene and Pliocene deposits in the west, above referred to, are underlaid by the White river groups of the Oligocene, whose outcrops of Brule clay and Chadron formation also have been mentioned.
This formation helps to build up the central plateau, and a band outcrops around its edge.