Again, the most convenient site for oil wells is the crest of an anticline or "dome," where an impervious stratum imprisons the gas and oil in a subjacent saturated layer under pressure.
(I) The first is the great anticline of the Pennine Hills which dominates the northern half of England from the Scottish border to Derby.
On the south side of a well-marked anticline in the Upper Old Red Sandstone at North Sannox, the Carboniferous strata reappear on the coast with a south dip showing a similar ascending sequence for about half a mile.
Where they dip away from the axis of movement the structure is termed an anticline or anticlinal fold; where they dip towards the axis, it is a syncline or synclinal fold.
The principal structural feature is the broad anticline, its axis running north and south, which has brought up the Carboniferous Limestone; this uplifted region is the southern extremity of the Pennine Range.
The whole region may be looked upon as formed by an arch or anticline of Carboniferous strata, the axis of which runs north and south; the centre has been worn away by erosion, so that the Coal Measures have been removed, and the underlying Millstone Grit and Carboniferous Limestone exposed to the influences which form scenery.
Across the moors, on the western side of the anticline, the vast and dense population of the Lancashire coal-field is crowded in the manufacturing towns surrounding the great commercial centre, Manchester, which itself stands on the edge of the Triassic plain.
From the upland of Salisbury Plain, which corresponds to the axis of the anticline marking the centre of the double fold into which the strata of the south of England have been thrown, the great Chalk escarpment runs north-eastward; fingers of Chalk run eastward one each side of the Weald, forming the North and South Downs, while the southern edge of the Chalk sheet appears from beneath the Tertiary strata at several places on the south coast, and especially in the Isle of Wight.
The dissection of the great east and west anticline in the south-east of England has resulted in a remarkable piece of country, occupying the east of Hampshire and practically the whole of Sussex, Surrey and Kent, in which each geological stratum produces its own type of scenery, and exercises its own specific influence on every natural distribution.
Of England are the two Tertiary basins of London and Hampshire, separated by the dissected anticline of the Weald.
(I-17) thrown into an anticline (AA') and syncline (BB').
The particular bed marked EF has been entirely removed by denudation from the top of the anticline, and is buried deep beneath the centre of the syncline.
The observer in passing northwards along the axis of that anticline finds himself getting into progressively higher strata as the fold sinks down.
2 there is obviously a general inclination of the beds towards the71orth, besides the outward dip from the anticline and the inward dip from the syncline.
Hence the anticline noses out to the north and the syncline to the south.
In describing rock-folds special terms have been assigned to certain portions of the fold; thus, the sloping sides of an anticline or syncline are known as the "limbs," "slopes," "flanks" or "members" of the fold; in an anticline, the part X, fig.
The crest-line of an anticline or trough-line of a syncline is rarely horizontal for any great distance; its departure from horizontality is designated the "pitch," and the fold is said to pitch (or dip) towards the north, &c. Most simple folds - with the exception of very shallow curvatures of wide area, - when considered in their entirety, are seen to be somewhat canoe-shaped in form.
The northern part of the western side of the anticline is broken off by a great fault in the valley of the Eden, and the scarp thus formed is rendered more abrupt by the presence of a sheet of intrusive basalt.