synclines

Drilling for oil has in time involved ever smaller synclines and more sophisticated techniques to image them (tomagraphy) and directional drilling.

61 Nobel Laureates can’t be wrong daniel 2008

The greater pressure results in anticlines and synclines that are inclined and asymmetrical (Figure 6).

Folding and faulting in the Earth's crust 2007

Both anticlines and synclines are the result of compressional stress.

Folding and faulting in the Earth's crust 2007

Anticlines and horsts are good sites for oil accumulation forming oil reservoirs whereas synclines and grabens are suitable for water accumulation forming aquifers or groundwater basins.

Folding and faulting in the Earth's crust 2007

Many drillers suppose that the gas seeks the anticlines and the oil the synclines, but others, equally long-headed, discard entirely all theory of this kind, and drill wherever it may be most convenient or where other operators have already demonstrated the existence of gas.

Burroughs' Encyclopaedia of Astounding Facts and Useful Information, 1889 Barkham Burroughs

Almost all rock formations have some inclination to the horizon, and the constant change of this inclination produces a series of waves, the crests of which are known as anticlines, and the troughs as synclines.

Burroughs' Encyclopaedia of Astounding Facts and Useful Information, 1889 Barkham Burroughs

In certain fields, oil and gas have been found in the tops of anticlines in water-saturated rocks, and farther down the flanks of folds or in synclines in unsaturated rocks.

The Economic Aspect of Geology 1915

Though this young assayin 'feller talks big about folds an' uplifts, synclines an 'anticlines.

Rimrock Trail 1906

Casey sabed a bit about synclines, I reckon, fo 'he kept faith in the camp, on'y he realized it' ud take a heap of money to develop, meanin 'to dig through the porphyry, I suppose.

Rimrock Trail 1906

Under long-continued erosion, anticlines may be degraded to valleys, while the synclines of the same system may be left in relief as ridges.

The Elements of Geology William Harmon Norton 1900