A synopsis of the geology of Durham and part of Northumberland / by Richard Howse and J.W. Kirkby.

  • Howse, Richard, 1821-1901.
Date:
1863
Catalogue details

Licence: Public Domain Mark

Credit: A synopsis of the geology of Durham and part of Northumberland / by Richard Howse and J.W. Kirkby. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    Belford on the north road, forming conspicuous ridges as far as Kyloe Crags. On the South Tyne the Whin sill occurs at the highest part of the river, and it is brought by faults into most of the small burns that run into it from the west. In the Wear it is brought in at Burtree-ford by the fault mentioned above. Little Whin Sill.—This small whin sill, which was so carefully described by Sir Walter Trevelyan in the Trans, of the Nat. Hist. Soc., is generally confounded with the former, but it occupies, as stated in the above reference, a higher position in the limestone series, and is much finer grained and more compact in structure than the above. It occurs only in the neighbourhood of Stanhope in Weardale, where it occupies the bed of the river for several hundred yards. It then rises to the west, and is seen in section occupying the same relative position in the strata, and gradually becoming thinner till it disappears altogether. It forms therefore a wedge-shaped mass towards the west. It is situated in a bed of limestone, composed of three posts or layers (three-yard limestone Weardale—five-yard limestone Alston Moor, see section above). It occurs uniformly between the upper and middle post or layer of this limestone bed, and is abruptly cut off towards the east. Another intercalated mass of basalt occurs at Bolam, con- nected with the Coctfield dyke. The particulars of this may be seen in the Cambridge Transactions. Two opinions have been expressed in regard to the mode in which the Whin sill has become interstratified with the carboniferous rocks. One by Prof. Sedgwick in the Cambridge Transactions, that it was intruded or thrust in in a molten state after all the rocks of the series had been formed and consolidated; and the other, by Mr. Hutton, that it was poured over as lava on the superjacent strata before the upper beds were formed. The latter hypothesis is uttei'ly untenable if we consider for a moment that there is no volcanic ash underlying any part of
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