Cheviot

The Cheviot Hills are a large expanse of rugged upland straddling the southeast Scottish border with England, about eighty miles from Edinburgh. Although none of the hills are tall enough to count as a three thousand foot ‘Munro’, this is nevertheless a generally rather remote area with few roads or paths, swept by frequent rainstorms and bisected by numerous small rivers.


The Cheviot hill itself is 2,674 feet high. All the Cheviot rivers eventually drain eastwards into the North Sea. Those rising north of the Cheviot watershed run into either the Till or the Tweed, while those on the southern side run into the Coquet or North Tyne.

The Cheviots represent the most southerly Scottish outcrop of the Old Red Sandstone lavas and are centered around a large intrusive granite core.


The topography has been likened to an inner and outer plateau, the latter being composed of andesite lava. It is suggested that these were formed by an initial explosive volcanic event followed by the outpouring of numerous lava flows, possibly over an extended period of time. These dominate the topography of the region and have been dated to the Lower Devonian period, about 380 million years ago. Following the initial volcanic event, the lavas were then subject to the intrusion of a large body of granite. It is this intrusion that today comprises the higher points of the Cheviot Hills including the Cheviot Hill itself.
Although the granite is relatively resistant to erosive processes, the softer lavas have been subject to extensive weathering by stream action with the formation of numerous steep-sided valleys. Glacial action has resulted both in agate-bearing rocks being revealed "in situ" and a wide distribution of "float’"material throughout the region.


Within this area numerous types of agates and jaspers are found, although not in the same quantities as those from the more accessible Midland Valley to the north. Indeed, in a typical day, the collector would be lucky to find more than two or three quality stones. Unlike many agate locations in the Midland Valley, there are also relatively few Cheviot sites where agate bearing rocks outcrop. Because the terrain is mainly coarse grass and heather, these are fairly rare although on some of the steeper hills slopes substantial amounts of screes are found and many of these can be productive of agate.

Agates can be found in the extensive shingle banks adjoining many Cheviot Rivers.

Many Cheviot agates are similar to those from more northern localities and they are often strongly coloured with predominating reds and pinks. Certain less familiar stones also occur, including an apparently unique form of alternately banded agate and coarse crystalline quartz. Fortification agates can sometimes be large, up to 150-200mm in diameter, although it is unusual to find vein agates wider than 50mm. Some of the smaller (10 - 30 mm) fortification agates display remarkably detailed, intensely coloured structures.
Beautifully coloured and patterned jaspagates, trending into jasper, are also found in the Cheviots. Many of the jaspagate veins run for a considerable distance across the hillsides.
To the northeast of the Cheviot, near Hawick, streams running north from the watershed have produced a wide variety of examples of agate and jaspagate. The Jed, Oxnam and Kale waters run northward discharging into the River Tweed. Because of the extensive glacial deposits through which they run, all these river valleys contain large amounts of agate-bearing gravel continually being redistributed by winter floods.

 

 

Some of these specimens are from the collection of Paul Forster. They were originally collected from the Cheviot Hills by the late Gilbert Hall who was a member of the Stanley Lapidary Club. They are exceptional specimens and typical of the Cheviot agates.

 

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