W. A. E. Ussker — Subdivisions of the Trias. 167 



near Stogumber and at Minehead ; and with modifications, here and 

 there, between Minehead and Dawlish ; the fragments in this variety 

 are generally of grit. 



Breccias of shale fragments in sand matrix are a kind of modifica- 

 tion of the Dawlish variety, and occur in the Crediton and Tiverton 

 valleys, and near Stogumber. 



Brecciated loam, with seams of red clay, occurs in Exeter, where 

 it furnishes material for brickmahing ; the shale fragments, being 

 very small, are burnt in the brick and do not militate against its 

 utility. This variety is largely developed in the Crediton valley, it 

 is generally associated in its very local instances of occurrence with 

 dark red clay, which appears either to replace it or to occur inter- 

 calated, as in, and near Exeter, and in the Crediton valley. Beds of 

 hard red sandstone occur in the brecciated loam of Exeter. 



Some varieties of the Breccia series so much resemble the gravels 

 resting on the older rocks and frequently obscuring their junction 

 with the Breccia, that, in the absence of good sections, they are 

 hardly distinguishable from them. These contain rounded sub- 

 angular and angular stones of grit and quartz, with intercalated beds 

 of rock sand, as at Bradninch ; or are chiefly composed of angular 

 fragments and also contain pieces of shale, as on the north side of the 

 Tiverton valley. Breccio-conglomerates occur between Bathealton 

 (south of Wiveliscombe) and Williton; they contain pebbles, sub- 

 angular and angular fragments of grit, quartz, and, very occasionally, 

 limestone, in a rather coarse sandstone matrix ; the beds of Sampford 

 Peverell and Halberton form a kind of connecting link between the 

 breccio-conglomerates and the hard Breccias of Heavitree (near 

 Exeter) and Teignmouth. 



The lowest division occupies a considerable area between Tiver- 

 ton, Exeter, Crediton and the south coast : west of Collumpton, it is 

 almost entirely composed of sandstone, but the presence of two or three 

 small patches of breccia seems to indicate the concealment of tbe lower 

 beds, possibly by overlap. Between Collumpton and Grinham Bridge 

 (south-west of Thorn St. Margarets), the lower division is feebly 

 represented, and, in places, either represented by clay undistinguish- 

 able from the overlying marls, overlapped by them, or faulted out. 

 At Canon Leigh (near West Leigh limestone quarries), a few beds of 

 lower sandstone are shown faulted against the older rock, as also at Hor- 

 ridge Down, in the railway cutting, south of Wiveliscombe. Between 

 Thorn St. Margarets and Wiveliscombe, this division is much affected 

 by faults, and nowhere fully represented ; between Wiveliscombe 

 and Williton, it is well shown, and exhibits many phases ; between 

 Williton, Minehead and Porlock it is frequently faulted out, but 

 occurs about Luckham (near Porlock) and at Minehead. 



Disturbances. 



The red beds of South Devon and West Somerset are so much 

 affected by faults that dips in any of the divisions must be taken with 

 extreme caution ; and as small faults affecting single homogeneous 

 members would not be nearly so readily recognized as those affecting 

 different divisions, most estimates of thickness based on breadth of 



