Vol.58.] To THE PHYSICAL GEOGRAPHY OF THNIR AGE, 191 
near Paignton, and about Torquay. Fragments of shale and grit 
are abundant when they rest upon the Culm-Measures north of the 
Tiverton Valley; those of igneous rock predominate at Dawlish 
and Teignmouth, and almost exclude all others in parts of the 
Crediton Valley.” The red matrix is more or less sandy ; sometimes 
rather incoherent, at others hard enough to furnish a good building- 
stone.” The mass often shows stratification, and is occasionally 
interrupted locally by bands of sand or clay, into which it passes. 
These breccias are exposed over an area, east and north of Dart- 
moor, which is not unfrequently from 6 to 8 miles broad. The 
maximum thickness of the group, sandstones and breccia, is about 
1000 feet; but I cannot find a precise statement as to the latter, 
which, however, must sometimes reach a few hundred feet. It will 
be inferred from what has been said that the fragments have not 
travelled for any great distance. The sedimentaries have been 
derived, as the case may be, from Devonian or Carboniferous strata. 
For the igneous fragments also we probably need not go very far.* 
Many of the more compact may have been derived, as suggested by 
Mr. Worth, from almost contemporaneous volcanoes at no great 
distance. ‘The ordinary granite of Dartmoor is said to occur rarely, 
. but fragments of a fine-grained rock, in which crystals of felspar 
are conspicuous, seem to me likely to represent external portions of 
the massif which have now been removed. If so, some of them 
’ can hardly have travelled less than 7 or 8 miles. 
VII. Tar Brecotas oF tHe THURINGERWALD. 
- So many authors have described this typical example of Roth- 
liegende breccia, that I shall content myself with referring to their 
publications and giving an epitome of some notes which I made in 
the summer of 1900, when Mr. Hill and I visited Eisenach. 
A great mass of this rock forms the western end of the Thiiringer- 
wald hill-region, which cannot be less than 600 feet in thickness. 
Slight indications of stratification are generally visible; and in the 
lower part,’as may be seen in the Annathal, and in the Georgenthal 
west of the Wartburg, it is regularly interstratified with beds of sand 
or marl into which it passes rapidly, as shown in the appended 
section (fig. 1, p. 192). When the breccia is not thus interrupted, 
it often forms bold crags. The matrix, which frequently makes up 
about half the volume, is dull red in colour and more or less sandy. 
The fragments vary in shape from angular to subangular, are 
commonly less than 2 inches in diameter, but occasionally 4 or 5 
inches, and sometimes rather over 12. On the Wartburg they 
1 Here they are generally subangular or even rounded, and from the 
Devonian Limestone. 
* For the variations in the materials and their shape, see Ussher, Quart. 
Journ. Geol. Soc. vol. xxxii (1876) p. 588. 
3 As, for example, St. Mary’s Church, north of Teignmouth, and Heavitree 
near Exeter. 
* For the fullest information on this subject, see R. N. Worth, Quart. Journ. 
Geol. Soc. vol. xlvi (1890) p. 69. 
