Horace B. Woodward — Notes on the Devonian Rocks. 449 
noting a few facts in the local geology, some reinarks be raade on 
the work that has been done, so that if possible more labourers may 
be tempted to come into the field. 
Düring a year’s residence at Newton Abbot (1874-75), wbile 
engagod in the revision of the boundaries of tlie Secondary and 
newer deposits, I was enabled to gather a few facts which may be 
of interest concerning the succession of the Palseozoic rocks in that 
neighbourbood ; but I should mention that my work was restricted 
to the older rocks immediately bordering the Secondary strata, as a 
revision of the Palmozoic rocks is postponed, so far as the Geological 
Survey is concerned, until the Six-inch Ordnance Maps are issued. 
The publisbed maps of the Geological Survey sbow but two 
general divisions in tlie Devonian rocks, the slaty group having one 
colour, and the limestones anotber. The relations of these are not 
exhibited, and one migbt conclude that tlie limestones occurred at 
dilferent borizons as great lenticular or isolated masses. A careful 
examination of the ground, however, soon dispels this notion ; and 
wben the boundaries are traced out, it will be found that tlie fre- 
quently abrupt terminations of the limestone are due to well-marked 
faults. Wlierever positive evidence was to be obtained, a definite 
sequence in the Devonian rocks was manifest — the limestones forrn- 
ing an upper group, tlie slates a middle one, and red sandstones a 
lower group. It must be admitted that this positive evidence is not 
often obtained in sections actually showing a junction or super- 
position, but it is very clearly established wben the beds are traced 
out over the ground. The relation of the rocks to tlie form of the 
countryis very clear, and the aetual boundary-line between the lime- 
stones and the slates beneath may usually be defined witbin a few 
feet. Wben, as is often tlie case in some limestone quarries, tlie 
dip of the beds cannot be distinguished amidst the cleavage and 
jointing, the general inclination can be determined when the 
boundary with the slates bas been drawn, according as the line 
runs a long way or but a short distance into tlie ravines and valleys 
that intersect tlie escarpments. In tliis way the little masses of 
limestone mar Woolborough and the slates of Abbots Iverswell, as 
noted by Jukes and Dr. Holl, can be readily correlated with the 
Devonian limestones and slates, instead of being classed with the 
Culm-measures, as represented on the Geological Survey Map. 
These beds are abruptly faulted against the Culm-measures on the 
west. 
The slates may be clearly traced beneath the limestone south- 
east of Daccombe, at Barton, Anstey’s Cove, Wickaborough, and 
other places. The boundary with the red sandstones beneath is not 
so well marked, for the lithological characters are not so sharply 
defined, nor have we the benefit of the springs avhich are thrown off 
at the junction of the slates with tlie limestone. 
The relations of the red sandstones to the beds above are, how- 
ever. well shown at Cockington. Aquarry about a quarter of a mile 
north-east of Livermead shows beds of red sandstone dipping a little 
to tlie east of north, wliile furtlier west they are shown dipping a 
DECADE II. — YOL. IV, — XO. X. 29 
