OF THE EILDON HILLS, IN ROXBURGHSHIRE. 213 
In the little basin to the south of Melrose, which has been so far described, 
we farther find a local and nearly concealed deposit of the red or Dryburgh sand- 
stone, which possesses considerable interest. It lies between the back of the 
* Quarry Hill,” which is a remarkable eminence of trap tufa close to the railway 
station at Melrose, and the strata of greywacke which we have seen to skirt con- 
tinuously the north-west slopes of the Eildons. This curious deposit may be easily 
detected in the wood inclosing a very small ravine with the local name of “ the 
Duke’s Glen,” and whose position will be best indicated by the numbers 28 and 29 
on the map. Itis here very nearly in contact with the trap tufa just mentioned. 
The strata absolutely resemble those at Dryburgh, four miles lower down the banks 
of the Tweed. They are purplish-red and white alternating, consisting of sandstone 
- mixed with much slate-clay, and are here occasionally very much altered in tex- 
ture; the soft sandstone becoming very white and crystalline, and the slate-clay 
becoming extremely hardened, without losing its power of being diffused in water 
by steeping. The strata are horizontal; and they are intermixed in some places 
with trap rock, intermediate between trap tufa and felspar rock. The altered 
sandstones and shales extend up both branches of the little stream until they 
touch the greywacke between the numbers 18 and 19, the former being iron- 
shot strata of greywacke, vertical and running north-east by east, the latter is 
the altered slate-clay of a pearl-grey colour, which can here only form a narrow 
strip dividing the red sandstone from the Eildon trap. I have not succeeded in 
tracing this patch of red sandstone farther west, at least with any certainty. 
T now come to speak of the trap tufa of Melrose, a rock always interesting in 
its geognostic relations, and on which my repeated examinations throw some light. 
It is a very perfect rock of its kind; including numberless fragments of felspar 
porphyry, usually rather small, and united by an earthy basis, which is either of 
a yellowish-brown or of a leaden-grey colour. It also contains many small frag- 
R; ments of a pearl-grey hue and uniform texture. These I believe to be portions of 
the altered slate-clay already spoken of. It is rather extensively quarried as a 
building material, for which it is exceedingly well adapted, as it is soft’ at first, 
and hardens on exposure. 
___In the Dingleton Burn, already mentioned, it may be seen that the vertical 
_ strata of greywacke run towards the “Quarry Hill,” without the slightest discon- 
_ tinuity or swerving ; and though we cannot trace the junction, it is all but certain 

that the mass of trap tufa must cut off the greywacke strata abruptly. Iwas able 
to detect traces of the greywacke in a very imperfect section immediately behind 
the Melrose Station, which is within a short distance of the lofty escarpment 
of trap tufa, so that the transition is probably extremely abrupt. The trap tufa 
is separated throughout from the Eildon trap by greywacke strata. I imagine that 
it is more recent than the Eildon trap. It has unquestionably succeeded the 
deposit of the Dryburgh sandstone. as is also manifested by the alterations which 
