948 PROFESSOR J. PRESTWICH ON THE EVIDENCES OF A SUBMERGENCE 
lying the shelly grit, while in fig. 17 (their fig. 11) it rests on a remnant of a Eaised 
Beach, lying on a platform of marine erosion. 
Fig. 17 .—Section at Princes Lines (the sketch only is after Ramsay and Geikie). 
of, Limestone Rubble-drift or head (Newer agglomerate, No. 5, of the authors), 
c, Raised Beach (Gravelly conglomerate of the authors). 
Why this agglomerate is taken to be more recent than that in Bosia Ba}^, is 
that it contains fragments of Mammalian bones, which the other is supposed not 
to do. But it seems to me rather a reason to prove that that breccia (No. 1) is 
occasionally ossiferous, and also that it is newer than the Baised Beach. The 
uncertainty of the occurrence of bones is, as before mentioned, one of the features of 
the Bubble-drift. Mr. Smith speaks only of one breccia with remains of the extinct 
Mammalia, though he considered that there was a re-constructed breccia of modern 
date formed by the washings and debris of the older breccia, which it consequently 
closely resembles, that resemblance being aided by the continued deposition of 
carbonate of lime and cementation of the mass. This differs, howmver, from the older 
cave breccia and from the agglomerates of the authors in containing the remains of 
later Man and his handiwork, and of recent animals. The distinction has been well 
shown by Mr. Busk.* 
With respect to the origin of the breccia, Messrs. Bamsay and Geikie attribute 
their older agglomerate on the western slopes to severe cold at the time “ when the 
Bock had a wider area of low ground at its base, and when, so far as we know, it was 
not tenanted by land animals.” They justly, however, observe, “ something more 
than the mere action of strong frost is needed to account for the presence of the wide¬ 
spread and massive agglomerate of Bosia and Buena Vista.” How% then, is the trans¬ 
port of large blocks and the accumulation of the debris in so large a volume over 
the small incline of 8° to 9° (in places not more than 2° to 3°) for a distance of at least 
550 yards from the base of the main slope, to be accounted for ? Winter torrents will 
not suffice. A cone of dejection spreads out fan-shaped, and would not extend so far 
beyond tlie foot of the main slope, and the debris would show symptoms of wear and 
rolling, as well as a gradation from coarso to finer materials. ‘‘But in the great 
limestone-agglomerates, not onl}'' are the stones all more or less sharply angular and 
arranged generally without any reference to size or figure, but tlie agglomerate at the 
foot of the Bock is not sensibly coarser than that wdiich occurs at Bosia Bay, a 
distance of 500 or 600 yards away.” It is, therefore, impossible to look upon the 
rubble as a talus, or as thrown out by cones of dejection. 
* ‘ Trans. Inter. Coiigr. Pretis. ArcLasology,’ Norwich Meeting, 1869. 
