310 REV. J, F. BLAKE ON A REMARKABLE INLIER | [| May 1902, 
many are not unlike the rocks that might be gathered from the 
very locality with which I am here dealing. 
A similar origin has been suggested by Mr. Stebbing’ for the 
boulders in the Chalk; and it is not unlikely that hereafter other 
curious breccias and scattered angular stones may be referred to the 
same Class of erratics. 
Discussion. 
Mr. H. B. Woopwarp remarked that he had given his explanation 
of the breccia-beds in the discussion on Prof. Bonney’s recent paper. 
He saw no occasion for the introduction of ice-action. The 
conditions existing in the Moray Firth were even now somewhat 
similar to those of Upper Jurassic times, for there are steep and 
lofty cliffs, such as those by the Sutors of Cromarty, whence great, 
shoots of rock fall on to the foreshore and into the sea. ‘The 
relations between the Jurassic and older rocks had been modified 
by post-Jurassic disturbance, as some of the non-brecciated beds 
were much broken in proximity to the great fault. He was glad 
to be in general agreement with the Author regarding the sequence 
of the strata. He had obtained near Navidale a large ammonite 
of the ‘ giganteus *-type, and this, together with the Jsastrea, had 
suggested the existence of Portlandian Beds. 
Mr. Hupreston said that he had no intimate acquaintance with 
the locality, and he expressed regret that Prof. Judd was not present 
to give his views on the additional matter brought before the 
Society. His classic paper on the ‘Secondary Rocks of Scotland ’ 
had left as a legacy to future geologists the explanation of the 
breccia-beds—a challenge which the Author had taken up. The 
present paper was full of details, and only those intimately.ac- 
quainted with the locality could grapple with the descriptive 
portions. ‘lhe Author was especially capable of determining the 
horizons at which these breccia-beds occur, and it was interesting: 
to note that they commence in Middle Kimeridge times, and 
culminate in the zone of Perisphinctes Pallasi (? Ammonites biplex). 
Hence the horizon of the chief breccia-beds was pre-eminently 
Portlandian, as indeed had been inferred by Prof. Judd, and it 
was further emphasized by the occurrence of Jsastraa oblonga. 
The sting of the paper was in its tail—that is to say, in the 
suggestion as to the origin of the breccia-beds. Such beds had 
always been fruitful of divergent opinion as to their mode of 
formation, and when geologists were hard pressed for an explanation 
of facts involving heavy transport, they usually had recourse to ice- 
action. Such a theory in this case was peculiarly inappropriate. 
The fauna and flora of the Jurassic Period generally indicated 
warmth, and the plant-remains of the Portlandian especially so. 
Take the case of /sastrwa itself, a reef-building coral requiring a 
tropical temperature, with an isotherm of 68° Fahr. at the very 
least. How were we to explain this in conjunction with a postulated 
1 Quart. Journ. Geol. Soe. vol. liii (1897) p. 218. 
a 
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