TRANSACTIONS OF SECTION C. 1017 
7. On certain Diatomaceous Deposits (Diatomite) from the Peat of 
Aberdeenshire. By W. Ivison Macapay, F.C.S., FIC. 
The material was found below the peat in certain districts of Aberdeenshire, 
but principally in the basin in which lie Loch Kinnord and Dayiu. After removal 
of the surface peat fuel the lower and more highly mineral portion was cut in 
blocks and air dried. The substance then consisted of almost pure diatomacea 
bound together by the remains of sphagnum, equisetacea, &c. Besides being found 
underlying peat, the substance was also obtained on the shores of Loch Kinnord, and 
the more pure diatoms were thickly distributed over the bottom of the deeper por- 
tions of the lake. These latter. however, from the want of the binding obtained from 
the marsh plants above stated, could not be rendered readily available for market. 
An interesting point regarding these deposits was, that, whilst in Loch Kinnord 
an abundant supply of the diatoms could be obtained, in the neighbouring Loch 
Davin scarcely a single diatom (recent or fossil) was found. This was probably due 
to the fact that, whilst the feeding waters of Loch Kinnord flowed from hills con- 
sisting of a coarse and much disintegrated granite, and consequently containing 
a considerable proportion of soluble silica, the Loch Davin waters were obtained 
from hornblendic mountains, and held much less soluble silica in solution. 
The material was principally used for the manufacture of dynamite, and a 
considerable quantity had been forwarded to the works for this purpose. 
Other uses could be found for the material, suchas the manufacture of ultra- 
marine, for which from the very small proportion of iron present the diatomite 
was more especially to he recommended. As an absorbent, it was of fully double 
the value of the ordinary German varieties of Kieselepolr. 
The paper was illustrated by specimens and diagrams.! 
8. List of Works on the Geology, Mineralogy, and Paleontology of 
Staffordshire, Worcestershire, and Warwicksnire. By W. Wutraker, 
B.A., F.G.S., Assoc. Inst.C.H.—See Reports, p. 780. 
FRIDAY, SEPTEMBER 11. 
The following Papers and Reports were read :— 
1. The Volcanves of Auvergne. By Temprst AxpErRson, M.D., B.Sc. 
The modern dry plate process of photography has placed in the hands of 
geologists the power of rapidly and faithfully recording and reproducing before 
an audience of any size many geological and especially volcanic phenomena which 
it would be impossible adequately to describe in words. 
By means of the oxyhydrogen lantern a number of photographs were shown on 
the screen which had been taken by the author in the volcanic district of the 
Auvergne and adjacent parts of the Velay and Vivarais, in Central France. 
Cones of scorize with craters were contrasted with the Domitic Puys in Auvergne, 
and these again with the Phonolitic hills in the district of the Mezenc. The 
appearances of various lava streams both on the surface and where exposed in 
sections were shown, especially those of the valleys of Jaujac and Montpezat. 
Lakes in extinct craters were contrasted with those formed in pre-existing valleys 
bebind dams of volcanic ejecta, and the general scenery of volcanic rocks was com- 
pared with that of other adjacent formations. 
1 Trans. Edin. Geo. Soc., vol. iv.; Trans. Min. Soe. of Great Britain, 1884; 
Chemical News, November 21, 1885. 
