THE GEOLOGISTS' ASSOCIATION
At the meeting held at University College, Gower Street, W.C.1, on Friday, December 5th, 1919, the following lecture was delivered: "Geological Work on the Western Front," by W. B. R. King, B.A., F.G.S. A short description was given of the geology of that part of Belgium and France over which military operations were conducted by the British Armies between 1915 and the summer of 1918. It was mainly confined to the lithological divisions and did not deal with the palæontological side of the subject. The main physical features were taken, showing how they are connected with the geological structure. The effect of the geology and geological structure on certain questions of military operations was dealt with, notably with regard to water supply and military mining and dug-out construction. Particular attention was paid to the problem of obtaining water from boreholes in the Landenien (Thanet) sands, the causes and effect of the seasonal variation of water-level in the chalk, and the problem of the military mines near Messines, Givenchy-les-la-Bassée, and Souchez. The lecture ended with a description of certain maps which were prepared for the armies in France, and notes on several other problems which had to be dealt with by the geologists attached to General Headquarters.
On Friday, January 2nd, 1920, Dr. A. E. Trueman, F.G.S., read a paper on "The Liassic Rocks of the Cardiff District." The author said that the greater part of South Glamorganshire, from Cardiff westwards to beyond Bridgend, consists of lower Liassic rocks (Hettangian and Lower Sinemurian), which are well seen in some 20 miles of magnificent cliff sections. Only meagre descriptions of these rocks have been hitherto published. A detailed study has been undertaken, first because nowhere else in this country are such continuous sections of these rocks available, and, secondly, because the normal deposits consisting of limestones and shales seen near Cardiff, when traced westwards, pass into a littoral facies of massive limestones and conglomerates. In the present communication an account of the normal Liassic rocks of the Cardiff district is given, as this will form a basis for the correlation of the modified deposits further west. The lecture was illustrated by lantern-slides and specimens.