A paper by Mr. J. Lomas on “Desert Conditions and the Origin of the British Trias” appeared last year in the Proceedings of the Livepool Geological Society, and was reprinted, with some slight abridgement, in the November and December numbers of this Magazine. Valuable and suggestive as it is, I venture to think that its author, as is not unfrequent with enthusiastic advocates, is attempting to prove too much. I have more than once expressed my belief that the pebble beds of the Bunter, perhaps also its Upper and Lower Sandstones, were deposited on a lowland by mountain-fed rivers, and think it very probable that this lowland, in consequence of its temperature rather extreme, as is the case in Turkestan and parts of Persia; the occasional wind-worn sands being due to the one cause and the angular breccias to the other. But I think the Keuper Marls, on the whole, aqueous rather than æolian in origin, and the Lower Keuper Sandstones, with the Waterstones, indicative of the gradual setting in of inland sea conditions. From time to time, before the salt lake attained its greatest dimensions, the wind might blow the lowland dust into dunes or carry it away from the shore till much of it settled down beneath the water, but I still think that a large part of the material, which now forms the red marl, was brought down as river mud to this magnified Dead Sea, by the streams which had formerly transported sand and pebbles. In regard to this, however, we cannot at present speak dogmatically. More study is needed of the constituents of the Keuper Marl, of fluviatile, lacustrine, and even marine muds, as well as of the lighter æolian deposits, before we can determine what parts wind and water have respectively taken in making this member of the Trias. Here, however, I may remark that neither Professor Watts nor Mr. Walcot Gibson was the first to observe that in the Charnwood Forest region the Keuper fills up hollows in the older rocks.

One of the most beautiful features at the Giants' Causeway, from an artistic as well as a geological point of view, is the broad red zone that divides the Lower from the Upper Basalts. As is well known, this zone of lithomarge, bole, and laterite is remarkably persistent in north-eastern Ireland, and represents an interval of Eocene time when volcanic activity was lessened and when the basalts ceased to appear at the surface. At the same time, however, sporadic eruptions of rhyolite occurred, and some of the cones of acid lava supplied material for an interbasaltic conglomerate of rhyolite pebbles, which was discovered several years ago by Mr. A. McHenry near Glenarm.

Upon Sheet 339 (Devonshire) of the new Geological Survey maps, one instance out of the very numerous outcrops of igneous rocks thereon indicated proves to be of unusual interest by reason of its peculiar constitutional modifications in different parts of the same mass. The rockin question occurs about four and a quarter miles 15° north of west from Newton Abbot, near to the hamlet of Bickington, within the limits of a farm named Lurcombe. It is an intrusive amidst the shales and grits of the Culm, occurring almost on the junction-line between that series and the Devonian, whose massive limestones and volcanics dominate it in elevation within a quarter of a mile on the south-east.

The following observations on the Upper Keuper are mainly from the Charnwood district, wherein the relations of the Keuper to the older rock beneath are easily studied. The observations are arranged under three heads.

The following is a brief account of some minute Crinoid calyces, which appear to have been hitherto undescribed, sent me by Dr. Arthur Rowe, who obtained them from the Micraster cortestudinarium zone of the Upper Chalk.

In view of the interest which charriages and extensive overthrusts of low inclination are exciting in various parts of the world, an interest which has steadily increased since Nicol first put forward his explanation of the anomalous position of the Moine gneisses, it may be worth while to place before readers of the Geological Magazine a brief account of a remarkable structure in the Pyrenees, which has been noticed by various geologists, but only recently explained, by Bresson, as another example of overthrusting, and named by him the “nappe de recouvrement de Gèdre-Gavarnie,” after two villages in the neighbourhood. I have the less hesitation in doing this because the phenomena, considering their importance and their setting amidst the magnificent scenery of the lofty central parts of the range, appear to have received less attention from English geologists than they deserve. For these reasons also, other questions in Pyrenean geology are afterwards discussed in the light of some recent observations.