n6 SCIENCE PROGRESS 



of the island. It is compared with rock-platforms of the same 

 height on the coasts of Norway and Western Scotland. 



Glacial deposits of Eocene age are described from south- 

 western Colorado by W. W. Atwood (Professional Paper 95 — B, 

 United States Geological Survey, 191 5). A typical boulder 

 clay, with a subordinate pebbly till, rests unconformably upon 

 a Cretaceous shale, and is unconformably overlain by an Eocene 

 conglomerate. This discovery leaves only the Ordovician, 

 Silurian, Jurassic, Oligocene, and Pliocene at present without 

 some record of glacial action. 



Petrology. — The Carboniferous igneous rocks of parts of 

 the Clyde plateau have been dealt with in papers on the geology 

 of the Kilsyth Hills, by J. V. Harrison (Trans. Geol. Soc. Glasgow, 

 1 91 6, 15, 315), and on the igneous rocks of Bute, by W. R. 

 Smellie (ibid. 334). Mr. Harrison describes the usual types of 

 basalt lavas from this plateau, along with bostonite and kerato- 

 phyre dykes. Mr. Smellie describes the probably Arenig 

 epidiorite and serpentine of Scalpsie Bay, but the bulk of his 

 work deals with an interesting series of Carboniferous igneous 

 rocks. Several trachyte (or bostonite) lavas, rich in albite, are 

 intercalated with the ordinary plateau basalts and mugearites. 

 A minor intrusion in South Bute carries numerous xeno- 

 liths of fresh basic and ultrabasic plutonic rocks, including 

 gabbro, anorthosite, augite-peridotite, diallage-rock, hyper- 

 sthene-rock, and serpentine, which may represent samples of 

 the unknown buried plutonic products of Carboniferous igneous 

 activity in Scotland. 



The petrology of the Permian necks and associated in- 

 trusions of the Fife coast between Largo and St. Monans is 

 described by Mrs. Wallace (Trans. Geol. Soc. Edinburgh, 1916, 

 10, 348). Some of the rocks are nepheline-basalts ; others are 

 described as analcite-basalts and monchiquites. Large xeno- 

 crysts of hornblende, augite, biotite, and anorthoclase, occur in 

 the tuffs and dykes, also olivine and hornblende nodules. 

 These necks and their contents are similar in most respects to 

 the Ayrshire vents of the same age. 



The igneous rocks of the Berwyn Hills (North Wales) are 

 described in a posthumous paper by T. H. Cope, whose work 

 has been edited by C. B. Travis (Proc. Liverpool Geol. Soc, 

 Cope Memorial Volume, 191 5, pp. 115). The rocks are of Bala 

 age, and consist of rhyolites and andesites with their respective 



