Revieivs — Geological Survey, Great Britain. 373 



latest period of folding took place after the deposition of the Middle 

 Miocene (Sarmatian). The Central Caucasus was raised to its present 

 height, its folds pinched in to become fan-folds, and the transverse 

 fractures were developed on which Kazbek and Elburs built up their 

 huge piles of lava. 



The different formations are described and lists of their included 

 fossils are given. The Quaternary and Recent deposits include Coast 

 deposits of the Caspian up to 10 metres above the present level. Old 

 Caspian and Black Sea deposits up to 26 metres, and the Aralo- 

 Caspian Stage with terraces at 96 and 186 metres. 



In the Pliocene the Pontian division contains gas in the Apsheron 

 Peninsula. The Miocene and Oligocene beds yield much petroleum. 

 The Cretaceous and Jurassic are Avell developed, and an outline is 

 given of their stratigraphy. Basal conglomerates of the Jurassic lie 

 un conformably on the eroded surface of the Palaeozoic schists, of 

 whicli they contain pebbles. 



Triassic beds occur in the Western Caucasus, in the upper basins 

 of the Bielaya and Little Laba Rivers, unconformably overlying 

 Upper Carboniferous. The Palaeozoic schists are probably in the 

 main of Carboniferous age, though some may possibly be Silurian. 

 A description is given of the main divisions of the igneous rocks 

 which occur, and a note on the glaciers concludes the pamphlet. 



Dr. Oswald's work is of the greatest value, and must form the 

 basis of all future explorations in this most difficult but remarkably 

 interesting country. 



III. — SUMMAKT OF PeOGKESS OF THE GEOLOGICAL SuRVEY OF GkEAT 



Britain and tbe Museum of Practical Geology for 1913. 8vo; 

 pp. 107. Dulau & Co., 1914. Price Is. 



rpmS number of the Summary of Pro(/ress shows the interesting 

 jL nature of the work which has been accomplished during the 

 past year and the large number of new and important facts which 

 that work has brought to light. 



The record of field-work is condensed into seventy pages. It is 

 arranged as usual according to the different districts in which work 

 has been prosecuted. 



In England and Wales we find that in the Denbighshire district 

 the surveying has been carried southwards into Shropshire, while the 

 part of Cheshire included in the district has been completed and some 

 further colliery information alone remains to be gathered in Flintshire. 

 The Corwen-Glyn Grit has proved a valuable guide in disentangling 

 the structure of the Ordovician rocks, but it has been found difficult 

 to separate the Llandovery and Tarannon Beds, though the presence 

 of both is proved by the graptolites. The examination of the 

 Carboniferous Limestone escarpment south of Llangollen has been 

 finished, and in Flintshire some sandstones hitherto regarded as Lower 

 Coal-measures are now proved to be Millstone Grit. In Cheshire the 

 survey of the peninsula of AVirral is now complete, and a commence- 

 ment has been made on the deeply drift-covered Triassic area near 

 Oswestry. 



