322 Reviews — Cotteswold Naturalists' Field Club. 



Bulletin No. 471 (1912) consists of " Contributions to Economic 

 Geology (short papers and preliminary reports), Part II, Mineral 

 Fuels". The subjects dealt with are petroleum and natural gas, coal 

 and lignite ; including gas in Alabama, petroleum and gas in Kentucky 

 and Utah, petroleum in California and Wyoming, coal in North 

 Carolina, Colorado, North Mexico, Utah, and Wyoming, lignite and 

 coal in Montana, and lignite in North Dakota. These short papers 

 and reports occupy, with index, etc., 663 pages, and they are 

 accompanied by 62 plates (maps and sections) and 15 text-illustra- 

 tions. They include topographic and geologic descriptions, records 

 of borings, analyses, etc. 



Taking, for example, the report on the " Geology of the San Juan 

 Oil Field, Utah ", by Mr. E. G. Woodruff, we learn that the oil-field 

 is situated in the vallej' of the San Juan River in south-eastern Utah, 

 that the area is part of the Colorado Plateau, consisting of much 

 irregular and uneven ground, of which about 80 per cent is destitute 

 of vegetation, and subject to erosion by the local and occasional, 

 but copious, rains. There are two canyons with precipitous walls, 

 about 1,400 feet deep, and possessing grand scenic beauty. More 

 than 5,000 feet of strata ranging fiom Carboniferous to Jurassic are 

 exposed in the field, and it is in the older strata, the Goodridge 

 formation of the Pennsylvanian S3'^stem, that the oil occurs. The oil 

 is generally found in sand or sandstone, but small quantities occur in 

 limestone. The Goodridge Sand, 26 feet thick in places, is one of the 

 most productive beds. Oil springs issue from different strata near 

 the level of the San Juan River, the highest seeps in geological position 

 being those from the Goodridge Sand, the lowest being in stratigraphic 

 distance 1,450 feet below. The deepest well is 1,425 feet, but in 

 some situations oil occurs at about 150 feet from the surface. It is 

 noted that all the prolific wells are situated in synclinal strata, the 

 area being "moderately complicated by north-south folds". 



Bulletin No. 501 (1912) is on "The Bonnifield Region, Alaska", 

 by Mr. S. R. Capps. The region contains productive auriferous 

 placers and extensive lignite deposits ; there are also possibilities of 

 lode-mining. The report i§ well illustrated by photographic views 

 and maps. 



XII. — Cotteswold Naturalists' Field Club. 



PART I of vol. xviii of the Proceedings of this Club (1913) 

 contains the address of the President, the Rev. Walter Butt, 

 who dealt with some problems connected with Prehistoric Man, and 

 concluded that the earliest safe evidence of man's existence in the 

 British Islands was in the Mousterian stage. Reports of various 

 excursions contain much of geological interest, especially in reference 

 to Droitwich, Cleeve Hill, Thornbury and Aust, Painswick and 

 Kimsbury Castle, Bath and Box (the report on which contains 

 a plan of the Box quarries). A more distant excursion was made 

 to Bridport (outside the bounds of the Club), and the report is 

 accompanied by some excellent photographic views of cliff scenery. 

 The original articles include a paper, with one plate, on "Some 



