520 



SCIENCE 



[N. S. Vol. LI. No. 1325 



ature and partly from his own field observations, 

 illustrating the three possible types of joint sys- 

 tems (1) max. tension = horizontal, min. tension = 

 vertical (weight of overlying beds) ; (2) max. ten- 

 sion :^ horizontal (anticlinal bending), min. ten- 

 sion = horizontal and at right angles together 

 (synclinal bending); and (3) max. tension := ver- 

 tical (upward relief), min. tension = horizontal. 



Notes on concretions : W. A. Tarr. Concretions 

 found in a black shale of the Pennsylvanian in 

 Boone county, Missouri, are believed to be syn- 

 genetic in origin. Eeasons for so believing are the 

 coanposition of the concretions (mainly clay and 

 silica), the arching of the beds over them, absence 

 of stratification lines passing through the concre- 

 tions, lack of evidence of lateral crumpling, slicken- 

 sides due to the consolidation of the beds around 

 the concretion, and the volume of the concretions. 



The Devonian of Balls county, Missouri: Gilbert 

 P. Moore. 



Notes on the coal industries of northeastern 

 France, Belgium, the Saar District and Westphalia : 

 H. r. Crookes. 



Data gathered by the writer for the War Dam- 

 ages Board of the American Commission to Negoti- 

 ate Pea«e, in Paris, on the coal industry of west- 

 ern Europe, shows, among other things, that, of 

 the reserves of eoal, Germany now controls 28 per 

 cent., England 49 per cent., France 7 per cent, and 

 Belgium 4 per cent. 



The aequiisition by Prance of the Saar district 

 does n<rt solve that country's future requirements 

 of coking coal for her Lorraine iron ore, because 

 of the fact that it is impraetioable to smelt the ore 

 with Saar coke unless it is mixed with about 20 

 per centt. of Westphalian or equally good coke. 

 Taken alone, Saar coke has been found to have 

 about 67 per cent, the e£B.ciency of Westphalian 

 coke. 



With the opening up of the Oampine Basin in 

 Belgium, France will be able to reduce her coke im- 

 ports from Westphalia, but, even so, she must rely 

 on the latter district for her principal supply of 

 blast furnace coke. 



Aside from a gain in actual eoal reserves of over 

 16 billion tons, it is estimated that the net mone- 

 tary igain by the acquisition of the German in- 

 terests in coal lands, mines, equipment and coke 

 plants in the Saar district is 411 million francs. 



The dependence of the French and Belgian metal- 

 lurgical industries on Westphalian eoke is offset by 

 the former's control of iron ore, for France now 

 controls about 85 per cent, of the iron ore reserves 



of Europe. It has been advocated that a portion of 

 the German indemnity be paid annually in terms 

 of Westphalian coke. This would permit of the en- 

 tire domestic coal production of both France and 

 Belgium being diverted to industries other than 

 metallurgic, but at best would be only a ternporary 

 arrangement. The exchange of iron ore for West- 

 phalian coke, arbitrated by a committee from each 

 country, might be a better solution, and is one that 

 has been recommended. 



The influence of the differential compression of 

 sediments on the attitude of bedded roclcs : Maurice 

 G. Mehl. The diminution of the height of a col- 

 umn of sediment upon consolidation is brought 

 about chiefly by the loss of water through the 

 weight of the column. The rate of compressibility 

 for shales is greater than for sands because of the 

 differences in the shape of the particles. In the 

 plate-like particles of shale there is a larger sur- 

 face and hence a greater separating water film 

 per unit volume of shale. The compressibility of 

 sand is very slight while for shale it may be as 

 high as 20 per cent. It f oUows that any difference 

 in the total thickness of types of sediments with 

 different rates of compressibility in adjacent col- 

 umns will impart secondary dips to all beds above 

 the irregularities. Unequal thicknesses of totals 

 may arise through the lateral gradation of one 

 type into another or through the actual thinning of 

 a bed of a given type. Likewise any irregularity 

 on an unyielding depositional surface will tend to 

 produce different totals in the overlying columns 

 of sediments. While the small isolated dome-like 

 anticlines typical of the Mid-Continent oil field may 

 have acted as localizing influences for the expres- 

 sion of later thrusts acting through great dis- 

 tances it is thought that these small structural 

 features are chiefly the result of the differential 

 compression of sediments. 



Compression of sediments as a factor in the for- 

 mation of coal basins: E. B. Beanson. 



On the Pennsylvanian stratigraphy in the mid- 

 continent region: E. 0. Moore. 



Episodes in BocTcy Mountain orogeny: C. L. 

 Dake. West of Cody, along Greybull and Sho- 

 shone Elvers, are a series of yellow sandstones and 

 red and gray shales with conglomerate layers. The 

 conglomerates, which include granite pebbles, in- 

 volve erosion down to the pre-Cambrian, and the 

 beds rest with slight angular unconformity on the 

 Cody (Niobrara and Pierre) shale. These con- 

 glomerates are themselves folded and are involved 

 in large overthrust faults. This implies two epi- 



