400 abstracts: geology 



The arc spectrum of iron was used in accordance with the recommen- 

 dations of the International Wave-Length Committee. The method 

 of procedure was that of Buisson and Fabry (Journal de Physique, 

 7: 169. 1908). Most of the wave lengths were determined by means of 

 three or more interferometers in which the orders of interference ranged 

 from 15 to 60 thousand waves. The International secondary standards 

 were used in this comparison instead of the fundamental cadmium 

 standard. The mean difference between the present observations and 

 the International standards is about one part in four million. 



Comparisons with all the grating observations of iron lines which 

 have been made on the LA. system prove that more secondary stand- 

 ards were needed to obtain the highest accuracy in grating interpola- 

 tions. Some of the grating observations show a difference in wave 

 length which is a function of the intensity of the line. The measure- 

 ments with' the interferometer appear to be quite free from this effect. 



In the course of the investigation over 600 lines were examined by 

 means of several interferometers in order to discover the limiting or- 

 ders of interference. This gave an idea of the width or sharpness of 

 each line. The data on sharpness were then correlated with intensity, 

 pole effect, and pressure shift. K. B. 



GEOLOGY. — Geology and oil prospects of the Cuyama Valley, Califor- 

 nia. Walter A. English. U. S. Geological Survey Bulletin 631 

 M, pp. 191-215. 1916. 

 The Cuyama Valley area lies within the California Coast Ranges, 

 south of the important oilfields which border the San Joaquin Valley 

 along its southwest side. Although written primarily as a discussion 

 of the oil possibilities the report also brings out certain features of the 

 complicated Coast Range structure and stratigraphy. 



The rocks outcropping are a thick Cretaceous formation of dark 

 shale, and Tertiary clayey and diatomaceous shales and sandstones. 

 The Cretaceous beds are quite uniform in lithologic character and vary 

 little from beds of the same age in other parts of the Coast Ranges. 

 The Tertiary formations, however, are of extremely variable lithology. 

 During parts of Tertiary time the shore line probably crossed the Cu- 

 yama area, for in going from west to east within this area the lower 

 and upper Miocene rocks are traceable from marine beds typical of 

 Coast Range deposition into non-marine beds of the type of the Ter- 

 tiary formations present in the Mojave and Tehachapi regions to the 



