ransome: the ray quadrangle 383 



distinct beds but does exhibit a pronounced striping, due to the 

 alternation of dull red and dark gray or nearly black bands 

 parallel with the planes of stratification. These as a rule are 

 less than one foot thick. About midway between the top and 

 bottom of the formation the striped beds are overlain by fairly 

 massive beds, up to 6 feet thick, of even-grained buff or pinkish 

 quartzite associated with flaggy, variegated, red, brown and 

 gray beds and with some layers of red and grayish shale that 

 are suggestive of the Pioneer shale. In the upper part of the 

 formation the beds become thin, flaggy, and rusty. The Drip- 

 ping Spring quartzite, as may be seen from fossil ripple-marks, 

 sun-cracks, and worm-casts, visible on exposed surfaces of the 

 beds, was deposited in shallow water. It contains, however, no 

 pebbles in the Ray cjuadrangle, and their absence, together with 

 the banding of the lower beds as seen in section, serves to dis- 

 tinguish it from the pebbly cross-bedded Troy quartzite to be 

 described later. The formation is in most localities in the Ray 

 quadrangle closely associated with intrusive masses of diabase, 

 usually in the form of sheets. Some of the characteristics of 

 the quartzite are probably due to the effect of these intrusions. 



Mescal limestone. The Mescal limestone conformably overlies 

 the Dripping Spring quartzite and in the Ray quadrangle is well 

 exposed in the Mescal Mountains from which the formation takes 

 its name. It is represented in the Globe quadrangle in a numT3er 

 of small fault blocks and as inclusions in diabase, but when the 

 Globe report was written the limestone of these isolated masses 

 was not known to be distinct from and older than the Devonian 

 and Carboniferous limestones. It w^as consequently included in 

 the ''Globe limestone" of that report. 



The Mescal is composed of thin beds that have a varied range 

 of color but are persistently cherty, the siliceous segregations as 

 a rule forming irregular layers parallel with the bedding planes. 

 On weathered surfaces these layers stand out in relief and give 

 to the limestone the rough gnarled banding that is its most 

 characteristic feature. The general hue of the formation is gray 

 or white, but some beds are j^ellow, some buff and some rusty 



