PETROGRAPHIC GEOLOGY AND DESCRIPTIONS. 461 



Olasolyte. Quartz. Amygdaloid.] 



No. 632A. CLASOLYTE.' 



From a point about half a mile west of No. 630. 

 lief. Annual Report, x, page 63. 



Mccj. Vein about half an inch wide, composed of a central band about one- 

 fourth of an inch wide of hard, granular substance of a brown color, and on each side 

 a band of reddish "chalcedonic" quartz, each about an eighth of an inch wide. The 

 first appears to be composed of fine clastic materials, but the quartz band on either 

 side of it is evidently of chemical deposition and is in wavy layers similar to the 

 layering in agates. 



Mic. The framework of the clastic grains is dark with iron oxides. The grains 

 are partly of quartz and partly of plagioclase, and there are occasionally areas of 

 greenish thalite (?) These grains are sometimes rounded and sometimes angular. 



One section. 



Aye. Manitou. 



I'ni/in-k. The term clasolyte is adopted from Wadsworth (Michigan Geological 

 Survey Report, published 1893, page 147), which is applied by him to a fragmental 

 rock which fills fissures in an older rock from above. N. H. w. 



* 



No. 632B. QUARTZ. (GeodeJ 



In the same beds as No. 632A. Quartz geodes in basalt, with some amethyst and agates. Lying just 

 above a conglomerate. 



Ref. Annual Report, x, page 63. 



Meg. The specimen consists of the quartz crystals of a siliceous geode presenting 

 their terminal facets, becoming massive quartz and finally agate-like bands, the last 

 serving as attachment to the basalt in which the geodic mass was originally formed. 



No section. 



Aye. Manitou. N. H. w. 



No. 633. AMYGDALOID. 



Immediately underlies No. 632. Thin, irregular beds of amygdaloidal trap containing red amygdules 

 graduating into No. 634. 



Ref. Annual Report, x, page 63. 



No section. 



Age. Manitou. N. H. w. 



No. 634. AMYGDALOID. 



Immediately underneath No. 633, near the top of the conglomerate. 

 Ref. Annual Report, ix, page 41; Annual Report, x, pages 63, 64. 



Meg. Contains agate, stilbite, laumontite and chlorite. The red coatings, 

 which are apparently of heulanditic material, prevail along the red seams that cross 

 and recross the rock. In some cases the red material penetrates the whole, and is 



