WARRE.V AND PALACHE. — QUI.VCY PEGMATITES. 



133 



now exposed is about 20 feet. The indications are that it may extend 

 upward into the granite toward the south for some distance. 



Figure 1. 



Sketch of cross-section of upper portion of the large Fallon quarry pipe. 



A, outer dark colored zone 2 to 5 inches wide, finer in grain than the granite, 

 richer in dark silicates; both margins richer in dark silicates than the middle, 

 and with an arrangement of minerals parallel to the margins, a, offset in the 

 band. 



B, zone of graphic-granite 2 to 4 inches wide. An intergrowth of microcline- 

 albite microperthite (GO per cent) and quartz (30 per cent) with a few scat- 

 tered i)risms of riebeckite. Passes almost imperceptibly into the next zone. 



C, principal zone of unequal, but prevailingly coarse-grained granite or 

 pegmatite; contain.^ a streak of grai)hic-granite (crossed) and numerous large 

 crystals of riebeckite-aegirite. ci, concentration of fine zircon, quartz, aegirite 

 rich material next to quartz center, c^, quartz bleb (2 or 3 inches) with 

 penetrating aegirite prisms. 



D, c<'ntral mass of quartz, grayish-white and massive, penetrated by radiat- 

 ing acgirito groups and large aegirite-ricbcckite cr\'stals along margins (dn) 

 and containing centrally masses of sulphids with fluorite (di). One foot wide 

 by two high, roughly. 



Compare with Figure 13, Plate 1. 



The concentric structure of this ma-ss is marked as in the other pij)e3, 

 but little if any radial structure can be seen. The section expo.sed in 

 the quarry wall shows that in its general characteristics it is closely 



