Rossland Dyke

Syenite of one of the Coryell Intrusions (see 031-00-036) is cut by a 1.5 m thick dyke in the col between Record and Granite Mountains. The rock contains about 5% polygonal pseudoleucites, augite prisms (37%), brown biotite (20%), apatite and magnetite and a matrix largely composed of material identical to that forming the pseudoleucites; this is difficult to determine, but probably comprises orthoclase, altered nepheline and zeolite. A chemical analysis is given by Daly (1912, p. 368).