stripes
The Golden Horn batholith is an approximately rectangular intrusion of 37x11 km in the Northern Cascades (Misch, 1966, Plate 7-1). The rocks are generally leucocratic and include a peralkaline granite and biotite granites. The peralkaline granite contains perthite, sodic amphiboles, sometimes aegirine, minor biotite and accessory fluorite, magnetite, zircon, apatite and carbonate. Stull (1973) distinguishes three types of alkaline amphibole; euhedral, early arfvedsonite, subhedral osannite and late riebeckite which is commonly found in miarolitic cavities.
MISCH, P. 1966. Tectonic evolution of the northern Cascades of Washington State: West-Cordilleran case history. In Tectonic history and mineral deposits of the western Cordillera. Special Volume, Canadian Institute of Mining and Metallurgy, 8: 101-48.
STULL, R.J. 1973. Calcic and alkali amphiboles from the Golden Horn batholith, North Cascades, Washington. American Mineralogist, 58: 873-8