The Florence tribune., 1901-10-19

hence tn be considered older than the rock. Most of these schistose rocks are s;lvery muiscovite quartz on the Providence mine schists with fribolete in many cases. Some are doubtless altered eiyneisses, while others are metamorphosed algonkian sedimentary rocks. Those near the voeauic area are much kaolinized, small granite veins or dykes penetrate the schists. Several diabase dykes in eruptive granite are shown. They are all small | and short and are numerous only near the Conley Spring, on the west side of the mountain of the East King. These | are probably of algonkial ore, belong ing to u series of wide distri button in tho front range and not with the rock of the volcano. Augite is commonly changed to uralite hornblend in these dykes.
 1 The andesytes, though not very diff fesent in character, are the two princi pal rocks oferuption. The oreimpor- tant type is an augite hornblend ande syte. with some mica in the Andes and the St. Louis lode. It is probably the earliest massive of the volcanic and the smallest areas of the hills, peaks in the Silver King Basin, also of the old Wonoh Wather mine on Queen creek, are regarded as representing a large body which has been in great degree destroyed by explosive outbursts or covered by tue tuff and braces of the eruption. This andesyte is character ized by its large prysmatic crystals oi apetite, which are often larger than any other constituent of the rock. The second andesyte variety occurs in the dykes cutting the braces. especially about the Silver Crown mine. Easter ly to Conley Spring the rock is aa au- gite andesyte, with some hornblend and mica and had denser ground mass than the earlier type. Some andesyte, rich in mici, occurs iu dykes on the trail to Queen Creek to the Silver Queen mine, shows gray and black and pea. rock, and carbonates of copper and s small percentage of gold.
 The especially characteristic rock O the region is phonolite It occurs il numerous narro V dykes, both withii aud without the main volcanic area ant is the only one of the volcanic type having such distribution It sls, occurs in several isolated bodies cap ping granite and blue car bonate of linn range on Queen Creek, for some mile east. t.rly and nurtheriy on ali sides o the center as in trachite, on the wes side of Queen Creek. These masses ar, thought to be remnants of large in.li ned dykes in an ernptive granite simi lar to those sho wn on the east side c Queen Creek in the carbonate of linn just west of tke volcanic center. Thi origin is further suggested by the pho nolite bodies on the west side in tn ' granite on Queen Creek, which are cleai ly lateral intrusion into the high lak
 beds near the granite surface. No sur Ifa... Hou,r of ,,l,or ,l;ta .,..., .,,,., ;daat;
 fable on the west range of mountains
 On Queen Creek phonolite was pro duct of several epochs of eraptions 10
 part of the braces, contains phonolt ' fragments and this brace is cut by pho s nolite dykes. The dykes are also o o several epochs-
 Y The phonolite consists of an aka l. feldspar nepheline sodalite nosean ut s pyroxene, which is the great part aegi ' rene accessory minerals are sometime presented. The most notable or. l. being lowenite and peculiar bl, e amphibole. The small ykes are dens l, of greenish gray color and have pro . nouuced fssial or schistose structur t. due to the arrangement of the predt k minant scales or mieolite of feldsp E parallel to the dyke walls a few glas. ;s sanidine tablets gave more or less di
 tinct porphyritic structure to mai
 masses. The phonolite of the Que,
 Creek Jurassic mountain range and
 the smaller bodies is porphyritic thou - the unusual development of nepheli nd in numerous microscopic reddish cry UT tals analite occurs in dense cavities F. certain places.
 es The large mass of the South Co - stock, California and St. Louis gro
 of mines and mountain in the Si l'