IGNEOUS AND CRYSTALLINE ROCKS. 129 
J k. L 
i 
BO Siicisesccave aaeesaceans ise teers wel axa Madde voudledds Ae cnn we ee ae seN 66. 46 58.74 
Als O3 sncisaee resceme mente a Se seems sme aaererinee seating ya MOEER! 14.14 15. 09 
PG gO ge ser vse nisieieiaizinioncicnt: 3s axsheinmmraliche nev tneiwejaleprcaysiete ks Sada aememaneke<aists ae erdeede ees 4.07 4. 66 
BOO ce cores rs env Siok ies We ENB aye See Renan ae Ree oe ees - 40 84 
MeO, sores sveswocaant op feuecaaes ME dba dadewees dowinaieiementieicls eateaes . 67 2.75 
CAO cise na tetemcie te ho Secures omar eeties deta glasknee ou neeae .78 2. 68 
IN Bg Oss ets iai castes tjeyseniacde CG Sys Siexch aeaske eda Soagerta settee ets ea eter tego eurete 1.26 25 
Ri Oe td tateutioegettund af Ro keaecis lla ainiace nearness He ae 9. 26 8.05 
TG! 8 6105 is cra reraie(e caine dartindor areas? SObiieiatssncsaieiats Saar acepataecis ns Grae Auectichav «18 2.08 
FO ab Ove OS ven arcicccavers same micitiss Smarereateiataisisineaencioies uneanne 1.28 3.09 
WM OB stars actyaciticaaiantnwr atiaciiukie, Gus ghidtenaciiwanetbekaay aw gemee 83 - 98 
LOS serecdean ascents samara tes cently vd eer een oh he hoe -05 - 02 
COS nuvisass earners ia. Seep NRTES Hh) PARRA EE WE oA Sit eisgesitg We Serena nas none 61 
P95 2 ie cineca We eee Ng nan thten aaeeen Se akimsniensigneeeG4e figs Seaasheieelend 225 - 40 
esgeac (eset Shee gag cAchas Siena ke ean AIRS SS, BARR eee al nad SIS cacao a MISE ca Sas none none 
IM Ooze Shs iaicre baseiepo ads A eaacasi GO achedehn ney Vesa rien Gey ant 5 Oieiae eeteers See 03 -09 
BO os spe See anceps se utr ad eye Sla Sas use aQeczcheesS Syd abate mele patna WE secre eaaaae 06 07 
ISO), seas wsieieae adres Ae TM auiaes HER yaerenGe WaeiameNt Nels sitie weaisiseacnelnnien oamang pein - 03 04 
100.35 | 100. 44 
NEVADA. 
1. TONOPAH DISTRICT. 
Rocks A to F, inclusive, represent hornblende andesite and its various alterations. 
Collected by J. E. Spurr, and partly published in P, P. 42. Analyses by George 
Steiger, record No. 2067. 
A. Hornblende andesite, California-Tonopah shaft. Pantellerose. The freshest 
obtainable. Contains andesine, pseudomorphs of chlorite after hornblende, some 
quartz, pyrite, and apatite. 
B. Hornblende andesite, also relatively fresh. No.2 shaft. Kallerudose near pan- 
tellerose. Contains partly altered, striated feldspars, and pseudomorphs of quartz, 
pyrite, etc., after biotite and hornblende. The rock is partly altered to quartz and 
muscovite. 
C. Kaolinic alteration of the andesite, from a pit in the saddle between Halifax 
shaft and the Mizpah mine. Entirely altered to quartz, kaolin, and muscovite. 
D. The andesite, altered to chlorite and calcite; Mizpah shaft, 675 feet down. 
Contains chlorite, calcite, a little quartz, feldspar, sericite, hematite, zircon, and apatite. 
E. Hornblende andesite, partly altered to orthoclase (?), Mizpah Hill. Ferro- 
magnesian minerals completely decomposed. Some secondary quartz is present. 
F. The andesite altered to quartz and muscovite, Mizpah vein. Little more than 
quartz and muscovite can be made out. 
\ B Cc D. E F 
SiOz 58.47 | 60.45 | 71.14] 55.60 | 73.50 72.98 
Al2Oz 16.85 | 17.78 | 15.24] 16.70] 14.13 14. 66 
Fe203 2.04 5. 86 1.77 2.23 1.51 1.01 
FeO 3212 «25 26 3.51 26 16 
MgO. 3.84 1.55 .16 2. 60 21 33 
CaO 1,35 1.04 - 09 4,27 12 18 
Na2O 4. 30 3. 58 24 4. 08 24 none 
2 < 3.14 2.11 6.31 3.17 5.11 6. 03 
H20 at 105°....- . 1.10 2. 86 +85 - 88 1.07 97 
H20 above 105°... -| 3.59 2.93 2. 87 3. 06 2.81 2.95 
HO 8s esiosie acess 77 81 48 72 47 44 
CO es oioee 52 | none | none 2.76 | none none 
PaQjcetccmsiewe 35 - 28 +05 09 16 
BO ge siesta none | none 05 | none Te \ecsaetciccese 
tua nis MESURE WAGE lacianereisloe Keamiaimtnsic snkeaiclale| eeewtinagets [pesnd si yaya 02 | none (3 eee 
FeSz...... 49 2 0G sacs acsvesrally one oven aterecntets undet. 
MnO...... . 26 | undet. | undet. |undet. | undet. | undet. 
BaO.... ell 07 17 12 -19 | undet. 
nsfaad is Naentiaastene ia dokencnateornaie ls teed Hawt aotate oS 2 eee ees Pee eee eee 
100. 42 | 99.63 | 99.70} 99.98 | 99.91 99. 87 
SrO not looked for. 
