GRANITIC ROCKS OF PIKES PEAK QUADRANGLE 
following complete and careful analyses made by Mr. W. F. 
Hillebrand of the U. S. Geological Survey. 
TABLE OF CHEMICAL ANALYSES 
I II III IV Vv 
(2128) (2531) (2530) (2369) 
SS) asic ca OneiereeS 77.03 75.17 Bait 73.90 74.90 
1,284 I.253 I,225 I,221 1.248 
IMO oaue ciclo 13 .10 .18 07 a2 
.OOT -OOT .002 .000 2OOT 
IM O@ln ooaau's 3 12.00 12.66 13.28 13.65 12.89 
.116 .122 .129 +132 .125 
Hea Op ccnys cer .70 22) 94 28 58 
+004 .OOT .006 .OOT .003 
HEOR Moe cct ss .86 1.40 .O7 42 .QI 
or2 fede) O13 005, .O12 
(NEMO) ood eisai lines tr. life tires! alin eee eae 
CVO aatievarene .80 83 I.II DB 74 
O14 .OI14 020 .004 O13 
oul O)eravetersiacs ally Bette te eee Our yall <a wervettsencich hell's la Pass onakoreer ol Wee Sateen ean 
BAO Ss ostese sass tr. .03 (tie. (Cicer any PP aye tee ten fs 
INI Oi reteis fost hi -04 05 .05 .14 .07 
,OOT .OT .OOT -003, .OOT 
KR Ol sats cee 4.92 5-75 5.22 7.99 5.92 
1052 Roloha 2055 .085 .063 
INGOs arene 3.21 2.88 3.79 2.53 3.10 
.O51 .046 .061 +040 +050 
CTO) S Bierereeese tr. Sls (iF, tr. (HMO dl oi cdeeae te 
MIG OM oe onc 14 .16 .16 15 51 
Hin Oi .30 62 31 .92 55 
Ban ©) esreess sts) ss tr. 03 tr. 05 02 
eres tyei sce e'd 36 ahi! SSSR AIP W) crwiavas oredls 31 
GO pra8 3's sloteelll aay ees hater canal (avo R nen oerer Ren [ie peeesec tlc eas Pease anne Paes 
100.55 100.26 100.38 QOS ili iliers: ae 
Mess Eso... 55 3B RD ORIN Ones acheter etch eh [k ages eee 
100.40 100.13 100.16 99.75 100.26 
237 
* Below 110° C. { Above 110° C. 
I. (2128.) A coarse grained granite of the Pikes Peak type 
taken from the western side of the Pikes Peak massif at a place 
