50 ANALYSES OF ROCKS AND MINERALS, 1880-1908. 
“A. B 
SiO2. 51. 08 69, 56 
AlzO3 11. 37 15. 52 
Fe203 11.17 1.67 
FeO 5. 64 1.19 
SNAG OD gadis pesca pctlst goes oe eS, AA eared 3.96 41 
LO ia sce anova selena ody ciasecaa vals as HO ae taco iceland ka cin iste Sea 5. 20 1.20 
NaaO 2 siois saci ccenonaede ed ead wrmb amined eesdateinemenenmae: ssaermeemien dene eee 5. 54 4.46 
DRO) csc ecg ie tc eee a gc peg nc eS lace a pS Mo and SYN aie 1.50 4.68 
PUG OPA TOs cccrctsrctsiavaiacinias sta xia necyareccinsnicnnseroioie noe aiomiarceretaneatonnets ee aerate at wast nel 84 
TTSO AD OM CHINO cca ssscte scan siseeucreiatoirstsnatemscians oi sea) teyeietal pleat ersten ziataigi zi chaveaciacatermceeetatasaiate nies ese -19 -67 
NORTH CAROLINA. 
Rocks A to F collected by Arthur Keith, who furnishes the petrographic data. 
Analyses B, C, D, and E by W. F. Hillebrand, record No. 1707. Analyses A and F by 
H. N. Stokes, record No. 1710. 
A. Porphyritic rhyolite, 2 miles west of Barmers Elk, Watauga County. Adamellose. 
Contains orthoclase and plagioclase, with less quartz, epidote, chlorite, and pyrite. 
B. Quartz porphyry, 24 miles northwest of Blowing Rock, Watauga County. Mag- 
deburgose. Contains quartz and orthoclase, with subordinate sericite, chlorite, and 
biotite. 
C. Diorite, east end of Hump Mountain, Mitchell County. Awvergnose. Contains 
plagioclase, orthoclase, and hornblende, with less quartz, biotite, magnetite, and 
garnet. 
D. Garnetiferous diabase, 1} miles southeast of Cranberry. JII. 4.4.4,5. Contains 
plagioclase and hornblende, with less garnet, biotite, and magnetite. 
