CLARKE.] 
IC4NE0US AND CRYSTALLINE ROCKS. 
65 
GEORGIA. 
Rocks collected by A. H. Brooks, who supplies the petrographic 
data. Analyses by H. N. Stokes, record No. 1727. 
A. Meta-quartz-diorite, 2 miles southwest of Sweden, Gordon 
County. Gordonose. Contains plagioclase, near labradorite, green 
hornblende, sometimes diallage, much vitreous quartz, and accessory 
magnetite, ilmenite, and orthoclase. Also secondary epidote, zoisite, 
uralite, chlorite, garnet, calcite, and leucoxene. 
B. Augite-niicrocline-granite, 1 mile east of Rowland, Bartow 
County. Toscanose. Contains microcline, some plagioclase, abun- 
dant pyroxene partly altered into chiefly uralite and chlorite, some 
biotite with frequent inclusions of rutile, much blue vitreous quartz, 
apatite, zircon, and magnetite. 
C. Quartz-gabbro, 2 miles southeast of Walleska, Cherokee County. 
Ilarzose. Closely related to B. Contains essentially plagioclase, near 
labradorite and augite. Accessory magnetite, ilmenite, apatite, and 
zoisite. Orthoclase is sparingly present. Quartz occurs in vitreous 
masses. 
A. 
B. 
C. 
SiO, 
69. 87 
12. 02 
1.42 
3.49 
2.30 
7. 86 
.66 
.11 
. 18 
.89 
.69 
.17 
.16 
none 
none 
trace 
. 43 
none 
none 
none 
(?) 
67. 98 
14. 84 
1.00 
3. 15 
.91 
2. 17 
2.66 
4.76 
.14 
.49 
.84 
. 34 
trace 
.20 
trace 
trace 
none 
.OS 
trace 
trace 
trace 
.21 
56. 20 
Al 2 o s - 
15.46 
Fe 2 3 
1.54 
FeO 
9. 76 
MgO 
1.83 
CaO 
5. 39 
Na 2 
2.78 
K 2 
2. 56 
H 2 OatllO° 
.16 
H 2 above 110° . . 
.59 
TiO, 
2.25 
P,0, 
1.13 
MnO 
.13 
BaO 
.17 
SrO 
trace 
Li 2 - 
none 
CO, ... . 
none 
S 
.07 
SO, 
trace 
CI 
trace 
F 
trace 
C (graphite) 
100. 25 
1)9. 77 
100. 02 
Bull. 228—04 
