4:U  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,   1903.  [bull. 225. 
Analyses  of  clays— Paleozoic  and  Lower  Cretaceous — Continued. 
Number. 
22. 
23. 
24. 
25. 
26. 
27. 
28. 
29. 
30. 
31. 
32. 
Silica 
P.ct. 
68.23 
20.35 
3. 20 
.34 
Tr. 
.74 
7.16 
P.ct. 
GO.  90 
L8.98 
7.68 
Tr. 
Tr. 
Tr. 
13.36 
/'.  ct. 
63. 27 
L9.68 
3. 52 
1.30 
Tr. 
1.20 
9.80 
P.ct. 
67.10 
19.37 
2.88 
Tr. 
.73 
.67 
7.79 
P.ct. 
65. 58 
19.  23 
4.48 
Tr. 
Tr. 
6.90 
P.  ct. 
68.10 
21.89 
2.01 
.80 
.28 
.40 
5.75 
P.ct. 
i\.>.  49 
24.  84 
Tr. 
1.26 
Tr. 
Tr. 
7.80 
P.  ct. 
70.  00 
21.31 
2.88 
.20 
Tr. 
Tr. 
6. 85 
P.  ct. 
67.  50 
19.84 
6.15 
.12 
.10 
7.05 
/'.  ct. 
m.  45 
18.53 
2.40 
1.50 
1.25 
Tr. 
9.46 
I'.rt. 
(11.90 
25.  21 
Ferric  oxide 
Tr. 
Tr. 
Tr. 
8.90 
100. 02 
100. 92 
98.77 
98.54 
96. 19 
99.23 
99.39 
101. 24 
101.36 
99.59 
99.05 
Coal  Measures. 
Lower  Carbon- 
iferous. 
Silurian    and 
Cambrian. 
Lower  Cretace- 
ous (Tusca- 
loosa). 
U 
!  I 
7. 
8. 
9. 
1(1. 
11. 
12. 
i:;. 
n. 
i.\ 
16. 
17. 
18. 
19. 
20. 
21. 
22. 
23. 
24. 
25- 
27. 
28. 
29. 
30. 
81. 
32. 
Dark  yellow  shale  from  Coal  Measures,  W.  H.  Graves,  near  Birmingham,  Jeffer- 
son County. 
Light  gray  shale  from  same  locality. 
5.  Fire  clay,  near  Valley  Head,  Dekalb  County. 
China  clay,  Eureka  mines,  Dekalb  County. 
China  clay,  Rock  Run,  Cherokee  County  (Dykes  ore  bank). 
Fire  clay,  Rock  Run,  Cherokee  County. 
Pottery  clay,  Rock  Run,  Cherokee  County. 
China  "clay,"  J.  R.  Hughes,  Gadsden,  Etowah  County. 
Stoneware  clay,  Blount  County. 
Stevens,  Fire  clay,  Oxanna,  Calhoun  County;  probably  too  much  free  sand. 
Stoneware  clay,  Coosada,  Elmore  County. 
Pottery  clay,  McLean's,  near  Edgewood,  Elmore  County. 
Stoneware  clay,  Chalk  Bluff,  Elmore  County. 
Fire  clay,  Woodstock,  Bibb  County. 
Fire  clay,  Bibbville,  Bibb  County. 
Fire  clay,  Hulls  Station,  Alabama  Great  Southern  Railroad,  Tuscaloosa  County. 
Pottery  clay,  H.  H.  Cribbs,  Alabama  Great  Southern  Railroad,  Tuscaloosa  County. 
Pottery  clay,  J.  C.  Bean,  Mobile  and  Ohio  Railroad,  Tuscaloosa  County. 
Fire  clay,  J.  C.  Bean,  Mobile  and  Ohio  Railroad,  Tuscaloosa  County. 
Stoneware  clay,  Roberts's  mill,  Pickens  County. 
Pottery  clay,  Cribb's  place,  Lamar  County. 
Stoneware  clay,  H.  Wiggins,  Fayette  County. 
26.  Pottery  clay,  W.  Doty,  Fayette  County. 
Blue  clay,  railroad  cut  near  Glen  Allen,  Marion  County. 
China  clay,  Briggs  Frederick,  Marion  County. 
Pottery  clay,  10  miles  southwest  of  Hamilton,  Marion  County. 
Pottery  clay,  Thomas  Rollins,  Franklin  County. 
Pottery  clay,  J.  W.  Williams,  Pegram,  Colbert  County. 
China  clay,  Pegram,  Colbert  County. 
THE  PORTLAND   CEMENT   MATERIALS   OF  CENTRAL  AND   SOUTH- 
ERN  ALABAMA. 
The  raw  materials  suitable  for  the  manufacture  of  Portland  cement 
which  occur  in  central  and  southern  Alabama  are  argillaceous  lime- 
stones, purer  limestones,  and  clays. 
The  limestones  valuable  as  cement  materials  occur  mainly  at  two 
horizons,  viz,  in  the  Selma  chalk  or  Rotten  limestone  of  the  Cretaceous, 
and  in  the  St.  Stephens  formation  of  the  Tertiary.  The  clays  available 
are  residual  clays  derived  from  the  decomposition  of  these  two  lime- 
stone formations,  the  stratified  clays  of  the  Grand  Gulf  formation,  and 
alluvial  clays  occurring  in  the  river  and  creek  bottoms.  It  is  possible 
that  later  investigation  may  show  that  some  of  the  other  stratified 
clays  of  the  Tertiary  formations  are  suitable  for  cement  making,  and 
this  is  especially  likely  to  be  the  case  with  the  clays  of  the  lowermost 
Cretaceous  or  Tuscaloosa  formation. 
