STATE GEOLOGIST. 
Chemically, the variations are just as wide, and hence it is easy 
to see that we can have alluvial clays high in lime, or iron, or silica, 
although as a rule the alumina is never high, due to the fact that the clay 
substance is usually low. 
In the sandy varieties the total silica may be 90 per cent., in the 
calcareous the calcium carbonate may be 20 or 25 per cent. 
ferruginous clays the ferric oxide may be as high as Io to 14 per cent. 
The following analyses represent typical alluvial clays: 
= 
Sample Number. 
Ingredients. 
1 2 3 
STI Cae Nae uals Coes ar R er YOM LeMay tal 3 63.73 VATS 61.93 
ARITA eye WIE) ON LA ECE CUD a pa 2 W717 12.55 19.87 
METI CHORIGC lnc rr eecaencles Gia een a eeek cashes 5.85 5.28 7.83 
ATTY ete eye aT: ete REIL AS OY ca) Sifay de 0.58 1) 5 2S 1.61 
Map INE STA ee senciaiey, Soran tier ahs ecard ieee, 0.97 0.85 O. 00 
PO GAS ee pe rratie hk na thy rea Orn Dh Be 
Ba 2.38 
STOO Way ya sea SR a se al UO ae A he EL trae te 0.67 
CONS EYaINS SiN Ce Se Ia a Rien oe ah eat ey 4.90 BBS 5.91 
IMO TS GUT ee eee ee mh US ESE oil auc ect PO Gui Minion es ay es late ila wie Ja 
% SiO, 
335 71 5.96 Seale 
% Al,O; 
Molecular ratio—Silica to Alumina......... Bub Sk HO. 83 o ik hs aN) ea 
No. 1 is an alluvial clay from Columbia, Ohio. 
Nos. 2 and 8 are clays quoted by Langenbeck as typical alluvial clays. 
The rational analyses of Nos. 2 and 3 were found to be as follows: 
Per Cent. 
No2.| No. 3: 
Clava Sullostamcewe erie cle attr. haystolste enschede tate 39.12) 67.90 
(CADENA RAPE IS Cok a Nal RS scene Maa OU mae CPU SBE) PA ee 
Beldspathie Detritus var sereautclercreerenl/ alos): 8.55) 10.83 
sb Gy Iw, ak 
In the 
