77/e Jf issonri Lead (ind Xitir tfi'iKisifa. — llohcrlsim. 285 
THE MISSOURI LEAD AND ZINC DEPOSITS. 
By James D. Robertson, E. M.. St. Louis, Mo. 
Note. In the recently published transactions of the Bridgeport meeting ot the Amer- 
ican Institute of Mining Engineers is a paper by Mr. Arthur Winslow having the above 
ititle. This paper is itself based upon an e.xhaustive report on the lead and zinc depos- 
its of Missouri prepared by Mr. Winslow, while state geologist, from work prosecuted 
during the last five years. In this work the writer assisted. The original report is very 
broad in scope, the design being to make it a work of reference on lead and zinc, with 
Missouri as a center: a work which would be of general utility to this important indus- 
try of the state. It thus contains brief descriptions of lead and zinc deposits in other 
countries, general statistical tables, descriptions of processes and other matter of wide 
bearing. The general geology of the mining areas is described in great fullness and 
their history and problems are treated. Interest is centered, however, in the ore depos- 
.its of the state, detailed descriptions of the numerous ore bodies are given and their 
structure, composition and origin are discussed in a comprehensive way. The recent 
papers of Posepny. Jenney and others have awakened renewed interest in these topics 
in general, and especially as atlecting the deposits of the Mississippi valley; and the ap- 
pearance of the report is hence very timely. The following paper is essentially an ab- 
stract of the general discussion of the lead and zinc deposits of Missouri as set forth in 
the repoit. 
The lead and zinc deposits of Missouri have of recent years 
become of such importance as to cause tiiat state to rank first 
in the production of zinc and lead ores. In the year endinjj^ 
June 30, 1893. there was produced 40.300 tons of lead ore and 
108,600 tons of zinc ore. The year ending June 30, 1894, 
showed a production of 52,000 tons of lead ore and 89,150 
tons of zinc ore, a decrease in tlie latter item but a decided 
increase in the former, in spite of hard times. 
All of the deposits of lead and zinc are found in that por- 
tion of the state south of the Missouri river. Geographically 
and categorically the deposits fall into tliree districts. These 
a re : 
1. The southwestern district, comprising Jasper, Newton, 
McDonald, Barry, Lawrence, Dade, Greene, Webster, ( 'hristian, 
Taney, Stone and portions of Wright, Douglas and Ozark 
counties. 
2. The southeastern district, comprising Fianklin, Jetl'er- 
son, St. Francois, Perry, Ste. Genevieve, JNladison, Iron, Wash- 
ington and portions of Crawford, Reynolds and Cape (Jirar- 
deau counties. 
3. The central district, composed of Cole, Moniteau, Mor- 
gan, Kenton, Hickor\% Camden, Miller and parts of Pulaski, 
Laclede, Maries, Osage and Pettis counties. 
In the central and southeastern districts the rocks are 
niainl^^ of tlie Ozark stage of the Lower Silurian, and in these 
rocks occur the ore deposits. In the southwestern district the 
