CONTENTS 



PAGE 



Introduction 1 



History of the Industry • 2 



Geography of the Washington County' District 4 



Location of the Barite Areas 4 



Topography 5 



Relief 5 



Plateaus and escarpments 6 



Drainage 7 



Physiographic record 8 



Soils 10 



Alluvial soils 10 



Residual soils , 1 1 



Elvins soil 11 



Potosi soil 11 



Proctor soil 12 



Soils from the Gasconade and Roubidoux 



formations 12 



Wind-blown soils 12 



Climate 13 



Vegetation 13 



Culture 13 



Inhabitants 13 



General Geology of the Washington County District 14 



Outline of the General Geology 14 



Stratigraphy 16 



Elvins formation 16 



Petrography of the formation 16 



Upper part of the Elvins 21 



Age and correlation 22 



Potosi formation 24 



Petrography 25 



Age and correlation 29 



Eminence chert 29 



Economic importance - 30 



Proctor formation 30 



Petrography 31 



Age and correlation 33 



Economic importance 33 



VII 



