Add to ORKGSamples of carbonaceous material from several exposures of the Cedar Valley formation have been studied in order to establish a basis for calling the material a coal. Examination has shown that the material is a cannel\u27\u27 coal, and it is believed to be one of the earliest known coals in North America
This report on coal is a more comprehensive report. The report discussed distribution, the geologica...
A stratigraphic study of the plant microfossils m the Iowa Pennsylvanian coals by the maceration met...
Until February, 1906, Nebraska was termed the state without a mine, and may still be called the st...
Samples of carbonaceous material from several exposures of the Cedar Valley formation have been stud...
Samples of carbonaceous material from several exposures of the Cedar Valley formation have been stud...
The nomenclatural history of some Upper Cherokee coals of Iowa is reviewed, beginning with the 1870 ...
The chemistry department of Iowa Wesleyan College first began a preliminary chemical analysis on som...
The Cretaceous Cambria coal, located in the western part of the Black Hills in Weston County, Wyomin...
The district at hand is one somewhat remote from any known field of productive Coal Measures, but be...
The district at hand is one somewhat remote from any known field of productive Coal Measures, but be...
Estimates of strippable coal reserves were made for 12 counties in south-central Iowa, for the purpo...
Recent analysis of an abundant coal flora dislodged from coalballs,\u27\u27 or sulphur balls of t...
A stratigraphic study of the plant microfossils m the Iowa Pennsylvanian coals by the maceration met...
A stratigraphic study of the plant microfossils m the Iowa Pennsylvanian coals by the maceration met...
A stratigraphic study of the plant microfossils m the Iowa Pennsylvanian coals by the maceration met...
This report on coal is a more comprehensive report. The report discussed distribution, the geologica...
A stratigraphic study of the plant microfossils m the Iowa Pennsylvanian coals by the maceration met...
Until February, 1906, Nebraska was termed the state without a mine, and may still be called the st...
Samples of carbonaceous material from several exposures of the Cedar Valley formation have been stud...
Samples of carbonaceous material from several exposures of the Cedar Valley formation have been stud...
The nomenclatural history of some Upper Cherokee coals of Iowa is reviewed, beginning with the 1870 ...
The chemistry department of Iowa Wesleyan College first began a preliminary chemical analysis on som...
The Cretaceous Cambria coal, located in the western part of the Black Hills in Weston County, Wyomin...
The district at hand is one somewhat remote from any known field of productive Coal Measures, but be...
The district at hand is one somewhat remote from any known field of productive Coal Measures, but be...
Estimates of strippable coal reserves were made for 12 counties in south-central Iowa, for the purpo...
Recent analysis of an abundant coal flora dislodged from coalballs,\u27\u27 or sulphur balls of t...
A stratigraphic study of the plant microfossils m the Iowa Pennsylvanian coals by the maceration met...
A stratigraphic study of the plant microfossils m the Iowa Pennsylvanian coals by the maceration met...
A stratigraphic study of the plant microfossils m the Iowa Pennsylvanian coals by the maceration met...
This report on coal is a more comprehensive report. The report discussed distribution, the geologica...
A stratigraphic study of the plant microfossils m the Iowa Pennsylvanian coals by the maceration met...
Until February, 1906, Nebraska was termed the state without a mine, and may still be called the st...