Add to ORKGThese geodes occur in Lime Creek shales. They are rather unusual in containing a number of roundish cavities rather than the customary rough opening. The cavities are lined with: 1. small rhombic calcite crystals which are bronzed with limonite; 2. occasional tabular and fan-shaped aggregates of barite crystals. The mode of formation is obscure
In the extreme north western corner of Iowa there is a small area of very hard, thoroughly vitreous ...
An extensive layer of limestone boulders was exposed by the steam shovels in getting out crushed roc...
Mineral inclusions found in geodes from the Warsaw formation of southeastern Iowa are described. The...
Associated with dismembered parts of Dikellocephalus minnesotensis in the St. Lawrence limestone, at...
Brochure of what is Geode is and how they are formed. Also that the General Assembly declared the Ge...
A study of the literature reveals at least eight ways in which limestone conglomerates may be formed...
At the state quarries, or North Bend quarries, in sections 5 and 8 of Penn township, Johnson County,...
Twenty years ago one of our most prominent Iowa scientists, Mr. Frank Springer, announced the discov...
A very prominent outcrop of the Otis limestone occurs along the valley of Indian creek at a point kn...
Pyrite-Quite recently there have been obtained from limestone cavities in Lee County some small but ...
In the process of road-making west of Middle Amana, in 1931, the grader exposed the country rock ben...
Small calcareous plates, possibly from Asteroidea or other Echinodermata, occur in the Maquoketa sha...
As a terranal name Lake Valley is applied to a remarkable blue limestone occurring at the famous sil...
About three miles east of Independence, Iowa, there are cross-bedded, water-laid deposits of sand an...
The rock exposed in quarries southwest of Garner, Iowa, has been in question as to its stratigraphic...
In the extreme north western corner of Iowa there is a small area of very hard, thoroughly vitreous ...
An extensive layer of limestone boulders was exposed by the steam shovels in getting out crushed roc...
Mineral inclusions found in geodes from the Warsaw formation of southeastern Iowa are described. The...
Associated with dismembered parts of Dikellocephalus minnesotensis in the St. Lawrence limestone, at...
Brochure of what is Geode is and how they are formed. Also that the General Assembly declared the Ge...
A study of the literature reveals at least eight ways in which limestone conglomerates may be formed...
At the state quarries, or North Bend quarries, in sections 5 and 8 of Penn township, Johnson County,...
Twenty years ago one of our most prominent Iowa scientists, Mr. Frank Springer, announced the discov...
A very prominent outcrop of the Otis limestone occurs along the valley of Indian creek at a point kn...
Pyrite-Quite recently there have been obtained from limestone cavities in Lee County some small but ...
In the process of road-making west of Middle Amana, in 1931, the grader exposed the country rock ben...
Small calcareous plates, possibly from Asteroidea or other Echinodermata, occur in the Maquoketa sha...
As a terranal name Lake Valley is applied to a remarkable blue limestone occurring at the famous sil...
About three miles east of Independence, Iowa, there are cross-bedded, water-laid deposits of sand an...
The rock exposed in quarries southwest of Garner, Iowa, has been in question as to its stratigraphic...
In the extreme north western corner of Iowa there is a small area of very hard, thoroughly vitreous ...
An extensive layer of limestone boulders was exposed by the steam shovels in getting out crushed roc...
Mineral inclusions found in geodes from the Warsaw formation of southeastern Iowa are described. The...