Bulletin of the United States Geological SurveyThe Survey, 1956 - Geology |
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Page 474
Geological Survey (U.S.). Galena dolomite . Formation Member Units of local usage Maquoketa shale . Total thickness ... Ion dolomite member . Limestone , medium - gray , very argillaceous ; green shale Blue . 6-7 partings ; thins to gray ...
Geological Survey (U.S.). Galena dolomite . Formation Member Units of local usage Maquoketa shale . Total thickness ... Ion dolomite member . Limestone , medium - gray , very argillaceous ; green shale Blue . 6-7 partings ; thins to gray ...
Page 475
... Ion , the uppermost member of the Decorah formation . Like the Guttenberg , the Ion dolomite member is a limestone in the Dubuque subdistrict except where solutions have altered it to dolomite . The Ion , throughout the mining district ...
... Ion , the uppermost member of the Decorah formation . Like the Guttenberg , the Ion dolomite member is a limestone in the Dubuque subdistrict except where solutions have altered it to dolomite . The Ion , throughout the mining district ...
Page 480
... member but defined also a north- easterly - trending fold at the top of the ... Ion members of the Decorah formation . It cuts across northwestward - dipping strata indicated by structure contours drawn on the top of the cherty unit of the ...
... member but defined also a north- easterly - trending fold at the top of the ... Ion members of the Decorah formation . It cuts across northwestward - dipping strata indicated by structure contours drawn on the top of the cherty unit of the ...
Page 482
... dolomite member Guttenberg limestone member 30 O- Decorah formation Galena : dolomite 3 A ' 853.1 ' B 847.7 ' NORMAL ... Ion members , and con- siderable silicification and extreme thinning by solution ( from a normal thickness of 17 ...
... dolomite member Guttenberg limestone member 30 O- Decorah formation Galena : dolomite 3 A ' 853.1 ' B 847.7 ' NORMAL ... Ion members , and con- siderable silicification and extreme thinning by solution ( from a normal thickness of 17 ...
Page 484
... dolomite member is dolomitized , and thinning in the Guttenberg limestone member is not notable , although the ... Ion members of the Decorah formation show little solution effect , are limestone rather than dolomite , and are not ...
... dolomite member is dolomitized , and thinning in the Guttenberg limestone member is not notable , although the ... Ion members of the Decorah formation show little solution effect , are limestone rather than dolomite , and are not ...
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Common terms and phrases
abundant abundant_ argillaceous beds and blue Behnke-Krug area blue beds blue-green brown shale buff C. E. Brown calcite chert is common chert is sparse_ Cherty unit drab clay bed clear calcite Collar elevation dark-brown dark-gray Decorah formation deposits Depth to water dolomite member gray Driller Dubuque County Dubuque subdistrict Durango feet west Ferry shale member finely to medium ft Depth feet Galena dolomite gray chert green shale Guttenberg limestone member hole 1 Location host rock Ion dolomite member Iowa iron content iron sulfide leached white chert light-gray limestone member oil Little Maquoketa River loess Maquoketa shale medium crystalline medium-grained member clay bed member gray beds member oil rock mottled Noncherty unit yellow-sandy Platteville formation pyrite Sample study shale member clay slight limonite staining sparse Spechts Ferry shale sphalerite strata Strike and dip Structure contours drawn study and logging Surficial syncline Total depth vuggy vugs Wallis area zinc and lead Zinc Iron