Cretaceous stratigraphy in a northeast-trending transect, northern Utah to south-central South Dakota
Explore the source record for details and available documents.
IMAP↗
Geology topics
Thomas A. Ryer
Publications and source records attributed to Thomas A. Ryer.
The effects of volcanic ash on the maceral and chemical composition of the C coal bed, Emery Coal Field, Utah
Volcanic ash which fell in the peat swamp that formed the Upper Cretaceous C coal bed (Ferron Sandstone Member of the Mancos Shale, Utah) produced semi-impermeable layers that caused the ponding of surface waters. Coal samples from directly above tonsteins (altered volcanic ash partings) are enriched in desmocollinite, telinite, and detrocollinite, as a result of poorly drained swamp conditions; coal samples from directly below tonsteins are enriched in semifusinite, inertodetrinite, and fusinite, as a result of well-drained conditions. Leaching of the volcanic ash or the incorporation of volcanic ash in peat provided a source for many elements (including Zr, Nb, Th, and Ce) that are enriched in coal samples taken from directly above and below tonsteins.
Utah↗
Cross section of the Ferron sandstone member of the Mancos Shale in the Emery coal field, Emery and Sevier counties, central Utah
Explore the source record for details and available documents.
Utah↗
The Muddy and Quitchupah Projects: a progress report with descriptions of cores of the I, J, and C coal beds from the Emery coal field, central Utah
Explore the source record for details and available documents.
Open-File Report↗
Use of altered volcanic ash falls in stratigraphic studies of coal-bearing sequences: an example from the Upper Cretaceous Ferron Sandstone Member of the Mancos Shale in central Utah.
The Ferron consists of 5 delta cycles, each of which includes one coal zone which contains at least one, and usually several, laterally persistent kaolinitic claystone partings. Laboratory study of the partings demonstrates that they represent altered volcanic ash falls. These partings have proven particularly useful in reconstructing the depositional history of the C coal bed of the Emery coal field which accumulated in a basin that developed concurrently with subsidence of the delta plain during both the constructive and destructive phases of the third delta cycle.-from Authors
Geological Society of America Bulletin↗
Thickness change involved in the peat-to- coal transformation for a bituminous coal of Cretaceous age in central Utah
The ratio of the thicknesses of a layer of peat and the coal bed formed from that peat has been calculated for a bituminous coal bed in central Utah. The method used involves comparison of the thickness of peat eroded by a laterally migrating channel system with the thickness of coal now absent from the outcrop. The peat:coal thickness ratio calculated by this method is approximately 11:1.
Journal of Sedimentary Petrology↗