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Lower Mississippian Lithostratigraphy, Northern Arkansas, Walter L. Manger, Jack L. Shanks
Lower Mississippian Lithostratigraphy, Northern Arkansas, Walter L. Manger, Jack L. Shanks
Journal of the Arkansas Academy of Science
Lower Mississippian lithostratigraphic units in northern Arkansas are (ascending order) the Bachelor, St. Joe, and Boone Formations. These formations disconformably overlie Middle Ordovician to Upper Devonian strata and are overlain disconformably by Meramecan or Chesterian strata. The Bachelor Formation is generally a thin (less than 0.3 m), persistent, orthoquartzitic sandstone with common to abundant phosphatic pebbles overlain by a green silty shale. In northwestern Arkansas, the Bachelor Formation commonly lacks sandstone. The Bachelor Formation has been confused previously with the Sylamore (Upper Devonian) and older sandstone units. Although commonly regarded as a member of the Boone Formation, the St. Joe …
Regional Carbonate Deposition Of The Pitkin Limestone (Chesterian): Washington And Crawford Counties, Arkansas, Robert E. Tehan
Regional Carbonate Deposition Of The Pitkin Limestone (Chesterian): Washington And Crawford Counties, Arkansas, Robert E. Tehan
Journal of the Arkansas Academy of Science
The Pitkin Limestone overlies black shale of the Fayetteville Formation and is the youngest Mississippian unit in the Paleozoic succession of northwest Arkansas. Five major fades have been delineated within the formation by apetrographic examination of samples collected from 17 measured sections: (1) oolith facies, (2) bioclast facies, (3) nodular limestone-shale facies, (4) mudstone facies, and (5) lime mud mound facies. The distribution of these facies in the Pitkin Formation suggests that Fayetteville terrigenous sedimentation was succeeded by the deposition of widespread oolith shoals and skeletal blanket sand bodies across the northern Arkansas structural platform. Sparse accumulations of lime mud …
1974 Nonflood-Stage Chemical Loads Of The Buffalo River, Arkansas, Kenneth F. Steele, George H. Wagner
1974 Nonflood-Stage Chemical Loads Of The Buffalo River, Arkansas, Kenneth F. Steele, George H. Wagner
Journal of the Arkansas Academy of Science
Dissolved Ca, Mg, Na, K, Fe, Mn, and Zn loads of the Buffalo River generally show trends along the river attributable to changes in geology and vary with the season because of concentration by evapotranspiration and dilution by rain. Suspended material element loads show neither seasonal trends nor trends along the river. The Fe load for the river is predominantly in the suspended material, the Mn load is divided approximately evenly between dissolved and suspended material, and Ca, Mg, Na, K, and Zn are predominantly in the dissolved load.
Algal-Bryozoan Carbonate Buildups Within The Pitkin Limestone (Mississippian-Chesterian), Northwest Arkansas, Alex T. Warmath
Algal-Bryozoan Carbonate Buildups Within The Pitkin Limestone (Mississippian-Chesterian), Northwest Arkansas, Alex T. Warmath
Journal of the Arkansas Academy of Science
More than 14 biohermal buildups have been recognized within the Pitkin Limestone (Mississippian-Chesterian) in eastern Washington and western Madison Counties, northwest Arkansas. These buildups resemble previously described algal mounds in upper Pennsylvanian strata of the Midcontinent region, but differ in their faunal and floral constituents. The mounds are composed of calcilutite with variable amounts of spar and fossil allochemical grains. Associated flanking facies consist of mixed biosparite near the core, grading outward into oosparite. A few zones of shaly, poorly washed biomicrite containing rounded clasts bearing Archimedes fragments are interbedded with the flanking mixed biosparite facies. These clasts appear to …