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Full-Text Articles in Physical Sciences and Mathematics
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 …
Experimental Testing Program In Elementary Chemistry: A Preliminary Report, Billie G. Broach, Howard L. Hodges
Experimental Testing Program In Elementary Chemistry: A Preliminary Report, Billie G. Broach, Howard L. Hodges
Journal of the Arkansas Academy of Science
An experimental testing program is described which utilizes questions that are partly computer composed, in addition to a section composed by the instructor, and a retesting option to the student. Results from a trial of the program for one term indicate that (1) course grades were improved, (2) the student withdrawal failure rate was unaffected, and (3) the employed students took greater advantage of the retest than did the unemployed students.
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.
Semiquantitative Infrared Analysis Of Diketones And Anhydrides In A Reaction Mixture, Dominic T.C. Yang, F. H. Watson Jr., J. O. Lay, R. Getty
Semiquantitative Infrared Analysis Of Diketones And Anhydrides In A Reaction Mixture, Dominic T.C. Yang, F. H. Watson Jr., J. O. Lay, R. Getty
Journal of the Arkansas Academy of Science
The ozonolysis of a hydroxymethylene ketone yields a mixture of diketone and anhydride. Treatment of hydroxymethylene camphor with ozone affords, in addition to the expected camphor quinone, a surprisingly large amount of camphoric anhydride (56%) via Baeyer-Villager reaction. Use of infrared absorption to analyze the relative amounts of camphor quinone and camphoric anhydride in a reaction mixture was studied by comparing peak heights of their carbonyl stretching bands.
Composition Of Arkansas Grapes During Maturation, Cameron Jones, Dominic T.C. Yang, Thomas O. Whitley
Composition Of Arkansas Grapes During Maturation, Cameron Jones, Dominic T.C. Yang, Thomas O. Whitley
Journal of the Arkansas Academy of Science
Changes in organic acid and glucose content during maturation and ripening of grapes grown in Arkansas in 1973 are shown for four French hybrid varieties, S5279, S10878, SV23- 657, and S13053, and for four rotundifolia varieties, Scuppernong, Tarheel, Fry, and Magoon. In all varieties the concentrations of malates and tartrates were highest in the early stages of berry growth after veraison. During ripening the titratable acidity decreased and Balling and pH measurements increased. Although varieties reached maturity on different dates, changes in parameters followed similar curves typical for grapes of the species but occurring over a short period (Johnson and …
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 …