Plain Conditions Research Articles

Palynology of the Lower Jurassic R0nne Formation on Bornholm, eastern Denmark

Outcrop material from the Lower Jurassic R!!nne Formation on the Danish island of Bornholm, in the Baltic Sea, has been investigated palynologically. The 34 samples examined came from sections through the Munkerup, Sose Bugt and Galgel0kke Members, which amount to about 210 m in stratigraphic thickness in the type area. The aim of this study was to reevaluate the established stratigraphy defined by Gry (1969) and Gravesen et al. (1982) and characterize the three members by means of palynomorphs. 108 taxa have been recorded of which 67 are spores, 39 are pollen grains and 7 aquatic palynomorphs. Most of these are of little biostratigraphic value but the associations and relative abundances of a small number of selected species can be used to differentiate between the members, and correlations with other sequences elsewhere in Denmark, as well as in southern Sweden (Scania), Germany and Poland are possible. The assemblages from the Munkerup and lower part of the Sose Bugt Members are referred to Lund's (1977) Pinuspolleni­tes- Trachysporites Zone and considered to be of Hettangian age. The upper part of the Sose Bugt and the Galgel(<lkke Members both correlate with Lund's (1977) unnamed zone with Cerebropollenites macro­verrucosus, now called the Cerebropollenites macroverrucosus Zone (Dybkjrer, in press) for which a Sine­murian age has previously been suggested. The Galgel0kke assemblages are more taxonomically im­poverished and poorly preserved than those from the Sose Bugt Member, and there is no palynological evidence to indicate whether they are any younger. They could represent sediments that were deposited at the same time in different environments. The palynological data on all three members of the R0nne Formation support previous environmental interpretations, indicating lacustrine to delta plain conditions of deposition.

A model for evaluating the three-dimensional groundwater dividing pathline between a contaminant source and a partially penetrating water-supply well

Effluent from septic tank-drainfields can degrade groundwater quality and contaminate nearby water-supply wells. Such groundwater contamination is a problem in the unsewered subdivisions of the sand plain of central Wisconsin, for example. To help planners minimize the risk of direct contamination of a water-supply well by a septic system, a model was developed to estimate the location of the critical dividing pathline between a rectangular contaminant source (the septic tank drainfield) and a partially penetrating pumping well. The model is capable of handling three-dimensional, transient flow in an unconfined, homogeneous, anisotropic aquifer of infinite areal extent, under a regional horizontal hydraulic gradient. Model results are in very good agreement with several other numerical and analytical models. Examples are given for which the safe, horizontal and vertical separation distances to avoid well water contamination are determined for typical central Wisconsin sand plain conditions. A companion paper (Harmsen et al., 1991) describes the application of this model, using a Monte-Carlo analysis, to study the variation of these separation distances in the Wisconsin sand plain. The model can also be applied to larger scale problems and, therefore, could be useful in implementing the U.S. Environmental Protection Agency's new well head protection program.

Paleogeographic Evolution of Late Paleozoic Taos Trough, Northern New Mexico: ABSTRACT

The Taos trough (or Rowe-Mora basin) of northern New Mexico was one of several tectonically active cratonic basins associated with the late Paleozoic Ancestral Rockies. As the basin and adjacent uplifts evolved, the depositional systems and paleogeography varied in conjunction with changing tectonic stability, fluctuating End_Page 687------------------------------ sediment input, evolution and integration of sediment dispersal systems, and varying water depth. Morrowan time was characterized by a widespread transgression by a shallow sea flanked by low-lying, muddy strand plains. At this time the surrounding uplifts were relatively low-relief features and supplied only fine-grained sediment to the basin. By Atokan time, vertical movements elevated the Uncompahgre uplift to the west of the trough, and coarse alluvial fan, braided stream, and fan-delta complexes prograded eastward into the basin. During this episode of intense diastrophism to the west, the eastern side of the trough remained fairly stable and a broad, shallow-marine shelf sloped gently off the Sierra Grande arch. Farther south, carbonates accumulated on the Pecos shelf. This general depositional and paleogeographic pattern continued into Desmoinesian time. However, to the north the Cimarron arch had become a major positive feature by earliest Desmoinesian time and several braided stream-fan-delta systems prograded southward and southwestward into the basin. By middle Desmoinesian time an extensive coastal plain had developed along the western margin of the trough, with low-sinuosity rivers feeding lobate deltas. A major middle to late Desmoinesian transgression inundated this coastal plain and shallow shelf conditions prevailed throughout most of late Desmoinesian time. In latest Desmoinesian time, southward prograding fluvial-deltaic systems began filling the northern part of the basin causing a net southward regression. By Early Permian time the basin was dominated by continental sedimentation with southward flowing braided streams. End_of_Article - Last_Page 688------------

Urea‐Ammonium Sulfate and Urea‐Ammonium Phosphate Evaluation as Nitrogen Sources in the Southeast

AbstractRecent increases in N fertilizer cost emphasize the need for information concerning the use of cheaper N sources to produce the most marketable yield per unit fertilizer cost. Urea‐ammonium sulfate (UAS) and urea‐ammonium phosphate (UAP) are two new fertilizer products in which urea is the main source of N. These materials were compared to ammonium nitrate (AN) as N sources for corn (Zea mays L., Coastal bermudagrass (Cynodon dactylin L. Pers.), and rye (Secale cereale L.).Each material was used to supply N at rates from 0 up to 448, 336, and 135 kg/ha on Coastal bermudagrass, corn, and rye, respectively. All crops were grown on Tifton soil (Plinthitic Paleudult; fine, loamy, siliceous, thermic). Corn was also grown on a Greenville soil (Rhodic Paleudult; clayey, kaolinitic, thermic). Recommended cultural practices normally used in the area were followed for each crop. Forage yield for Coastal bermudagrass and rye was measured and selected samples analyzed for ammoniacal N concentration. Corn grain yield was measured. Selected soil samples from the corn experiment were analyzed for nitrate‐N.Percent N increased in Coastal bermudagrass and rye forage as N application rate increased. Coastal bermudagrass recovered less N from both UAP and UAS than from AN at the 336 kg/ha N rate. All materials were equivalent as N sources for rye and corn. Irrigation of the corn was found to increase yields as well as nitrate‐N leaching. Applying 50% of the 336 kg/ha N at planting and the rest later to prevent leaching in corn production was no better on Tifton and Greenville soils than a single preplant N application of either 168 or 336 kg/ha. For Southeastern Coastal Plain conditions the two fertilizers evaluated could replace AN in corn and rye production without loss in N concentration, yield, or N use efficiency. The materials tended to be less efficient than AN in supplying N for Coastal bermudagrass production.

Crop Rotation and Irrigation Influence on Wheat Yield and the Correlations Climate-Yield in the Crişurilor Plain Conditions

The paper is based on the researches carried out during 2003-2008 in a long term trial placed in 1990 on the preluvosoil from Oradea. Climate indicator “de Martonne aridity index” (IdM) was used for quantification the correlation between climate and wheat yield in unirrigated and irrigated conditions and new class called “arid” was purposed for climate index characterization. Maintaining the soil water reserve on 0-50 cm depth between easily available water content and field capacity using the irrigation determined the increase of the IdM values for period IV – VI with 79% in 2003, 73% in 2004, 36% in 2005,16% in 2006, 162% in 2007 and with 131% in 2008; using the irrigation and the improvement of the microclimate conditions determined to obtain the yield gains, very significant every year and every crop rotation studied; both in unirrigated conditions and in irrigated conditions, the smallest yields wheat were obtained in monocrop and the biggest in the wheat – maize – soybean crop rotation; in the all three crop rotation, the direct links statistically assured were registered between the values of the De Martonne aridity index and yields in unirrigated and irrigated wheat. These correlations sustain the need of the irrigation in wheat from Crisurilor Plain; correlation between De Martonne aridity index is stronger (R2 = 0.7361xx) in the wheat – maize – soybean crop rotation in comparison with wheat – maize crop rotation (R2 = 0.6215x) and with wheat monocrop (R2 = 0.6105x). As consequence, crop rotation of wheat-maize-soybean is recomanded because the climate and microclimate conditions are better use.

Influence of the Pedological Drought and Irrigation on Quantity and Quality of the Maize Yield in the Crişurilor Plain Conditions

The paper is based on the researches carried out in Oradea during 2006-2008 in the following variants: V1= Irrigated, without irrigation suspending; V2= Irrigated, irrigation suspending in May; V3 = Irrigated, irrigation suspending in June; V4= Irrigated, irrigation suspending in July; V5= Irrigated, irrigation suspending in August; V6= Unirrigated. The hybrid use: Fundulea 376. Total nitrogen of the maize grains was determined in the laboratory of the Agricultural and Development Research Station Oradea. In the variant with optimum irrigation, water reserve on 0-75 cm depth was maintained between easily available water content and field capacity. Pedological drought was determined every year and the irrigation was need, too. The irrigation determined the increase of the total water consumption and yield gain in comparison with unirrigated variant. Irrigation suspending in different months determined the yield losses very significant statistically. The biggest protein content was registered in the variant without the irrigation suspending; the values registered in the variants with irrigation suspending in May, June, July and August and in the unirrigated variant are smaller, with differences statistically assured. There were a direct link between de Martonne aridity index values and water consumption, yield and protein content and an inverse link between pedological drought and yield quantity and protein content. These are the arguments for irrigation opportunity in maize from Crişurilor Plain

Researches Regarding the Crop Rotation and Irrigation Influences on Protein Content of the Wheat Grains in the Crişurilor Plain Conditions

The paper based on the researches carried out during 2006-2008 in the long term trial placed in 1990 on the preluvosoil from Oradea. Three kind of crop rotation (wheat – monocrop; wheat – maize; wheat – maize – soybean) were studied in unirrigated and irrigated conditions. The smallest content of the protein from wheat grains were registered in the wheat monocrop both nonirrigated and irrigated variant. In the wheat-maize and wheat-maize-soybean crop rotation the values registered were significant statistically bigger than in wheat monocrop. Irrigation determined the decrease of the protein content.

Paleoecologic, Sedimentary, and Structural History of the Late Tertiary Capistrano Embayment, California: ABSTRACT

The Capistrano Embayment comprises a distinct geologic unit of the southern California area. Paleobathymetry, sediments, and microfaunas within the embayment indicate that it has had a different structural history, different from the Los Angeles Basin on the north. Marine invasion of the trough began in the Paleocene and ceased in the Pleistocene. This report develops a detailed history of the embayment from middle Miocene to late Pliocene time using data from two well exposed sections within the boundaries of the embayment. Analogy between ecologic niches of living benthonic Foraminifera and fossil forms encountered indicates that middle bathyal depths were attained by the middle Miocene. By late Pliocene the trough was filled to shelf depths. Repetitive changes in morphology of benthonic species provides additional evidence of varying paleobathymetry. Variation in abundance of cool and warm-water planktonic Foraminifera indicates three periods of distinctly cool surface temperature between late Miocene and late Pliocene time. Increase in radiolarian diameter provides evidence for surface temperatures in sediments barren of Foraminifera. Peak radiolarian abundance suggests that the deepest point in basinal evolution existed in the early Pliocene at which time water depth neared 1,750 meters. Correlation of the two sections is based on: (a) a Mohnian horizon of Globigerina pachyderma which coil sinistrally, (b) the uppermost point of abundant radiolarian tests, (c) the uppermost point of the radiolarian Prunopyle titan, and (d) the horizon of peak radiolarian number. These mutually corroborative planktonic criteria demonstrate the time transgressive relationship of existing stages based on benthonic Foraminifera. Repettian faunas, for example, appear much earlier in the rapidly filling southern end of the embayment than in the northern deeper area. A restricted, oxygen-deficient, closed-basin system, characterized by laminated diatomaceous sediments, originated during a period of early Miocene diastrophism. Closed-basin conditions allowed only a marginal benthonic foraminiferal fauna to exist, analogous to the existing fauna of the oxygen deficient Santa Barbara basin. Restricted basin plain conditions prevailed until the end of the Miocene. Instantaneously deposited coarse sediments (turbidites) emphasize pulses of structural activity in the middle Miocene, late Miocene, and middle Pliocene. Sediments provide evidence of a landmass to the west of the embayment. Turbidites are recognized on the basis of displaced Foraminifera, plant material, and sedimentary structures. Paleoecologic and sedimentary analyses delineate a characteristic basin-filling sequence in the Capistrano Embayment, similar to events taking place today in the Gulf of California and off southern California. End_of_Article - Last_Page 361------------

The Use of Shot Peening to Reduce Weight

The object of this investigation was to explore the possibilities of utilizing the shot-peening process on laminated spring leaves from silico-manganese spring steel as a means of increasing the working stresses, and thus reducing weight without loss in fatigue life. The first part of the investigation showed that so far as fatigue tests alone were concerned it should be possible to increase the working stresses and thus save weight. To do this, however, would involve the bump stress exceeding the primitive elastic limit of the material. Investigation of the effect of scragging (prestressing) to the British Standards (B.S.) Test Deflexion of L2/900 t as at present adopted in manufacture showed that such scragging had practically no effect on the elastic limit, but that if the scrag deflexion was increased to approximately L2/400 t an increase in the apparent elastic limit of the order of 40 per cent of the primitive elastic limit could be obtained, and that such scragging also improved the fatigue life in both the plain and shot-peened conditions. It is considered that with effective scragging and shot peening it is probable that very considerable savings in weight, of the order of at least 20–25 per cent, and under certain conditions even more may be obtainable, provided trouble does not arise due to superimposed stresses of starting and braking torques, and possible embrittlement due to effective scragging. This does not seem to the author to be particularly likely at a weight saving of 20–25 per cent, but can be settled only by service trials which he feels should now be undertaken.

CAROLINA BAYS AND THEIR ORIGIN

Research Article| February 01, 1952 CAROLINA BAYS AND THEIR ORIGIN W. F PROUTY W. F PROUTY 1W. F. Prouty passed away June 27, 1949. The article was complete with the exception of the abstract, summary, and conclusions, and the selection and arrangement of a few illustrations which was done by C. E. Prouty, University of Pittsburgh. Search for other works by this author on: GSW Google Scholar Author and Article Information W. F PROUTY 1W. F. Prouty passed away June 27, 1949. The article was complete with the exception of the abstract, summary, and conclusions, and the selection and arrangement of a few illustrations which was done by C. E. Prouty, University of Pittsburgh. Publisher: Geological Society of America Received: 14 Sep 1949 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1952, The Geological Society of America, Inc. Copyright is not claimed on any material prepared by U.S. government employees within the scope of their employment. GSA Bulletin (1952) 63 (2): 167–224. https://doi.org/10.1130/0016-7606(1952)63[167:CBATO]2.0.CO;2 Article history Received: 14 Sep 1949 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation W. F PROUTY; CAROLINA BAYS AND THEIR ORIGIN. GSA Bulletin 1952;; 63 (2): 167–224. doi: https://doi.org/10.1130/0016-7606(1952)63[167:CBATO]2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The Carolina Bays have a known distribution along the Atlantic Coastal Plain from northeast Florida to southeast New Jersey. Estimates based on actual counts in limited regions indicate a conservative figure of half a million bays in the entire area. Local areas show over 50 per cent coverage by bays.Statistical studies of orientation show a greater divergence of smaller bays from the mean than of larger bays. Smaller bays also show greater variation in ellipticity than do larger bays. Both facts are most satisfactorily explained by the meteoritic theory of origin. Multiple and “heart-shaped” bays overlap in patterns explained most logically by the impact of tandem meteorites, some likely explosive in nature. The probable mechanics of such phenomena is illustrated. Study of near-coast bays indicate that the bays are younger than the youngest Pleistocene terrace and some of the Coastal Plain drainage and older than at least one of the more recent marine transgressions.Magnetometer studies of 26 different bays all indicate associated spot highs, with no definite highs observed that are not readily associated with some bay.Laboratory experiments with projectiles involving simulated Coastal Plain conditions duplicate remarkably the cross-section and rim characteristics of the Carolina Bays and strengthen the meteoritic theory.Although the meteoritic theory in general is indicated by all critical analyses of the bays, a modified meteoritic theory (air-shock wave) is offered to better explain additional data. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.