bluuebunny/crossref_metadata_2025_split huggingface dataset:
A SIMPLE MODEL OF A DIAGENETIC SYSTEM
Authors: SMALLEY I. J. 
Published: June 2006

SUMMARYAt the moment of deposition an ideal sediment has certain topological properties. The diagenetic process is driven by the reduction of surface area and this process is considered in relation to the topological properties. The connectivity and genus increase as cementation occurs and in some systems may decrease again. Relations between genus, density, depth of burial and time are considered for a sand‐sandstone system.
DIE SALINITÄTSFAZIES VON KEUPERSEDIMENTEN AUFGRUND VON BORGEHALTSBESTIMMUNGEN
Authors: HELING D. 
Published: June 2006

SUMMARY The salinity facies of the Keuper sediments on the basis of the determination of boron content The boron concentration of illites from sediments of the German Keuper Basin has been investigated in order to define palaeosalinity. The regional boron distribution of the Schilfsandstein and Lettenkeupersandstein Formations which have been sedimented in great lateral uniformity plainly corresponds with the current directions evaluated from cross‐bedding measurements. Short‐time variations of palaeosalinity during the Gipskeuper Formation have no effect on boron concentration, thus confirming the laboratory experiments of the installation of boron in illites which indicated that considerable time is required for establishing the boron‐ illite equilibrium. The present investigations show that boron in illites can be success‐ fully applied to regional problems provided that close consideration is given to the mineralogical composition of the sediment.
FORTRAN PROGRAMME FOR THE ANALYSIS AND GRAPHICAL PRESENTATION OF GEOLOGICAL DATA
Authors: DAVIES DAVID K. , BEVAN JACQUELINE M. 
Published: June 2006

SUMMARYComputers are being used increasingly for the analysis of quantitative geological data. An outline is given of the advantages of contemporaneously using both computer and a connected automatic plotter. It is suggested that the quality of the automatic plotter output is such as to preclude the services of a draftsman in the preparation of many graphics for publication.
SIGNIFICATION DES ÉTUDES RÉCENTES SUR LES ROCHES ARGILEUSES DANS L'INTERPRÉTATION DES FACIES SEDIMENTAIRES (Y COMPRIS LES SÉRIES ROUGES)
Authors: MILLOT GEORGES 
Published: June 2006

SUMMARY The significance of recent studies on the argillaceous rocks in the interpretation of sedimentary facies (including the red beds) Attapulgite and sepiolite are clay minerals, neoformed in the alkaline chemical facies. The ions, Si, Al, Mg, which are necessary for authigenesis, are leached from the continent under humid tropical conditions. Lateritic profiles originate only on the continents. If erosion begins again, the siderolithic facies, which contains a great proportion of inherited kaolinite, succeeds the alkaline chemical facies. These two facies are mutually connected in space and time.The “red‐sandstone” facies consists of a reworking of altered rubidied sands, which originate in warm climates with alternating humid and dry seasons. It is the maintenance of erosion by living tectonics which determines the intensity of the alteration. The “bituminous‐coal” facies corresponds to conditions which are analagous to the previous periods, but more humid, with more intense subsidence and a higher general base level of erosion. Bituminous‐coal facies and red‐sandstone facies are characterized by the predominance of illite and are connected in time.In the geochemical cycle, detrital argillaceous series succeed the carbonated and saliferous facies. Under certain conditions, these chemical facies indue a positive transformation, i.e., aggradation under the influence of the confined environment.Thus, the detrital, transformed or neoformed clay minerals can be used as palaeogeographical or palaeoclimatical indicators
SPACE PHOTOGRAPHY: A NEW ANALYTICAL TOOL FOR THE SEDIMENTOLOGIST
Authors: WOBBER FRANK J. 
Published: June 2006

SUMMARYGeologists increasingly concerned with detailed laboratory analyses at times overlook space‐age techniques that promise the collection of valuable sedimentological data. Orbital remote sensing, and particularly space photography, can provide synoptic environmental data for geoscientists including those familiar with applying aerial photography to the analysis of sedimentary environments. Color space photographs obtained incident to the Gemini Program provide unique tools for analyzing sedimentary environments and processes and provide data that cannot be duplicated by conventional aerial photographic techniques. The principal advantages of orbital geoscience data collection include frequency of coverage leading to environmental analysis within the full spectrum of seasonal contrasts, and opportunities for environmental syntheses by synoptic observations. Gemini space photography is an available source of semi‐quantitative data concerning changing environmental phenomena and mechanisms of sediment distribution. It also enables the survey and inventory of global sedimentary landforms. With the application of advanced sensors, increased system resolution, and repetitious photographic coverage, speedier and more reliable quantitative sedimentological analyses can be performed.
A SEMIAUTOMATIC MICROSCOPIC PARTICLE SIZE ANALYZER UTILIZING THE VICKERS IMAGE SPLITTING EYEPIECE1
Authors: SCHUBEL J. R. , SCHIEMER E. W. 
Published: June 2006

SUMMARYMicroscopic size analysis is the most direct of all size analysis procedures and is frequently used as a calibration technique for other methods. The commonly used microscopic procedures, however, are laborious and the results are frequently inaccurate because of the small number of particles measured by most investigators. Using the Vickers Eyepiece, we have built an inexpensive (> $ 1,000), semiautomatic microscopic size analyzer with which particles are sized, sorted into sixteen classes, and counted, accurately and quickly. The instrument combines direct observation with speed, accuracy, and ease of measurement to make it a valuable tool for the size analysis of a wide range of materials.
KORNGRÖSSENANALYSE GROBKLASTISCHER SEDIMENTE MIT HILFE VON AUFSCHLUSS‐PHOTOGRAPHIEN
Authors: NEUMANN‐MAHLKAU PETER 
Published: June 2006

SUMMARY Granulometric analysis of rudites on outcrop‐photographs As it is impossible to determine the grain‐size distribution of well‐consolidated rudites by sieving, it has been attempted to use outcrop‐photographs for their granulometric analysis. In order to assess the accuracy of this photo‐method, nineteen samples of poorly consolidated rudites were subjected to analysis by both methods. It resulted that the two sets of data obtained could be correlated rather well, using a relatively simple formula.Although some broader experimental work would still seem advisable, it became quite clear that the photo‐method is simpler as well as more accurate than the sieving method. It is therefore suggested to develop it as the standard method for granulometric studies of all rudites.
DAS KALZITGEFÜGE DER SPARITISCHEN KALKE DES PLASSEN (TITHONIUM, NÖRDLICHE KALKALPEN, OBERÖSTERREICH)
Authors: FENNINGER ALOIS 
Published: June 2006

SUMMARY The sparitic Plassen Limestone (Tithonian, N.K.A., Upper Austria) The sparitic Plassen Limestone (Tithonian, N.K.A., Upper Austria) shows various types of calcite‐fabric. We distinguish fibrous, fibrous‐drusy, and drusy cavity fillings. While the fibrous fabric can be interpreted as submarine precipitation soon after sedimentation, an explanation of the drusy calcites as submarine or subaerial precipitation remains an open question. There are, however, indications of subaerial influences. For the origin of the dismicrites an interpretation as shrinkage structures may be considered.
WHERE MOST GRAINS OF VERY COARSE SAND AND FINE GRAVEL ARE DEPOSITED
Authors: RUSSELL RICHARD J. 
Published: June 2006

SUMMARYAlthough supplied to rivers, grains of about 1–6 mm diameters are notably deficient in fluvial deposits because they are more readily entrained and more rapidly transported than grains of larger or smaller size. Very coarse sand and fine gravel are rarely found in shallow‐water sediments for the same reason. Currents, mainly of wave origin, concentrate these grains in beaches, where they are present in more‐than‐ordinary abundance.
SUSPENDED LOAD IN THE RÍO DE LA PLATA DRAINAGE BASIN
Authors: DEPETRIS P. J. , GRIFFIN J. J. 
Published: June 2006

SUMMARYThe Río de la Plata Drainage Basin is the second largest in South America, with more than 75% of its discharge provided by the Paraná River and the remainder by the Uruguay River. Erosion rates, and silt‐ and clay‐size mineralogy indicate that most of the basin loads are provided by the mountainous environment‐type.
COMPOSITION OF MAGNESIAN CALCITES OF ALGAE AND PELECYPODS BY ELECTRON MICROPROBE ANALYSIS1
Authors: MOBERLY RALPH 
Published: June 2006

SUMMARYElectron microprobe analyses of skeletal carbonate structures in coralline algae and pelecypods show that the magnesian content of the calcite depends on skeletal growth rates. Growth rate is a function of certain variables, including water temperature, light, and physiological cycles. The Mg‐content of calcareous sediment from specific organisms is not, therefore, mainly dependent on water temperature, as is generally believed, but also on the other factors affecting growth.
EVOLUTION OF ZIRCONS IN SEDIMENTARY AND METAMORPHIC ROCKS: A REPLY
Authors: SAXENA S. K. 
Published: June 2006

SUMMARYIn a discussion Kalsbeek (1967) suggests that my idea of an authigenic origin of zircons seems to be the result of mis‐identification of authigenic titaniferous minerals as zircon. Kalsbeek appears to have formed this opinion firstly because he sees all the crystals (Saxena, 1966a, plate IV) as zircons. I never mentioned this. Since 70% of the matrix in the sandstones consists of such aggregate, the very idea of having so much zircon in the rock would be fantastic and absurd.
DEPOSITION IN THE PROCESS OF HYDRAULIC TRANSPORT1
Authors: BAGNOLD R. A. 
Published: June 2006

SUMMARYA simple theory is outlined, based on the conservation of energy, whereby such diverse processes as wind‐blown and river‐transported sediments, mud‐flows and sand avalanches can be brought together and explained in terms of the established concepts of general physics. It is shown that the mean rate of transport of sediment in turbulent suspension is determined by the whole size distribution of the transported sediment rather than by any arbitrarily defined mean size. This suggests that more detailed studies of the changes which occur in size distributions during the cycle of erosion transport and deposition would throw much‐needed light on the underlying processes.
THE ROLLABILITY APPARATUS
Authors: WINKELMOLEN A. M. 
Published: June 2006

SUMMARYA new instrument to measure a functional‐shape property of sand grains is presented. This property, which is called “rollability”, is measured on the inside of a slightly inclined, revolving cylinder mantle. During the rolling shape segregation takes place and the time it takes the grains to emerge from the cylinder is a measure for their rollability.The measurements are performed on 1/4–phi sieve fractions. Only very little material is needed for a measurement (30–200 mg) and the measurements last on the average 70 sec. Sizes between 88–700 μ are most suitable. Static electricity on quartz—the snag in most similar methods—is eliminated. The repeatability is 1% plus or minus. Since the measurement is completely automatized, personal bias is excluded.This paper is meant to enable copying of the instrument,1 whereas methodology and results in regional applications have been treated elsewhere (WINKELMOLEN, 1969).
CONSOLIDATION AND SEDIMENTATION‐COMPRESSION STUDIES OF A CALCAREOUS CORE, EXUMA SOUND, BAHAMAS
Authors: MILLER DONALD G. , RICHARDS ADRIAN F. 
Published: June 2006

SUMMARYA comparison is made between the void ratio and pressure relationships resulting from a laboratory consolidation test and a sedimentation‐compression computation on a short core of calcareous mud or ooze of low plasticity. Geo‐technical measurements of grain size, bulk density, Atterberg limits, water content, vane shear strength, pore‐water salinity, and carbonate content are graphically related to depth in the core. Results of the laboratory consolidation test on this material differ markedly from the in‐place relationship between void ratio, or water content, and the effective overburden pressure, or burial depth, shown by the sedimentation‐compression curve. The previous maximum consolidation pressure, based on laboratory consolidation test data, is about 60 times greater than the computed in‐place effective overburden pressure. An explanation for this difference would include the different magnitudes of time available for consolidation, cementation occurring in‐place, and orientation of the constituents. It is suggested that results of the consolidation test on carbonate muds or oozes should be interpreted with caution for geological and engineering purposes.
ELECTRON MICROSCOPY APPLIED TO QUARTZ GRAINS FROM A TROPICAL ENVIRONMENT
Authors: DOORNKAMP JOHN C. , KRINSLEY DAVID 
Published: June 2006

ABSTRACTThe examination, with a scanning electron microscope, of 200 quartz grains from a tropical environment (Uganda) shows the nature of chemical weathering on these grains. Five main types of features occur: solution pits; solution crevasses; chemical etching along quartz structures; blocky forms probably resulting from swelling; and widespread disintegration of the grain surface. Few of these features have previously been recorded.
THE DISTRIBUTION OF PENNSYLVANIAN‐AGE COAL PARTICLES IN RECENT RIVER SEDIMENTS, OHIO RIVER, KENTUCKY, AS AGE AND SEDIMENT RATE INDICATORS
Authors: MOORE BRUCE R. 
Published: June 2006

ABSTRACTThe weight percentage of coal particles increased suddenly toward the upper levels of the river sediments. This increase is attributed to the onset of coal washing and mining operations in approximately the last 150 years. The distribution of these coal particles facilitates recognition of Recent sediments less than this age and also gives indications of sedimentation rates and regions of scour and deposition on the river banks and islands. The maximum rate of sedimentation found at the downstream end of an island was 114 cm/150 years equivalent to 450 cm of pore‐free sediment in 1,000 years.
BED‐LOAD SEDIMENTS
Authors: MOSS A. J. 
Published: June 2006

ABSTRACTApplication of sieve and size‐shape analyses (Moss, 1962) to natural and artificial bed‐load deposits of shallow, unidirectional currents revealed that a textural sequence parallels one of primary structures. With increasing grain size and/or transporting power, sedimentary characteristics followed the stepwise pattern: fine ripple bed stage → coarse ripple bed stage → dune bed stage → rheologic bed stage.Bed roughness (A population grain size) strongly influences sedimentation in the first three, the “bare bed” stages. Respectively, they evidently represent enclosure of the A population particles within the viscous sublayer, their protrusion above the layer which remains influential in their interstices, and the contraction of the layer to insignificance allowing almost fully turbulent flow. Transitions between these bed stages cause major changes in the A and B populations and take place on the bed. Transitions involving the rheologic bed stage, however, take place above the bed, reflecting changes in saltation intensity. The rheologic layer, a moving mass of particles kept dispersed by collisions but gravitationally held to the bed, produces distinctive sediments. Bed‐load sediments can form from arbitrary mixtures in seconds of time or centimetres of travel.Ripples and dunes form only if flow conditions near the bed are fairly steady. Ripples, evidently sensitive to temporal current direction changes, are more readily prevented from forming than are dunes. Whereas structures dominate beds between parallel flume walls, in natural flows, often rife with temporal flow perturbations, plane beds are the more common. The characteristic textural features of the bed stages are shown whether or not the structures develop.Evidently temperature‐sensitive, the fine to coarse ripple bed stage transition could probably be used as a basis for water palaeothermometry.
PETROGRAPHY AND GEOCHEMISTRY OF RHOMBIC, CALCITE PSEUDOMORPHS FROM MID‐TERTIARY MUDSTONES OF THE PACIFIC NORTHWEST, U.S.A.
Authors: BOGGS SAM 
Published: June 2006

ABSTRACTMarine, mid‐Tertiary mudstones and siltstones of northwestern Oregon and western Washington contain unusual calcite pseudomorphs that commonly form the nuclei of carbonate concretions. These pseudomorphs typically have the shape of rhombic prisms, with dipyramidal terminations, that are much elongated due to multiple twinning (?). They appear similar to the glendonite pseudomorphs of New South Wales, however, their rhombic (orthorhombic?), prismatic form is at variance with the reported monoclinic form of the glendonite pseudomorphs. Internally, the pseudomorphs consist of granular calcite that takes the form of large ovoid crystals, radial or spherulitic crystals, fibrous but non‐radiating crystals, and mosaic crystals of clear spar.The original mineral, believed to be aragonite or one of the hydrated carbonates, probably formed in soft, organic‐rich mud, possibly in the burrows of marine organisms. Changes in physico‐chemical conditions caused early solution of the original mineral, leaving hollows or molds that quickly filled by precipitation of granular calcite. Judging from the low δC13 values of the pseudomorphs, the carbonate carbon of this granular calcite was supplied from CO2 produced through decay of local masses of organic matter. Concretionary calcite, supplied from a different source as shown by much higher δC13 values, formed around the pseudomorphs. The entire pseudomorphic and concretionary process took place only a short distance below the depositional interface, prior to compaction and lithification of the host mudstone.
Origin of red beds in a Cambrian flysch sequence, Canadian Appalachians, Quebec
Authors: LAJOIE JEAN , CHAGNON ANDRÉ 
Published: June 2006

ABSTRACTThe basal unit of this flysch sequence consists of about 700 m of rhythmically interlayered red and green claystone intercalated with feldspathic sandstone and lithic conglomerate. Chemical analyses show that both types of claystones have approximately the same Fe2O3 content (8%).The presence within green claystone of inarticulate brachiopods, thin laminations of phosphate and pyrite, coupled with a high Mn content (Fe/Mn : 27) together with the composition of the chlorites, suggest that green mud was deposited slowly in a marine environment under reducing conditions. The hematite content of red claystone averages 4%. The Fe/Mn is high (71), and the clay fraction contains chamosite in addition to chlorite and illite. These characteristics favour a paralic oxidizing environment for the red muds.Rapid resedimentation of red sediment from a paralic environment into the green lithotope, rather than a lateral variation of facies, is suggested by: (1) the distribution of the two hemirhythms in the stratigraphic column, (2) the presence in the red hemirhythm of large slump structures, contorted laminations, and pebbly claystone, and (3) by the internal sedimentary structures of the coarse fraction.
Lithified carbonate sediment and zeolitic tuff in basalts, Mid‐Atlantic Ridge
Authors: GARRISON ROBERT E. , HEIN JAMES R. , ANDERSON THOMAS F. 
Published: June 2006

ABSTRACTBasaltic boulders dredged from the Mid‐Atlantic Ridge contain lithified coccolith‐foraminiferal ooze in fractures and small pockets. Textural and isotopic studies of this sediment provide no evidence for high temperature metamorphism. The lithified carbonate sediment occurs together with palagonitized basaltic glass and zeolitic tuff, and appears to have been squeezed into cracks and other voids within the congealed margins of partly‐cooled basalt pillows which intruded soft carbonate ooze. Thermal metamorphism probably was precluded by rapid heat dissipation in convecting pore waters and by the thermal stability of calcareous microplankton. Low temperature alteration of basaltic glass appears to have provided the chemical milieu for precipitation of calcite cement as well as zeolites in the sediment.
Selective transport of heavy minerals by shoaling waves
Authors: MAY JAMES P. 
Published: June 2006

ABSTRACTA model to account for the occurrence of heavy mineral concentrations as discrete lamina on beaches is presented. The model is based on the shoreward variation in the distribution of bottom fluid velocities due to shoaling, progressive, gravity, water waves. This variation causes certain portions of the sediment population to be transported shoreward at a faster rate than other portions. On moderate energy shorelines composed of sand‐sized sediment the selectively transported portion may include the relatively hard‐to‐move heavy mineral fraction. Wave tank experiments with artificially prepared sediment populations provide empirical support for the proposed model. Under certain wave conditions it was found that the heavy mineral fraction of the sediment population moved shoreward at a faster rate than did the light mineral fraction.
Whistling sand beaches in the British Isles
Authors: RIDGWAY K. , SCOTTON J. B. 
Published: June 2006

ABSTRACTBeaches which squeak or whistle when walked on have been known for many years. The phenomenon is shown to be more common than has previously been thought: sand from thirty‐three beaches in the British Isles has been found to whistle. Size distributions of all these sands have been obtained by sieving, and the particle shape distribution in the peak size fractions has been measured by using a vibratory shape‐sorting table. A physical mechanism has been suggested for the production of the whistle, which depends upon a close size grading coupled with a spherical grain shape. The locations at which whistling sand occurs correlate quite well with the landward ends of bed‐load partings in the continental shelf sand transportation pattern as determined from side‐scan Asdic surveys.
Transportation of detrital materials on the lunar surface: evidence from Apollo 15
Authors: LINDSAY JOHN F. 
Published: June 2006

ABSTRACTThe thickness frequency distribution of stratigraphic layers intersected by the Apollo 15 deep core suggests that the majority of impact events reworking the lunar soil are small and produce ejecta blankets with an average thickness of less than 1·D5 cm. The energy frequency distribution of the meteorites producing the layers may be bimodal. The impacting meteorites produce both normal and reverse graded beds which appear to be the end products of two depositional mechanisms. First, the normally graded beds appear to be produced in base surges as escaping gases fluidize the flowing debris and larger particles move downwards in response to Stokes Law. Second, if the gas loss from the base surge is excessive the fluidization may cease and inertial grain flow dominates. In this situation the beds are reverse graded as larger particles move under dispersive pressure to the region of minimum shear stress at the upper boundary of the base surge. The same processes also produce measurable shape sorting of the particles in the beds.
An evaluation of CM patterns for grain‐size studies of fine grained sediments
Authors: VANDENBERGHE N. 
Published: June 2006

ABSTRACTGrain‐size data of Boom clay (Belgium) are represented on CM, AM, LM diagrams as suggested by Passega. They show a typical ‘uniform suspension’ pattern. It is argued that a ‘uniform suspension’ pattern can be due simply to the clay‐rich nature of the sediments. As these sediments are not deposited by a single transport mechanism, the ‘uniform suspension’pattern does not necessarily indicate a specific transport mechanism.