bluuebunny/crossref_metadata_2025_split huggingface dataset:
CRYSTAL CASTS IN UPPER TRIASSIC LOCKATONG AND BRUNSWICK FORMATIONS
Authors: VAN HOUTEN FRANKLYN B. 
Published: June 2006

SUMMARYUpper Triassic Lockatong argillite (lacustrine facies) and reddish‐brown Brunswick mudstone (mudflat facies) contain numerous pseudomorphs after glauberite. Those in the Brunswick Formation are large calcite casts of complete crystals both isolated and in bunches in beds a few inches thick, or are slender skeletal crystal casts forming open‐work rosettes in massive mudstone. Those in analcime‐rich dolomitic Lockatong argillite are smaller, more slender, skeletal crystal‐casts filled with dolomite and analcime; most of them are scattered through the rock but locally arranged in vague geometric patterns; less commonly they form conspicuous rosettes and downward‐ diverging conical sprays.Many glauberite crystals (and rarely halite in the Brunswick mudstone) grew in soft mud during Late Triassic time, thus emphasizing dryness and the role of saline water in the later history of the closed carbonate‐sulphate Lockatong lake. Early extraction of calcium and magnesium carbonates and later of sodium and silica during each chemical cycle left the lake enriched in calcium, sodium, and sulphate. These crystallized as glauberite and possibly anhydrite in lake‐bottom mud and in surface mudcracks during the waning of a chemical cycle.Crystals of the soluble salts in the Lockatong mud were then replaced by dolomite and analcime from solutions released during dewatering of the mud.
A REVIEW OF THE ORIGIN AND CHARACTERISTICS OF RECENT ALLUVIAL SEDIMENTS
Authors: ALLEN J. R. L. 
Published: June 2006

SUMMARYRecent alluvial sediments are reviewed with respect to their geometrical, textural, structural and biological characteristics. These properties are related to the physiographic occurrence and hydraulic geometry of streams and to the dynamics of flowing water as controlling sediment transport‐deposition and stream morphological activities. Based on this data, three‐dimensional facies models are presented as an aid to the identification of ancient alluvial sediments, which are briefly reviewed also.
SUBMARINE FLOOD TUFFS (IGNIMBRITES) ASSOCIATED WITH TURBIDITES IN OLIGOCENE DEPOSITS OF RHODES ISLAND (GREECE)
Authors: MUTTI E. 
Published: June 2006

SUMMARYTwo pyroclastic sheet‐like deposits were found by the author between the stratigraphic sequence of marine Oligocene sediments of the Vati Group (Rhodes Island, Greece). The lower one is described in this paper.Its uniform thickness over a large area suggests an origin from submarine ash flow. This assumption is also supported by some welding phenomena observed in several thin sections. Submarine eruption of ignimbritic type is advocated to account for these properties. This type of volcanism agrees well with tectonic and paleogeo‐graphic evolution of the Vati Group basin.Strong analogies and relationship between submarine ash flows (gaseous suspension) and turbidity currents (watery suspension) are pointed out. The new term of “igniturbidites” is proposed to characterize some pyroclastic turbidity current deposits genetically related to submarine ash flows.The paleogeographic reconstruction of the Vati Group basin gives some information about the location of the volcanic eruption area and about the submarine travelling of the ash flows.
RECHERCHES SUR LE COMPORTEMENT HYDRAULIQUE DES DEBRIS ORGANOGENES
Authors: BERTHOIS L. 
Published: June 2006

SUMMARYPresentation of investigations on the hydraulic content of fragments of lamelli‐branches dredged on the continental shelf (diameters between 12 and 0.51 mm).These lamellar fragments have fall velocities greatly different from those of quartz grains with which they are able to coexist in a sediment. The data of G. Rittinger (in TRASK, 1939) and R. W. Budryk (in TRASK, 1939) are not applicable to these fragments.The author points out the interest of a basic documentation for the dynamic study of sedimentation.
RELATIONSHIP BETWEEN LONGITUDINAL AND TRANSVERSAL CURRENTS IN THE PALEOGENE OF THE TARCAU VALLEY (EASTERN CARPATHIANS)
Authors: JIPA DAN 
Published: June 2006

SUMMARYIn the Paleogene of the Tarcä Valley (Rumania) the largest part of the thick‐bedded and coarse‐grained material was supplied by longitudinal paleocurrents from a distant source. The longitudinal supplies were independent of the lateral ones.
THE INTERNAL PALEOGENE FLYSCH OF THE EASTERN CARPATHIANS: PALEOCURRENTS, SOURCE AREAS AND FACIES SIGNIFICANCE
Authors: CONTESCU L. , JIPA D. , MIHAILESCU N. , PANIN N. 
Published: June 2006

SUMMARYAfter a brief review of the structure, the stratigraphy and the facies of the Rumanian eastern Carpathians flysch zone, the authors analyse the main paleocurrent directions on the internal facies of the paleogene flysch. The most important and numerous currents were longitudinal and came into the flysch trough from an outlet area situated in the Carpathian arc region. For this reason it is inferred that the principal source of detrital material was represented by the Pannonian–Transylvanian internal massif.The crystalline core of the eastern Carpathians furnished only a small quantity of clastics, which were transported into the trench by means of transversal, relatively weak currents. The role of different structural elements (platforms, cordilleras, internal massifs) in providing detrital material is briefly discussed. Finally, an attempt is made to outline the paleogeographic evolution of the eastern Carpathians during the Paleogene.
CROSS‐BEDDING IN THE SALEM LIMESTONE OF CENTRAL INDIANA
Authors: SEMINAR SEDIMENTATION 
Published: June 2006

SUMMARYIn the middle Mississippian Salem Limestone of central Indiana 693 measurements showed that sediment transport during Salem deposition was to the southwest, as during deposition of most of the late Paleozoic sands of the Illinois Basin. Crossl bedding direction is variable, however, and noticeably bimodal. Oscillating tida‐currents on a shallow marine shelf are believed to have caused pronounced bimodality in the Salem Limestone and in the associated Ste. Geneviève and Harrodsburg Limestones.
SOME APPLICATIONS OF THEORY AND EXPERIMENT TO THE STUDY OF BEDDING GENESIS
Authors: JOPLING ALAN V. 
Published: June 2006

SUMMARYThe origin of many sedimentation units deposited in granular cohesionless materials can be rationally explained by utilizing the concept of the profile of equilibrium. This basic concept can be formally expressed in terms of the variables, or groups of variables, that characterize a sediment transport system. A change in one or more variables or a shift in local base level will generally cause a shift in the spatial position of the profile, resulting in either aggradation or degradation. As shown by flume experiments, the rate of shift of the profile is a critical factor in bedding genesis.A relatively large and rapid upward shift of the profile results in the deposition of a tabular or wedge‐shaped unit of cross‐bedding, i.e., a laboratory delta. On the other hand, a gradual upward shift of the profile results in the deposition of a sequence of horizontal bedding that is commonly associated with intercalations of ripple or dune cross‐bedding. For the intermediate case of a moderately rapid shift of the profile, the depositional sequence includes trough units and poorly‐defined tabular units of cross‐bedding with numerous intercalations of horizontal bedding. The concept of the profile of equilibrium therefore provides a rationale for considering the depositional framework for sedimentary structures produced by current flow.
SCOUR RIPPLES IN THE LUDLOVIAN OF SOUTH RADNORSHIRE, WALES
Authors: BAILEY R. J. 
Published: June 2006

SUMMARYCalcareous siltstone beds in the sub‐littoral marine sedimentary rocks of the highest Ludlovian (Upper Whitcliffian) in south Radnorshire display symmetrical ripples with wave lengths around 30 cm. These structures are interpreted as having been formed by the deposition of calcareous silt layers in conformity with bottom surfaces previously scoured into a pattern of symmetrical, gently‐rounded, crests and troughs; hence, they are termed scour ripples. There is some evidence of a longitudinal relationship between the scour ripples and the scouring and depositing currents involved in their formation.
THE DETERMINATION OF THE DIRECTION OF TRANSPORT OF FLUVIATILE ARENITES BY ORIENTATION ANALYSES OF THE DETRITAL MICA
Authors: DIESSEL C. F. K. 
Published: June 2006

SUMMARYA simple method of determining the strike and dip of the AB planes of mica flakes in etched slides of arenaceous sediments by means of a universal stage mounted on a stereomicroscope is described.The polar stereograms constructed from such measurements in fluviatile sandstones show monoclinic symmetry due to up‐current imbrication which compares well with the orientation of plant fossils, current bedding structures and the general current pattern. An angular discordance exists between these features and the direction of sole marks.An example is given of how analyses of the orientation and imbrication of mica flakes can assist in the solution of sedimentation problems of coalfield geology.
THE SURF “BREAK”: KEY TO PALEOGEOGRAPHY?
Authors: TANNER WILLIAM F. 
Published: June 2006

SUMMARYAncient geosynclinal coastal deposits, preserved and exposed for present‐day examination, probably represent interior—and hence protected—shores, and were therefore characterized by low‐to‐moderate breaker energy levels, as is the modern Gulf of Mexico. Modern low‐energy beach sand size distributions are distinguished by an inflection, here called the surf “break”, formed by a winnowing or statistical filtering process, by the breakers, in the finer sizes. The result is a two‐segment curve having an intersection in many cases not far from 1.5 phi. If the energy level is very low, a tail of fines may be added, producing a three‐segment curve having two inflection points. Along high energy beaches, the surf “break” occurs at such large grain sizes that it cannot be preserved in sand; whether or not it can be recognized in gravel is not known.Ancient sandstones which represent the breaker zone, along a low‐to‐moderate energy coast, should also exhibit the surf “break”. The Lyons Sandstone, a known Permian beach deposit, provides an example. Other examples are cited.Any useful indicator of the shoreline position, in lithified rocks, should have three characteristics: ease of recognition, high reliability, and strong probability of preservation. The surf “break” scores reasonably well on all three points. Hence it may be an important key to paleogeography. Nevertheless, there still remains a question inasmuch as certain river sands have similar inflections. Whether these kinks were inherited from near‐by, but older, beach deposits, or were formed by stream action, is not known. The reliability of the surf “break” is estimated at 80% or better, except for the case where near‐shore sands, of whatever age, are reworked briefly by running water.
THIN‐SECTION ANALYSIS OF SANDSTONES ON WEIGHT‐FREQUENCY BASIS
Authors: SAHU BASANTA K. 
Published: June 2006

SUMMARYThe weight‐frequency size distribution is generally accepted to be log‐normal (phi‐normal) for sandstones, but the nature of number‐frequency distribution of particles in sandstones is largely unknown. This paper develops the theory of correction procedure for the observed weight‐frequency moments obtained by thin‐section analysis of sandstones (and clastic sediments in general) which was not available so far.
MORPHOLOGY, INTERNAL STRUCTURE, AND ORIGIN OF GLAUCONITE PELLETS
Authors: TRIPLEHORN D. M. 
Published: June 2006

SUMMARYGlauconite pellets exhibit considerable variety in morphology and internal structure. Recognized morphological types are: (1) ovoidal or spheroidal; (2) tabular or discoidal; (3) mammillated; (4) ellipsoidal; (5) vermicular; (6) composite; and (7) fossil casts, internal molds, or replacements. Types of internal structures include: (1) random microcrystalline, (2) oriented microcrystalline, (3) micaceous, (4) organic (?) replacements, (5) coatings on detrital grains, and (6) fibroradiated rims.These characteristics can be used to interpret the origin and/or subsequent history of pellet types. Suggested origins include: (1) chemical precipitation, (2) expansion and alteration of detrital mica, (3) alteration of fecal pellets, (4) alteration of clay fillings of fossil tests, (5) mechanical aggregation, and (6) chemical replacement.Not all glauconite pellets exhibit diagnostic characteristics with regard to their genesis. Original morphologies may be obscured by abrasion (reworking) prior to final burial. Internal structures may be changed by recrystallization or other diagenetic processes.It is concluded that glauconite pellets have multiple origins. They can form from several different parent materials and by several different processes. Frequently, however, characteristics which might reveal the original nature of the pellets have been lost during reworking and diagenesis.Inasmuch as glauconite occurrences differ in kind and variety of pellets, recognition of pellet types and their distribution is potentially useful for stratigraphic correlation or environmental determinations.
BORON IN CLAYS AND ESTIMATION OF PALEOSALINITIES
Authors: LERMAN A. 
Published: June 2006

SUMMARYExperiments on the uptake of boron by some clays from artificial sea‐water solutions at room temperatures show that the uptake is proportional to the concentration in solution, and takes place in relatively short time. The uptake process can be described by the Freundlich adsorption equation, with the constants in the equation, k and b, varying from one clay to another. Additional factor which apparently promotes the boron adsorption by clays is the occurrence of a sodium‐borate complex in saline waters. The boron concentrations in a sequence of marine Cretaceous sediments derived from a fairly localized source area show variation much greater than can be accounted for by a model which assumes (1) nearly constant boron concentration in illitic‐montmorillonitic clays prior to their deposition in the sea, and (2) changes in the boron concentration in solution as may be expected under slight variations in sea water of near “normal” salinity. Differences in the properties of clay‐mineral polymorphs, in predepositional histories of the clays, and possible adsorption from interstitial waters, render inconsequential the estimates of the boron concentrations in the waters at the time of deposition.
SEDIMENTARY CHARACTERISTICS AND CLIMATIC ANALYSIS OF EASTERLY DUST STORMS IN THE NEGEV (ISRAEL)
Authors: YAALON DAN H. , GINZBOURG D. 
Published: June 2006

SUMMARYSedimentary and meteorological characteristics of easterly dust storms causing severe damage in the Negev in November 1958 are analysed. Though the heavy storm originated in weather conditions outside of the affected area, the intense dustiness was of a more local nature. The sedimentological character of the dust indicates that the largest portion was of local origin, picked up by the turbulent current in the loess area of the northern Negev on its passage westward. Total quantity of sediment transported in the Beersheba Basin is estimated to be 10–20 million tons.The analysis of climatic data and of sedimentary characteristics of several other dust samples indicates that though severe dust storms can produce dramatic effects in transporting and deposition of aeolian dust, the rare occurrence of easterly dust storms does not make it likely that they were responsible for the import of aeolian sediments found in the northern Negev.
A COMPUTER PROGRAM FOR GRAIN‐SIZE DATA1
Authors: SCHLEE JOHN , WEBSTER JACQUELINE 
Published: June 2006

SUMMARYThe computer program presented here seeks to improve estimation of statistical parameters for grain‐size data by use of interpolated values. Interpolation is made by fitting a series of overlapping parabolas to the data, and follows the method of Snyder (1961). The values are used in moment formulas to compute standard statistical measures. Skewness and kurtosis are reduced by the interpolation data, and extreme positive values of kurtosis tend to be greatly reduced. The program also picks major modes, the median, and sediment type.
THE CONTINENTAL MARGIN OFF THE ATLANTIC COAST OF THE UNITED STATES: CARBONATE IN SEDIMENTS, NOVA SCOTIA TO HUDSON CANYON1
Authors: HÜLSEMANN JOBST 
Published: June 2006

SUMMARYA joint survey by the Woods Hole Oceanographic Institution and the U. S. Geological Survey, begun in 1962, aims at the geologic exploration of the Atlantic continental margin. This report describes the distribution of carbonate in the surface sediments between Nova Scotia and Hudson Canyon. Samples of surface sediment on a 10‐mile grid reveal that over more than 90% of its area the shelf sediment contains less than 5% calcium carbonate. These low values are due to low production by aquatic organisms, a consequence of low average water temperatures. A few locales on the shelf have high carbonate concentration owing to a prolific sessile or nearly sessile fauna. Seaward of the shelf concentrations of calcium carbonate increase regularly with depth to about 30% on the upper continental rise; this increase reflects a greater relative abundance of planktonic Foraminifera due to a decrease in the rate of deposition of land derived detritus. Limestone outcrops are very rare in the area.
WOODY DEBRIS ON THE MAINLAND SHELF OFF VENTURA, SOUTHERN CALIFORNIA
Authors: UCHUPI ELAZAR , JONES GILBERT F. 
Published: June 2006

SUMMARYLand plant debris occurs in appreciable quantities in the shelf sediments off Ventura, southern California. Concentrations range from less than 2 g (wet weight)/1 (less than 250 g/m2) to 53 g/1 (10,662 g/m2). The highest values are found near the outer edge of the shelf.
OCCURRENCE OF HIGH‐ANGLE STRATIFICATION IN LITTORAL AND SHALLOW NERITIC ENVIRONMENTS, CENTRAL GEORGIA COAST, U.S.A.1
Authors: HOYT JOHN H. 
Published: June 2006

SUMMARYHigh‐angle stratification (greater than 20°) is produced in several areas of shallow marine sedimentation along the barrier islands of the central Georgia coast. The maximum angle of inclination is 30° which is the angle of repose for the saturated, fine‐grained, angular sand of this area. High‐angle stratification forms in the following locations:(1) The depositional margin of tidal channel inlets. Under some wave and current conditions, sand accumulates near low tide level and steepens the depositional interface to the angle of repose. (2) The steep face of asymmetrical megaripples developed by tidal currents. Ripples with amplitudes as much as 3 ft. and wave lengths of 20–40 ft. commonly develop in channel inlets and other areas of sand sediments. (3) The steep face of sand waves formed in channel inlets. These large asymmetrical ripples have amplitudes as great as 12 ft. and wave lengths of ca. 300 ft. Lengths along the crests are over 600 ft. (4) The landward side of low bars developed on the beach. Bars and troughs (ridges and runnels) are common on the beaches of this area. The bars, which are as much as 5 ft. high, shift landward by deposition on the steep landward face. (5) The oceanward side of large sand waves at the mouth of offshore tidal channels. Large sand waves are located 6 miles offshore from Doboy Sound inlet in 20–25 ft. of water. The steep face of these asymmetrical sand waves is orientated toward the ocean. Amplitude of these large ripples is as much as 17 ft. and length along the crests is over 1/2 mile.
AN ELECTRON MICROSCOPE STUDY OF THE SURFACE TEXTURE OF SAND GRAINS FROM A BASAL CONGLOMERATE
Authors: WOLFE M. J. 
Published: June 2006

SUMMARYQuartz grain surface textures from the basal glauconitic chalk of the Belemnitella mucronata Zone southwest of Belfast, Northern Ireland, show the effects of solution during the last stages of diagenesis of the limestone. The postulated chemical environment, in which quartz is more soluble than calcite, is one of moderate temperature and pressure and alkaline circulating ground water.
14C DATES OF CALCAREOUS SAMPLES, HERON ISLAND, GREAT BARRIER REEF1
Authors: WOLF KARL H. , ÖSTLUND GÖTE 
Published: June 2006

SUMMARYTwo samples of plant‐rich limy sand collected from the 9‐ and 11‐ft.‐level of the Heron Island cay were subjected to 14C dating. Uncertainties related to secondary changes and contaminations, and the unknown transportation history of the woody material prior to accumulation at Heron Island, in combination with the relatively young age of the carbon, did not result in 14C values useful for correlation and absolute dating purposes.
DEFINING GRADIENTS IN A SAMPLE OF SEDIMENTARY ROCK
Authors: DAHLBERG E. C. , GRIFFITHS J. C. 
Published: June 2006

SUMMARYThree orthogonal planes (two vertical and one horizontal with respect to the apparent bedding structure) of a core sample of seemingly graded graywacke sandstone have been petrographically analyzed in order to determine the form and characteristics of the lithologic gradients in the specimen.Compositional and textural properties were sampled in thin section according to an orthogonal grid pattern on each of the three faces.Variability among rows and columns (plus interaction) with respect to each petrographic variable was tested by analysis of variance using a two way classification. A larger number of properties show significant variation among the rows of the sampling grid (thus in a vertical direction) than in the horizontal plane of the apparent bedding.Quality control models with confidence limits, which display graphically trends in the individual constituents, indicate that feldspar proportion, mica proportion, and quartz grain size exhibit significant gradients (above the level of analytical error) in the direction perpendicular to the bedding. Quartz proportion oscillates in a non‐systematic fashion, and quartz grain shape shows no trend in the vertical planes of the specimen. The petrographic variability observed in the horizontal plane of the bedding is generally trendless.Partial trend surfaces show that the trends in quartz grain size are dominant, but are not simple in form according to the comparative reductions in total variation achieved by fitted surfaces of successively higher degree. Again, the major portions of variability are explained by the surfaces fitted to planes perpendicular to the bedding. The textural homogeneity of the rock in the horizontal (bedding) plane is reflected in the relatively subdued trends exposed by the surfaces in this direction.Taking grain size as an example, a 1: 1 correspondence is established between this property and the theoretical effects of settling in a liquid medium by a functional relationship; it is shown that only 25 to 40% of the total grain size variation in the specimen is attributable to this process.It is concluded that the interpretation of natural sedimentation processes from analysis of petrographic properties is complex due to the interaction of the processes and the interdependencies among the measurable properties which result.
AUTHIGENIC CEMENTATION OF SCORIACEOUS DEEP‐SEA SEDIMENTS WEST OF THE SOCIETY RIDGE, SOUTH PACIFIC1
Authors: MORGENSTEIN MAURY 
Published: June 2006

SUMMARYHarmotome‐rich scorias and indurated tuffaceous mudstones occur in sediments west of the Society Ridge, South Pacific. Diagenetic alteration of mafic palagonite produces the following authigenic minerals: harmotome, phillipsite, goethite, limonite and montmorillonite. A major mode of induration of pyroclastic‐rich marine sediments is the devitrification of mafic palagonite producing the following diagenetic cementing minerals: phillipsite, harmotome, limonite, and to some extent, manganese and ferromanganese oxides.