ALBERT

Notes: The following dimensionless parameters (two of them well-known and five of them new) are defined for determination of ripple mark geometry: ripple index (RI), ripple symmetry index (RSI), continuity index (CI), bifurcation index (BI), straightness index (SI), and two different parallelism indices (PI1 and PI2).In general, RI = 15 or less indicates wave or water current origin; RI = 17 or more indicates wind or swash origin. RSI = 1.5 or less indicates wave or swash types; RSI = 3 or more indicates wind or water current types. CI = 15 or more suggests wind or wave origin; CI = 10 or less suggests water current origin. BI = 10 or more suggests wave varieties; BI = 1 or less suggests wind varieties. SI = 102 or more indicates wind or deep-water wave types; SI = 15 to 102 indicates wind or wave types; SI =4 or less indicates current types. PI1 = 7 or more suggests wave origin; PI1 = 1 or less suggests water current origin. PI2 = 0.4 or more is probably the result of swash or water current action. PI2 = 0.2 or less is probably the result of wind or wave action. Longitudinal ripple marks (such as rib-and-furrow) and deformed or modified varieties (such as flat-topped tidal-flat ripple marks and nearly- flat-topped intermittent creek ripple marks) have been excluded, inasmuch as (1)they are commonly easy to identify from their appearance, and (2)they are difficult to measure with ordinary methods.Plots of two indices against each other on coordinate paper can be particularly useful; the best combinations are RI vs. RSI, and RI vs. PI1, although several other pairs are almost as good. Where all seven parameters can be obtained, the confidence one can have in the interpretation is close to 98%.The effects of current bias, or depth bias, on wave-type ripple marks, extend to both the symmetry (RSI) and to sediment-transport interpretations. Unless the investigator is reasonably sure that no such bias is present (i.e., RSI = 1.0 instead of some significantly higher value such as 1.5), wave-type ripple marks cannot be used to determine direction of either wave approach or sediment transport. If no such bias is present, wave-type ripple marks still cannot be used to determine precise sediment transport direction. If RSI = 1.0 precisely, it is not even necessary that the ripple crests parallel the waves that formed them. The same restrictions apply to the interpretation of micro-crossbedding (that is, ripple mark internal structure). Despite these seemingly severe limitations, general geometry commonly permits a reliable interpretation, and hence ripple marks can provide a great deal of useful data for paleogeographic interpretations.The swash-zone variety of ripple marks includes two sub-types: those modified by a small but unmistakeable hydraulic jump, and those not so modified. The RI can be used to distinguish between these two, even when they were not observed to form.

Notes: 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

Notes: The paper describes tests made on a small river to examine the practicability of measuring quantitatively, by tracer methods, sand transport occurring over a rippled bed in a natural channel. Three principal tracer methods, all previously verified under steady flow conditions in a laboratory channel, and identified as the spatial integration, time integration and steady dilution methods, were examined by introducing radioactive and fluorescent tracers to represent a narrow size fraction of the bed sand. The serious limitations of the time integration and steady dilution methods under conditions of unsteady solids discharge were exposed by a sudden flood discharge occurring during the course of the study. An approximate method, based on the time integration approach, but also requiring some spatial tracer data, is suggested, whereby an estimate of the transport is possible in the case of highly variable sand discharge. However, it is seen that in the sand case, the spatial integration method offers the most workable and informative tracer method for use in natural rivers. The results, by this method, were generally consistent with those given by the summation of the measured suspended-solids flux and the transport occurring either by surface creep or in close vicinity to the bed. The latter quantity is determined from the downstream advance of the ripple bed-forms, and methods are described for its derivation from ultrasonic echo sounder records of bed profiles. Finally sand transport values are calculated for a number of river discharges and for two laboratory channel tests using various well-known computational procedures—Einstein, Bagnold, modified Einstein, Meyer-Peter and Muller, and Laursen procedures. Significant differences in the computed values for individual flow conditions are observed.

Notes: Few examples are given to demonstrate that crushing of hard sedimentary rocks practically does not break up the heavy minerals present in the rock. Also the ratios of the various minerals mostly are not changed.

Notes: The type Lindsey Bridge Member of the Moorefield Formation of northeastern Oklahoma consists of 24 ft. of massively cross-bedded limestone. Cross-bed shape, lithologic variation, grain size and sorting, distribution of insolubles, and distribution of fossils and fossil burrows can be explained with reference to a hydrodynamic model developed in recent flume studies.Three facies can be distinguished in this unit: (1 Thei) foresets, thick-bedded, well-sorted, fine to medium crinoidal grainstones, dipping at angles up to 1° (2) toesets, which are thin-bedded, poorly sorted, skeletal packstones notably more fossiliferous than the foresets, with which they are laterally gradational; toesets dip at approximately 5°-8° (3) bottomsets, composed of argillaceous, fine-grained (mainly silt-size), skeletal limestones. Foresets overlie previously deposited bottomsets; this geometry is typical of regressive sedimentation.The exposure is adjacent to a pre-Moorefield topographic high. As currents crossing this high entered a basin on the downcurrent side, flow separation occurred. Bed material load was deposited mainly on the foreset slope, suspension material mainly in toeset and bottomset areas. The poor sorting of the toesets is in part due to reverse circulation, formed by the flow separation, which transported bottomset sediment back toward the foreset. Jopling (1965b) has shown that this depositional geometry produces tangential cross-beds similar to those seen in this outcrop. Differential settling velocity, substrate stability, and abundance of organic detritus influenced other sedimentologic properties of the deposit.

Notes: If a modified version of the Zingg system is used particles can be subjectively classified into four shape classes. The roundness of a particle can be estimated by assessing the flat/convex/concave ratio and can then be represented as a point on a triangular net; this point can also indicate the Zingg class of the particle.

Notes: 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.

Notes: The occurrence of the rare phenomena of a booming sand is recorded and an account given of its behaviour in the field. Its sedimentological properties are compared with those of a squeaking sand from the seashore. Both sands are moderately to wellsorted, and show similar roundness and sphericity. The desert sand is silent, whereas the seashore sand can be made to emit a noise in the laboratory. The marked distinction between the sands lies in the mechanical analyses based on the number frequency of grains, rather than on the weight frequency. A “body-centred cubic” packing has been proposed for the desert sand and a “rhombic” packing for the seashore. Shear-box tests on the disturbed sands appear to support the hypothesis of two different modes of packing. The source of the characteristic booming sound is discussed, but it is suggested that an explanation is more likely to be forthcoming from field investigation than from small-scale laboratory studies.