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The new interpretation of the geological history of the west and south-west Pacific, in the light of plate tectonic theory, is that the islands formerly lay much closer or in contact with each other and with the land masses which form the western rim of the Ocean. There have been massive increases in separation during the Tertiary because of ocean floor spreading. Plant distribution patterns in the region are re-interpreted against this history. Old World Winteraceae (centred around the Coral Sea) and Ficus section Pharmacosycea (ranging east to New Caledonia) are considered in detail. Attention of geologists is drawn to enigmas of phytogeography whose interpretation await refinement of the geological reconstruction, namely the high endemism of New Caledonia and amphi-Pacific plant genera of the lowland humid tropics. [ABSTRACT FROM AUTHOR]

Focuses on the map of the floor of the world ocean. Funds provided by the Geography Branch of the U.S. Office of Naval Research for the production of the map; Division of the receipts for the map supplement.

Discusses the conditions of the linear sand banks in the southern North Sea considered to have large-scale mobile bed forms in dynamic equilibrium. Movement of sand streams in opposing directions of either side of the bank; Accumulation of sand which is believed to result in continuing the growth of the bank parallel to the direction of flow of the tidal currents.

Methods whereby an Asdic may be used empirically to examine the sea bed are discussed. They indicate that on flat sea bottoms the effects of impedance and attenuation combine to produce a record usually distinctive enough to broadly classify the sediment over which the vessel is passing. These methods were used to interpret an area of unconsolidated sand, gravel and mud in the region of Arklow off the east Irish Coast. Echo-sounder traverses and sea bed sampling were also employed to assist with the interpretations. The sea bed is composed of dissected residual gravels covered in places with mobile sand displaying a great variety of high-energy bed forms. Mechanisms of sub-littoral sediment circulation, based largely on the bed forms recognized in the Asdic records, are also discussed. [ABSTRACT FROM AUTHOR]

Describes the first stages of echinoderm overgrowth by calcite, observed in partially cemented limestones from boreholes in the floor of the Persian Gulf. Development of the overgrowth as spires in the direction of the c-axis of calcite; Presence of all essential features for the early stages in the development of overgrowths in fully cemented Jurassic limestones.

Points out that large areas of the sea floor in the Persian Gulf are composed of lithified carbonate sediment. Contemporaneous cementation; Operation of the process in areas of relatively normal salinity and temperatures; Effect of low rates of sedimentation, sediment stability and high initial permeability of the sediments.

Curved or planar discordant surfaces occurring within a limited stratigraphic range immediately beneath shallow marine deposits represent penecontemporaneous shear surfaces along which slumps have moved. Rotated packets of strata frequently retained within the curved discordant surfaces show both internal and external evidence of having moved laterally. Movement is considered to have been triggered off by a sudden shock or shocks which may have been either of sedimentary or tectonic origin. The slumping occurred at the change in gradient between slope and shallow marine shelf deposits. [ABSTRACT FROM AUTHOR]

The crystallinity and mineralogy of both the glauconite and the clay fraction of samples from six contemporary marine environments were investigated by X-ray diffraction. In those areas where glauconite is now forming, the mineralogy and the degree of crystallinity of both the glauconite pellets and the associated clay fraction are similar. In contrast, detrital and relic glauconites are observed to have mineralogies that are different from their clay fractions. No consistent relationship was observed between degree of crystallinity and color of the pellets. Further, only two classes of glauconite as defined by BuRsT (1958) were common: expandable, interlayered clays and two or more clay minerals in a mixed assemblage. Based on the clay fraction-glauconite similarities and other supporting evidence, glauconite on the Scotia Ridge is concluded to be authigenic. Glauconite from Santa Monica Bay, California and from the continental shelf off Morocco appear to be detrital. Glauconite pellets in the shelf sediments off Guinea and the southeastern Atlantic Shelf of the United States are both detrital and authigenic. The poor crystallinity exhibited by the Chatham Rise glauconite is in contrast to the well-crystallized associated clay fraction and indicates that they are not genetically related. However, the origin of this glauconite remains in doubt. [ABSTRACT FROM AUTHOR]

Tile 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 = 0.2 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%.

Focuses on the correlation of some Atlantic turbidities. Distance covered by individual turbidities; Turbidity in cores from the continental rise; Impact of the local erosion of sea floor on turbidity; Effect of the correlation of turbidite and pelagic sediment contents of the cores on the lateral extent of individual turbidities.

Presents cross-bedding data measured in a marine sand for which the environment of deposition, age, geometry and local extent are known. Data suggesting that the wave path, topography of the depositional surface and local rates of subsidence varying during deposition of the cross-bedded sand resulting in a uniform distribution of the cross-bedding sets.