Desert Sediments: Ancient and Modern (Geological Society Special Publication No. 35)

Desert Sediments : Ancient And Modern / K. W. Glennie -- Vertical Exchange Of Coarse Bedload In Desert Streams / A. P. Schick, J. Lekach & M. A. Hassan -- Fluviatile Deposits And Morphology Of Alluvial Surfaces As Indicators Of Quaternary Environmental Changes In The Southern Negev, Israel / S. Grossman & R. Gerson -- Plio-pleistocene Raised Channel Systems Of The Western Sharqiya (wahiba), Oman / J. K. Maizels -- Tectonic Control Of Desert Sediments In Rift Basins : Ancient And Modern / L. E. Frostick & I. Reid -- Ancient Ephemeral Stream Deposits : A Local Terminal Fan Model From The Bunter Sandstone Formation (l. Triassic) In The Tønder-3, -4 And -5 Wells, Denmark / H. Olsen -- Alluvial Fan Dissection : Relationships Between Morphology And Sedimentation / A. M. Harvey -- Quaternary Landforms, Sediments, Depositional Environments And Gastropod Isotope Ratios Of Adrar Bous, Tenere Desert Of Niger, South-central Sahara / M. A. J. Williams, P. I. Abell & B. W. Sparks -- Aeolian Abrasion Of Quartz Particles And The Production Of Silt-size Fragments : Preliminary Results / W. B. Whalley ... [et Al.] -- The Mechanics And Geological Implications Of Dust Transport And Deposition In Deserts With Particular Reference To Loess Formation And Dune Sand Diagenesis In The Northern Negev, Israel / K. Pye & H. Tsoar -- Rates And Modes Of Dust Accretion And Deposition In An Arid Region-- The Negev, Israel / R. Gerson & R. Amit -- Wind-blown Materials And W African Soils : An Explanation Of The 'ferrallitic Soil Over Loose Sandy Sediments' Profile / H. Vine -- Continental Sabkha Pans And Associated Nebkhas In Southern Kuwait, Arabian Gulf / A. Gunatilaka & S. Mwango -- Dune Networks / A. Warren & S. Kay -- Complex Star Dunes And Associated Aeolian Bedforms, Hopeman Sandstone (permo-triassic), Moray Firth Basin, Scotland / L. B. Clemmensen -- Late Palaeozoic Cold-climate Aeolianities, Southern Cooper Basin, South Australia / B. P. J. Williams, E. K. Wild & R. J. Suttill -- Aeolian Sedimentation From The Galtymore Formation (devonian), Ireland / R. A. Carruthers -- The Statistical Analysis Of 'mixed' Grain Size Distributions From Aeolian Sands In The Libyan Pre-desert Using Log Skew Laplace Models / E. C. Flenley, N. R. J. Fieller & D. D. Gilbertson -- Grain-size Variation On A 'complex' Linear Dune In The Namib Desert / I. Livingstone -- Discrimination Of Depositional Environments Using Sedimentary Characteristics In The Mega Kalahari, Central Southern Africa / D. S. G. Thomas -- Silica And Calcium Carbonate Replacement Of Plant Roots In Tropical Dune Sands, Se India / D. A. Hendry -- Spring Mounds In Southern Tunisia / C. R. Roberts & C. W Mitchell -- Sand Sheets Of The Eastern Sahara And Ripple Blankets On Mars / C. S. Breed, J. F. Mccauley & P. A. Davis -- Surficial Deposits Of Qatar Peninsula / M. M. Ashour -- Remote Sensing Of Sediment Transfer Processes In Playa Basins / A. C. Millington ... [et Al.] Edited By L.e. Frostick, I. Reid. Includes Bibliographies And Index. Unconsolidated Kalahari sand covers 2.5 million km2 of central southern Africa, the 'Mega Kalahari', extending far beyond the Kalahari Desert of today. Relic aeolian, lacustrine and fluvial landforms indicate that in the Quaternary the Kalahari sand has been deposited and reworked by a variety of processes. Large areas of the sand have no identifiable landform associations, and because of this, sedimentological studies are necessary for a better interpretation of the palaeoenvironmental history of the Mega Kalahari. To this end, almost 200 Kalahari sand samples, in and not in identifiable landform associations, were collected and analysed in order to: investigate sedimentological characteristics; determine whether different processes have imparted distinct sedimentological characteristics to the sand; and thereby attempt to determine the depositional environments of samples without prior knowledge of the landform associations. Three methods have been used: (1) standard sedimentological techniques of grain size and shape determination; (2) multivariate discriminant analyses, to determine whether depositional environments could be better distinguished by considering grain size and shape parameters in combination; and (3) scanning electron microscope analyses of samples which lie centrally in any group identified by statistical analyses. Results indicate that aeolian processes have dominated the environmental history of the Kalahari sand, with only limited modification by subsequent processes. Multivariate discriminant analysis achieved only limited success in differentiating process environments. SEM investigations best identified the subtle modification of sand characteristics by non-aeolian processes, because individual grain textures are more readily adjusted than overall sample fabrics, and may therefore be the best technique for elucidating palaeoenvironments from sediment characteristics