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One thousand grains selected from sieved samples of a bioclastic sand have been individually measured, weighed and timed in free unhindered fall at terminal velocity in a 250 cm column of sea water. Four fall regimes are represented: straight fall, spinning and spiral modes and erratic tumbling. As size increases grains pass through this series at rates dependent upon shape and effective density. Computed best‐fit curves for velocities/intermediate diameter and an equivalent sphere/intermediate diameter illustrate considerable divergencies in behaviour between the eleven grain types and five shape classes examined. Current methods of analysis of carbonate sediments, by sieving, by grain‐counting of components, and by sedimentation balance, provide different kinds of information which it is impractical to consider as having any simple relationship to each other.

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The Lis ˇov Granulite Massif differs from neighbouring granulite bodies in the Moldanubian Zone of southern Bohemia (Czech Republic) in including a higher proportion of intermediate-mafic and orthopyroxene-bearing rocks, associated with spinel peridotites but lacking eclogites. In addition to dominantly felsic garnet granulites, other major rock types include quartz dioritic two-pyroxene granulites, tonalitic granulites and charnockites. Minor bodies of high-pressure layered gabbroic garnet granulites and spinel peridotites represent tectonically incorporated foreign elements. The protoliths of the mafic-intermediate granulites (quartz-dioritic and tonalitic) crystallized $360-370 Ma ago, as indicated by laser ablation inductively coupled plasma mass spectrometry U-Pb ages of abundant zircons with well-preserved magmatic zoning. Strongly metamorphically recrystallized zircons give ages of 330-340 Ma, similar to those of other Moldanubian granulites. For the overwhelming majority of the Lis ˇov granulites peak metamorphic conditions probably did not exceed 800-900 C at 4-5 kbar; the equilibration temperature of the pyroxene granulites was 670-770 C. This is in sharp contrast to conditions of adjacent contemporaneous Moldanubian granulites, which are characterized by a distinct HP-HT signature. The mafic-intermediate Lis ˇov granulites are thought to have originated during Vise ´an metamorphic overprinting of metaluminous, medium-K calc-alkaline plutonic rocks that formed the mid-crustal root of a Late Devonian magmatic arc. The protolith resembled contemporaneous calc-alkaline intrusions in the European Variscan Belt.