Early Permian anhydrite–gypsum strata in central Spitsbergen show deformation of sulphate nodules in dolostone (chicken-wire structure) to varying degrees from imbricate to extreme flattening and elongation. These shear zones often occur between undeformed layers of apparently similar strata.

The shear zones indicate a minimum displacement of between 0.5 and 1.5 km to the ENE of Zechstein and later strata over the Nordfjorden Block. Resultant folding and faulting over the Billefjorden Fault Zone represent an eastward manifestation of the Eocene West Spitsbergen Orogeny.

The concept that reptilian tooth implantations fall neatly into a number of separate categories which can be used in phylogenetic studies is called into question. The use of microfocal X-radiography in preliminary studies of reptilian dentitions reveals that, at least in sphenodontids, there is no clear distinction between acrodonty and pleurodonty. Although the technique is used here specifically in connection with microvertebrates, it may have considerable potential in evaluating internal structures in a wide range of fossils.

Calcareous algae in limestones of the Permian Chihsia Formation near Nanjing, China, are preferentially replaced by quartz. Replacement postdates both cementation by sparry calcite and also neomorphic alteration of the original skeletons to sparry calcite. It is thus diagenetically relatively late. The original replacement silica could have been massive opal CT, opal CT lepispheres, or quartz. Lepisphere-like bodies occur in a few specimens. Megaquartz rims represent later overgrowths on the silicified skeletons. Although the original ultrastructure of the algal skeletons is not preserved, the preferential silicification allows fine details of the skeletal morphology of the algae to be observed and the distribution of silica indicates the style of replacement which has probably occurred. In some specimens it is possible that dissolution of the skeleton was followed by void-filling by silica, including the possibility of lepisphere formation. But in other cases in situ replacement, probably by massive opal CT or quartz, is reflected by the replacement of the outer parts of calcite crystals by silica. This process produces a network of silica, and as it proceeds the calcite centres of the grains become progressively smaller until silica replacement is complete. Sponge spicules may have provided the most important silica source for replacement. It is proposed that water-insoluble organic films surrounding matrix grains, and now preserved as bituminous material, protected the matrix from replacement thus promoting selective late diagenetic silicification of these fossils.

New data obtained from the study of the Kenyan and Tanzanian coastal basins establish a rifting period at the end of the Karoo sedimentation (Upper Triassic/Lower Jurassic), in the northeastern margin of Gondwanaland. The rifting period was followed by an erosive phase and then transgression of a Tethyan sea during the Middle Jurassic. This leads to a modification of the stratigraphic succession of the region and gives new datas about the nature of separation and drifting of Gondwanaland, the genesis of the proto-Indian ocean and the paleoposition of Madagascar

Aporate sphinctozoan sponges of the Family Cliefdenellidae Webby, 1969, are described for the Upper Ordovician (Ashgill) of northern and northwest China, including the new genus Khalfinaea and a new species K. shaanxiensis. They are characteristic cliefdenellids with conico-cylindrical and branching forms, a single central tube defined by a thickened, sieve-like endowall, and a filling of irregularly orientated astrorhizal canals, vesicles and thickened (?trabecular) tissue

Taxonomic relationships of the other cliefdenellids are also discussed. The conception of the genus Cliefdenella Webby, 1969, is restricted to those forms with massive, hemispherical to explanate form and multiple, bundled vertical excurrent canal-clusters, and the new genus Rigbyetia is introduced to include conico-cylindrical and branching forms with a central tube composed of a single, vertical, bundled, excurrent canal-cluster

In terms of their biogeographical record, the cliefdenellids have a restricted distribution in the Upper Ordovician (middle Caradoc-Ashgill) ‘fold-belt’ successions of the Palaeo-Pacific region (eastern Australia, Alaska and northern California) and in Asia (northern China, and in the Chinese and Soviet Altai)

The previously termed Hanadir Shale of Saudi Arabia is described and re-defined as the Hanadir Formation. At the type locality of Al Hanadir the unit is probably entirely of Llanvirn age while further north shelly faunas of possible Llandeilo age occur in the upper part. Trace fossil assemblages with abundant cruzianids (C. furcifera, C. rugosa, C. goldfussi), Pelecypodichnus, Didymaulichnus and Diplichnites indicate an Arenig age for beds in the upper part of the underlying Saq Formation, while the top of this unit yielded hitherto unrecorded pendent and biserial scandent graptolites, a sparse shelly fauna of lingulacean brachiopods, Neseuretus sp. and the trace fossils Cruziana? imbricata and Phycodes.

Recent field work on Gough Island combined with K–Ar dating of the lavas requires revision of the age and volcanic stratigraphy. Four main periods of volcanic activity on the island are recognized. These comprise the eruption of the Older Basalt Group which ranges in age from 2.5 to 0.52 Ma, the intrusion of aegerine-augite trachyte plugs (0.8−0.47 Ma), voluminous trachyte extrusion (0.30–0.12 Ma) and finally to eruption of the Edinburgh Basalt (0.20–0.13 Ma).

Within the Older Basalt Group three phases of activity can be recognized; the earliest involving the eruption of pillow basalts and hyaloclastites when the island emerged from below sea level. This was followed by subaerial as-type lava flows and also dyke intrusion (phase two) which probably contributed to forming a large shield-type volcanic island, which in turn supported the eruption and deposition of flat-lying flows on an angular unconformity (phase three). Intrusion of aegirine-augite trachyte plugs occurred concurrently with the latter stages of Older Basalt eruption. After a period of considerable erosion the voluminous trachyte lavas and pyroclastics were erupted. The Edinburgh Basalt, erupted in the vicinity of Edinburgh Peak, represents the youngest volcanic activity on the island.