Naturally occurring linear features recognisable on aerial photographs may be related to bedrock tectonics. The identification and analysis of such linear elements, “megajoints”, reveals much information about the style and dimensions of subsurface geologic structures. Various terminologies, as applicable to air photo linears, are brought together and analysis is carried out in four test applications of Permyakov's original methods, the calculation of three-dimensional parameters from two-dimensional data. Some comparison is made with other techniques. Much of this linear vector analysis is carried out manually but possibilities exist for mechanical analysis and synthesis using certain up-to-date techniques. The methods described are applicable to many fields of academic and practical geology at or above the reconnaissance level.

A recent excavation at Newtown Unthank, 9 km west of Leicester, has permitted study of the sub-alluvial gravels of the Rothley Brook valley. The junction of the gravels with the underlying Keuper Marl is sharply contorted, with an upward progression from undisturbed bedrock, through displaced marl and siltstone layers into masses of marl which have apparently been thrust up into the overlying gravel and incorporate many foreign stones. Possible causes of the structures are outlined, and reasons adduced for believing them to be of periglacial origin and of Weichselian age. Comparable occurrences have been recorded from elsewhere in the Soar basin, and also from other parts of the Midlands, and these are briefly discussed.

Ignotrypa multivincula gen. et sp. nov., (Polyzoa, Cryptostomata), is described and figured from the Lower Devonian Garra and Nubrigyn Formations of central western New South Wales. It has a typical fenestrate meshwork but the carinae are thickened and joined laterally by numerous connections.

Xenodiscacean ammonoids from Dzhulfa in Soviet Transcaucasia, assigned to Tompophiceras, Bernhardites and Paratirolites, have been interpreted as indicating that the enclosing beds, which also contain tetracorals, productacean brachiopods and goniatites, are Lower Triassic. Critical examination of the identifications shows that these beds should be regarded as Permian, not Triassic. Tompophiceras and Bernhardites are based on Triassic type species but the specimens from Dzhulfa are not demonstrably congeneric. Interpretation of Tompophiceras as a genus with a fastigate venter is rejected. Paratirolites, previously regarded as Triassic, is evidently Permian, and is now recorded from Madagascar, this being the first record outside Transcaucasus. New evidence is presented concerning the exact age of Glyptophiceras. The Dzhulfa section has been interpreted as providing a continuous transition, in the marine facies, between beds of Permian and Triassic age. This interpretation is rejected. It remains probable that there are no sections, in any part of the world, that do so.

Breadcrust blocks (bombs) on Vulcano, Sicily, show features which indicate that when they were of viscous lava they broke when stress was applied rapidly, and later flowed when it was applied slowly. If the magma of granitic intrusions behaves similarly, the perplexing “relict dykes” can be explained as due to the breaking of the magma and the injection of dykes into the fractures.

A correlation of the predominantly limestone deposits of the Bathonian (Middle Jurassic) stage in Central England is presented on the basis of the available ammonites. This is related to the standard sequence of Bathonian zones, which are briefly discussed in the introduction. All ammonites from the area of stratigraphic importance are listed. There is nothing to suggest that any of the zones are absent because of erosion or nondeposition, except in the East Midlands at the base of the Bathonian.

The regional metamorphism of the Pakhals in the Yellandlapad area is synchronous with folding and is superimposed in the east by dislocation metamorphism due to overthrust. The development of ottrelite is contemporaneous with the overthrust. It is suggested that the conditions of growth of ottrelite may be distinctive from those of chloritoid.

Examination of a contact between Late Devonian intrusive acid igneous rocks and Siluro-Devonian Mathinna hornfels. and the unconformity between these rocks and the overlying Permian beds, has revealed the relative ages of the joints developed. The steep joints of the acid igneous rocks are demonstrably of pre-Permian age although they form a pattern identical to those of the Permian beds, and each joint set is correlated with approximately parallel trending sinuous normal faults. The repeated development of the steep joints is attributed to reactivation of a fundamental mechanism. Some of the joints in the igneous rocks occur between compositional layers which have inherited their shape from the form of the joint-governed contact with the hornfels.

Study of arenite—rudite bodies within the traditional Welsh basin reveals two contrasted modes of situation, here termed concordant and discordant It is inferred that the former represent submarine fans developed on relatively level topography and the latter represent submarine channels adjacent to (and incising) major breaks in palaeoslope. The size and disposition of these palaeoslopes makes their control by deep fractures very probable.

A new interpretation of a polygonal pattern of ridges in the Marble Hill Dolomitic Limestone, at Ballymore, suggests that it was formed by a soft-bodied, worm-like organism.

The structures are comparable with stromatolites seen in modern “flats” environments and tufa occurring in joints in the granite—gneiss basement is compared with modern and fossil forms. Finely laminated (? varved) carbonates with a large lateral persistency (1: 50,000) are referred to periods of high water level and are believed to show evidence of seasonal algal bloom. The presence of widespread stromatolite structures is consistent with earlier environmental interpretations of the Orkney rocks.

Commonly used variation diagrams do not convincingly distinguish strongly alkaline, alkaline and calc-alkaline rocks over the full range of silica contents, especially for more acid varieties. In particular, the Rittmann Suite Index, a, becomes invalid once SiO2 exceeds about 70%.

Seismic refraction surveys of the buried channels of the Exe near Exmouth indicate the presence of an early period of channelling into New Red Sandstone breccias to a base in excess of −52 m* followed by a period of gravel infilling of these channels and then their partial re-excavation to a base in excess of −30 m. Terraces formed during stillstands within the early regression occur at depths of −25, −31·4, and −36 m and within the later regression at −5·8, −10.4, −13.7, −17·1, −22 and −27·1 m. Control of the orientation of the channels by fault planes within the New Red Sandstone is also indicated. Correlation of the periods of channelling with early and late Weichselian sea-level lows is suggested, indicating a middle Weichselian (Paudorfian) age for the gravels. Similarities with buried channels occurring in Southern Ireland are noted and wider correlations attempted.

New exposures of Upper Llandovery and Cambrian strata are described from the southern Malvern Hills. The rocks occur in a small faulted outlier between Midsummer and Hollybush Hills, within the main Pre-Cambrian outcrop. The Cambrian is represented by a thin succession of Malvern Quartzite and Hollybush Sandstone and is overlain by an Upper Llandovery limestone with a basal conglomerate containing rounded pebbles of Hollybush Sandstone. The new exposures weaken the case for a major post-Llandoverian fault at the western boundary of the local Pre-Cambrian outcrop, but provide further evidence of an important phase of pre-Llandoverian tectonism in the Malvern area.

Faunas of brachiopods, graptolites and conodonts from the Llandoverian limestone allow a correlation with the C5 substage of the shelly sequence, the griestoniensis graptolite zone and a position near the boundary of the celloni and amorphognathoides conodont zones.

Pebbles of derived Portland chert and limestone have been found in the Upper Purbeck Beds at Friar Waddon, Dorset. The Unio Bed at this locality is of unusual lithology with derived phosphatic fossils and with fish teeth. The presence of this chert in the Upper Purbeck Beds and its apparent absence in Lower Purbeck pebble beds suggests that a major phase of silicification in the Portland Stone took place at about Middle Purbeck times. Furthermore, erosion of the Portland Beds occurred in the Weymouth region, probably on the crest of the Weymouth anticline, during Upper Purbeck times.

The calcite of brachiopod, lamellibranch and echinoid shells from the Upper and Middle Chalk of Hertfordshire and Bedfordshire is partly replaced by chalcedonic silica. The crystallographic forms of the silica are described, and its diagenetic emplacement inferred from thin section studies.

Previous records are revised, and new identifications of reptiles are presented, based on a study of specimensin older collections. Amphibious marine forms of Alpine Trias and Muschelkalk affinities are recognized from the Midlands, albeit on tantalizingly incomplete material. Such evidence as the reptiles provide indicates an early to mid-Ladinian age for the upper part of the Building Stones, the boundary between Anisian and Ladinian here being taken to lie within the Middle Muschelkalk.

It is suggested that the name beerbachite be reserved for fine- to medium-grained granular dyke rocks of gabbroic composition occurring in coarser-grained gabbro. It should not be used for basic granular hornfelses or xenoliths.