A sequence of 11 tetracoral and conodont faunas, ranging from early Gedinnian to late Givetian, is recognized in the Lower and Middle Devonian limestones of New South Wales and Victoria. These faunas are not only important stratigraphically in eastern Australia, but also provide a basis for the correlation of the Australian Devonian with overseas stages. A table of correlation is given for the principal Devonian limestone sequences of New South Wales and Victoria.

A simple visual method for distinguishing important Devonian atrypid brachiopod taxa, and for separating the Atrypidae and Palaferellidae family-groups is outlined. The thickness, distribution, and repetition of the three layers of impunctate atrypid shell wall differ markedly from one genus to the next and show a general evolutionary trend towards reduction and simplification.

Osculocystis, a new scoliocystine cystoid, is characterized by reduced oral plates which form a tubercle; three pectinirhombs, B2: IL2, L2: R1, and L4: R4; and apparently only one brachiole. Osculocystis is based on a single specimen of the type species, O. monobrachiolata, from the Lower Silurian of Buildwas, Shropshire. It is the first recorded Lower Silurian cystoid from Britain and is most closely related to Glansicystis Paul.

The restrictions proposed by Jung (1958) on the definition and use of the term tholeiite, and the more recent drastic proposal for its abandonment (Chayes, 1966) are considered. Both proposals are rejected and re-emphasis given in support of the broad use of the term both as a rock and magma type, and as a progenitor of an igneous rock series.

An account is given of Yelele, a Miocene volcano, situated on the Turkana escarpment, north-east Uganda. It is composed of lavas and dykes of nephelinite, phonolite, tephrite, and trachyte together with olivine-bearing varieties, and has a central plug of ijolite and nepheline syenite.

The lavas are described and compared with those of other eastern Uganda centres and the petrogenesis discussed in the light of experimental data from the Geophysical Laboratory of the Carnegie Institution of Washington.

A northern (Yelele) plagioclase-bearing suite of lavas and a southern (Elgon) melilite-bearing suite are derived by different fractionation trends from an olivine melanephelinite parent which itself is the dense portion of a nephelinitic parent magma.

Macrofabric (stone orientation) and microfabric studies of the four tills exposed in the coastal areas of East Yorkshire indicate that the regional direction of ice movement during both the Saale and Weichsel Glaciations was from north-east to south-west. The Saale (Basement) Till was considerably modified by the advance of ice during the Weichsel Glaciation; in particular, the stones in the Basement were reorientated so that their long axes now lie at right angles to the direction of movement of the Weichsel ice sheet. The fabrics of the three Weichsel tills (Drab, Purple and Hessle) are alike, and it is suggested that all three were deposited from one composite ice sheet. The relationship of vertical joints in the Basement and Drab Tills to directions of ice movement is discussed; those in the Basement possibly originated as ac tension joints inherited from the parent ice, whereas some of those in the Drab are probably conjugate shear joints formed during post-depositional deformation of the till.

Recent studies in N.W. England have indicated the need for a review of Wenlock and Ludlow (Silurian) stratigraphy. Detailed re-mapping, mainly for the first time since 1872, has modified and more clearly defined the established terminology. Determinations of new graptolite and shelly faunas have resulted in a revision of some earlier work and the establishment of a modern zonal classification for parts of the Wenlock and Ludlow. Lithofacies are broadly summarized and described with comments on some palaeocurrent data.

The petrographical and geochemical characteristics of some basic sills and dykes from Southern Rhenish Schiefergebirge are described. The dykes are generally more altered than the sills and are classified into two types according to their relation to the lead-zinc veins found in the area. The distribution of some trace elements in the sills and dykes is given and the nature and mechanism of alteration are discussed.

Patterns of joints in flat-lying Permian rocks have been compared with those of folded Mathinna beds, of Siluro-Devonian age, across an exposed unconformity, and with those of a nearby Late Devonian granite. The patterns of the Permian rocks and the granite are similar, and each joint set appears to be related to parallel-trending post-Permian faults in the region. However, there is no representation of the joint sets of the Permian rocks in the Mathinna beds, considered to be due to shear failure either along bedding up to 18 degrees from the expected position, or along pre-existing open joints up to 65 degrees away. Lack of apparent order in the deflection and termination of joints against one another in the Mathinna beds indicates contemporaneity of formation of the open continuous fractures of differing attitudes, suggesting that the initial form of joints is as minor discontinuous cracks, which later develop into the open joints examined in surface outcrops.

The pre-Pliocene sub-aereal surface of the London Clay in the Orford area of Suffolk is discussed. It is shown that south of Aldeburgh the slope of the London Clay towards the north must be less than previously thought and that prior to the deposition of the Coralline Crag a major river ran approximately from south to north in the area studied. This river course may help to explain the sudden drop of the London Clay surface north of Aldeburgh which has not been fully accounted for previously.

Early diagenetic, micritic, carbonate concretions from Namurian goniatite bands in Staffordshire and Derbyshire contain Radiolaria and sponges excellently preserved owing to replacement by ankeritic dolomite anhedra. The microfossils are detectable only by acid etching of limestone surfaces and thin sections. Preservation by the dolomite is believed to occur under restricted conditions in which silica solution and dolomite crystallization post-date a phase of rapid calcite crystallization.

Analyses, determined with the electron-probe, are given of the porphyroclast minerals of the peridotite-mylonites of St. Paul's Rocks.

Rhythmic layering in the Freetown Complex and in some other layered intrusions may be due to the different powers of nucleation of the primary minerals from an undercooled magma. It is suggested that, in slowly cooled intrusions, the total number of crystals per cm3 in a rock (whole rock index) is a measure of the amount of undercooling; rocks with a low whole rock index crystallized at or near the equilibrium temperature while rocks with a high index crystallized under conditions of undercooling. If this is so, then it is possible to determine the order of abundant nucleation of the primary minerals by graphical means. Only a slight amount of undercooling, perhaps of the order of 4 or 5° C, is necessary to produce marked changes in the order of separation of the minerals from the magma.

The Lettereeneen fault, a newly recognized structure, brings the Mweelrea and Maumtrasna Groups of the Partry Series (Caradocian-Llandeilian age) into contact. The stratigraphy of the Mweelrea Group, of red bed facies, is followed from the presence of welded tuff horizons; no such markers exist in the Maumtrasna Group which lies unconformably upon the former.

Sedimentary structures of shallow water origin occur in each group. Three types of conglomerate recognized in the area are examined. The immature feldspathic sandstones increase in arkosity upwards.

A proluvial or proluvio-marine environment of deposition is suggested, with debris derived from an eastward extension of the metamorphosed Dalradian rocks of the Connemara Cordillera and foothills of sedimentary and volcanic rocks.

The historical development of the stratigraphic nomenclature of the Llandovery of north Connemara is described. The lowest beds are red sandstones and interbedding keratophyre passing up into a complex sequence of grey, green and red clastics with shelly facies fossils. Above this are red and green mudstones and siltstones with rare graptolites. In the east these are overlain by coarse sandstones and conglomerates. The conglomerates are probably allochthonous. In the west this coarse facies is developed earlier and laterally interfingers with the shelly facies clastics and overlying mudstones. The sub-Wenlock unconformity reported by McKerrow and Campbell from this region is reinterpreted as an appearance of this interfingering.

Recent excavations on Dungeness have provided excellent sections through the deposits of its late Holocene beach-plains. The material at the surface is loose shingle, but at a depth of a few feet this passes down into gravel packed with sand. The gravel in turn rests upon almost stoneless sand with marine shells, the contact between the two deposits falling from - 13 feet O.D. in the most northerly section to - 24 feet in the most southerly.

It is confirmed that the more pebbly deposits were laid down on an actively prograding foreshore, as has generally been supposed. Problems are raised, however, by the low levels of their base and by some of their structural and lithological features. These are discussed, and explanations are offered where possible.

A new specimen of the rare spiriferide brachiopod Bittnerula zitteli (Bittner), from the St. Cassian beds (Triassic) of the Italian Alps, has a well-preserved ventral umbo with a small sub-apical pedicle foramen and no cicatrix of attachment. Bittner's interpretation of the genus, as attached by cementation, is therefore rejected. There is now no authenticated case of cementation attachment in any spiriferide brachiopod, or in any articulate brachiopod outside the Strophomenida. The evolutionary history of cementation, and the affinities of the problematical Thecideacea, are discussed briefly in the light of this discovery.

The Jurassic and Cretaceous sequence of Spitsbergen, Svalbard archipelago, is described and a revised lithostratigraphical scheme, of four formations, is proposed. The main episode of tectonic activity, together with dolerite intrusion, was in late Jurassic-early Cretaceous times and is represented by a non-sequence and local unconformity between the two lower formations. The faunal succession is also discussed.

Elongated belemnites illustrated by Albert and Arnold Heim were not deformed as brittle bodies, because the guards have undergone recrystallization. A tentative hypothesis is put forward to integrate the mechanical and chemical processes in the belemnites. During progressive extension of the belemnites carbonate material has diffused from highly stressed fragments of the guards into “low-stress” spaces between the fragments.

The problem of the genesis of these biohermal structures is re-examined to test the hypothesis that they are bank sediments and not knoll-reefs. The study is based largely on the field work of the Geological Survey (Earp et al., 1961). It is argued that depositional dips have not been increased by differential compaction and it is demonstrated, by elimination of the tectonic component of the existing divergent dips, that original dips locally exceeded 60 degrees. It follows that the knolls possessed some rigidity of frame and the term “reef” seems appropriate. It is argued that the Worsaw and Twiston knolls rose upwards of 600 feet above the surrounding muds.

The conclusions of the Clitheroe Memoir that certain beds of the Worston Shale Group formerly thought to post-date the knoll limestone are in fact of the same age is accepted, but it is argued that these sediments, which are not differentiated from other deposits by the Survey officers, follow a non-sequence.