On the basis of stratigraphic, tectonic, and metamorphic studies in certain critical Pre-Cambrian areas of Nagpur-Bhandara-Drug region and twenty-six K-Ar age data of representative samples, the authors have suggested a new generalized succession and correlation of the dated orogenic cycles and phases, and have drawn the following conclusions:-

(a) Amgaon cycle closed during the period 1444–1730 m.y.

(b) Sakoli cycle (I phase) closed at 1330 m.y., and during Sausar orogeny (864–996 m.y.) the north-western part of Sakoli syn-clinorium was deformed and metamorphosed (862–950 m.y.).

(c) Sausars and Sakolis, both post-Amgaon in age, were deposited in separate basins and had different tectonic histories.

(d) Nandgaon folding phase (< c. 1200 m.y.) affecting Bijli rhyolites is younger than Sakoli (I phase), and Chattisgarh Cuddapahs are younger than Khairagarh phase (< c. 600 m.y.).

(e) In Bastar area Bailadila cycle closed at c. 2100 m.y.

A simple theoretical explanation is given for the formation of systematic tension joints in sedimentary rocks. This theory shows that the frequency of occurrence of joints in a bed of rock is dependent upon the physical properties of the rock bed, the physical properties of the surrounding rock beds, the thickness of the rock bed, and the degree of tectonic deformation.

A late Pre-Cambrian eugeosynclinal stratigraphic sequence in the western part of the Scandinavian mountain chain is established. In the Möre region the succession is about 11 km thick. The wellknown late Pre-Cambrian miogeosynclinal sequence in the eastern part of the chain corresponds to the upper part of the eugeosynclinal sequence.

Measurement of the anisotropy of magnetic susceptibility of Westphalian sandstones from the southern part of the South Staffordshire Coalfield shows that there is a weak preferred grain orientation. There is a significant within-sample consistency of fabric lineation and the results agree with other geological evidence. The palaeocurrent pattern is complex as may be expected within a fluvial or deltaic regime. This preliminary study suggests that this magnetic fabric technique may be used to determine the detailed palaeocurrent pattern within the Upper Carboniferous of the Midland Province.

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.

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.

Six volcanic vents, trachybasaltic bosses, and new dykes replaced by kaolinite were discovered. The vents are built of trachybasaltictrachytic and basaltic plugs and of tuffisites and tuffs. In the trachybasalts, plagioclase and anorthoclase display complicated reaction phenomena, reflecting changes in crystallization conditions. The trachybasaltic and trachytic bodies were emplaced first and subsequently were altered to kaolinite (Upper Jurassic). Magmatic activity was resumed after an intense erosion period leading to the formation of the vents and of the Lower Cretaceous basaltic volcanic complex which was in part extruded through these vents.

At Cil-maenllwyd (Cardiganshire) glacial outwash sands were found to contain layers of small wood fragments. A radiocarbon age determination of 33,750 yrs B.P. indicates that the wood fragments are probably of Middle Würm age, and that the last glaciation of St. George's Channel occurred during the Main Würm. Pollen and spores contained in the sands suggest that the environment prior to the last glaciation was at one stage predominantly forested. The organic remains are thought to relate to the problematical “ Middle Würm Interstadial ”, rather than the Paudorf Interstadial.