The geosynclines of North America were a subject of study and classification by the writer some twenty years ago. In the succeeding years, field studies have been directed toward solving some of the problems that appeared. The following is written to bring out the reasons why geologists from different regions, having differing experiences, reach conflicting opinions about relationships and terminology, and the history of the origin of some of the terminology has not been published previously.

The new genus, Psigraptus, containing P. arcticus n. sp. and genotype and P. lenzi is proposed for two-branched and three-branched reclined graptolites with isolate autothecae. The genus is known only from the Bryograptus-Clonograptus Zone (Tremadocian), Yukon Territory.

Brøggerhalvøya is situated on the north-west coast of the island of Vestspitsbergen. It is shown to contain a fold and overthrust complex of Tertiary age. Large northerly movement of Pre-Cambrian rocks, previously metamorphosed in the Caledonian diastrophism, occurred over deformed but unmetamorphosed Permo-Carboniferous and Tertiary rocks on a major curved over-thrust. The structure is complicated by rapid plunge variations and subsidiary faulting. The existence of a large klippe is demonstrated and the formation of curved thrust surfaces is discussed.

A brief summary of the stratigraphy is given and its important relationship to the structure discussed. A new lithostratigraphical scheme of nomenclature is proposed.

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.

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 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.

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.

Preliminary mapping of south-western Andorra has disclosed the presence of late Llandoverian graptolites in rocks of previously unknown age