An agreed short text in English, French and German, presents a unified statement on those aspects of stratigraphy that require formal international acceptance. The statement is designed to avoid philosophical hazards and misunderstandings between the three language communities; it also harmonizes differences of three national traditions as far as is yet possible.

Stratigraphy is presented as an indivisible science dependent for its successful pursuit and synthesis on the application of numerous widely different methods.

The argument is presented in successive numbered steps to facilitate its critical discussion.

The 18 curve from the 1390 m long ice core from Camp Century, Greenland, shows climatic changes that are easily correlated with known glacial and non-glacial events of North America and north Europe and are thus indirectly dated. With a known chronology, the glacial dynamic changes of the Greenland Ice Sheet can be calculated for the last 125,000 years. It is concluded that the dynamics of the Greenland Ice Sheet have changed drastically during this period and that these changes are directly related to major changes of climate and extension of the Wisconsin and Weichselian glaciations. Logarithmic time scales earlier applied to this curve must therefore be incorrect.

The junction in Newlands Beck between the steeply dipping Skiddaw Slates striking N–S, and Borrowdale Volcanic rocks dipping gently to the SE is interpreted as an angular unconformity, and indicates the existence of pre-Borrowdale Volcanic folding. There is no cleavage associated with this folding, however, the ENE–WSW Caledonoid cleavage being the only one present, and this is common to both Skiddaw Slates and Borrowdale Volcanics.

Glaucophane schists from Oscar II Land in western Spitsbergen are described for the first time. Although lawsonite, aragonite and pumpellyite have not been found, the mineral assemblages correspond generally with glaucophane schist assemblages known from elsewhere. The results of three XRF chemical analyses are presented, and five K/Ar radiometric determinations. The radiometric dating and field evidence both suggest that the glaucophane schists are a result not of the Tertiary orogeny which affected this part of Spitsbergen, but of the earlier Caledonian orogeny.

Quartz–microperthite–hornblende–garnet–plagioclase granulites belonging to the Highland Series of Ceylon are described. The invariable presence of accessory graphite suggests their metasedimentary origin and their chemical composition indicates a possible derivation from feldspathic sandstones. Although the mineral assemblage of these granulites is diagnostic for the upper almandine–amphibolite facies, they are interlayered with orthopyroxene-bearing charnockites of the granulite facies. It is concluded that PHO was initially higher in the sandstones than in the surrounding rocks, and that it remained so during metamorphism under granulite facies conditions, thereby retarding the dehydration reactions that took place elsewhere in the vicinity.

Myrmekite in a two-feldspar migmatite suite has two distinct modes of occurrence: (i) marginally embaying potash feldspar, and (ii) in replacement aggregates after that mineral, the other major constituent of the pseudomorphs being a muscovite-quartz intergrowth. Electron-probe data give quartz proportionalities agreeing with the predictions of existing theories. It is shown that these theories, which refer to either exsolution or small-scale metasomatism, share a common foundation of kinetic impediment to AlSi diffusion. In neither case need one assume the presence of ‘Schwantke's molecule’ as a component of potash feldspar. The two myrmekite occurrences here described are interpreted in terms of essentially simultaneous exsolution and hydrative replacement processes operating as regional metamorphic temperatures began to decline from their climactic values. The existence of exsolution myrmekites of ideal quartz proportionality is not in itself evidence for the existence of ‘Schwantke's molecule’.