The classic late Tournaisian plant-bearing locality at Oxroad Bay was investigated by detailed field mapping, lithological logging, studies of clast orientation, thin-section petrography and analyses of bulk geochemistry. The lithologically and structurally complex, c. 45 m-thick succession includes eight plant-bearing exposures (each consisting of up to 16 phytofossiliferous horizons) that have yielded 43 anatomically-preserved organ-species and 19 adpressed organ-species. All floral assemblages are allochthonous s.l. and demonstrate a wide range of preservation states. They occur in five successive facies (braided flood-plain, shallow volcanigenic lacustrine, terrestrial mass-flow/base-surge, shallow biogenic lacustrine, dominantly terrestrial reworked ashes) that reflect increasing influence of several basaltic tuff-ring volcanoes on an ocean-marginal lowland bordering the Southern Uplands Massif. The variable local climate reflected proximity to the proto-North Sea and eruptive seeding of the atmosphere with ash particles. Base-surges, seismically-initiated mass-flows and volcanically-induced wildfires restricted the development of mature soils and of edaphic climax communities. These disturbances created a sequence of mosaic palaeocatenas that supported a wide range of sub-communities at any one moment in time. At least some of the relatively k-selected species that occupied the preceding, fluvially-dominated terrain were extirpated by the persistent volcanism, yielding to immigrants that were better pre-adapted to the unstable environment. Low levels of competition allowed non-adaptive n-selection, enhancing the establishment potential of evolutionary innovations.

The Kenmore inlier exposes the most intensely deformed part of a major Laxfordian shear zone whose NE margin occurs at Diabaig, N of Loch Torridon. The Laxfordian (post-Scourie dyke) deformation commences with two very intense deformations D1 and D2, producing LS fabrics in dykes and gneisses associated with heterogeneous, locally very large, and typically prolate strains under amphibolite-facies metamorphism. D2 also produced widespread mesoscopic folds. The finite strain was measured at 135 localities using grain-aggregate shapes in Scourie dykes. The combined D1-D2 elongation lineation plunges gently to NW or SE, and the planar fabric appears to have been sub-horizontal before the D3 deformation, which produced NW-SE upright folds under retrogressive metamorphism.

The D1-D2 structure is attributed to a major sub-horizontal shear zone with a top-to-NW movement, a minimum vertical width of 2·5 km and estimated minimum displacement of c. 19 km. The upper (NE) wall of the shear zone at Diabaig exhibits dextral-normal (NE-down) D1 movements. The D2 structures are attributed to superimposition of sub-horizontal movements on earlier inclined D1 fabrics as the shear zone evolves. The D3 refolding reflects a change to a dextral transpressive regime.

The numerical taxonomic analysis of encrinurine trilobites by Temple and Tripp (1979) is extended to 28 described Chinese species, 35 other Chinese samples, and 13 non-Chinese species, in addition to 56 species analysed previously. The 132 entities are coded for 34 cranidial and pygidial attributes, and are ordinated on the eigenvectors of the interattribute correlation matrix for 32 attributes. Chinese material falls into four clusters informally compared with Coronocephalus, Kailia, Encrinuroides and Encrinurus. The Encrinurus-like Chinese species occur mainly in Northern China and have links with non-Chinese species.

Foraminiferal studies have been used in palaeo-environmental reconstructions of the marine Cretaceous succession (upper Aptian to Maastrichtian) of the Sergipe Basin, in northeastern Brazil. The foraminiferal assemblages show broadly three types of response to changes in environment: (1) variations in morphotypes of the taxa present; (2) changes in specific and generic diversity; and (3) changes in relative abundance.

Twelve palaeocommunities, characterised by the relative dominance of the major foraminiferal groups, can be recognised in the succession. Their palaeoenvironmental distribution is proposed as a model with reference to the Sergipe Cretaceous sequence.

An intimate relationship is inferred among foraminiferal association distribution patterns, trophic structures (community feeding strategy, dwelling habits, substrate niche patterns) and water-mass conditions (depth-related in part). It is suggested that the distribution patterns may be a direct response of the functional adaptive morphology of the foraminiferal tests to individual characteristics of behavioural structure (preferential dwelling microhabitat and trophic strategy versus environment). The approach is a simple, yet very powerful tool, for the interpretation of foraminiferal palaeocommunities and palaeoceanographic research. It may also permit interpretation of palaeocommunity strategies in terms of adaptation rate and selection response (i.e. “r-selection” versus “k-selection”) to variable environmental conditions.

Sanders and Johnston (1989) have recently suggested that the Stac Fada Member is a fluidised peperite rather than a volcanic mudflow as thought by Lawson (1972) and the writer (1988). I agree that the volcanic mudflow hypothesis is flawed, but give reasons below for thinking that the new hypothesis is also untenable.

We welcome the views of A. D. Stewart (1990) on our interpretation of the unusual lithology and contact relations of the Stac Fada Member at Stoer. Stewart contends that our lower breccia body is a down-faulted outlier of the main breccia body and is therefore not a feeder. He thus rejects our notion that the Member is a peperitic extrusion: he also rejects the previously published view that the Member is a volcanic mudflow. Instead he suggests that the Stac Fada Member is one of several muddy volcanic horizons in the Stoer Group, all of which underwent post-depositional disturbance.