Detailed mapping, stratigraphic logging and structural analysis of the Hawasina Window culmination in the central Oman Mountains of Arabia reveals an extremely complex thrust geometry and structural history. The initial thrust sequence involved a southwestward propagating stacking during telescoping of the Arabian continental margin slope (Sumeini complex), and time-equivalent, more distal Tethyan basin (Hawasina and Haybi complexes) facies rocks. The Semail thrust, carrying the 12 km-thick ophiolite sequence, progressively overlaps Haybi and Hawasina duplexes towards the SW. Late stage “leap-frog” thrusts have punched Sumeini duplexes higher up into the earlier thrust stack locally reversing the normal stacking order. SW-directed thrusts and SW-facing folds in the SW and NE-directed backthrusts and NE-facing backfolds in the NE have created a fan structure cored by the Jebel Rais “pop-up” composed of Sumeini slope facies rocks.

The palaeogeographic presence of a large NE-facing promontory in the Cretaceous shelf edge is inferred beneath the Window. The frontal ramp of this promontory was sufficiently large to inhibit the overthrusting of large volumes of Hawasina and Haybi complex rocks. The whole central part of the Window shows NE-facing and verging backfolds and backthrusts affecting all duplexes from the lowest Sumeini up to the Semail ophiolite. The promontory is bounded by major lateral ramps to the NW (Wadi Shafan area) and SE (Jebel Milh area). A map and four balanced cross-sections are presented here to promote a complex model for the structural evolution of the Hawasina Window.

Since 1860, in which year De Bary published his great work Die Mycetozoen, the investigation of the life-history of members of the Mycetozoa has aroused a considerable amount of interest, and a great deal of important research has been carried out in this connection. The group of organisms is particularly interesting, because it lies on the borderline between plant and animal kingdoms, and it is very possible that a detailed investigation of several species of the Mycetozoa might be of considerable assistance in elucidating certain obscure points in the life-histories of higher members of both the great natural groups. The term “Mycetozoa,” which we owe to De Bary, will be used throughout in preference to the older term “Myxogastres” invented by Fries (32, p. 2), and that of “Myxomycetes” first employed by Link (32, p. 2). “Mycetozoon,” or “fungus-like animal,” is a very appropriate description of a member of the group, since during part of its life-history it exhibits distinctly animal-like characters, and the individuals move rapidly by means of flagella, whilst later, during the development of the sporangium, a plant-like form is assumed. The combination of plant and animal characters has given rise to much discussion as to the position of the Mycetozoa in plant or animal kingdom, and the group has been claimed by both zoologists and botanists.

Few plants of Carboniferous age have appealed so strongly to the scientific observer as the huge woody trunks of a coniferous type that have been discovered from time to time in beds of that system. The appeal has come from different points of view at different times; thus these trees were hailed by Witham (1831, pp. 1–2), Lindley and Hutton (1831, p. xiii), and Hugh Miller (1849, p. 186) as evidence of the existence of higher coniferous plants in abundance during a period to which the current consensus of scientific opinion had assigned only members of the lower plant families, or would admit only an infrequent occurrence of higher forms. These remains were therefore important in discussions concerning the development of plant life, and were cited by Hugh Miller (1849, p. 185) in his attempt to combat the then embryonic ideas of evolution—the recrudescence of Lamarckian ideas—current under the name of “the development hypothesis.” Miller, however, recognised one significant point, namely, that they represented a land flora as distinct from one occupying a water habitat (1849, p. 202).

A sequence of upward fining cycles contain braid bar structures in the coarse member. Bars, medially placed in the stream are recognised either by radiating large foresets or by identifying bar tail sediments with converging dips to their foresets. Lateral bars are recognised by the growth of major sandstone sheets oblique to the direction of channel trend and over slough mudstone. The fine member contains structures which indicate a direction of flow in the same direction as the channel, suggesting that only the unlevéed part of the floodplain is preserved.

The direction of transport for the Old Red Sandstone sediments is perpendicular to the direction of bar accretion. This is accounted for by assuming the section dealt with to be on the NNW margin of a cone which builds outward to the NE, and where the river building the cone swings from one side to the other. An upward increase in cycle thickness within the section is possibly the result of an increase in the size of the cone and the consequent amalgamation of the coarse members.

An evolving pattern of fluvial dispersal responsible for the Lower Old Red Sandstone magnafacies has emerged from a stratigraphical and geographical consideration of palaeocurrent structures, clast lithology and fauna, sandstone composition, and sandstone detrital heavy-mineral assemblages. The evidence suggests that the Post-Ludlow (Downton) and lower Gedinnian rocks formed mainly in the joined Dingle–Shannon and Anglo–Welsh basins, fed from metamorphic complexes in NW Britain or beyond. Contemporaneous sedimentation in the Caledonian basin was restricted to its northeastern end. Later in the Gedinnian, the Dingle–Shannon and Angle–Welsh basins appear to have become separated by the uplift of a broad and extensive belt of mainly Lower Palaeozoic sedimentary and volcanic rocks; included in this belt were outcrops of Post-Ludlow strata representing the earlier stream of metamorphic detritus. Granite intrusion, which reduced the density of and consequently uplifted the crust, occurred widely in the regions dividing and bordering these basins, and may be causally connected with their separation in the Gedinnian. The Caledonian basin appears to have remained a separate feature.

Since the early discoveries made by A. G. Bain a little over one hundred years ago, and which were described by Owen between 1844 and 1876, the South African Karroo beds have yielded a steady stream of new and interesting remains of Permian and Triassic amphibians and reptiles. Our fossil-bearing beds cover about 200,000 square miles. Some exposed areas are very rich, and others covered by soil and wind-blown dust are for all practical purposes quite barren. Still at any time there must be many hundreds of thousands of fossils lying exposed and waiting to be collected. Many do not last long, and weather to powder within a year if not collected; and new ones are always being exposed. In 1935, I sent Professor Camp of America to a farm where, in one day, he collected a hundred good skulls. I had been on this same farm only six months before and collected sixty skulls. One can go there every year and get a large collection. The large majority of skulls are duplicates—but new fossils may turn up at any time.

Although it is unlikely that the east of Sutherland will ever rival the west in geological renown, its varied interests have already furnished material for a considerable literature. Attention has been specially focussed upon a down-faulted coastal strip of Mesozoic rocks, which, starting at Golspie, extends north-eastwards for twenty miles through Brora and Helmsdale to the county boundary at the Ord (fig. 1). Golspie itself stands on a narrow outcrop of Trias. Jurassic follows, with a generally ascending sequence that leads up to Kimmeridgian at Kintradwell, a couple of miles north of Brora (fig. 2). Beyond this Corallian reappears, but only for a short distance. Then Kimmeridgian returns and holds the coast-line continuously for nearly nine miles, until, at the Ord, it disappears beneath the sea. The width of the Kimmeridgian exposures is occasionally three-quarters of a mile, but generally much less.

In this study we examined variations in ore and other trace-metal concentrations in titanite, a ubiquitous product of magmatic (and subsequent sub-solidus) crystallisation in oxidised silicic magmas. Accessory titanite occurs in the Tuolumne Intrusive Suite (TIS), Sierra Nevada Batholith, as euhedral to anhedral, poikilitic, or interstitial grains. Zoned crystals of titanite were analysed by electron microprobe and synchrotron X-ray fluorescence for major and trace elements. Backscatter electron images reveal zoning, with bright areas correlating positively with total REE concentrations. REE concentrations generally decrease toward the edge of titanite crystals; however, some crystals are reversely zoned, and others exhibit oscillatory or patchy zoning; some grains contain discrete anhedral cores. Most elements in magmatic titanite decrease in concentration towards crystal rims, independent of host rock composition.

At least one major reduction event in the magma chamber(s) transiently stabilised ilmenite, now present only as inclusions in titanite, and resulted in a reduction in the REE concentration in titanite. We suggest the hypothesis that the reduction in the REE concentration in these zones is due to the diminished activity of the (REE)Fe3+ Ca−1Ti−1 exchange component; however, the scatter in the data, together with the operation of other exchange vectors for Fe and Al, did not allow us to test this hypothesis herein. Secondary (i.e. sub solidus, hydrothermal) titanite can be recognised on the basis of its chemistry, sometimes by its anhedral form, and by its position as an alteration rim around primary magmatic phases; however, secondary titanite growth on primary titanite crystals may be harder to discern. Secondary titanite rims on magnetite contain higher Cr, Zr and Mo, and lower REE, relative to magmatic titanite. U/Th ratios increase toward the rim of most titanite grains; however, Th decreases in concentration from core to rim. This is due, most likely, to complications resulting from the coupled substitutions necessary for replacement of Ca by tetravalent Th; factors of this sort are commonly overlooked in trace element analysis.

The analysed titanites are from rocks of the normally zoned TIS which ranges in 87Sr/86Sri, from 0·7059 (tonalite and quartz-diorite) to 0·7066 (granite). Many element ratios in the titanites exhibit little to no functional dependence on 87Sr/86Sri. However, log Mo/W increases with increasing 87Sr/86Sri, of the host unit from the equigranular quartz-diorite and tonalite, to the interior granodiorites, possibly reflecting the greater crustal contribution to the interior, more felsic units. Neither Mo nor W increase significantly from core to rim in titanite. If these trends are indicative of the general behaviour of these elements during in-situ fractionation, then these data suggest that Mo and W are not strongly incompatible, and indeed may behave compatibly, in some titaniteand magnetite-bearing granodioritic magmas.

§ 1. The variations of the surface-level of lakes due to the direct action of wind and rain, and the smaller disturbances caused by surface waves, of small or moderate length, due to the action of the wind and the movement of boats and animals, must have been familiar phenomena at all times. The first accurately recorded observation, that lake-levels are subject to a rhythmic variation, similar in some respects to the ocean tides, seems to have been made at Geneva in 1730 by Fatio de Duillier, a well-known Swiss engineer. Owing to the peculiar configuration of the Geneva end of Lake Léman, these variations occasionally reach a magnitude of 5 or even 6 feet; and Duillier mentions that they were known in his time by the local name of “Seiches,” which has now been applied to rhythmic alterations of the level of lakes in general.

A strong correlation exists between the Li isotopic compositions of CarboniferousTriassic granites from the New England Batholith, and the previously inferred involvement of sedimentary and mantle/infracrustal source components. Isotopically (Nd and Sr) juvenile, low-K, Cordilleran I-type granites of the Clarence River supersuite have δ7 Li= +2·2 to +8‰ similar to those of arc magmas, the inferred source of these granites (Bryant et al. 1997). Isotopic variability within this supersuite probably arises from heterogeneity within primary mantle-derived magmas, combined with subsequent modifications through interactions with crustal materials. Oxidised, high-K granites of the Moonbi Supersuite have more homogenous and slightly lighter Li isotopic compositions (δ7 Li= +1·9 to +4·2‰). The observed range of values lies within the range of arc magmas, and is consistent with partial melting of arc shoshonites within the crust (cf. Chappell 1978) or the involvement of high-K mantle-derived magmas (cf. Shaw & Flood 1981; Landenberger & Collins 1998). S-type granites of the Bundarra (δ7 Li= −0·1 to +2·1‰; average= +1˙3‰; n=6) and Hillgrove supersuites (δ7 Li= +0·4 to +1·7‰; average= +0·8‰) define a narrow range of isotopic compositions which are, overall, lower than those observed in NEB I-type granites or generally observed in primary arc magmas. Their isotopic compositions are equivalent to those typically observed in shales (primarily δ7 Li= −3·2 to +2·0‰; Moriguti & Nakamura 1998; Teng et al. 2004). No difference is evident in the isotopic compositions of the two S-type supersuites despite inferred differences in the degree of weathering experienced by the sedimentary protolith, or differences in mineralogy of the granites. Granites of the Uralla Supersuite, which have been have formed from mixtures of local meta-igneous and meta-sedimentary components, span a broad range of values (δ7 Li= −1·3 to +3·9‰) which overlap with both the sediment-poor New England Batholith I-type intrusions of the Clarence River and Moonbi supersuites, and the S-type granites of the Bundarra and Hillgrove supersuites. Lower δ7 Li values primarily occur in lower-K plutons from the northern portion of the Uralla Supersuite.

Overall, anatexis and magma differentiation do not appear to contribute to significant fractionation of Li isotopes relative to the inferred source components. However, subtly lower δ7 Li values, evident in the three leucogranites analysed herein, imply that subtle Li isotopic fractionation may occur in association with the exsolution of an aqueous fluid. Like most isotopic systems, the Li isotopic composition of rocks is not a definitive guide to source rock compositions, but given the results herein, the present authors suggest that it may play a very useful role in understanding crustal processes.

Late Palaeozoic alkalic basalts in and around the Midland Valley of Scotland contain a wide variety of ‘plutonic’ xenoliths. Pyroxene-rich ultramark xenoliths (wehrlites, clinopyroxenites and garnet pyroxenites) may be representative of younger components within a dominantly peridotitic upper mantle represented by ubiquitous magnesian peridotite xenoliths. Glimmerites and other biotite-rich ultramafic xenoliths are probable samples of metasomatised upper mantle facies.

Xenoliths composed mainly of plagioclase, clinopyroxene ± orthopyroxene ± magnetite are widespread. These pyroxene granulites may typify the lower crustal layers. Garnet granulites are rare; such rocks may formerly have been important with loss of garnet occurring through retrograde metamorphism. Anorthositic xenoliths are relatively common. The lower crust may consist largely of anhydrous rocks, of gabbroic to anorthositic composition, ccurring as stratiform bodies of metacumulates.

Other xenoliths of igneous origin include tonalitic and trondhjemitic gneisses. Although these may play some role in the lower crust, they may be more abundant in the mid-crustal domains underlying the deformed upper Precambrian and lower Palaeozoic supracrustal strata. Xenoliths of quartzofeldspathic, granulitic gneisses containing garnet ± sillimanite ± rutile are also of widespread occurrence; many of these are of metasedimentary provenance and are regarded as being derived from the mid-crustal layers beneath the Southern Highlands, Midland Valley and Southern Uplands and their Irish counterparts.

In southwestern North America, late Palaeozoic through Cenozoic granitoids and their related mineral deposits show consistent patterns that can be interpreted in terms of combined provincial, exposure and process controls. Voluminous Cordilleran magmatism began in the Permian and continued with few major interruptions through the Mesozoic and Cenozoic, reaching maximum fluxes in the mid-Jurassic, Late Cretaceous and Oligocene. Two distinctive types of broad-scale igneous suites formed. The first type consists of calc-alkaline to alkaline suites that vary regularly with time from early intermediate-mafic centres to late felsic centres over intervals lasting 20–50 Ma. These suites formed during periods of stable convergence and compressional tectonics, most notably in the late Mesozoic and early–mid-Cenozoic. The second type is compositionally varied, but shows no obvious secular variation in composition. This type formed during neutral to extensional tectonics in the mid-Mesozoic and the mid- to late Cenozoic. Regional (west to east) and secular (old to young) changes from calcic to alkalic compositions do not correspond to basement types; they point to tectonic rather than crustal controls on magmatic evolution, although basement signatures are clearly transmitted in isotopic systematics. Contrasting types of intrusive centres formed in the same lithospheric columns, suggesting that variability reflects thermal and stress regimes, subcrustal magma flux and crustal thickness. Simple thermal and mechanical models of limits on assimilation and magma uprise are broadly consistent with these patterns.

Igneous-related mineralisation is ubiquitous where epizonal environments are preserved, thus preservation (and exposure) form the first-order filter on metallogeny. Mineralisation includes porphyry, skarn, epithermal, replacement and syngenetic deposits of widely varying styles, metal contents and links to magmatic heat and materials. Metal contents and alteration styles correlate closely with igneous compositions and are broadly independent of setting, although systematic regional variations in metal ratios are documented. Ore element suites vary from Cu–Au–Fe associated with (quartz) dioritic to monzonitic intrusive centres through Cu–Zn–Mo–Pb–Ag–W–Au associated with broadly granodioritic centres, and finally to F–Mo–Zn–W–Ag–Be associated with metaluminous to strongly peraluminous granitic centres. A model that includes both composition and process controls rationalises this igneous correlation and the lack of strong regional control. Key features are (1) mineralogical controls on fluid compositions and (2) the efficacy of magmatic processes in producing voluminous ore-forming aqueous fluids. This interpretation is supported by field relationships, igneous petrographic and isotopic data, and theoretical considerations.

Ectocarpus siliculosus was named by Dillwyn (5) in 1809 and described by him in the British Confervœ of that date. It was included by Harvey (9) in the Phycologia Britannica under the same name, but according to Hauck (10) in the Meeresalgen Deutschlands und Oesterreichs the specific name should be attributed to Kützing (21), though Hauck himself, following Kjellman (12), is of the opinion that the plant should be regarded as a variety of E. confervoides (Roth) Le Jol. If this view be correct, the plant should be E. confervoides (Roth) Le Jol var. siliculosus (Dillwyn); but in a paper entitled “Beiträge zur Kenntnis einiger Ectocarpus-Arten der Kieler Föhrde” Kuckuck (15) discusses the validity of the species siliculosus. He emphasises certain important features, notably the size and shape of plurilocular sporangia and the frequent presence of a vegetative filament as a prolongation of the sporangium, and considers them to be characteristics clearly distinguishing this plant from E. confervoides (Roth), from which such features are lacking. Batters (1) evidently agrees with Kuckuck in the integrity of the species, but attributes the naming of it to Kützing. The plant therefore appears in the Catalogue of the British Marine Algœ as E. siliculosus Kütz.

The studies of which the results are here set forth were carried on at the Granton Marine Laboratory of the Scottish Meteorological Society, in the years 1886 and 1887. Our memoir is by no means a monograph, although our original aim was to investigate every species taxonomically, anatomically, and embryologically. Much further study would have been necessary to carry out this aim at all completely, but in August 1887, both of us, for different reasons, had to abandon our work at Granton and leave Scotland. We have thought it better to publish the notes and drawings we had made, because they will probably be of service to British naturalists interested in the Polychæta, no extensive work on these forms having appeared in English since Johnston's Catalogue of Non-Parasitical Worms in the British Museum, which was published 1865, and which is now a very inadequate guide to the study of the subject. The greater part of the work of collecting, and much the larger part of the drawings, were done by Mr Ramage. A discussion of some anatomical points has been published separately by Mr Cunningham (“Some Points in the Anatomy of Polychæta,” Quart. Jour. Micr. Sci., 1887).

The following account of the anatomy of the head of a fœtal African Elephant was made possible by the acquisition of a single specimen, preserved immediately after extraction from the mother, who was shot in the Belgian Congo. As far as is known, this fœtus is the only well-preserved specimen in existence, the total number of fœtuses recorded since 1734 being twelve.

Apart from the skeleton, our knowledge of the anatomy of present-day Proboscideans is very meagre. The dissection hitherto carried out has been either a hasty study of the complete adult carcase, or a more lengthy observation of preserved portions of the animals. Both methods lead to inaccuracy, and provide an explanation of the numerous discrepancies in the accounts. When, therefore, the present Congo foetus was acquired by purchase from the Belgians who preserved it, and Professor D. M. S. WATSON kindly allowed me to have it for dissection, I determined to make the fullest possible use of this unique specimen. The dissection of the head was carried out under the Zeiss Binocular Dissecting Microscope, and sketches and photographs were prepared at intervals, so that every record should be kept.

Water of southerly origin replaced polar water very rapidly on the coast of NW Europe and an interstadial marine circulation with a weak North Atlantic Drift was fully established off both west Scotland and southern Scandinavia by roughly 12 800BP. A ‘warm’ interval detected in marine strata on the western Scottish coast at the beginning of the Windermere (Bølling plus Allerød) Interstadial lasted from this date to perhaps 12 400 BP and another towards its close from about 11 250 to shortly after 11 000 BP. During the Younger Dryas Stadial polar water returned by about 10 850 BP and was present until about 10 200–10 100 BP. The changes in water circulation at the beginning and end of the Windermere Interstadial and at the end of the Younger Dryas seem to have taken place within the limits of radiocarbon dating, perhaps within a few decades. Warming at the beginning of the Holocene Interglacial may have taken place in two phases, during the first of which, from about 10 100 BP to possibly 9600 BP, marine temperatures seem to have been lower than at present, more especially on the east coast of Scotland and in southern Sweden. Full marine interglacial circulation may not have been established until 9500 BP. Water depth in the Faeroe–Shetland Channel may have been a major factor in controlling sea and air temperature from Scotland northwards during the Windermere Interstadial and Holocene Interglacial and, by implication, during earlier interglacials and interstadials.

This paper describes three mid-Tertiary intrusions from the Henry Mountains (Utah, USA) that were assembled from amalgamation of multiple horizontal sheet-like magma pulses in the absence of regional deformation. The three-dimensional intrusion geometries are exceptionally well preserved and include: (1) a highly lobate sill; (2) a laccolith; and (3) a bysmalith (a cylindrical, fault-bounded, piston-like laccolith). Individual intrusive sheets are recognised on the margins of the bodies by stacked lobate contacts, and within the intrusions by both intercalated sedimentary wallrock and formation of solid-state fabrics. Finally, conduits feeding these intrusions were mostly sub-horizontal and pipe-like, as determined by both direct observation and modelling of geophysical data.

%The intrusion geometries, in aggregate, are interpreted to reflect the time evolution of an idealised upper crustal pluton. These intrusions initiate as sills, evolve into laccoliths, and eventually become piston-like bysmaliths. The emplacement of multiple magma sheets was rapid and pulsed; the largest intrusion was assembled in less than 100 years. The magmatic fabrics are interpreted as recording the internal flow of the sheets preserved by fast cooling rates in the upper crust. Because there are multiple magma sheets, fabrics may vary vertically as different sheets are traversed. These bodies provide unambiguous evidence that some intrusions are emplaced in multiple pulses, and that igneous assembly can be highly heterogeneous in both space and time. The features diagnostic of pulsed assembly observed in these small intrusions can be easily destroyed in larger plutons, particularly in tectonically active regions.

Two models for the heating responsible for granite generation during convergent deformation may be distinguished on the basis of the length- and time-scales associated with the thermal perturbation, namely: (1) long-lived, lithospheric-scale heating as a conductive response to the deformation, and (2) transient, localised heating as a response to advective heat sources such as mantle-derived melts. The strong temperature dependence of lithospheric rheology implies that the heat advected within rising granites may affect the distribution and rates of deformation within the developing orogen in a way that reflects the thermal regime attendant on granite formation; this contention is supported by numerical models of lithospheric deformation based on the thin-sheet approximation. The model results are compared with geological and isotopic constraints on granite genesis in the southern Adelaide Fold Belt where intrusion spans a 25 Ma convergent deformation cycle, from about 516 to 490 Ma, resulting in crustal thickening to 50–55 km. High-T metamorphism in this belt is spatially restricted to an axis of magmatic activity where the intensity and complexity of deformation is significantly greater, and may have started earlier, than in adjacent low-grade areas. The implication is that granite generation and emplacement is a causative factor in localising deformation, and on the basis of the results of the mechanical models suggests that granite formation occurred in response to localised, transient crustal heating by mantle melts. This is consistent with the Nd- and Sr-isotopic composition of the granites which seems to reflect mixed sources with components derived both from the depleted contemporary mantle and the older crust.

The district described is of considerable relief, according to British standards. Pitlochry lies 300 or 400 ft. above sea-level, while two summits, south-west of the River Garry, reach 2559 ft., and Ben y Gloe, north-east of the same, attains to 3671 ft. Exposures are everywhere sufficient for the mapping of groups, but they seldom permit of the following of individual beds or the recognition of the pitch of isoclinal folds.

The Geological Survey has mapped the whole district on the six-inch scale, and published Sheets 55, 56, 64, and 65 of the one-inch Map of Scotland—all except Sheet 64 accompanied by explanatory memoirs.

Among the commonest and most abundant plant-remains in the Carmyllie and Cairnconon Beds of the Caledonian Lower Old Red Sandstone are branched linear axes about 2 mm. in width. These often occur in a fragmentary condition, but more connected portions demonstrating the morphology of the plant are also found. Though often associated with Parka and Nematophyton, the plant known as Zosterophyllum myretonianum is usually readily recognisable by its definite outline and uniform diameter, by its modes of branching, and by the remains of structure which it sometimes retains. As will be seen below, the axis of this plant was traversed by a single median strand that was composed of tracheides. Zosterophyllum is thus of special interest as the most ancient vascular plant known from British rocks. Some other plant-remains that may be confused with it have also been met with, though less commonly. These will be briefly considered, not merely for this reason, but on account of the very different and peculiar type of structure they exhibit.