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The results from exploration geochemical stream sediment surveys of the central Wales lead-zinc orefield by undergraduates from the University of Portsmouth between 1979 and 2003 are now available on open access at www.geologis.com for further investigation. Details are given here of the procedures of collection, preparation and chemical analysis of the samples together with an estimate of analytical precision. Log-probability plots for different sub-areas give different results depending on the proportion of anomalous to background values. Important details are lost when undivided data for the whole study area are used. Comparison of repeat surveys of the same area shows that the findings obtained are consistent even though sampling sites differ. The Portsmouth results are compared with those of the British Geological Survey’s G-BASE survey for the area. The two sets of data are compatible and the Portsmouth data enhance the utility of the G-BASE survey. The value of the Portsmouth database for environmental studies and for mineral exploration is illustrated with examples, demonstrating that undergraduate training can, over a period of time, provide an important source of data.

Synopsis The Southern Uplands (southern Scotland) and Lake District (northern England) terranes contain thick and extensive sequences of macroscopically homogeneous, Lower Palaeozoic wacke-type sandstone. There is a close spatial relationship between the outcrop of biostratigraphically defined rock units and distinctive patterns of element distribution in stream sediments derived from those units, with the stream sediment patterns indicating cryptic compositional variations that are not otherwise apparent. Analysis of the stream sediment composition relative to whole-rock values shows that it is not a direct surrogate for the underlying bedrock. Instead, elevation and depletion trends for any given element are controlled by the nature of its mineral host(s) and provide a previously unappreciated means of assessing the detrital mineralogy, and hence provenance of the bedrock sandstones. Stream sediment composition also provides a valuable alternative means of evaluating possible correlation between different stratigraphical sandstone units. Further, since the fine-grained matrix to the wacke sandstones makes a major contribution to the stream sediment, an assessment of the latter allows variations in matrix composition to be taken into account. Examples are given from the Silurian turbidite sequences of the central and southern Southern Uplands (Gala, Hawick and Riccarton groups; the affinity of the Ross Formation with the Hawick Group is demonstrated) and the southern Lake District (Windermere Supergroup).

Synopsis The helically coiled Torquigraptus linterni sp. nov. has a biostratigraphical range restricted to the sedgwickii and halli graptolite biozones of the upper Aeronian. In southern Scotland it occurs in the Moffat Shale Group (Birkhill Shale Formation) at the western end of the Ettrick Valley and at Dob’s Linn, and is also known from a mudstone interbed in turbidite sandstones to the north of the Megget Dam. Its associates include Torquigraptus magnificus (Přibyl & Munch), recorded for the first time in Scotland. Together, these two Torquigraptus species provide additional useful tools for correlation of lithostratigraphy in the central part of the Southern Uplands.

Strange and multistrange baryon production is expected to be enhanced in heavy ion interactions if a phase transition from hadronic matter to a Quark-Gluon Plasma takes place. The production yields of Λs, Λ s, Ξ−s, and Ξ + s relative to the production of negative particles are presented for sulphur-tungsten interactions at 200 GeV/c per nucleon. These production yields are compared to those produced in proton-tungsten interactions and the enhancements of strange and multistrange baryons and antibaryons are presented.

The pre- and syn-Caledonian rocks of the Isle of Man are now known to comprise three distinct units: the early Ordovician Manx Group, the mid-Silurian Dalby Group and the ?late Silurian-early Devonian Peel Sandstones. The Manx Group is dominated by Arenig deep-marine turbidites and debrites deposited in oxygenated basins on the northwest-facing margin of Avalonia. Its organization into a sand-rich lower part and a mud-rich upper part invites comparison with the Skiddaw Group (Lake District) and Ribband Group (Leinster) and points to control by margin-wide events, in part eustatic sea- level changes. Episodes of mass-wasting and Fe-Mn fluid exhalation also correlate along the margin. A mid-late Ordovician volcanic arc is missing above the Manx Group, although parts of its intrusive substructure may be preserved. The Dalby Group comprises northwest-derived turbidites, sedimented into an anoxic basin during Wenlock (mid-Silurian) time. These turbidites were deposited in a successor basin above the Iapetus suture zone. The Dalby Group sits with a tectonic contact on the Manx Group. No evidence has been found of a pre-Silurian cleavage. The main Caledonian D1 and D2 shortening phases are post-Wenlock, comparable in age with those further along the margin in the Lake District and Leinster. The Peel Sandstones preserve a Lower 'Old Red Sandstone' sequence, mostly removed by post-Caledonian erosion elsewhere along this outboard part of the Avalonian margin. The unit does not host a definite Caledonian cleavage, and it must have been deposited late in the deformation history. The granitic intrusions into the Manx Group range from early in D 1 to late in D2. The intrusions generate only local aureoles, and the high metamorphic grade in parts of the Manx Group may be enhanced by favourable protolith compositions.

SUMMARY The Lake District Boundary Fault Zone (LDBFZ) lies at the boundary between the Permo-Triassic East Irish Sea Basin and the Lower Palaeozoic Lake District Block. It divides northwards, within west Cumbria, into a network of fault strands that lie within the cover sequence of Upper Palaeozoic and younger rocks and Lower Palaeozoic basement rocks, and terminates at the St Bees Fault Zone. The earliest evidence of movement across the LDBFZ during the Ordovician is drawn from the component Thistleton Fault which has a volcanotectonic origin and bounds blocks of distinctive stratigraphy and structure. Reactivation of the LDBFZ in response to regional tectonic events occurred during the Late Palaeozoic, Mesozoic and Cainozoic. Oblique reverse displacement during the late Carboniferous was associated with Variscan basin inversion. East–west extension and syndepositional normal displacement accompanied the formation of the East Irish Sea Basin during Permian and early Triassic times. Analysis of fracture mineralization phases from the fault zone strands demonstrates repeated fault activity from mid-Triassic to early Cretaceous times. Slickenside data from the Sellafield area indicate these phases of Mesozoic faulting accommodated dip-slip displacement and south-west-directed extension. Regional uplift during the Cainozoic was accompanied by basin inversion; oblique-reverse displacement across the LDBFZ at this time was accompanied by Cainozoic folding of the hanging-wall block. The structural evolution and displacement history noted for the LDBFZ is likely to have been similar to that of other major faults of north-north-west trend in northern England, notably the Pennine Fault.

SUMMARY Knowledge of the fracture network is fundamental to the fluid transport and geotechnical modelling necessary to assess the suitability of a rock mass to host a potential underground repository for the disposal of radioactive waste. However, in the early stages of a site investigation programme, site-specific fracture data are frequently available only from boreholes. This was the case at Sellafield, where characterization of borehole fracture data presented a number of inter-related problems including the volume of data, two data sets for each borehole and borehole sampling effects. A solution to the presentation and interpretation of such data was found in simple graphical display which allows rapid appraisal of a range of fracture attributes in relation to depth, lithostratigraphy and structure or in any other context. The succession sampled by the boreholes in the immediate vicinity of the proposed repository at Sellafield comprises three major units. The Borrowdale Volcanic Group, of Ordovician age, is unconformably overlain by a Permo-Triassic cover sequence comprising up to 100 m of sedimentary breccia (Brockram) succeeded by c. 450 m of the fluvial St Bees Sandstone to rockhead. Fracture data from these are available from logging of the borehole core and from interpretation of resistivity and acoustic images of the borehole wall, providing accurate frequency and orientation information respectively. These show that the discontinuity character of each of the major units is distinctive, indicating overall lithological control on the fracture network. Fracture frequency in the sedimentary cover rocks is relatively low, especially in the Brockram, and orientation patterns are dominated by bedding. The fracture frequency in the volcanic rocks is generally high and orientation typically very variable in the volumetrically dominant welded ignimbrites. However, interbedded units of non-welded lapilli tuff and breccia have lower fracture frequency and simpler orientation patterns. In all units, variations in fracture frequency and orientation character on a scale of a few metres to 100 m can be correlated with fault intersections indicating a structural overprint. Borehole sampling effects are illustrated by comparison of data from differently orientated boreholes and the underlying causes reviewed. Orientation bias is a well known problem usually addressed by weighting according to the probability of the borehole intersecting a planar feature in a particular orientation. However, data from borehole wall imagery are subject to additional sampling effects which reduce the effectiveness of such weighting. A different approach is suggested, using the probability density function of the population from non-censored parts of the sample.

Strange and multistrange baryon and antibaryon production is a useful probe into the dynamics of the hot hadronic matter created in central heavy ion interactions. Relative production yields and transverse mass spectra are presented and compared for pW and SW interactions.

Faraday rotation data from a pair of polarimeters located in Tucson, Arizona during the first half of 1990 have been examined for evidence of traveling ionospheric disturbances. With the use of digital filtering techniques, oscillations in total electron content (TEC) with periods ranging from 20 to 90 minutes and amplitudes of 1–5 × 1016 m−2 have been detected in the data. When present, the oscillations persist for varying time intervals (usually several hours) and show considerable variation from day to day. Although the viewing geometry (nearly along the local magnetic field line) is not ideal for observation of TIDs, these oscillations do appear to be real ionospheric oscillations. We have examined the possibility that the oscillations are not caused by actual changes in electron content but rather are due to changes in the Faraday rotation resulting from the motion of the ionospheric plasma along a magnetic field line and the resulting change in effective magnetic field strength. Our calculations indicate waves with displacement amplitudes of a few tens of kilometers would be sufficient to explain the observations. We also examined the possibility that the oscillations could be due to actual changes in TEC by using a one-dimensional F region model and imposing a plausible wind oscillation (simulating a gravity wave). We found that a wave with a velocity amplitude of 15 m s−1 was also sufficient to explain the observations. We expect that the observations are best explained by a combination of the two effects, that is, an actual oscillation in electron content and an oscillation in Faraday rotation, both caused by gravity waves in the thermosphere. We estimate that for the 90-min oscillations, 25% of the amplitude is due to the Faraday rotation effect and 75% is due to an actual change in TEC.

Results on Ks0 production at central rapidity in sulphur-tungsten interactions are presented. The selection procedure used to identify Ks0 particles through their decay to two charged pions is described. The mT spectra for Ks0, Λ and Λ and the relative production rates K s 0 Λ and K s 0 Λ , calculated in the kinematic region pT > 1 GeV/c and 2.5 ≤ yLAB ≤ 3.0, are discussed.

We present preliminary results about charged particle production in SS collisions at 200 GeV/ c per nucleon, obtained by WA94 experiment at CERN-SPS. The particle identification has been provided by the Omega RICH; a silicon telescope and an array of multiwire proportional chambers (MWPC) have been used to track particles to the RICH detector. Details about particle tracking and identification procedure are also reported.

Synopsis The Moniaive Shear Zone is a recently delineated major zone of enhanced ductile deformation (up to 5 km wide) within the Southern Uplands of Scotland. The northern margin of the zone coincides with the Orlock Bridge Fault at the boundary between Ordovician and Silurian grey-wackes. Outwith the shear zone, the greywackes are typically weakly deformed, with the regional S1 fabric being developed within mudstone interbeds. Within the shear zone, Silurian Gala Group greywackes are deformed by locally pervasive linear and planar fabrics which yield a consistent sinistral sense of shear. The shear-zone fabric, in general, dips steeply towards the NW with its strike being sub-parallel to that of the regional S1 cleavage. Detailed petrological and micro-structural studies have demonstrated that the Moniaive Shear Zone comprises several zones of high strain enclosing lenticular domains of relatively low strain. The relationship between the Moniaive Shear Zone and the Cairnsmore of Fleet Granite indicates that the main phase of ductile movement on the zone occurred prior to 392 Ma although the exact age of ductile deformation on the shear zone is uncertain.

Strange and multistrange baryon and antibaryon production is a useful probe into the dynamics of the hot hadronic matter created in central heavy ion interactions. Relative production yields and transverse mass spectra are presented for Λ, Λ, Ξ− and Ξ+ hyperons produced in central sulphur-tungsten interactions at 200 GeV/c per nucleon.

The Orlock Bridge Fault separates the Ordovician and Silurian turbidite sequences within the Southern Uplands thrust belt. A large biostratigraphical break and the 1 km wide sinistral Slieve Glah Shear Zone associated with the fault in northern Ireland led to previous interpretation as a major regional structure, possibly a terrane boundary. In Scotland, however, the stratigraphical break is much less and an association with inliers of the Moffat Shale Group suggests that the fault is essentially similar to the other tract-bounding faults which originated as syn-D1 thrusts within the imbricate stack. Localized sinistral deformation apparent along the trace of the Orlock Bridge Fault in southwestern Scotland, associated with post-1 reactivation, is comparable to that seen at Slieve Glah. Further east, a broad zone (up to 8 km) of sinistral ductile deformation, the Moniaive Shear Zone, is recognized adjacent to the Orlock Bridge Fault over a strike length of about 100 km. However, this zone differs from the Slieve Glah Shear Zone in its width and its location relative to the fault, suggesting that it is not simply related to the fault but represents a more regional deformation. Sinistral reactivation of the Orlock Bridge Fault was possibly initiated in the Wenlock during the peak of sinistral shear at the thrust front, although it may have developed over a long time contemporaneously with, but locally post-dating, the Moniaive Shear Zone. The latter deforms porphyroblasts with the thermal aureole of the c. 392 Ma Cairnsmore of Fleet granite pluton, which was emplaced into and largely post-dates the shear zone, but is deformed by the Orlock Bridge Fault. Major dip-slip reactivation of the fault post-dates the Moniaive Shear Zone and regional metamorphism and probably occurred in the Carboniferous or Permian. There is some evidence for a deep crustal feature coincident with the Orlock Bridge Fault, possibly the boundary between different crustal blocks in the collage of terrane fragments accreted during the final closure of Iapetus, which may explain the unusual extent of the reactivation of the Orlock Bridge Fault within the allochthonous Southern Uplands thrust stack. However, the situation of the fault within the Southern Uplands terrane and, in Scotland, the biostratigraphical evidence of no major stratigraphical break across the fault and the lack of any clear relationship between the Orlock Bridge Fault and the Moniaive Shear Zone indicate that the fault should not be regarded as a terrane boundary.

In the northern part of the Southern Uplands, restricted volumes of basic igneous rocks occur at or near the base of the Ordovician sedimentary strata. These rocks have previously been interpreted as ocean-floor tholeiites representative of the subducted Iapetus oceanic plate, preserved as tectonic slivers in a fore-arc accretionary prism. The alternative, back-arc basin model proposed for the Southern Uplands on sedimentological evidence raises questions over the origin of these rocks. New geochemical data and previously published data clearly indicate that the volcanic material does not have a simple single source. The oldest (Arenig) volcanic rocks from the Moffat Shale Group associated with the Leadhills Fault include alkaline within-plate basalts and tholeiitic lavas which possibly display geochemical characteristics of midocean ridge basalts. In the northernmost occurrence, alkaline and tholeiitic basalts contained within the Caradoc Marchburn Formation are both of within-plate ocean island affinity. To the south, in the Gabsnout Burn area, the Moffat Shale Group contains lenticular bodies of dolerite and basalt which have characteristics of island-arc to transitional basalts. This complex association of basaltic volcanic rocks is, at the present time, difficult to reconcile with either a simple fore-arc or back-arc setting for the Southern Uplands. However, the increasing arc-related chemical influence on basic rock geochemistry towards the southeast may tentatively be used in support of a southern arc-terrane, and as a result, a back-arc situation for the Southern Uplands basin. An alternative is that these volcanic rocks may represent the local basement to the basin and include remnants of an arc precursor to the Southern Uplands basin.

Multi-strange baryon and anti-baryon production is expected to be a useful probe in the search for Quark-Gluon Plasma formation. We present the transverse mass distributions of negative particles, K o s, Λs, Λ s, and Ξ − s produced in sulphurtungsten interactions at 200 GeV/c per nucleon and give the corrected ratios Λ Λ, Ξ − Λ and Ξ − /Λ . We note that our ratio Ξ − / Λ appears large in comparison to that from p p interactions.

We report results on the production of strange baryons/antibaryons with 1, 2, and 3 units of strangeness (Λ, Ξ and Ω) and mesons (K s 0 , K + and K − ) in WA85 experiment at the CERN SPS. This experiment was designed to study the production of strange particles in central SW collisions at 200 GeV/c per nucleon, in the central rapidity region with medium to high p t . We have measured the inverse slopes of the m t distributions of such particles and the production ratios Λ /Λ, Ξ + /Ξ − , Ξ − / Λ , Ξ + / Λ , K s 0 / Λ , K s 0 / Λ , (Ω − + Ω + ) (Ξ − + Ξ + ) and K + K − . Preliminary results on the production ratios Ξ − / Λ and Ξ + / Λ in pW collisions at 200 GeV/c are also presented.

SUMMARY The subdivisions of the Sherwood Sandstone Group, previously recognized on geophysical and lithological criteria in boreholes offshore in the East Irish Sea Basin, can be identified in the onshore exposures and boreholes of west Cumbria. The term St Bees Sandstone Formation is here restricted to the lower, fluvial, fine-grained sandstone, with claystone and siltstone partings, exposed around St Bees. This formation is sharply overlain by softer and coarser grained, aeolian and subordinate fluvial sandstone, which contains abundant, well-rounded aeolian sand grains, referred to the newly defined Calder Sandstone Formation. Higher sandstone has been separated from the Calder Sandstone Formation by its finer grain size and by geophysical log signatures. This is referred to the Ormskirk Sandstone and is dominantly aeolian in origin. Similar divisions of the Sherwood Sandstone Group can be recognized in the Carlisle Basin, and may also be present in other onshore areas, but await formal definition.

Experiment WA91 searches for non-\(q\bar q\) mesons produced in the central region in the reaction pp→pf(X0)ps at 450 GeV/c using the CERN Omega Spectrometer. WA91 is a continuation of the WA76 experiment which has studied this reaction using beams of 85 and 300 GeV/c. Preliminary results from experiment WA91 are presented. In particular the X(1450) and X(1900) observed for the first time in the π+π-π+π- channel of the WA76 experiment at 300 GeV/c are confirmed by the WA91 data.

The reaction pp → pƒ(π + π − π + π − )p s has been studied at 450 GeV/c in an experiment designed to search for gluonic states. In addition to the well known ƒ 1 (1285) , the π+π−π+π− mass spectrum shows evidence for two states pre only observed by the WA76 experiment, the X(1450) and X(1900). An analysis of the X(1450) shows that it is a relatively narrow state (Γ = 56 ± 12 MeV) with I(JPC) = 0(0++) which decays to ϱ0π+π−. The X (1900) could either b single broad state (Γ = 370±70 MeV) with I(JPC) = 0(2++) or possibly separate states.

We have extracted from the full WA85 1990 data set a sample of 14ω − + ω − candidates. We describe the selection criteria, and give a measurement of the ω − /ω − ratio at central rapidity and PT > 1.6 GeV/c.

The reactionpp→pf(π+π−γ)ps, where theπ+π−γ system is centrally produced, has been studied at 300 GeV/c. Theπ+π−γ mass spectrum shows evidence for aρ0γ decay mode of theη′ (958) andf1 (1285). The branching ratio (f1(1285)→ηπ+π+)/(f1(1285)→ρ0γ) is found to be 5.0±0.7. No evidence is found for aρ0(770)γ decay mode of theE/f1 (1420) for which an upper limit BR (E/f1(1420)→ρ0γ)

The Notre Dame and Exploits subzones of Newfoundland's Dunnage Zone are correlated with the Midland Valley and Southern Uplands of Scotland, using detailed comparisons of two key Lower Palaeozoic successions which record similar histories of extension and compression. It follows that the Baie Verte Line, Red Indian Line and Dover Fault are equivalent to the Highland Boundary Fault, Southern Upland Fault and Solway Line, respectively.The Betts Cove Complex and overlying Snooks Arm Group of the Notre Dame Subzone are analogous to the Ballantrae Complex of the Midland Valley, both recording the Arenig evolution and subsequent obduction of an arc and back-arc system. The Early Ordovician to Silurian sequence unconformably overlying the Ballantrae Complex is poorly represented in the Notre Dame Subzone but important similarities can still be detected suggesting corresponding histories of continental margin subsidence and marine transgression.In the Exploits Subzone, Early Ordovician back-arc volcanic rocks are overlain by Llandeilo mudstones and Late Ordovician to Early Silurian turbidites. A similar stratigraphy occurs in the Northern and Central Belts of the Southern Uplands and both areas have matching transpressive structural histories. Deeper erosion in the Exploits Subzone reveals Cambrian and Early Ordovician volcano-sedimentary sequences structurally emplaced on the Gander Zone, and such rocks are probably present beneath the Southern Uplands. Combined data from the Notre Dame Subzone and Midland Valley suggest an Arenig southeast-dipping subduction zone. Early Ordovician volcanic rocks in the Exploits Subzone and Southern Uplands have back-arc basin geochemistry and support the model of the Southern Uplands as a transition from back-arc to foreland basin. Preferential emergence of the Dunnage Zone and contrasts between Exploits Subzone and Southern Uplands turbidite basins are attributed to collision of Newfoundland with a Laurentian promontory and Scotland with a re-entrant. This hypothesis also explains the transpressive structural regime common to both areas.

Multi-strange baryon and antibaryon production is expected to be a useful probe in the search for quark-gluon plasma formation. We present the transverse mass distributions of negative particles, Λ' s , Λ ' s and Ξ − ' s produced in sulphur-tungsten interactions at 200 GeV/c per nucleon and give the corrected rations Λ /Λ, Ξ − /Λ and Ξ − / Λ . Our ratio Ξ − / Λ appears to be larger than that from pp interactions.

The reactionpp→pf(ηπ+π−)ps where the ηπ+π− system is centrally produced has been studied at 300 GeV/c incident momentum at the CERN Ω spectrometer. The ηπ± mass spectrum shows a strong δ/a0(980) signal having a mass of 984±4 and Γ=95±14 MeV. The ηπ+π− mass spectrum shows η′ andf1(1285) signals over little background. A spin-parity analysis of the ηπ+π− system shows evidence for aJPC=1++ peak at thef1(1285) mass but no evidence for the pseudoscalar states η(1270) andl/η(1440). No evidence is found for the ηππ decay of theE/f1(1420) meson for which we set an upper limit BR(E/f1(1420)→ηππ)

Production of multi-strange baryons and antibaryons is expected to be a useful indicator in the search for Quark-Gluon Plasma formation. Production of Ξ− and Ξ − has been observed for the first time in ultra-relativistic heavy ion interactions by the WA85 Experiment. We describe the procedure used to select these cascade candidates and show that Ξ− and Ξ − decays can be identified. Preliminary ratios of Ξ/Ξ production in sulphur-tungsten and proton-tungsten interactions are also presented.

Results from the WA85 Experiment at the CERN Ω Spectrometer are presented. A 200 A GeV/ c beam of 32 S ions was used with a tungsten target. The apparatus is used to detect V 0, s and charged tracks in the range p T > 0.9 GeV/ c and 2.3 Y lab Λ and negative hadrons all show a linear increase with rapidity density in the range 70–140 as expected from models based on a superposition of independent NN collisions.

[1] Lookup tables have been constructed that address group delay and RF carrier phase advance for transionospheric signal propagation referenced to a ground-based transmitter. The tables are based on parameterizations of ray-tracing results using the Reilly ray trace/ICED, Bent, Gallagher (RIBG) model with the magnetic field turned off. The quantities of interest are incremental group and phase path lengths referenced to straight-line distance between transmitter and receiver and are designated by Δlg and Δlp (as defined, both quantities are positive). Equations are presented that relate these quantities to group delay and ionospheric Doppler shifts. Tables currently in use are three-dimensional, expressed in terms of frequency (f), elevation angle (θ), and straight-line total electron content (TECSL). At high frequencies, Δlg and Δlp can be accurately expressed by a straight-line propagation formula that is proportional to TECSL. With decreasing frequency, these quantities become greater than their straight-line counterparts due to additional refraction effects, including ray bending. Extensive ray-tracing runs have been performed under a variety of ionospheric conditions to produce scatterplots of Δlg and Δlp versus TECSL for given pairs of [f, θ] values. The current ranges in these variables are from 20 to 100 MHz and 5° to 90°, respectively. The tables contain coefficients from fourth-degree polynomial fits to the distributions of points within the scatterplots. Where scatter is problematic, the introduction of a fourth parameter, slab thickness, is shown to significantly reduce this scatter. Magnetic field effects are discussed and are shown to have a small effect on table coefficients. Discussion is also included on the use of the tables with a model ionosphere.

Production of charged particles identified by a multi cell threshold Cerenkov counter in proton-tungsten and central sulphur-tungsten collisions at 200 GeV/c per nucleon is discussed. The π±, p and p production ratios and transverse mass spectra at central rapidity and pT > 0.6 GeV/c are presented and compared with results from other experiments at the same beam energy.

The primary aim of the WA85 experiment is the study of strange and multistrange baryon and anti‐baryon production. Particles are detected in the kinematic window of central rapidity and pT≳1.0 GeV/c. Results on the production of Λ, Λ,Ξ− and Ξ− hyperons in proton‐tungsten interactions from the 1990 run are presented and compared with the sulphur‐tungsten data.

Strange and, especially, multistrange baryon and anti‐baryon production is expected to be a useful probe in the search for Quark‐Gluon Plasma formation. A review of WA85 results on strange and multistrange particle production in SW and pW interactions at 200 GeV/c per nucleons is presented. In particular, mT distributions and relative ratios are presented for Ξ−s, Ξ−s, Λs, Λs, and K0s.

New results on the production of charged kaons in Sulphur‐Tungsten interactions have been obtained by the WA85 Collaboration. We present mt spectra for K+ and K− particles and the ratio

Strange and multistrange baryon and antibaryon production has been studied in sulphur sulphur interactions at 200 GeV/c per nucleon at central rapidity. Particle production ratios and transverse mass spectra are presented for Λ, Ξ−, Ξ and Ξ−. In addition preliminary results on charged kaon production are presented, and the status of identified charged particle track reconstruction using the Omega RICH is reviewed.

We have measured the (Ω−+Ω+)/(Ξ−+Ξ+) production ratio in central S‐W collisions to be 0.8±0.4 at central rapidity and pT≳1.6 GeV/c.

In the SW part of the Southern Uplands of Scotland the relatively thin Moffat Shale Group (late Ordovician–early Silurian) is succeeded by a thick development of Silurian greywackes, of variable turbiditic facies. This includes late Llandovery (Telychian) quartzose greywackes with interbedded thin graptolitic shales of the turriculatus and crispus biozones, in the upper part of the Gala Group, a sequencewhich is laterally equivalent to the basal part of the Hawick Group. The age of the finer-grained calcareous Hawick Group, which here includes 1. the Ross Formation, ranges from late Llandovery (turriculatus Biozone) to early Wenlock (riccartonensis Biozone). The Riccarton Group, which contains thick units of thinly-bedded siltstones and mudstones, is of Wenlock age (riccartonensis to lundgreni biozones). Within this sequence, all the biozones of the standard graptolite zonal scheme have been recognised in the area, with the exception of the crenulata Biozone of the late Llandovery (Telychian Stage) and the murchisoni and ellesae biozones of the Wenlock (Sheinwoodian Stage). Details of the graptolite biostratigraphy areclosely comparable with those of the markedly thinner sequences of northern England. Acritarchs occur throughout the sequence but are most numerous and best preserved in the Gala Group. Poorly preserved chitinozoa and spores are also present, the former occurring sporadically throughout the succession but the latter become common only in the Riccarton Group.

Production of Ξ − and Ξ − has been observed for the first time in heavy ion interactions by the WA85 Experiment. Multistrange baryon and antibaryon production is expected to be a useful probe in the search for quark-gluon plasma formation. We describe the procedure used to select these cascade candidates and show that Ξ − and Ξ − decays can be identified. The ratio of Ξ Ξ production, corrected for geometrical acceptances and reconstruction efficiencies, is 0.39 ± 0.07 for sulphur-tungsten interactions in the central rapidity interval 2.3 Y lab p T >1.1 GeV/ c .