A STATISTICAL PROCEDURE TO EVALUATE CLEAN-UP STANDARDS

The object of this paper is to develop a suitable statistical procedure to evaluate clean-up standards athazardous waste sites.Under the assumptions that contaminant masses at a site follow a gammadistribution and that the data from the pre-remediation baseline sample as well as from the interim orfinal sample taken after a certain period of operation are both distributed as gamma with the same shapeparameter but different scale parameters,we derive a uniformly most powerful unbiased test of thehypothesis that a specified percentage of contaminant mass has been reduced.A large-sampleapproximation of the exact test procedure and a comparison with the likelihood ratio test are provided.     

Late Pleistocene and Holocene glacial history of James Ross Island, Antarctic Peninsula

Studies of Quaternary glacial stratigraphy and morphology around the Antarctic Peninsula have shown that James Ross Island in the western Weddell Sea probably has the best occurrences of stratigraphic sections with dateable material in the region. The stratigraphy includes sections with indefinite radiocarbon age, and three separate aminozones can be recognized. Except for indications of an early deglaciation around c . 10,000 BP, the field evidence from northern James Ross Island suggests a glacial readvance around 7000 BP. It is concluded that the readvance reflects the combined effects of eustatic sea level rise and Holocene warming, leading to increased precipitation and a positive mass balance. The most recent large-scale deglaciation in the area took place around 6000–5000 BP. This confirms the evidence from lake sediments and moss banks in other parts of the Antarctic Peninsula region, which shows that, in most cases, the initiation of organic deposition took place after c . 6000 BP. The literature on the Holocene glacial and environmental history of the region is reviewed in light of the new field evidence.     

An undulatory discontinuity surface on a gently inclined muddy ramp: possible evidence of secondary helical flow from the geological record

An unusual, somewhat cryptic, undulatory discontinuity has been recognized near the basal contact of the Wanakah Shale Member of the Middle Devonian Ludlowville Formation in western New York. It is in part marked by undulating diagenetic limestone beds and concretionary horizons, but can be traced continuously by subtle surfaces of fossil and pyritic lags. This surface marks the top of parallel, elongate mud ridges trending approximately N-S, perpendicular to the inferred E-W depositional strike of the Appalachian Basin in western New York. These ridges are observed in the field as irregularly spaced mud swells which have up to 1.5 m of relief, and vary from 30 to 50 m or more in width. The intervening, broad, flat‘channel floors’ are characterized by dense concentrations of diminutive brachiopods with gastropods and styliolinids, which are gradually replaced by thin styliolinid horizons with abundant pyrite nodules and pyritized burrows over the tops of the swells. Traceable shelly horizons are observed to pinch out over the swells, suggesting a period of relatively undisturbed sediment-filling following the formation of the channellized surface. The interval of nearly barren shale below this irregular surface, however, contains concretionary horizons and rare styliolinid pavements which are themselves irregular, possibly indicating a changing topography for this surface through time. Previous taphonomic and palaeoecological studies of the lower Wanakah Shale Member have disclosed a well-defined regressive-transgressive cycle with more subtle superimposed subcycles. The undulatory surface described here occurs within the early regressive part of this cycle, and appears to record an accentuated regressive kick of a lower-order subcycle. The formation of this surface is therefore interpreted to be a consequence of regressive submarine erosion and sediment bypass, together with redeposition from suspension. The development of the‘channels’ and parallel longitudinal mud ridges was probably controlled by helical flow cells within offshore-directed bottom currents. They may be the first recorded instance of sedimentary furrows described from the geological record. Taphonomic and biofacies data indicate relative depths below average storm wave-base, suggesting that sediment winnowing and redeposition occurred at depths only rarely affected by the direct impact of storm wave agitation.     

Petrogenesis of Mesozoic, Peraluminous Granites in the Lamoille Canyon Area, Ruby Mountains, Nevada, USA

Two groups of closely associated, peraluminous, two-mica graniticgneiss were identified in the area. The older, sparsely distributedunit is equigranular (EG) with initial     

Late Holocene climatic history of northern Germany and Denmark: peat macrofossil investigations at Dosenmoor, Schleswig-Holstein, and Svanemose, Jutland

Plant macrofossil remains have been analysed from two raised peat bogs in northern Germany and Denmark. The quantified vegetation reconstructions of each profile were subjected to multivariate analyses to extract records of changing bog surface wetness (BSW), which are interpreted in these rain-fed bogs as being proxy climate signals. Age/depth models were constructed using radiocarbon dates and a number of drier and wetter phases were defined. The records both register cooler/wetter conditions around 2700, 1800 and 1400 cal. yr BP, and at the beginning of the Little Ice Age around AD 1250–1350. These rising bog water tables must have been reflected in poorer conditions for agriculture, and in particular near Dosenmoor where the profile records a catastrophic change to such conditions culminating at 2750–2600 cal. yr BP.     

What status for the Quaternary?

The status of the Quaternary, long regarded as a geological period effectively coincident with the main climatic deterioration of the current Ice Age, has recently been questioned as a formal stratigraphic unit. We argue here that it should be retained as a formal period of geological time. Furthermore, we consider that its beginning should be placed at the Gauss-Matuyama magnetic chron boundary at about 2.6 Ma, rather than at its current position at about 1.8 Ma. The Quaternary would be formally subdivided into the Pleistocene and Holocene epochs. The global chronostratigraphical correlation table proposed is enclosed at the back of this issue.     

The Rare Earth Elements and Uranium in Garnets from the Beinn an Dubhaich Aureole, Skye, Scotland, UK: Constraints on Processes in a Dynamic Hydrothermal System

Garnets from skarns in the Beinn an Dubhaich granite aureole,Isle of Skye, Scotland, have a large range of concentrationsof uranium (0·2–358 ppm) and the rare earth elements(REE) (23–4724 ppm). Variations in these concentrationscorrelate with major element zonation within the garnets, andwith changes in the shape of REE patterns. Typical patternsin most garnets display light REE (LREE) enrichment, flat heavyREE (HREE) distribution and a negative Eu anomaly. These patternsare interpreted to represent equilibrium trace element exchangebetween pre-existing pyroxene, hydrothermal fluid and calcicgarnets. Iron-rich zones are characterized by positive Eu anomaliesand an increase in the abundance of the LREE relative to theHREE. These patterns are interpreted as resulting from changesin REE speciation related to the introduction of externallybuffered fluid to the skarn system. Relatively Fe-poor zonesshow strongly HREE-enriched patterns with negative Eu anomaliesand in some instances depletions in Y relative to Ho and Dy,which are interpreted as resulting from surface sorption ofthe REE during rapid, disequilibrium garnet growth. Strong correlationsbetween U abundance and the REE patterns indicate that the sameprocesses have affected U distribution. Both types of patterncan be modified by the effects of closed-system crystallizationon REE abundance in the fluid, and changes in fluid major elementchemistry. KEY WORDS: fractionation; garnet; hydrothermal; rare earth elements; skarn     

Hf Isotope Systematics of Kimberlites and their Megacrysts: New Constraints on their Source Regions

Kimberlites from Southern Africa, along with their low-Cr megacrysts,have unusual Hf–Nd isotopic characteristics. Group I andTransitional kimberlites define arrays trending oblique to,and well below, the Nd–Hf isotope ‘mantle array’,defined by oceanic basalts, i.e. they have negative     

Sustainable Development: The Economic and Environmental Case for Policy Reform

Abstract. Acceptance of the concept of sustainable development as a long term goal has shifted the nature of the debate about the environment and its relation to development. Previously, emphasis was on the adverse effects of economic development on the environment. It is now argued that a degraded and deteriorating environment is a threat to economic development. However, if the promise of sustainability is to be fully explored some fundamental changes must be made. The most important changes concern: first, the way ecological factors are integrated into economic decision making; second, the design of domestic policies; third, the emergence of environmental change as a force in international relations; and, fourth, the need to restructure the international economy and global political arrangements. Canada and New Zealand provide examples of efforts to tackle these issues, to halt environmental destruction and resource depletion, and to meet global development needs.