Radon and remediation measures near Băiţa-Ştei old uranium mine (Romania)

B?i?a-?tei mine is an open pit mine in NW Romania (West Carpathian Mountains). It was the largest surface uranium deposit in the world. Two means of uranium transport and dissemination were used over time. The first was the natural way, represented by transportation of geological sediments by Cri?ul-B?i?a River that crosses the B?i?a surface deposit. These sediments were used as building materials (stone, gravel, sand). The second way was related to the people living in this valley, who used also the uranium waste as building material. The preliminary indoor radon concentrations measured in the buildings ranged from 40 to 4000 Bq m^?3 with a mean value of 241 Bq m^?3. A focused radon survey facilitated the selection of 20 houses with the highest indoor radon that were therefore proposed for remediation. To find the radon sources of these houses, systematic investigations on radon were performed. The remedial measures for these 20 houses were tested on a chosen pilot house.     

A new perspective in identifying the precursory patterns of eruptions

The complexity of the processes responsible for volcanic eruptions makes a theoretical approach to forecasting the evolution of volcanic unrest rather difficult. A feasible strategy for this purpose appears to be the identification of possible repetitive schemes (patterns) in the pre-eruptive unrest of volcanoes. Nevertheless, the limited availability and the heterogeneity of pre-eruptive data, and the objective difficulty in quantitatively recognizing complex pre-eruptive patterns, make this task very difficult. In this work we address this issue by using a pattern recognition approach applied to the seismicity recorded during 217 volcanic episodes of unrest around the world. In particular, we use two non-parametric algorithms that have proven to give satisfactory results in dealing with a small amount of data, even if not normally distributed and/or characterized by discrete or categorical values. The results show evidence of a longer period of instability in the unrest preceding an eruption, compared to isolated unrest. This might indicate, even if not necessarily, a difference in the energy of processes responsible for the two types of unrest. However, if the unrest is followed by an eruption, it seems that the seismic energy released during the unrest (parameterized by the duration of the swarm and the maximum magnitude recorded) is not indicative of the magnitude of the impending eruption. We also found that, in general, unrest followed by the largest explosive eruptions have a longer repose time than those related to moderate eruptions. This evidence supports the fact that the occurrence of a large eruption needs a sufficient amount of time after the last event in order to re-charge the feeding system and to achieve a closed-conduit regime so that a sufficiently large amount of gas can be accumulated.Editorial responsibility: T. Druitt     

Holocene vegetation development in the catchment of Sägistalsee ( 1935 m asl), a small lake in the Swiss Alps

Pollen and plant macrofossils were analysed at Sägistalsee (1935 m asl), a small lake near timber-line in the Swiss Northern Alps. Open forests with Pinus cembra and Abies alba covered the catchment during the early Holocene (9000–6300 cal. BP), suggesting subcontinental climate conditions. After the expansion of Picea abies between 6300 and 6000 cal. BP the subalpine forest became denser and the tree-line reached its maximum elevation at around 2260 m asl. Charcoal fragments in the macrofossil record indicate the beginning of Late-Neolithic human impact at ca. 4400 cal. BP, followed by a extensive deforestation and lowering of the forest-limit in the catchment of Sägistalsee at 3700 cal. BP (Bronze Age). Continuous human activity, combined with a more oceanic climate during the later Holocene, led to the local extinction of Pinus cembra and Abies alba and favoured the mass expansion of Picea and Alnus viridis in the subalpine area of the Northern Alps. The periods before 6300 and after 3700 cal. BP are characterised by high erosion activity in the lake's catchment, whereas during the phase of dense Picea-Pinus cembra-Abies forests (6300–3700 cal. BP) soils were stable and sediment-accumulation rates in the lake were low. Due to decreasing land-use at higher altitudes during the Roman occupation and the Migration period, forests spread beween ca. 2000 and 1500 cal. BP, before human impact increased again in the early Middle Ages. Recent reforestation due to land-use changes in the 20th century is recorded in the top sediments. Pollen-inferred July temperature and annual precipitation suggest a trend to cooler and more oceanic climate starting at about 5500 cal. BP.     

Reconnaissance geology in Upper Chitral,Baroghil and Karambar districts (northern Karakorum,Pakistan)

During the summer of 1992 a geological expedition crossed the northern Karakorum range in northern Pakistan, from the Chitral to Karambar valleys, from the villages of Mastuj to Imit. Some of the areas visited were geologically unknown. A number of structural units were crossed, belonging to the Karakorum block or to other crustal blocks north of it. They are: (a) the axial batholith, in which three plutonic bodies have been identified, and (b) the northern sedimentary belt (NSB), in which three major tectonostratigraphic units form thrust stacks dipping to the north. Their internal stratigraphy and structural style are partly different. The most complete contains a crystalline basement, transgressed by a marine succession during the Early Ordovician. The youngest strata are represented by the Reshun conglomerate, of inferred Cretaceous age. The northernmost unit of the NSB is tightly folded, whereas the central one forms a monocline. Vertical faults, mainly strike-slip, dissect the thrusted slabs. Metamorphic deformation is absent or reaches only the anchizone in the studied sector of the Karakorum NSB. To the north of the Karakorum proper there are several other tectonic units, separated by vertical faults. They are, from south to north: (a) the Taš Kupruk zone, with metavolcanics of basaltic to latibasaltic composition; (b) the Atark unit, mostly consisting of massive carbonate rocks of Mesozoic age; and (c) the Wakhan slates which consist of a thick widespread succession of dark slates, metasiltites and sandstones. The fine-grained elastic rocks are supposed to be Palaeozoic to Early Triassic in age. The Wakhan slates are intruded by plutons belonging to the East Hindu Kush batholith, from which a single K/Ar age on muscovite gave a Jurassic age.     

If Quebec Goes . . . The ‘Exodus' Impact?

In this paper, we explore migration aspects of the 1995 Quebec Sovereignty Referendum with data from a survey administered to non-francophones in Montreal two weeks prior to the Referendum. While the Quebec sovereignty issue has been around for some time and earlier exodus from the province, particularly among anglophones, is largely regarded as “forced” in some way, this study neither confirms the 1995 Sovereignty Referendum as a paramount factor in explaining outmigration from Quebec nor points to a real reluctance to leave Montreal. The decision to move is influenced by the interplay of a multitude of factors. The political influence is only an added factor to longstanding economic decline and cultural clash. Moreover, if there is any impulsion, the degree varies among different cultural and socioeconomic groups.     

A large marine ecosystem governance framework

A large marine ecosystem (LME) governance framework, developed from a need to effectively address the sustainable management of the shared living marine resources of the Caribbean, is proposed. The framework is based on four propositions and focuses on a linked examination of two well-known components of LME-level governance: the policy cycle process by which decisions are made and the multi-level nature of LMEs. It accommodates the diversity of policy cycles at multiple levels and the linkages among them required for effective governance of LMEs. The framework takes into account of factors such as context, purpose, jurisdictional scale, capacity and complexity and provides a means to identify critical areas for intervention.     

Benthic Community and Sediment Types: A Structural Analysis

Abstract. The distribution of the macrobenthic community, in relation to various physical and chemical characteristics of the sediment, was studied along the coast of Southern Tuscany (Central Tyrrhenian) in an area under the influence of the Ombrone River outflow.
The zonation of the benthos was found to be primarily under the control of a gradient of water movement, as is reflected by variations in the sediment structure from the coast to the open sea. This correlation is somehow influenced by secondary gradients such as the degree of mixing of the sediment and the deposition of terrigenous materials along the river plume.     

K-ar ages of the yemen plateau

The temporal evolution of the Yemen Trap series is examined in the light of K-Ar radiometric data.Rifting and volcanic activity characterize the Yemen plateau between 30 and 20 m.y. confirming a fairly common history of the Afro-Arabian plate on both sides of the Red Sea.