Chemistry of rainfall,throughfall and stemflow in a eucalypt forest and a pine plantation in south-eastern Australia: 1. Rainfall

Rainfall samples were collected from several hundred rainfall events. Up to nine samples per event were collected from sites 3–500 m apart. They differed substantially in both concentration and composition, even though great care was taken to wash all collectors beforehand. Dryfall, storage and analytical procedures could not explain the variation. When data for rainfall events of similar size (but very different cation inputs) were examined, the major differences were associated with the prevailing wind direction. Events leading to high concentrations were associated with easterly winds and showed the influence of a marine source. Chemical concentration and composition were not altered by the occurrence of a drought year followed by a very wet year. The mean pH was 5·3 and ranged from 4·6 to 5·8. For a given event, a difference of 0·5 often occurred between collection sites. Regular seasonal variations in the concentration of NO₃-N and the NO₃/NH₄ ratio occurred, with the ratio being higher in summer due primarily to bush fires. Organic nitrogen comprised 14% of total nitrogen.     

Fluorite deposition in hydrothermal systems

During the formation of fluorite deposits fluorite is precipitated either as a consequence of changes in temperature and pressure along the flow path of hydrothermal solutions or due to fluid mixing, or as the result of the interaction of hydrothermal solutions with wall rocks.A decrease in temperature in the flow direction is the most appealing, though still unproven, mechanism of fluorite deposition in Mississippi Valley fluorite deposits.Mixing can produce solutions which are either undersaturated or supersaturated with respect to fluorite. The most important parameters are the temperature, the salinity, and the calcium and fluoride concentration of the fluids prior to mixing.A variety of wall rock reactions can lead to fluorite precipitation. Among these reactions which increase the pH of initially rather acid (pH ≤ 3) hydrothermal solutions are apt to be particularly important.     

龙门山彭县-灌县断裂的活动构造与地表破裂

2008年5月12日在龙门山发生了8.0级特大地震,彭县-灌县断裂亦发生了同震地表破裂.在前期对龙门山活动构造研究的基础上,汶川特大地震发生后,在灾区进行了多次的野外调查和国际合作考察,重点对汶川地震的地表破裂和地质灾害开展了详细的详细野外地质填图,利用全站仪和GPS对地表破裂进行了精确的测量,研究了的地表破裂地貌错位、构造组合和运动学,已实地测得地表破裂数据70余组(其中彭县-灌县断裂地表破裂数据20余组).文章以彭县-灌县断裂地表破裂为切入点,在彭县-灌县断裂的关键部位开展了详细的野外地貌测量,主要测量了彭州磁峰、白鹿、绵竹金花和汉旺等地的地表破裂,标定了彭县-灌县断裂破裂带的垂向断距和水平断距,结果表明该地表破裂南西起于彭州磁峰,向北东延伸经白鹿、绵竹金花至绵竹汉旺,全长约40～50km.地表破裂带沿彭县-灌县断裂带的走向断续分布,单个破裂长度在几米到500余米不等,破裂带切割了多种类型的地貌单元,包括山脉基岩、河流阶地、冲洪积扇、公路、桥梁等,同时也使道路发生拱曲、破坏和桥梁垮塌或移位.其以脆性破裂为特征,以逆冲一右旋走滑为特点,断面倾角较陡,北西盘为上升盘,南东盘为下降盘,垂直位错介于0.39～2.70m之间,水平位错介于0.20～0.70m,平均垂直位错为1.6m,平均水平位错为0.6m;地表最大错动量的地点位于彭州白鹿镇,其中最大垂直断错为2.7±0.2m,最大水平断错为0.7±0.2m.垂直位错与水平位错量之间的比值为2:1,表明该地震地表破裂带不仅存在逆冲运动分量和右旋走滑运动分量,而且逆冲运动分量大于右旋走滑运动分量,显示了彭县-灌县断裂破裂带具有以逆冲和缩短作用为主、右旋走滑作用为辅的破裂性质.其与映秀-北川断裂带的地表破裂相比较,该断裂的地表破裂程度远小于映秀-北川断裂带的地表破裂程度,主要表现在地表破裂的长度较短,垂直位错和水平位错也相对较小,而且为以逆冲作用为主.初步研究结果表明,彭县-灌县断裂与映秀-北川断裂地表破裂的平面组合样式显示为两条在平面上近于平行的北东向地表破裂带,其间由一条南北向的次级地表破裂带(小鱼洞断裂)将它们相连结,地下破裂面的剖面组合样式显示为叠瓦状,并在汶川地震震源附近或震源的上方相连的,是同"根"的.     

Agents of low temperature ocean crust alteration

¹⁸O and⁸⁷Sr/⁸⁶Sr isotopic data from smectites, calcites, and whole rocks, together with published isotopic age determinations, alkali element concentration data and petrographic observations suggest a sequential model of ocean floor alteration. The early stage lasts about 3 m.y. and is characterized by palagonite and smectite formation, and solutions with a large basaltic component, increasing with temperature which varies from 15° to 80° C at DSDP site 418A. Most carbonates are depositedafter this stage from solutions with a negligible basaltic Sr component and temperatures of 15° to 40° C. Water of seawater Sr and O isotopic composition is shown to percolate to at least 500 m into the basaltic basement. No evidence was found for continuing exchange of strontium or oxygen after 3 m.y.Lamont-Doherty Geological Observatory Contribution number 3199     

Putting stakeholder engagement in its place: how situating public participation in community improves natural resource management outcomes

Stakeholders in natural resource management decisions are also multifaceted individuals and members of communities; as such, they bring complex histories, experiences, values, aspirations, and relationships to public participation processes. When these processes fail to take this social context into account, multiple problems can result, including a perceived lack of process trustworthiness; perceived focus on issues that seem immaterial or irrelevant; failure to equitably represent and take account of diverse voices; and failure to engage participants in productive dialogue. In this article we evaluate the Community Voice Method (CVM) as a way of addressing those problems by better situating public participation in place. CVM is a mixed-method approach to public participation in which stakeholders are interviewed and the interview data is presented through a film, which is then screened at public meetings to catalyze dialogue. We draw on 14 years of CVM projects addressing natural resource management issues in the United States, the United Kingdom, and the Caribbean. Through an overview of nine projects and their results, and more in-depth consideration of three, we elucidate how this method fosters trustworthy, relevant, representative, and productive public participation that has resulted in community capacity-building, institutional capacity-building, and stakeholder-guided policymaking.

     

Notes on the origin of inertinite macerals in coals: Observations on the importance of fungi in the origin of macrinite

Macrinite is a, generally, rare inertinite maceral, often incorporating remnants and fragments of other macerals, including vitrinite, liptinite, and other inertinite. The associated inertinites include multiple forms of funginite. Funginite is also commonly found in association with vitrinite of slightly elevated reflectance and with degraded varieties of vitrinite. Together with the highly degraded macrinite, the latter two associations are here inferred to be part of a continuum of fungal and microbial degradation of peat. In any case, the origin of some macrinite is potentially distinct from that of inertinite generated by fire.     

DNA adduct formation and DNA strand breaks in green-lipped mussels (Perna viridis) exposed to benzo[a]pyrene: dose- and time-dependent relationships

Green-lipped mussels, Perna viridis, were exposed to 0, 0.3, 3 and 30 micrograms l-1 (nominal concentrations) B[a]P under laboratory conditions over a period of 24 days. Mussels were collected on day 0, 1, 3, 6, 12, 18 and 24, and the levels of DNA adducts and DNA strand breaks in their hepatopancreas tissues monitored. Mussels exposed to 0.3 and 3 micrograms l-1 B[a]P showed marked increases in strand breaks after 1 day of exposure. DNA strand break levels in these mussels remained high and significantly different from the control values until day 3 for the 0.3 microgram l-1 treatment group, and day 6 for the 3 micrograms l-1 treatment group. This was followed by a gradual reduction in strand breaks. After 12 days, the levels of both groups had returned to the same level as that of the control. No increase in DNA strand breaks was observable in mussels exposed to 30 micrograms l-1 B[a]P in the first 12 days of exposure, but a significant increase was observed from day 12 to day 24. Increasing B[a]P concentrations resulted in elevated DNA adduct levels after 3-6 days of exposure, but this pattern of dose-related increase disappeared after 12 days. These results indicate that a better understanding of the complex interactions between exposure levels and durations is crucially important before DNA adduct levels and DNA strand breaks in P. viridis can be used as effective biomarkers for monitoring genotoxicants in marine waters.