Geochemical evaluation of mineralization potential of the Somie-Ntem area within the Tikar plain,Cameroon: implication on petrogenesis     

Yannah  Mero  Fodoué  Yaya  Kwékam  Maurice  Mbassa  Benoit Joseph  Tifang  Juliana Amboh  Kagou  Armand Dongmo  Ayonghe  Samuel Ndonwi 《中国地球化学学报》2022,41(5):861-886

Acta Geochimica - Somie-Ntem area of the Tikar plain belongs to the western Cameroon Domain. The lithology of the plain has been characterized, and the mineral potential is still unclear despite...  相似文献   

Thin on the Ground - By Anthony Young     

Maurice  Keech 《The Geographical journal》2008,174(3):289-289

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Biogeochemistry of dimethylsulfide (DMS) and dimethylsulfoniopropionate (DMSP) in the surface microlayer and subsurface water of the western North Atlantic during spring   总被引：6，自引：0，他引：6  

Gui-Peng Yang  Maurice Levasseur  Sonia Michaud  Michael Scarratt 《Marine Chemistry》2005,96(3-4):315-329

Sixteen surface microlayer samples and corresponding subsurface water samples were collected in the western North Atlantic during April–May 2003 to study the distribution and cycling of dimethylsulfide (DMS) and dimethylsulfoniopropionate (DMSP) and the factors influencing them. In the surface microlayer, high concentrations of DMS appeared mostly in the samples containing high levels of chlorophyll a, and a significant correlation was found between DMS and chlorophyll a concentrations. In addition, microlayer DMS concentrations were correlated with microlayer DMSPd (dissolved) concentrations. DMSPd was found to be enriched in the microlayer with an average enrichment factor (EF) of 5.19. However, no microlayer enrichment of DMS was found for most samples collected. Interestingly, the DMS production rates in the microlayer were much higher than those in the subsurface water. Enhanced DMS production in the microlayer was likely due to the higher concentrations of DMSPd in the microlayer. A consistent pattern was observed in this study in which the concentrations of DMS, DMSPd, DMSPp (particulate) and chlorophyll a in the microlayer were closely related to their corresponding subsurface water concentrations, suggesting that these constituents in the microlayer were directly dependent on the transport from the bulk liquid below. Enhanced DMS production in the microlayer further reinforces the conclusion that the surface microlayer has greater biological activity relative to the underlying water.  相似文献   

A comparison of suspended particulate matter from nepheloid and clear water     

Marian B. Jacobs  Edward M. Thorndike  Maurice Ewing 《Marine Geology》1973,14(2):117-128

Particulate matter from the nepheloid layer and from regions of clearer water have been examined under the light microscope to determine particle concentration, size and composition. The total count of suspended particles is a basic difference between water samples from nepheloid layers of the North American and Brazil basins, and samples from the clearer water over the Mid-Atlantic Ridge in both the North and South Atlantic. The nepheloid layer of the North American Basin has four times, and the Brazil Basin three times the particle density of clearer water over the mid-ocean ridge. A greater percentage of particles of < 2 μ size prevails in nepheloid water ranging from 85–96% as compared to a range of 76–87% in the clear water. Non-opaque mineral grains form the major constituent.  相似文献   

Fossil viruses     

Maurice Tucker 《Geology Today》2020,36(4):156-160

Viruses are very much in the news these days, unfortunately, but what about their geological history? Are viruses preserved in the fossil record? If so, how does that happen, and how far back do they go? And what about the roles of viruses in the environment? Are they significant or were they just the nasty invisible parasites we regard them to be today, disrupting life as we know it and leading to the very sad and untimely death of 1000s of people? Or were they both—good and bad? This article explores some of these issues.  相似文献   

Crayfish gastroliths     

Ethan A. Tucker  Maurice E. Tucker 《Geology Today》2019,35(1):26-28

Crayfish produce small button‐like gastroliths in their stomachs. These curious calcitic objects are increasingly common in lakes and streams in the UK and Europe as the invasive American crayfish increase their domination of freshwater environments. These stomach stones are also present in the geological record.  相似文献   

Market penetration metrics: tools for additionality assessment?     

Sivan Kartha  Michael Lazarus  Maurice LeFranc 《Climate Policy》2013,13(2):147-165

Abstract

Project-based emission reduction or ‘offset’ programs are being implemented widely, from the CDM (Clean Development Mechanism) to corporate voluntary efforts and municipal and state-level activities. Additionality assessment remains a central and persistent challenge in all programs. Concerns have been raised with methods currently used, such as investment analysis, barrier analysis, and performance thresholds. They have been variously critiqued for high costs, resistance to standardization, weak environmental integrity, and susceptibility to gaming. Technology penetration rates provide another means to infer additionality, and could be a potentially useful complement to other methods. The notion is that emerging technologies with low but increasing penetration rates typically require some type of support, as might be provided through offsets markets, to compete effectively in the marketplace. For penetration rate analysis to provide a useful tool for additionality assessment, several fundamental questions need to be addressed. What do penetration rates represent and how can they be measured? How can additionality evaluation utilize penetration rates? For which sectors and project types are the use of penetration rates most promising? This article shows that penetration tests have a mixture of pluses and minuses, with greater relevance in certain market niches and regions. Reasonable ranges for penetration thresholds are discussed, along with partial crediting approaches to reduce ‘knife-edge’ effects.  相似文献   

The charcoal trap: Miombo forests and the energy needs of people     

Werner L Kutsch  Lutz Merbold  Waldemar Ziegler  Mukufute M Mukelabai  Maurice Muchinda  Olaf Kolle  Robert J Scholes 《Carbon balance and management》2011,6(1):5

Background  

This study evaluates the carbon dioxide and other greenhouse gas fluxes to the atmosphere resulting from charcoal production in Zambia. It combines new biomass and flux data from a study, that was conducted in a miombo woodland within the Kataba Forest Reserve in the Western Province of Zambia, with data from other studies.  相似文献   

Deep structure of the northern Kerguelen Plateau and hotspot-related activity   总被引：5，自引：0，他引：5  

Philippe Charvis  Maurice Recq  Stéphane Operto  Daniel Brefort 《Geophysical Journal International》1995,122(3):899-924

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Coronal holes and icosahedral symmetry     

Herbert Kalisch  Wolfram Neutsch  Horst Fichtner  S. Ranga Sreenivasan  Maurice Shevalier 《Astrophysics and Space Science》2003,288(4):445-469

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