@Research Paper
<#LINE#>Li, Cs, Ta and Rb enrichment in metasedimentary intrusive body: a marker of rare metal potential mineralisation of pegmatite in origin, Musha-Ntunga area, Eastern Province, Rwanda<#LINE#>Jean de Dieu @Ndikumana,Anthony Temidayo @Bolarinwa,Adeyemi Gabriel @Oladapo <#LINE#>1-12<#LINE#>1.ISCA-IRJES-2018-022.pdf<#LINE#>Institute of Life and Earth Sciences, Pan African University, Ibadan, Nigeria & Department of Geology, University of Ibadan, Ibadan, Nigeria & Department of Mining regulation and Inspection, Rwanda Mines, Petroleum and Gas Board, Kigali, Rwanda@Department of Geology, University of Ibadan, Ibadan, Nigeria@Department of Geology, University of Ibadan, Ibadan, Nigeria<#LINE#>1/10/2018<#LINE#>15/12/2018<#LINE#>The study aims to geochemically characterize the pegmatite and elucidate the current processes occurred after the primary emplacement of ores in Musha-Ntunga area, Rwanda. The rare metal pegmatites intruded the metasedimentary rocks dominated by schists in Musha formation. The laboratory analyses of petrography and geochemistry were used. The petrographic analysis investigated mineral assemblages, and whole rock analysis for major elements by ICP AES and trace elements by ICP MS. Petrographic studies revealed the mineral assemblages include plagioclase, mica, tourmaline and muscovite. The results of geochemical analysis revealed medium to high silica content (in wt%) ranges from 67.08-70.66, the Al2O3 ranges 26.6-28.7 (in wt%), Na2O ~0.06 (in wt%) and CaO varies between (0.06-0.07) (in wt%) for the intrusive body of pegmatite in origin intruded metasedimentary rocks. These alterated intrusion of pegmatite in origin are enriched in trace elements of Rb(~715.18ppm ), Cs( ~34.43ppm), Li(~148.33ppm), W(~492.ppm), and the rare metals Nb(1154.16ppm~), Ta(>2500 ppm), and Sn(>10.000 ppm), the enrichment of those elements has commonly indicated a marker of a magmatic-hydrothermal alteration of pegmatite intrusion. The molar Na2O-Al2O3-K2O plot revealed that the pegmatites evolved from the peraluminous granite (or S-type). REE abundance in whole rock pegmatitic intrusive body was &#425;REE (~120.65ppm) signifying the moderate to high form of enrichment. The different plots such as K/Rb vs. Rb, Ta vs. Ga and K2O vs. Rb were plotted to appraise the mineralisation of pegmatites, with the K/Rb values (~ 20.0) less than 100 which are commonly accepted for mineralisation.<#LINE#>Dill H.G. (2015).@Pegmatites and aplites: Their genetic and applied ore geology.@Ore Geology Reviews, 69, 417-561.@Yes$Muchez P., Hulsbosch N., Dewaele S. and Wetenschappen M.Z.K.A.O. (2014).@Geological mapping and implications for Nb-Ta, Sn and W prospection in Rwanda.@Mededelingen Zittingen Koninklijke Academie Overzeese Wetenschappen, 60, 515-530.@Yes$De Clercq F. (2012).@Metallogenesis of Sn and W vein-type deposits in the Karagwe-Ankole belt (Rwanda).@PhD Thesis Katholieke Universiteit Leuven.@Yes$Dewaele S., Henjes-Kunst S., Melcher F., Sitnikova M., Burgess R., Gerdes A., Fernandez Alonso M., De Clercq F., Muchez Ph. and Lehmann B. (2011).@Late Neoproterozoic overprinting of the cassiterite and columbite-tantalite bearing pegmatites of the Gatumba area, Rwanda (Central Africa).@J. Afr. Earth Sci. 61, 10-26.@Yes$Tack L., Fernandez-Alonso M., De Waele B., Tahon A., Dewaele S., Baudet D. and Cutten H. (2006).@The NortheasternKibaran Belt (NKB): a long-lived Proterozoic intraplate history.@In: 21st Colloquium African Geology (CAG21), 03-05.07.2006, Maputo, Mozambique, Abstract volume, 149-151.@Yes$Hulsbosch N., Van Daele J., Reinders N., Dewaele S., Jacques D. and Muchez P. (2017).@Structural control on the emplacement of contemporaneous Sn-Ta-Nb mineralized LCT pegmatites and Sn bearing quartz veins: Insights from the Musha and Ntunga deposits of the Karagwe-Ankole Belt, Rwanda.@Journal of African Earth Sciences, 134, 24-32.@Yes$Pohl W. (1994).@Metallogeny of the northeastern Kibara belt, Central Africa-Recent perspectives.@Ore Geology Reviews, 9(2), 105-130.@Yes$Ikingura J.R. (1995).@petrology and Geochemistry of granites from the Karagwe -Ankolean ,(NE Kibaran) Belt,NW Tanzania.@Berliner geowiss. Abh. A175, Berlin, 25-36.@No$Okunlola O.A. and Jimba S. (2006).@Compositional trends in relation to Ta-Nb mineralization in Precambrian pegmatites of Aramoko, Ara and Ijero area, southwestern Nigeria.@Journal of Mining and Geology, 42(2), 113-126.@Yes$Cahen L., Snelling N.J., Delhal J., Vail J.R., Bonhomme M. and Ledent D. (1984).@The Geochronology and Evolution of Africa.@Clarendon Press, Oxford.@Yes$Fernandez-Alonso M. (2007).@Geological Map of the Mesoproterozoic Northeastern Kibara Belt.@Royal Museum for Central Africa, Tervuren (Belgium): ISBN: 978-90-74752-12-1; catalogue of maps and digital data, at "http://www. africamuseum.be.@Yes$Baudet D., Hanon M., Lemonne E., Theunissen K., Buyagu S., Dehandschutter J., Ngizimana W., Nsengiyuma P., Rusanganwa J.B. and Tahon A. (1988).@Lithostratigraphie dudomaines_edimentaire de la cha&icirc;neKibarienne au Rwanda.@Ann. Societe Geologique Belg, 112, 225-246.@Yes$Theunissen K., Hanon M. and Fernandez Alonso M. (1991).@Carte G_eologique du Rwanda, 1:200 000.@Service Geologique, Ministere de l'Industrieet de l'Artisanat, RepubliqueRwandaise.@Yes$Fernandez-Alonso M., Cutten H., De Waele B., Tack L., Tahon A., Baudet D. and Barritt S.D. (2012).@The Mesoproterozoic Karagwe-Ankole Belt (formerly the NE Kibara Belt): The result of prolonged extensional intracratonic basin development punctuated by two shortlived far-field compressional events.@Prec Res., 216, 63-86.@Yes$Varlamoff N. (1969).@Transitions entre les filons de quartz et les pegmatites stanniferes de la region de Musha-Ntunga (Ruanda).@Ann. Soc. Geol. Belg., 92, 193-213.@Yes$Slatkine A. (1967).@Aspects structuraux de la mineralisation stannifere du Rwanda.@Bull. Serv. G_eologique Rwanda, 4, 47-92.@Yes$C&#780;erny&#769; P. and Ercit T.S. (2005).@The classification of granitic pegmatites revisited.@The Canadian Mineralogist, 43(6), 2005-2026.@Yes$Tack L., Wingate M.T.D., De Waele B., Meert J., Belousova E., Griffin B., Tahon A. and Fernandez-Alonso M. (2010).@The 1375 Ma 'Kibaran event' in Central Africa: prominent emplacement of bimodal magmatism under extensional regime.@Precambrian Res., 180, 63-84.@Yes$Hulsbosch N., Boiron M.C., Dewaele S. and Muchez P. (2016).@Fluid fractionation of tungsten during granite-pegmatite differentiation and the metal source of peribatholitic W quartz veins: Evidence from the Karagwe-Ankole Belt (Rwanda).@Geochimica et Cosmochimica Acta, 175, 299-318.@Yes$Van Daele J. (2016).@Regional variation of and controls on the granite-related Nb-Ta-Sn deposits in the Rwamagana-Musha-Ntunga area, East Rwanda.@Master thesis, KU Leuven, 172.@No$Hanon M. and Rusanganwa J.B. (1991).@Carte G_eologique du Rwanda, Feuille Kigali, 1: 100,000 et note explicative. Departement de Geologieet de Min_eralogie du Musee royal de l@@No$Straurov O.D., Stolyarov I.S. and Isocheva E.I. (1969).@Geochemistry and origin of VerkhIset granitoid massif in central Ural.@Geochem. Intern., 6, 1138-1148.@Yes$Gordiyenko V.V. (1971).@Concentrations of Li, Rb, and Cs in potash feldspar and muscovite as criteria for assessing the rare-metal mineralization in granite pegmatites.@International Geology Review, 13(2), 134-142.@Yes$M&ouml;ller P. and Morteani G. (1987).@Geochemical exploration guide for tantalum pegmatites.@Economic Geology, 82(7), 1888-1897.@Yes$Boynton W.V. (1984).@Geochemistry of the rare earth elements: meteorite studies.@In: Henderson, P. (Ed.), Rare Earth Element Geochemistry, Elsevier, 2, 63-114.@Yes
<#LINE#>Tracking changes in land cover and adaptation strategies for food security in momo division, northwest Cameroon<#LINE#>Tassah Ivo @Tawe,Cornelius Mbifung @Lambi <#LINE#>13-28<#LINE#>2.ISCA-IRJES-2018-026.pdf<#LINE#>Department of Economics and Environmental Studies/National Centre for Education, Ministry of Scientific Research and Innovation Yaound&eacute;, Yaound&eacute; Cameroon@Department of Geography, Faculty of Social and Management Sciences, University of Buea, Buea Cameroon<#LINE#>26/10/2018<#LINE#>15/1/2019<#LINE#>Momo Division, one of the seven Divisions that make up the Northwest Region in the western highlands of Cameroon has experienced profound mutations in the land cover which has affected agricultural production and the food security situation of its population. It is in furtherance to this that this study was carried out with the main objective of examining the changes in the land cover situation and adaptation strategies of the local farming population to enhanced food production. Vital primary data were gotten through field survey, interviews and focus group discussions while information on the land cover situation was obtained using satellite images for the different observed periods and further complimented by ground truthing and expert judgement of the study area. Secondary data were obtained from both published and unpublished works. The results indicate that the various land parcels under investigation have experienced profound mutations from 1976-2016. However, the rates of change in the land parcels have been observed to be in fluxes. Findings further show that the landscape is largely hilly with lowlands occupying just 21.22%, while highlands 32.89% and the extremely highlands 45.89%. The population of the area has equally been increasing rapidlyand therefore necessitating adaptive measures to improve on farm outputs as agriculture and settlement have been observed to be in conflicts due to the limited land space. The adaptation strategies carried out by the local farming population to enhanced production are said to be unsustainable with spill-over effects that have impacted enormously on the climatic cycles and water regimes of the area. This paper therefore calls for urgent stakeholder intervention in the exploitation of the different land cover types to build the capacities of the rural farming population as resource managers. It concludes by drawing the attention of the State and most especially the local farmers to foster land resources conservation and invest in poverty alleviation initiatives which must be off-farm so as to reduce the huge pressure on the various land parcels under investigation and ensure environmental equity and justice.<#LINE#>Gimblett H.R. (2005).@Modelling Human-Landscape Interactions in Spatially Complex Settings: Where are we and where are we going.@In MODSIM 2005 International Congress on Modelling and Simulation, Modelling and Simulation Society of Australia and New Zealand. http://www.mssanz.org.au/modsim05/papers/gimblett.pdf@Yes$Schneider L.C. and Pontius Jr, R.G. (2001).@Modeling land-use change in the Ipswich watershed, Massachusetts, USA.@Agriculture, Ecosystems & Environment, 85(1-3), 83-94.@Yes$Lambin E.F. (2001).@Global land-use and land-cover change: what have we learned so far?.@Global Change News, 46, 27-30.@Yes$Bruijnzeel L.A. (2004).@Hydrological functions of tropical forests: not seeing the soil for the trees?.@Agriculture, ecosystems & environment, 104(1), 185-228.@Yes$Chomitz K.M. and Kumari K. (1998).@The domestic benefits of tropical forests: a critical review.@The World Bank Research Observer, 13(1), 13-35.@Yes$FAO (2000).@Global Forest Resources Assessment 2000, Main Report.@FAO Forestery paper, N&deg;140, 115-120.@No$Glowa-Impetus (2005).@GLOWA-Global Change and the Hydrological Cycle.@Bonn, Berlin, BMBF: 43.@No$Chowdhury R.R. (2006).@Driving forces of tropical deforestation: The role of remote sensing and spatial models.@Singapore Journal of Tropical Geography, 27(1), 82-101.@Yes$Lambin E.F. (2001).@Global land-use and land-cover change: what have we learned so far?.@Global Change News, 46, 27-30.@Yes$Tawe T.I. and Neh A.V. (2018).@The Implications of Unsustainable Agricultural Land Resources Exploitation in the Widikum-Menka Highlands, North West Cameroon.@International Journal of Law and Society, 1(1), 34. http://www.sciencepublishinggroup.com/j/ijls doi:10.11648/j.ijls.20180101.15@Yes$Report (2005).@Bureau Centrale des Recensement et des Etuded de Population.@@Yes$Batcha R.N.E. (2015).@Land use Land cover change and Food Security in the Santa- Babadjou Region: Western Highlands, Cameroon.@Unpublished Ph. D. Thesis, University of Yaound&eacute; 1, Cameroon.@No$National Institute of Cartography (1976).@Global Land Cover Facilities / Landsat MSS, February 1976/ National Institute of Cartography, Yaound&eacute;.@@No$Bambouye G.F. (2010).@Population Change, Agricultural Diversification and Environmental Dynamics in the Northwest Region of Cameroon.@Unpublished Ph. D Thesis, University of Yaounde 1, Cameroon@No
@Research Article
<#LINE#>Influence of increased vertical resolution in RegCM4.5 on summer climate simulation over West Africa<#LINE#>Adeniyi @M.O. <#LINE#>29-56<#LINE#>3.ISCA-IRJES-2018-025.pdf<#LINE#>Department of Physics, University of Ibadan, Nigeria<#LINE#>14/10/2018<#LINE#>26/12/2018<#LINE#>The response of climate parameters to increase in vertical resolution based on a fixed horizontal resolution is simulated using RegCM4.5. Eighteen and 23 vertical levels are used for the simulation with 50 km x 50 km horizontal resolution in the LEV18 and LEV23 experiments, respectively. All other model parameters are the same except for the number of model vertical levels. Most of the climate parameters are better resolved in the higher resolution experiment. Air temperature is well captured by both vertical resolutions at upper and mid troposphere but LEV23 performs better at the surface. Simulations of omega pressure velocity from both resolutions have biases in terms of vertical and north-south extents and strength. Increased vertical resolution generally improves the simulated climate and makes it more realistic.<#LINE#>Williams J.J., Esteves L.S. and Rochford L.A. (2015).@Modelling storm responses on a high energy coastline with XBeach.@Model. Earth Syst. Environ., 1(1-2), 3.@Yes$Yospin G.I., Wood S.W., Holz A., Boeman D.M., Keane R.E. and Whitlock C. (2015).@Modelling vegetation mosaics in sub-alpine Tasmania under various fire regimes.@Model Earth Syst. Environ., 1(3), 16.@Yes$Das Y., Mohanty U.C. and Jain I. (2016).@Development of tropical cyclone wind field for simulation of storm surge/sea surface height using numerical ocean model.@Modeling Earth Systems and Environment, 2(1), 13.@Yes$Shrivastava S., Bal P.K., Ashrit R., Sharma K., Lodh A. and Mitra A.K. (2017).@Performance of NCUM global weather modeling system in predicting the extreme rainfall events over the central India during the Indian summer monsoon 2016.@Modeling Earth Systems and Environment, 3(4), 1409-1419. http://doi.org/10.1007/s408001703878.@Yes$Jisan M.A., Bao S., Pietrafesa L.J., Shen D., Gayes P.T. and Hallstrom J. (2018).@Hurricane Matthew (2016) and its impact under global warming scenarios.@Modeling Earth Systems and Environment, 4(1), 97-109. https://doi.org/10.1007/s40808-018-0420-6.@Yes$Brown C., Greene A., Block P. and Giannini A. (2008).@Review of Downscaling Methodologies for Africa Climate Applications.@IRI Technical Report 08 - 05, IRI Downscaling Report. International Reasearch Institute for Climate and Society. Columbia University.@Yes$Jones C., Giorgi F. and Asrar G. (2011).@The Coordinated Regional Downscaling Experiment: CORDEX An international downscaling link to CMIP5.@CLIVAR Exchanges, 56(16), 34-41.@Yes$Nikulin G., Jones C., Giorgi F., Asrar G., Buchner M., Cerezo-mota R., Christensen O.B.,  DeQue M., Fernandez J., Hansler A.,  Meijgaard E.V., Samuelsson P., Sylla M.B. and Sushama L. (2012).@Precipitation climatology in an ensemble of CORDEX-Africa regional climate simulations.@J. Clim., 25, 6057-6078.@Yes$Liess S. and Bengtsson L. (2004).@The intraseasonal oscillation in ECHAM4 Part II: sensitivity studies.@Climate dynamics, 22(6-7), 671-688.@Yes$Land C., Ponater M., Sausen R. and Roeckner E. (1999).@The ECHAM4. L39 (DLR) atmosphere GCM - Technical description and model climatology.@DLR Forschungsbericht, 1999-31, 45. ISSN 1434-8454, Deutsches Zentrum fur Luft- und Raumfahrte, 51170 Koln, Germany.@Yes$Roeckner E., Brokopf R., Esch M., Giorgetta M., Hagemann S., Kornblueh L., Manzini E., Schlese U. and Schulzweida U. (2004).@The atmospheric general circulation model ECHAM 5.@PART II: Sensitivity of Simulated Climateto Horizontal and Vertical Resolution, MPI-Report 354, 56. (mpi_report_354.pdf, 10.7 MB).@No$Lindzen R.S. and Fox-Rabinovitz M. (1989).@Consistent vertical and horizontal resolution.@Monthly Weather Review, 117(11), 2575-2583.@Yes$Inness P.M., Slingo J.M., Woolnough S.J., Neale R.B. and Pope V.D. (2001).@Organization of tropical convection in a GCM with varying vertical resolution; implications for the simulation of the Madden-Julian Oscillation.@Climate Dynamics, 17(10), 777-793.@Yes$Pope V.D., Pamment J.A., Jackson D.R. and Slingo A. (2001).@The representation of water vapor and its dependence on vertical resolution in the Hadley Centre Climate Model.@Journal of climate, 14(14), 3065-3085.@Yes$Spencer H. and Slingo J.M. (2003).@The simulation of peak and delayed ENSO teleconnections.@J. Clim., 16(11), 1757-1774.@Yes$Ruti P.M., Rocco D.D. and Gualdi S. (2006).@Impact of increased vertical resolution on simulation of tropical climate.@Theor. Appl. Climatol., 85(1-2), 61-80.@Yes$Tang J.P., Zhao M. and Su B.K. (2007).@The effects of model resolution on the simulation of regional climate extreme events.@Acta Meteorologica Sinica, 21(2), 129-140.@Yes$Druyan L.M., Fulakeza M. and Lonergan P. (2008).@The impact of vertical resolution on regional model simulation of the West African summer monsoon.@International Journal of Climatology, 28(10), 1293-1314.@Yes$Zeng X., Wang M., Zhang Y., Wang Y. and Zheng Y. (2016).@Assessing the Effects of Spatial Resolution on Regional Climate Model Simulated Summer Temperature and Precipitation in China: A Case Study.@Advances in Meteorology. ID 7639567: 12 pages.http://dx.doi.org/10.1155/2016/7639567.@Yes$Elguindi N., Bi X., Giorgi F., Nagarajan B., Pal J., Solmon F., Rauscher S., Zakey A., O'Brien T., Nogherotto R. and Giulian G. (2014).@Regional climate model user's manual version 4.4. Earth system physics section.@The Abdus Salam International Centre for Theoretical Physics, Trieste.@Yes$Giorgi F., Coppola E., Solmon F., Mariotti L., Sylla M.B., Bi X., Elguindi N., Diro G.T., Nair V., Giuliani G., Turuncoglu U.U., Cozzini S., Gu&Dot;ttler I., O'Brien T.A., Tawfik A.B., Shalaby A., Zakey A.S., Steiner A.L., Storda F., Sloan L.C. and Brankovic C. (2012).@RegCM4 model description and preliminary tests over multiple CORDEX domains.@Climate Research, 52, 7-29.@Yes$Giorgi F., Solmon F. and Giuliani G. (2016).@Regional Climatic Model RegCM User's Guide Version 4.5 Trieste, Italy.@@No$Adeniyi M.O. (2014).@Sensitivity of different convection schemes in RegCM4.0 for simulation of precipitation during the Septembers of 1989 and 1998 over West Africa.@Theor. Appl. Climatol., 115(1-2), 305-322.@Yes$Mitchell T.D. and Jones P.D. (2005).@An improved method of constructing a database of monthly climate observations and associated high&#8208;resolution grids.@International journal of climatology, 25(6), 693-712.@Yes$Huffman G.J., Alder R.F., Morrissey M., Bolvin D., Curtis S., Joyce R., McGavock B. and Susskind J. (2001).@Global precipitation at one degree daily resolution from multi-satellite observations.@Journal of Hydrometeorology, 2, 36-50.@Yes$Yin X., Gruber A. and Arkin P. (2004).@Comparison of the GPCP and CMAP merged gauge-satellite monthly precipitation products for the period 1979-2001.@Journal of Hydrometeorology, 5(6), 1207-1222.@Yes$Bolvin D.T., Adler R.F., Huffman G.J., Nelkin E.J. and Poutiainen J.P. (2009).@Comparison of GPCP monthly and daily precipitation estimates with high-latitude gauge observations.@Journal of Applied Meteorology and Climatology, 48(9), 1843-1857.@Yes$Liebmann B. and Smith C.A. (1996).@Description of a complete (interpolated) outgoing longwave radiation dataset.@Bulletin of the American Meteorological Society, 77(6), 1275-1277.@Yes$Schumacher C. and Houze Jr, R.A. (2003).@Stratiform rain in the tropics as seen by the TRMM precipitation radar.@Journal of Climate, 16(11), 1739-1756.@Yes