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Articles 91 - 120 of 127
Full-Text Articles in Geology
Morphological Features Of Tyrosine Hydroxylase Immunoreactive Cells In The Mouse Islets Of Langerhans, A P Gesase, Y -I Satoh
Morphological Features Of Tyrosine Hydroxylase Immunoreactive Cells In The Mouse Islets Of Langerhans, A P Gesase, Y -I Satoh
Tanzania Journal of Science
The current immunohistochemical study used the antibody against tyrosine hydroxylase (TH) to observe the immunoreactive elements in the mouse pancreas. The results indicated the presence of immunoreactive nerve fibers and endocrine cells. The immunopositive nerve fibers appeared as thick and thin bundles; thick bundles were seen to run along the blood vessels giving out fine fibers to the wall. Varicose nerve fibers were seen in the islets of Langerhans and also in close association with the exocrine endpieces. The TH immunoreactive cells were oval-round in shape and some showed the central non-staining area and the dense staining peripheral zone. More …
Occurrence Of Digenean Larvae In Freshwater Snails In The Ruvu Basin, Tanzania, G. Nkwengulila, E. S. P. Kigadye
Occurrence Of Digenean Larvae In Freshwater Snails In The Ruvu Basin, Tanzania, G. Nkwengulila, E. S. P. Kigadye
Tanzania Journal of Science
A survey was carried out on digenean larvae infecting freshwater snails in five habitats in Dar es Salaam, Ruvu and Morogoro. 9424 snails belonging to 12 species from five families were examined for digenean infection from July 1996 – June 1997. 20 morphologically distinguishable cercariae were recovered. Multiple infections were not recorded. While the general prevalence of digeneans in snails was low (3.5%), variations occurred between seasons, among habitats and snail host species. Prevalence was high during the dry season but low in the rain season. Among habitats, highest prevalence was recorded at Kinondoni pond and lowest at Ruvu ponds, …
Absolute Migration Of Pacific Basin Mid-Ocean Ridges Since 85 Ma And Their Tectonic Implications For The Pacific Plate, Dcp Masalu
Tanzania Journal of Science
Mid-ocean ridges are major physiographic features that dominate the world seafloor. Their absolute motion and tectonics are recorded in magnetic lineations they created. The absolute migration of mid-ocean ridges in the Pacific basin since 85 Ma and their tectonic implications was investigated in this work and the results indicates that at about anomaly 21 (47 Ma) theEast Pacific Rise (EPR) and Juan de Fuca ridge experienced an abrupt change in their migration direction that persisted until about anomaly 6 (20 Ma), probably due to changes in subductionzone configuration in the northern Pacific. This may represent a period of tectonic instability …
Geochemistry And Nd - Isotopic Composition Of High Silica Rhyolites In The Neoarchaean Musoma-Mara Greenstone Belt, Northern Tanzania: Evidence For The Presence Of Older Continental Crust, S Manya
Tanzania Journal of Science
The high silica rhyolites of the Kibasuka Hill, although volumetrically minor, constitute a part of the greenstone sequence in the northern Musoma-Mara Greenstone Belt (MMGB). They are characterized by high silica contents (63.38 – 81.65 wt %), very low CaO (! 0.05 wt %), variable to unusually high K2O (2.24 – 13.43 wt %) most likely attributed to strong sericite alteration, and their major element composition are similar to those of melts derived from partial melting of metapelites. The samples have very low concentration of the transition elements, Sr (3.13 – 48.4 ppm) and very large negative Europium anomalies (Eu/Eu* …
An Assessment Of Methods For Sampling Carabid Beetles (Coleptera: Carabidae) In A Montane Rain Forest, B. A. Nyundo, J. G. Yarro
An Assessment Of Methods For Sampling Carabid Beetles (Coleptera: Carabidae) In A Montane Rain Forest, B. A. Nyundo, J. G. Yarro
Tanzania Journal of Science
Pitfall trapping is the traditional method for sampling carabid beetles and other grounddwelling invertebrates. Tests were carried out in the Udzungwa Mountains National Park between March 1999 and July 2000. Results indicated that pitfall traps were less efficient compared to manual searching methods, both in terms of relative abundance and species richness of carabid beetles. The results are discussed in the context of biodiversity inventories in theEastern Arc Mountains.
Varietal Role In The Management Of The Larger Grain Borer, Prostephanus Truncatus (Horn) In Stored Maize, C. P. Rugumamu
Varietal Role In The Management Of The Larger Grain Borer, Prostephanus Truncatus (Horn) In Stored Maize, C. P. Rugumamu
Tanzania Journal of Science
The study determined the amount of haemolymph vitellogenin (Vg) of the Larger Grain Borer (LGB), Prostephanus truncatus (Horn) vitellogenic females reared on different maize varieties. The varieties were ZM 521, ZM 421, ECAVL1-DLN, WEEVIL A, LOCAL 1 and LOCAL 2. Sodium Dodecyl Sulphate-Polyacrylamide Gel Electrophoresis (SDS - PAGE) was conducted on the insect haemolymph. F1 LGB adults from each variety were used to determine Indices of Susceptibility (IS) of the varieties to the insect pest attack. Percentages of Vg from female insects and IS were in the order ZM 521>ZM 421> ECAVL1-DLN>WEEVIL A >LOCAL 1>LOCAL 2. Weight …
Thermal And X-Ray Investigations Of Kowak Clay In Northwestern Tanzania And Its Possible Industrial Use, E. H. J. Lugwisha
Thermal And X-Ray Investigations Of Kowak Clay In Northwestern Tanzania And Its Possible Industrial Use, E. H. J. Lugwisha
Tanzania Journal of Science
A study of some properties of clays collected from selected sites in Kowak deposit in Tarime District was carried out in order to assess their suitability as raw materials in ceramic and its related industries. The silica (SiO2) content in the clays is predominant, and is about 66.89% followed by alumina (Al2O3) that is 20.2%. Haematite (Fe2O3) was found to be the third in abundance with an average of 3.58%. Other constituents are present in small proportions. Water loss at 105 oC lies between 2.70% and 2.76%. DTG, TG, XRD techniques and chemical analyses studied by AAS method were used …
Properties Of Fired Bodies Made From Tanzanian Talc-Clay Mixes For Ceramic Applications., E. H. J. Lugwisha
Properties Of Fired Bodies Made From Tanzanian Talc-Clay Mixes For Ceramic Applications., E. H. J. Lugwisha
Tanzania Journal of Science
Fired properties of talc-clay mixed bodies of different compositions were investigated for ceramic applications. Clays from Pugu and Malangali and talcs from two different sites in Kikombo deposits in Dodoma Region were used. Chemical analyses, X-ray analysis and Differential Thermal analysis for clays and talcs were used for the characterisation. Moulded mixed samples of clay and talc dried at room temperature at 1100C for 24 hours were fired at 1200, 1250, 1300 and 13500C for 6 hours. Both clay deposits consist mainly of kaolin. Talc1 - T1 is of higher purity than Talc - T2. Furthermore, the percentage shrinkage of …
Evaluating The Performance Of Leucaena Accessions For Agroforestry In Sub-Humid Environment, Southern Tanzania, A. E. Majule
Evaluating The Performance Of Leucaena Accessions For Agroforestry In Sub-Humid Environment, Southern Tanzania, A. E. Majule
Tanzania Journal of Science
The performance of Leucaena accessions on acid soils in eastern coast Tanzania for agroforestry was evaluated for three years. Plant tree parameters assessed were fodder yield and plant stem height, stem girth, the number of total branches and poles production. Also, Leucaena psyllid, a common pest threatening the plants was also counted. Soil parameters assessed were pH organic carbon, total nitrogen, exchangeable calcium and magnesium. Result showed significant difference in growth between Leucaena accessions. Leucaena leucocephal cv K8 and Leucaena diversifolia were able to grow fast reaching 4.7 and 3.3 m respectively within a period of three years. Leucaena diversifolia …
Sediment Characteristics And Hydrodynamic Setting Of Reef Platform Sediments Of Kunduchi, North Of Dar Es Salaam Harbour, Y. W. Shaghude, N. Nyandwi, A. N. N. Muzuka, A. M. A. M. Dubi, O. U. Mwaipopo
Sediment Characteristics And Hydrodynamic Setting Of Reef Platform Sediments Of Kunduchi, North Of Dar Es Salaam Harbour, Y. W. Shaghude, N. Nyandwi, A. N. N. Muzuka, A. M. A. M. Dubi, O. U. Mwaipopo
Tanzania Journal of Science
Sediment grain size distribution, carbonate content and current velocities for the Kunduchi area are used to determine its hydrodynamic setting and sediment characteristics. The sediment mean grain size generally decreases northward. The sediments consist of medium to coarse sand south of the Tegeta River and fine sand further north. The sediment sorting values, which lack a north-south trend, vary from moderately well sorted to poorly sorted. The skewness of the sediment vary from near-symmetrical to very negatively skewed while the peakedness (kurtosis) varies from platykurtic to leptokurtic. The carbonate content increases with distance offshore, whereas the siliciclastic component decreases with …
Stable Isotope Compositions Of Organic Carbon And Contents Of Organic Carbon And Nitrogen Of Lacustrine Sediments From Sub-Arid Northern Tanzania, Ann Muzuka
Tanzania Journal of Science
The stable isotope compositions of organic carbon (OC), and contents of OC and nitrogen for four sediment cores recovered from lakes Makat (located in the Ngorongoro Crater), Ndutu and Masek (located in the Serengeti Plains) are used to document sources of organic matter (OM) and climatic changes in sub-arid northern Tanzania during the late Pleistocene-Holocene period. Accelerate mass spectrometer (AMS) 14C ages on total OM for sediments collected from the Ngorongoro Crater Lake indicate that the sedimentation rate is approximately 17 cm/ka. The δC values from the 20 cm long core (short core) show a downcore increase, whereas that of …
Phosphorus Sorption In Relation To Soil Grain Size And Geochemical Composition In The Simiyu And Kagera River Basins, Tanzania, R. A. Tamatamah
Phosphorus Sorption In Relation To Soil Grain Size And Geochemical Composition In The Simiyu And Kagera River Basins, Tanzania, R. A. Tamatamah
Tanzania Journal of Science
The phosphorus sorption characteristics of eight surface soil samples representative of the land use and landscape in the Simiyu and Kagera River basins were determined using the Langmuir equation. The Langmuir P adsorption maximum (Cmax) ranged from 109 to 802 mg kg-1, while Langmuir coefficient (K) ranged from 59 to 736 mg L-1. Cmax and were positively correlated to clay content, aluminium (Al), and iron (Fe) and negatively correlated to calcium (Ca). By using stepwise regression, the combination of Al, Fe, clay and Ca predicted more than 94% of the variation in the P sorption capacity of soils samples from …
Petrography And Mineral Chemistry Of The Pelitic And Semi-Pelitic Gneisses Of The Merelani Tanzanite Mining Area, Northeastern Tanzania, E. P. Malisa
Tanzania Journal of Science
Sillimanite/kyanite + K-feldspar + quartz ± garnet + biotite ± Fe-Ti oxide-bearing rocks occur associated with calc-silicate rocks in the Merelani tanzanite mining area north-eastern Tanzania. The whole rock chemistry shows varying rock oxidation ratios, which are reflected in the mineralogical assemblages. Almandine garnet is oxidized to mixtures of hematite, quartz, and hydrous aluminosilicates in oxidized rocks and is absent in highly oxidized rocks. In the latter, ilmenite is oxidized into mixtures of rutile and hematite. Such relatively high temperature alteration/oxidation effects could have occurred with the influx of water. Absence of staurolite in these aluminium-rich rocks is indicative of …
Environmental Risks For Gemstone Miners With Reference To Merelani Tanzanite Mining Area, Northeastern Tanzania, Ep Malisa, Cp Kinabo
Environmental Risks For Gemstone Miners With Reference To Merelani Tanzanite Mining Area, Northeastern Tanzania, Ep Malisa, Cp Kinabo
Tanzania Journal of Science
Artisanal and small-scale gemstone miners are the workers with the highest health risk exposure in Tanzania. Gemstone mining at Merelani tanzanite mines which has gone to depths of 100 m or more in narrow straight and inclined shafts, underground artisanal miners work under a very harsh environment. Tanzanite deposits are located within sheared zones, lying along a deep-seated Lelatema fault zones. Rocks along these zones which are mainly graphitic and or/gypsum-bearing gneisses surrounded by limestone are soft, fractured and strongly weathered. Poor mining techniques, lack of geological background, chronic shortage of capital, and the lack of awareness on environmental pollution …
Levels Of Nitrate And Phosphate In Some Satellite Lakes Within The Lake Victoria Basin, Tanzania, Jj Kulekana
Levels Of Nitrate And Phosphate In Some Satellite Lakes Within The Lake Victoria Basin, Tanzania, Jj Kulekana
Tanzania Journal of Science
Levels of nitrates (NO3-N) and phosphates (PO4-P) in some satellite lakes within the Lake Victoria basin were determined in Kagera (Lake Burigi), in Mara (River Mara) and in Mwanza region (Lake Malimbe) during August/September 2002 (dry season) and January/February 2003 (wet season). Water samples were collected using a van Dorn water sampler at chosen points from both deep and shallow areas of the water bodies. Results of the two surveys revealed that deep and shallow areas of the lakes had varying nutrient levels. In deep waters, PO4-P values ranged between 0.171-0.225mg/l, 0.067-0.364mg/l, and 0.043-0.096 mg/l in Lake Malimbe, Burigi and …
Species Composition And Biomass Estimates Of Zooplankton In Some Water Bodies Within Lake Victoria Basin, Rk Waya, Ai Chande
Species Composition And Biomass Estimates Of Zooplankton In Some Water Bodies Within Lake Victoria Basin, Rk Waya, Ai Chande
Tanzania Journal of Science
Zooplankton communities were identified and their abundance and biomass estimated in some selected satellite lakes and Mara River in Lake Victoria basin, during wet and dry seasons in 2002. Samples were collected from eight water bodies. Three stations were sampled from each water body using a plankton net (40 µm mesh size) hauled vertically through the water column. The zooplankton community comprised mainly crustacea and rotifers. The results show that the number of species collected during the wet and dry seasons was 31 species and 28 species, respectively. The Shannon wiener diversity indices were not significantly different (Mann-Whitney U Test …
Contamination Of Water And Sediments By Obsolete Pesticides At Vikuge Farm, Kibaha Distric, Tanzania, M J Mihale, M A Kishimba
Contamination Of Water And Sediments By Obsolete Pesticides At Vikuge Farm, Kibaha Distric, Tanzania, M J Mihale, M A Kishimba
Tanzania Journal of Science
Sediments and water from Vikuge State Farm, Coast Region, Tanzania, where, in 1986, a “donation” of 170 m3 of partially expired pesticides were stored in an open shed- which eventually collapsed, were analysed for 80 different pesticide residues and metabolites. DDT and HCH, two of the most persistent organochlorines pesticides, were the most dominant pesticides found in both matrices. In sediments the levels were up to 99,620 mg/kg dry weight of ΣDDT and up to 7,400 mg/kg dry weight of ΣHCH. The mean total HCH concentrations were 0.95 μg/l in tap water, 0.28 mg/l in surface water and 3.09 μg/l …
Studies On The Fisheries And Biology Of Oreochromis Urolepsis (Pisces: Cichilidae) In The Mtera Resorvoir (Tanzania), F M M Chale
Studies On The Fisheries And Biology Of Oreochromis Urolepsis (Pisces: Cichilidae) In The Mtera Resorvoir (Tanzania), F M M Chale
Tanzania Journal of Science
The fisheries and some aspects of the biology of Oreochromis urolepis of the Mtera Reservoir (Tanzania) were examined in August 2002. It was observed that there was no proper management of the reservoir's fisheries. Beach seine fishing dominated the fishery. Nearly all the O. urolepis caught by this type of gear were juveniles. The number of fish caught by the beach seines was very high, some times up to 4,000 fish per haul. The beach seines also destroy the spawning sites for the tilapias. Mean total lengths of O. urolepis caught in gillnets of legal mesh sizes (ranging from 88 …
Ammonite Biostratigraphy Of The Jurassic Of Tanzania, S Kapilima
Ammonite Biostratigraphy Of The Jurassic Of Tanzania, S Kapilima
Tanzania Journal of Science
The present paper summarizes the previous biostratigraphical researches and incorporates the recent research findings on the Jurassic rocks in the coastal basin of Tanzania. The ammonites used for the biostratigraphical classification are from two sub-basins along the coastal belt of Tanzania: Mandawa (south) and Ruvu- Tanga (north). The oldest known ammonites from these basins are of Aalenian age. The biostratigraphical classification of the Jurassic sequence, on the basis of the vertical and horizontal distributions of the ammonite assemblages, permits the erection of eight sub stages of Jurassic: Upper Aalenian (Concavum-Zone), Bajocian (Humphrieasianum-Zone), Middle Callovian (Coronatum-Jason Zone), Upper Callovian (Lamberti-Athleta Zone), …
Petrology And Lithogeochemistry Of The Mineralized Tanzanite-Grossular Bearings Rocks In The Merelani-Lelatema Area, Northeastern Tanzania, Ep Malisa
Tanzania Journal of Science
The Merelani-Lelatema area, which is occupied by late Proterozoic metasedimentary rocks, lies along the Lelatema fault zone. The rocks are mainly pelitic and semi-pelitic gneisses, psammitic gneisses, hydrothermally altered rocks, crystalline dolostones, pegmatites and quartz veins. The occurrence of gem-quality tanzanite and grossular has been found to occur mainly in boudinaged pegmatitic veins and hydrothermal fracture fillings. These fracture fillings occur in brecciated and hydrothermally altered graphite-bearing gneiss in a mineral association containing glass-clear quartz, diopside, zoisite, graphite and calcite. The psammitic gneisses are more siliceous and enriched in feldspars. They are grouped into graphite-kyanite gneiss with thin interlayers of …
Metal Concentrations In Sediment And Fish Of Lake Victoria Near And Away From Catchments With Gold Mining Acctivities, Jf Machiwa
Tanzania Journal of Science
Concentrations of metals in sediment and fish as well as organic matter contents of sediment from Lake Victoria were investigated. The objective of the study was to compare levels of metals in sediment and fish from areas of the lake that are within and outside catchments with gold mining activities.The results showed that the concentration of As was less than 6 mg g-1 dw and Cd was below 1.9 mg g-1 dw in sediment samples. Lead, zinc and copper concentrations were highest (58.1±17.6 mg g-1 dw, 101.9±20.6 mg g-1 dw and 32.6±2.8 mg g-1 dw respectively) in sediment samples that …
Sediment Distribution And Composition On The Shallow Water Carbonate Basin Of The Zanzibar Channel, Yw Shaghude
Sediment Distribution And Composition On The Shallow Water Carbonate Basin Of The Zanzibar Channel, Yw Shaghude
Tanzania Journal of Science
Sediments of the shallow water carbonate basin in Zanzibar channel were investigated for composition and grain size distribution. The surface sediment composition was dominated by carbonate sands (with CaCO3 > 30%), except in the area adjacent to mainland coastline and a thin lobe which projects from Ruvu River to the middle of the channel. Mean grain size distribution closely resembles that of the carbonate content, where Tidally Dominated Reef Platform Sediments (TDRPS) located east of the Zanzibar channel were characterised by medium to coarse sands and the siliciclastic sediments adjacent to the mainland were characterised by fine sand. The TDRPS are …
Levels Of Pesticide Residues In Water, Soil And Sediments From Southern Lake Victoria And Its Basin, Leonia Henry, Michale A Kishimba
Levels Of Pesticide Residues In Water, Soil And Sediments From Southern Lake Victoria And Its Basin, Leonia Henry, Michale A Kishimba
Tanzania Journal of Science
Water, sediment and soil samples collected from Southern Lake Victoria and its basin were analysed for 76 organochlorine, organophosphorous, carbamate and pyrethroid pesticide residues. The samples were collected from sampling stations in nine districts on the Tanzanian side of the lake, namely Mwanza, Sengerema, Geita, Ngudu, Misungwi, Magu, Bunda, Tarime and Musoma Districts. DDT and HCH residues were the only detected pesticides. The concentration of total DDT was up to 1.6 mg/L in water, 600 mg/kg dry mass in sediments and 20 mg/kg dry mass in soil. The concentration of total HCHs were up to 0.2 mg/L in water, 132 …
Tectonic And Sedimentary Evolution Of The Coastal Basin Of Tanzania During The Mesozoic Times, S Kapilima
Tectonic And Sedimentary Evolution Of The Coastal Basin Of Tanzania During The Mesozoic Times, S Kapilima
Tanzania Journal of Science
The present paper reviews and updates the stratigraphy and tectonic evolution of the coastal basin of Tanzania during the Mesozoic times based on the interpretation of existing palaeontological and stratigraphical information and supplemented by recent fieldwork investigations by the author. Tectonic events largely controlled the evolution of the coastal basin of Tanzania and the Indian Ocean. These included the Karoo rifting during Permo-Triassic, the break up of the Gondwana Supercontinent, which started with rifting in the Triassic period, the opening of the Somali basin in the Middle Jurassic, and the Cenozoic rifting along the East African rift system. The Karoo …
Structural Evolution Of The Kilombero Rift Basin In Central Tanzania, A. H. Mruma
Structural Evolution Of The Kilombero Rift Basin In Central Tanzania, A. H. Mruma
Tanzania Journal of Science
Detailed geological and structural investigations at the northwestern scarp of the Cenozoic Kilombero Rift allow the drawing of its structural evolution and establishment of stress conditions that prevailed at the different deformational episodes at this rift zone. The structure, where the northwestern scarp of the Cenozoic Kilombero Rift System is located, starts by ductile deformation of granitic and gabbroic rock masses leading to the formation gneissic fabric and b-mineral lineation in the rocks. This deformation is of Precambrian age (most probably a Pan African deformation) and its kinematics are characterized by 320˚/20˚ tectonic transport direction (λ1). Later the area was …
Engineering Geological Mapping Of Dar Es Salaam City, Tanzania, K. A. Msindai
Engineering Geological Mapping Of Dar Es Salaam City, Tanzania, K. A. Msindai
Tanzania Journal of Science
Engineering geological mapping of Dar es Salaam city in Tanzania has been carried out using desk studies supplemented by field reconnaissance as well as limited laboratory tests. Desk studies involved interpretation of medium to large-scale topographical maps, Landsat imagery and sequential aerial photographs from 1953-1990. These studies also evaluated small to medium scale geological, pedological maps together with ground water data from 50 boreholes. Two basic maps were prepared, namely, geomorphological and geological map depicts the spatial extent of the Neogene geological formations. Three distinct sandstone terraces could be distinguished in Dar es Salaam region at 0-15 m and 30 …
Comparison Of Various Methods For Estimating Wave Incident Angles In The Nearshore Zone, As Ngusaru
Comparison Of Various Methods For Estimating Wave Incident Angles In The Nearshore Zone, As Ngusaru
Tanzania Journal of Science
Five different methods were examined for their suitability in estimating the inshore wave incident angles on a nearshore zone with a complex topography. Visual observation provided preliminary estimates. Two frequency independent methods and one frequency dependent method based on current meter measurements were examined. Another frequency dependent method based on collocated bottom pressure and current meter measurements was also examined. The results from all the methods provided a reasonably consistent estimate of the inshore wave incident angles. The frequency independent methods gave exactly the same results while the frequency dependent methods had a 5% relative error among themselves. Between frequency …
Studies On Benthic Denitrification In The Chwaka Bay Mangrove Sediments, Zanzibar, Sm Mahommed, Rw Johnstone
Studies On Benthic Denitrification In The Chwaka Bay Mangrove Sediments, Zanzibar, Sm Mahommed, Rw Johnstone
Tanzania Journal of Science
Denitrification was measured at three sites in a narrow tidal creek in the Chwaka mangrove ecosystem. Denitrification arising from water column nitrate (Dw) was low (< 0.1μM Nm-2h-1) and there was little spatial and seasonal variation in Dw rates in the creek. Coupled nitrification-denitrification (Dn) was found to be low, but within the range measured in other mangrove sediments. Average values ranged from 0.01 to 0.45 μM Nm-2h-1 and showed strong spatial variations. The low denitrifcation rates observed in the creek were possibly as a result of the low availability of NO3 and high C:N values of the organic matter in the sediment. Spatial variations in denitrification rates were due to variations in concentration levels of organic matter and possibly to disproportionate competition for inorganic nitrogen between denitrifiers and benthic autotrophs among sites. There were no seasonal differences in denitrification rates. Results from the present study suggest that sediment denitrification does not play a major role as a sink for N in this ecosystem
Interpretation Of Refelction Seismic Data From The Usangu Basin, East African Rift System, Ei Mbede
Interpretation Of Refelction Seismic Data From The Usangu Basin, East African Rift System, Ei Mbede
Tanzania Journal of Science
Reflection seismic data collected by AMOCO Tanzania Oil Company in the 80s, are herin used to correlate the main Usangu Basin parameters to those estimated from outcrop, gravity and aeromagnetic data. The seismic data are further used to constrain the geometry of crustal extension in this south-western sector of the East African Rift System (EARS) in Tanzania. Three distinct sedimentary packages on top of the basement reflector are interpreted and correlated to the Permo-Carboniferous Karoo rocks, the Jurassic/Cretaceous and Miocene Red Sandstone Group and Miocene to recent Lake Beds in the adjacent Rukwa basin, where the ages of the sedimentary …
Tectonic Setting Of Gabbroic Rocks In The Western Part Of The Lupa Gold Field, South-West Tanzania, Sr Mnali
Tectonic Setting Of Gabbroic Rocks In The Western Part Of The Lupa Gold Field, South-West Tanzania, Sr Mnali
Tanzania Journal of Science
There is a pronounced occurrence of gabbroic rocks in the western part of the Lupa gold field, SW Tanzania. These rocks occur in the peripheral part around the Saza-Chuya granodiorite with which it makes a gradiational, unchilled contact. The rocks have been altered or metamorphosed to low-grade greenschist facies as indicated by the presence of secondary epidote, penninite, chlorite, sericite and calcite. The majority of major-element oxides show scattered variation trends against immobile elements such as Zr, indicating some degree of element mobility during post-crystallization processes of alteration or metamorphism. Major-trace-element data show that the gabbroic rocks in the study …