Showing papers in "Journal of African Earth Sciences in 2003"

TL;DR: Laouni et al. as discussed by the authors showed that the terranes from Central Hoggar (LATEA) belonged to a single old passive margin, to which they gave the acronym name LATEA.

TL;DR: In this article, a review of the rock sequences and evolution of the eastern and central terranes of Hoggar is presented, focusing on the Neoproterozoic subduction-related evolution and collision stages in the central part of the Tuareg shield.

TL;DR: In this paper, a kinematic analysis of the central Cameroon shear zone (CCSZ) and its Sanaga fault relay, indicate early sinistral shear movement (phase D2) that was later followed by a dextral sheer movement during the Pan-African orogeny, and the correlation of tectonic events among the CCSZs, thrusting of the Yaounde Group and the deformation in the Lom Group indicate a diachronous deposition history of these groups, where the sedimentary and magmatic rocks of

TL;DR: Within carbonate sediments below tropical-subtropical oceanic surface waters, syndepositional dissolution of CaCO3 driven by organic matter oxidation can modify substantially the textural, compositional and early diagenetic characteristics of the resulting rock as mentioned in this paper.

TL;DR: In this paper, Landsat TM and radar JERS-1 SAR (L-Band) imagery of the Itremo area, central Madagascar were processed to emphasize structural geology features including folded quartzite ridges and plutons.

TL;DR: The Ngondo complex is a late-collisional pluton, which was emplaced around 600 Ma along a N030°E strike-slip shear zone in the southwestern part of the Neoproterozoic Fold Belt of Cameroon as discussed by the authors.

TL;DR: A geoscientific map and database for geology, mineral and energy resources of Ethiopia in a digital form at a scale of 1:2,000,000 is presented in this article.

TL;DR: In this paper, a detailed field and microstructural study of the mica schists, gneisses and pyriclasites of the Yaounde nappe in the Cameroon area was carried out and it appeared, however, that the D 2 deformation phase more likely corresponds to a major N-S and moderate E-W ductile pure shear extension, rather than compression.

TL;DR: Grain size distribution and heavy mineral content of beach and dune sediments from the Malindi Bay coast, Kenya were determined by dry sieving sediments; samples represent the upper 5 mm of surficial sediment, collected from the four main geomorphological units (beach, berm zone, foredune and dunefield), during three observation periods, covering the southeast and northeast monsoon seasons.

TL;DR: In this paper, three geographical groups are identified: the Silet-, Laouni- and Tamanrasset-Taourirts, which are aligned along mega-shear zones often delimiting terranes.

TL;DR: In this paper, a bivariate regression analysis of Africa's surface topography is performed, showing that this is a complexly folded surface with regionally elevated areas in southern and eastern Africa, and a topographically low northern and western Africa.

TL;DR: The Tassendjanet terranes exposed east of the Pan-African suture in western Hoggar (southwest Algeria), are reexamined in the light of new structural, petrologic and by the 40 Ar/39 Ar laser probe data on metamorphic micas and amphiboles.

TL;DR: Bauxite deposits in the Usambara Mountains of north eastern Tanzania occur as remnants of residual deposits on two geomorphologically related plateaus of Mabughai-Mlomboza and Kidundai as mentioned in this paper.

TL;DR: The In Ouzzal terrane (Western Hoggar) is an example of Archaean crust remobilized during a very high-temperature metamorphism related to the Paleoproterozoic orogeny (2 Ga).

TL;DR: In this paper, two major granulitic units are recognized in the Gour Oumelalen area, which are composed partially of Archean gneisses (Red Gneiss complex) with U-Pb zircon SIMS and TIMS ages of approximately 2.7 Ga.

TL;DR: The Singo granite in western central Uganda intrudes metasedimentary rocks that have experienced low-grade regional and contact metamorphism as discussed by the authors, and is generally massive, containing mainly plagioclase, K-feldspar, quartz, biotite, muscovite and opaques.

TL;DR: In this article, two structural domains are recognized: (i) the Northern Domain, primarily structured by N-S Eovariscan polyphased structures (D1 and D2) overprinted by a E-W D3-deformation allotted to a late Carboniferous phase; (ii) the Central-Southern Domain only deformed by D3.

TL;DR: In this article, the Euler deconvolution, the analytic signal and the local wavenumber methods were used to locate geological contacts and major faults in Eastern Hoggar (Algeria).

TL;DR: The Anfeg batholith as mentioned in this paper is a high-K calc-alkaline suite, characterized by low heavy REE contents and high LREE/HREE ratios, which can be attributed to a lithospheric delamination along the subvertical mega-shear zones that dissected the rigid LATEA former passive margin without major crustal thickening.

TL;DR: In this article, a study was conducted in the Souss Upstream Basin to identify the chemical characteristics and the origin of groundwater in an aquifer under semi-arid climate.

TL;DR: In this article, a simplified approach acknowledging three class groups (I-suitable water, II-conditionally suitable water and III-unsuitable Water) adopted from the three methods, is suggested in this paper.

TL;DR: In this paper, the distribution behavior of rare-earth elements and uranium in four profiles of the exploited phosphatic layer C1 of Hahotoe-Kpogame deposits in Togo was studied.

TL;DR: The Middle Neoproterozoic (Cryogenian) Sidi Flah Group rocks are located in the Saghro inlier of the Eastern Anti-Atlas and consists of siliciclastic detrital sediment, interbedded basaltic lavas and small ultramafic bodies as discussed by the authors.

TL;DR: The N-S trending Tuludimtu Belt in the extreme west of Ethiopia has been subdivided into five lithotectonic domains, from east to west, the Didesa, Kemashi, Dengi, Sirkole and Daka domains.

TL;DR: In this article, an angiosperm-based dating as Campanian (most probably Early Campanian) is suggested for the basal part of the Quseir Formation in the Bulaq area, central Egypt.

TL;DR: In this article, the physical processes associated with various aqueous bedform states and transitional bedforms are discussed in order to gain insights into their stability and morphodynamics in different sediment-sizes.

TL;DR: In this article, a soil sequence with iron duricrust is described in an area covered by tropical rain forest in South Cameroon, where the dismantling of the iron Duricrust was documented through a close observation of a soft duricust, which corresponds to a transitional stage in the degradation of a massive iron durricrust into a loose nodular horizon.

TL;DR: In the Djurab Desert (Chad), the fossiliferous sectors of Kossom Bougoudi, Kolle and Koro Toro have yielded a great amount of fossil hippo remains aged between ca. 5 and 3 Ma as mentioned in this paper.

TL;DR: The Nsimi experimental catchment (area: 0.60 km2, latitude: 3°10′N, 120 km SSE from Yaounde) has been selected for a study of the humid tropical area dynamics.