Journal Of African Earth Sciences Research Articles

Comments on the paper of Oyebanjo et al. (2018), Journal of African Earth Sciences 147, 402–410

Comments on the paper of Oyebanjo et al. (2018), Journal of African Earth Sciences 147, 402–410

Porphyry Cu-Au prospectivity modelling using semi-supervised learning algorithm in Dehsalm district, eastern Iran

Porphyry Cu-Au prospectivity modelling using semi-supervised learning algorithm in Dehsalm district, eastern Iran

Trends in the Collaboration Pattern of Moroccan Research in Earth Sciences from 1984 to 2019: A Case Study

The output of the Moroccan researchers in Earth sciences and their collaboration trends were studied for the period 1984-2019 using the example of the Journal of African Earth Sciences, the preferred journal of this community, and by using simple bibliometric indicators such as collaboration rate and collaboration level. The main results of the study are: (1) Moroccan researchers participated in 253 articles among which, only 12 were singleauthor papers. Multi-authorship is the rule with a mode of 4 authors per paper for 45 articles; (2) the number of authors reached 1251 in all papers. When only international collaboration is considered, 1051 authors are found, from which about 48% are from Morocco and 52% belong to other 31 countries; (3) International collaboration, which was exclusively with French researchers and institutions until the 1990s, grew in number but declined in share to 33- 42% in the last 15 years, while collaboration with other countries became more important because of the internationalization of research programs.

Reply to the discussion on “Influence of structures on drainage patterns in the Tushka region, SW Egypt. Journal of African Earth Sciences 136, 262–271 by C.A. Robinson, H. El-Kaliouby, E. Ghoneimˮ by B.S. Nabawy

The present study aims at conducting a detailed reservoir characterization of the Early Cretaceous Bentiu and Abu Gabra formations in Muglad basin which is one of the most prospective hydrocarbon basins in South Kordofan, SW Sudan. This can be achieved through integration between well logging (conventional), petrography (thin sections, and scanning electron microscopy SEM), and core data.Based on this integrated study, the Abu Gabra-Bentiu sequence is composed of two reservoir rock types (RRTs). RRT1 is composed of quartz arenite, whereas RRT2 is composed of quartz wacke. The best storage and flow capacities and the best reservoir quality are assigned for RRT1 due to its good to excellent porosity (20.0 ≤ ∅ ≤ 34.1%), permeability (138 ≤ k ≤ 4140 md), reservoir quality index (0.61 ≤ RQI ≤ 2.91 μm), and flow zone indicator (2.37 ≤ FZI ≤ 6.12 μm) values. This rock type is mostly assigned to two hydraulic flow units (HFU-1, and HFU-2) of Bentiu Formation which comprises 95% of the flow capacity of the sequence. The average reservoir parameters of the studied sequence, including shale volume, effective porosity and hydrocarbon saturation, equal to 31.6, 16.2 and 39.5%, respectively with 29.5 m as a total net-pay thickness.Petrographically, the relatively low contribution of the Abu Gabra Formation is due to its authigenic mineral content, compaction, and cementation.

Discussion on "Influence of structures on drainage patterns in the Tushka region, SW Egypt. Journal of African Earth Sciences 136, 262–271" by C.A. Robinson, H. El-Kaliouby, E. Ghoneim

The publication entitled Influence of structures on drainage patterns in the Tushka region, SW Egypt, Journal of African Earth Sciences 136 (2017) 262–271, introduced a preliminary geophysical study to delineate the hydrogeological potential of Tushka basin in south Egypt (Robinson et al., 2017). However, that study omitted some important topics that can greatly affect its final achievements in Tushka area, e.g. 1) The dominant meteorological conditions, 2) Geomorphological features, 3) Structural setting, 4) Petrophysical potential of the studied sequences, 5) Hydrothermal activities, 6) Hydrogeological system and connectivity with Lake Nasser, and 7) Quality control for the geophysical results.

Comments on “Paleoecology and paleobiogeography of Paleocene ostracods in Dineigil area, south western Desert, Egypt.” by Youssef et al., Journal of African Earth Sciences, 131 (2017) 62–70

In their recent paper, Youssef et al. (2017) published a quantitative study of Paleocene ostracod distributions in the Southwestern Desert of Egypt and recognized regional ecozones within a paleobiogeographic concept. To understand the significance of this ecozonation, a solid stratigraphic framework is required, though the authors only provided limited information. We demonstrate that fundamental aspects of their data representation and stratigraphic interpretation are incorrect, and thus not warrant utilization of the reported age of the ostracod record. For that reason, we stress that basic geological aspects of correlation between outcrops and creation of composite sections should be described in full detail upon publication. Based on our detailed reconstruction, the composite sequence at Bir Dungul spans calcareous nannoplankton Zones NP5-NP7/8, and mostly Thanetian in age, contrasting the observations of Youssef et al. (2017). The lowermost part of the sequence, suggested to comprise NP4 by Youssef et al. (2017) and thus Danian in age, cannot be dated because of lack of calcareous nannofossils and planktic foraminifera. Accordingly, there is no evidence in this sequence for the Latest Danian Event (as proposed by Youssef, 2014) either, and the potential relationship with the Mid Paleocene Biotic Event should be assessed critically. Consequently, accurate stratigraphic analysis, including biostratigraphy, remains essential to safeguard future paleobiogeographic interpretations along the edges of the Tethyan Ocean.

Seismic Hazard Assessment of the Democratic Republic of Congo and Environs Based on the GEM–SSA Catalogue and a New Seismic Source Model

A new probabilistic seismic hazard assessment has been performed for the Democratic Republic of Congo (DRC) and surrounding areas. The DRC encompasses both intra-plate and active tectonic areas associated with the Congo Craton and the western branch of the East African Rift System, respectively. The seismic hazard assessment is based on the new Sub-Saharan-Global Earthquake Model Sub-Saharan–Global Earthquake Model earthquake catalogue with homogeneous magnitude representation (Mw) created by augmenting available global catalogues (e.g. International Seismological Center (ISC)-Reviewed, ISC–GEM, GCMT) with information from local agencies and regional projects, particularly from the AfricaArray network. This catalogue spans from 1900 to 2015. The initial declustered catalogue has 782 events. The historical earthquake record is sparse with significant variation in completeness over time across different regions. After taking the completeness of the catalogue into account, the final declustered catalogue used to calibrate the magnitude-frequency distribution of events used for the seismic hazard assessment spans 55 years (from 1960 to 2015) with 398 events and a magnitude of completeness of about 4.5. The maximum credible magnitude of earthquakes was determined using the entire catalogue from 1900 to 2015. The seismotectonic zonation into 15 seismic source areas was done on the basis of the regional geological structure, neotectonic fault systems, basin architecture and distribution of thermal springs and earthquake epicentres. Also, consideration was given to a regional strain rate model developed for the East African Rift by Saria et al. (Journal of Geophysical Research, 119, 3584–3600, 2014) in the frame of the GEM Strain Rate Project. Tectonic information was derived mostly from the scientific literature and by integration of available datasets. The current area source model consists of a total of 15 seismic zones distributed over 6 main tectonic groups that we assume to have comparable rheological and mechanical behavior with respect to the underlying crustal geology. The definition of these groups is essential for the regional calibration of b values. The b value is expected to be regionally stable with variations less than the uncertainty limits, while the activity rate λ is liable to vary substantially from one seismic source zone to another. The Gutenberg–Richter seismic hazard parameters were determined using Aki’s maximum likelihood method Aki (Bulletin of the Earthquake Research Institute, Tokyo University, 43, 237–239, 1965) and Weichert’s method Weichert (Bulletin of the Seismological Society of America, 70, 1337–1346, 1980), and compared with extension of the Aki-Utsu b value estimator for incomplete catalogues Kijko and Smit (Bulletin of the Seismological Society of America, 102, 1183–1287, 2012). Hazard computations were performed using the OpenQuake engine (version 2.7.0-1). The peak ground acceleration (PGA) and spectral acceleration at periods of 0.05, 0.1, 0.2, 0.5, 1 and 2 s was calculated using four ground motion prediction equations (GMPEs): two for active shallow crust Chiou et al. (Earthquake Spectra, 30, 1117–1153, 2014); Akkar et al. (Bulletin of Earthquake Engineering, 12, 359–387, 2014) and two for stable continental conditions Atkinson et al. (Bulletin of the Seismological Society of America, 96, 2181–2205, 2006; Pezeshk et al. (Bulletin of the Seismological Society of America, 101, 1859–1870, 2011) for soil sites corresponding to Vs 30 = 600, 760 and 1500 m/s at 11 cities of the DRC and surrounding areas. The results are consistent with those obtained using the regional frequency-independent attenuation law of Mavonga (Physics of the Earth and Planetary Interiors, 62, 13–21, 2007b) developed in the Kivu Rift segment and others Twesigomwe (Journal of African Earth Sciences, 24, 183–195, 1997), and Jonathan (Some aspects of seismicity in Zimbabwe and Eastern and Southern Africa. M.Sc. thesis. Institute of solid earth physics, Univ. Bergen, Bergen, Norway, pp. 100 (1996)), using Crisis 2012 software.

Radiometric survey in geological mapping of basement complex area of parts of Southwestern Nigeria

Radiometric methods were used to investigate the radioactive properties of rocks in parts of southwestern Nigeria with a view to interpreting the geological structure and abundance of natural radioactive elements in the main type rocks. The airborne radiometric dataset of Ikole Sheet and ground radiometric data recorded from eight traverses in Akoko axis of the study area were processed. Results presented as maps and profiles displayed variations of high and low radioactive concentrations across the area. These maps showed moderate to very high concentrations and very low to low concentrations of the radioelements; uranium (4.5-13.0 ppm); (LLD-low limit of detection -3.0 ppm), Th (25.0-70.0 ppm); (8.5-16.0 ppm) and K (2.0-4.0 %); but the most often observed values are in the range 2.5-7.0 ppm, 22.0-30.0 ppm and 3.0-4.0% for U, Th, and K respectively. High concentrations imply that the rocks are crystalline, undeformed and are rich in feldspar and U-Th bearing minerals. While low radioactivity is attributed to varying geologic framework compositions; weathered materials or fluids formed as a result of intense metamorphism. The radiometric datasets proved valuable in delineating different rock types and serve as a complementary tool in identifying geochemical zoning of rocks in the area.ReferencesAjibade A.C. and Fitches W.R., 1988. The Nigerian Precambrian and the Pan-African Orogeny, Precambrian Geology of Nigeria, 45-53.Ajibade A.C., Woakes M. and Rahaman M.A., 1987.Proterozoic crustal development in Pan-African regime of Nigeria: In A. Croner (ed.) Proterozoic Lithospheric Evolution Geodynamics, 17, 259-231.Appleton J.D., Miles J.C.H., Green B.M.R, Larmour R., 2008. Pilot study of the application of Tellus airborne radiometric and soil geochemical data for radon mapping. Journal of Environmental Radioactivity, 99, 1687-1697.Arisekola T.M. and Ajenipa R.A., 2013. Geophysical data results preliminary application to uranium and thorium exploration. IAEA-CYTED-UNECE Workshop on UNFC-2009 at Santiago, Chile 9-12, July, 12.Bayowa O.G., Olorunfemi O.M., Akinluyi O.F. and Ademilua O.L., 2014.A Preliminary Approach to Groundwater Potential Appraisal of Ekiti State, Southwestern Nigeria. International Journal of Science and Technology (IJST), 4(3), 48-58.Bierwirth P.N., 1997. The use of airborne gamma-emission data for detecting soil properties.Proceedings of the Third International Airborne Remote Sensing Conference and Exhibition.Copenhagen, Denmark.Grasty R.L. and Multala J., 1991. A correlation technique for separating natural and man-made airborne gamma-ray spectra. In: Current Research, Part D, Geological Survey of Canada, 111-116.Grasty R.L., Minty B.R.S., 1995a. A guide to the technical specifications for airborne gamma ray surveys. Australian Geological Survey Organization, Record.Grasty R.L., Minty B.R.S., 1995b. The standardization of airborne gamma-ray surveys in Australia. Exploration Geophysics, 26, 276-283.IAEA, 1991. Airborne gamma ray spectrometer surveying, International Atomic Energy Agency, Technical Report Series, 323.IAEA, 2007.International Atomic Energy Agency. Safety Glossary, Terminology used in Nuclear Safety and Radiation Protection-2007 Edition.Jones H.A. and Hockey, 1964.The Geology of part of’ Southwestern Nigeria.Geological Survey, Nigeria bulletin, 31.Kearey P., Brooks M. and Hill I., 2002. An Introduction to Geophysical Exploration.3rd ed. Oxford: Blackwell Science, 262.Milsom J., 2003. Field Geophysics: The geological field guide series, John Milsom University College, London. Published by John Wiley and Sons Ltd. Third edition, 51-70.MontajTM Tutorial, 2004. Two - Dimensional frequency domain processing of potential field data.Nigeria Geological Survey Agency (NGSA), 2009. Geological map of Nigeria prepared by Nigeria Geological Survey Agency, 31, ShetimaMangono Crescent Utako District, Garki, Abuja, Nigeria.Omosanya K.O., Ariyo S.O., Kaigama U., Mosuro G.O., and Laniyan T.A., 2015. An outcrop evidence for polycyclic orogenies in the basement complex of Southwestern Nigeria. Journal of Geography and Geology, 7(3), 24-34.Oyawoye, M.O., 1972. The Basement Complex of Nigeria.In African Geology. T.F.J. Dessauvagie and A.J. Whiteman (Eds) Ibadan University Press, 67-99.Oyinloye A.O., 2011. Geology and Geotectonic Setting of the Basement Complex Rocks in Southwestern Nigeria: Implications on Provenance and Evolution. Earth and Environmental Sciences, 98-117. ISBN: 978-953-307-468-9.Rahaman M.A., 1981. Recent Advances in the Study of the Basement Complex of Nigeria.First Symposium on the Precambrian Geology of Nigeria, Summary.Rahaman M.A., Emofureta W.O. and Vachette M., 1983. The potassic-grades of the Igbeti area: Further evaluation of the polycyclic evolution of the Pan-African Belt in South-western Nigeria. Precambrian Resources, 22, 75-92.Woakes M., Rahaman M.A., Ajibade A.C., 1987. Some Metallogenetic Features of the Nigerian Basement. Journal of African Earth Sciences, 6(5), 655-664.

Reply to discussion by M. C. Alçiçek et al. on “Neogene-Quaternary evolution of the Tefenni basin on the Fethiye-Burdur fault zone, SW Anatolia-Turkey”, Journal of African Earth Sciences, 118, 137–148, by R. Aksoy and S. Aksarı

Reply to discussion by M. C. Alçiçek et al. on “Neogene-Quaternary evolution of the Tefenni basin on the Fethiye-Burdur fault zone, SW Anatolia-Turkey”, Journal of African Earth Sciences, 118, 137–148, by R. Aksoy and S. Aksarı

Reply to Ruban and Zorina’s (2015) discussion on the paper: “Danian/Selandian unconformity in the central and southern Western Desert of Egypt” by S. Farouk and E. El-Sorogy (2015; Journal of African Earth Sciences, 103, 42–53)

A global sea-level fall during the Latest Danian Event (LDE) is observed in a regional and worldwide context in widely-separated locations with different tectonic and depositional settings (Clemmensen and Thomsen, 2005). A similar trend in the central and south-western Desert of Egypt is synchronous with a weak tectonic event, which results in the absence of the upper portion of the regressive phase during the LDE, of the P3b Subzone which is seen in “tectonically stable” areas. This weak tectonic event is linked to more intense deformation of the Syrian Arc (Swell) of the Bahariya Oasis, which is synchronous with the global Laramide orogeny. Over the entire Dakhla Basin, the similar vertical sequence tracks can be traced across the area and indicate relative sea-level changes rather than shoreline shifts, and consequently reflect a eustatic origin. Correlation with the Arabian Plate charts (Sharland et al., 2001, 2004; Haq and Al-Qahtani; 2005; Simmons et al., 2007) do not match with the regional reconstruction of Farouk and El-Sorogy (2015) because these Arabian Plate charts are based on mega-sequences controlled by a dramatic tectonic event with erosion along the northeast Arabian plate (Haq and Al-Qahtani, 2005). Recently, after recalibration of many eustatic charts the conclusions made by Farouk and El-Sorogy (2015) concerning the late Danian sea-level fall (e.g., Haq et al., 1987; Hardenbol et al., 1998; Lüning et al., 1998; Guasti et al., 2005; Clemmensen and Thomsen, 2005; Schmitz et al., 2011; Gradstein et al., 2012) have been confirmed.

Comments on the paper of . Journal of African Earth Sciences, 58, pp. 489–506

Comments on the paper of . Journal of African Earth Sciences, 58, pp. 489–506

RETRACTED ARTICLE: Application of multivariate statistical methods and geochemical modeling to evaluate the surface water of Timgad Basin, East Algeria

After careful investigation carried out in accordance with the COPE guidelines the Editor-in-Chief and the Publisher have decided to retract this article. The text shows significant unattributed overlap with the following articles: Tiri, Ammar, Noureddine Lahbari, and Abderrahmane Boudoukha. ‘‘Hydrochemical characterization of surface water in the Timgad watershed, East Algeria’’, Desalination and Water Treatment, 2014. Tiri, Ammar, Noureddine Lahbari, and Abderrahmane Boudoukha. ‘‘Assessment of the quality of water by hierarchical cluster and variance analyses of the Koudiat Medouar Watershed, East Algeria’’, Applied Water Science, 2015. Belkhiri, L.. ‘‘Statistical categorization geochemical modeling of groundwater in Ain Azel plain (Algeria)’’, Journal of African Earth Sciences, 201101. Belkhiri, L.. ‘‘Application of multivariate statistical methods and inverse geochemical modeling for characterization of groundwater A case study: Ain Azel plain (Algeria)’’, Geoderma, 20101115. Vikram Bhardwaj. ‘‘Hydrogeochemistry of groundwater and anthropogenic control over dolomitization reactions in alluvial sediments of the Deoria district: Ganga plain, India’’, Environmental Earth Sciences, 01/2010. Li Peiyue. ‘‘Hydrochemical Formation Mechanisms and Quality Assessment of Groundwater with Improved TOPSIS Method in Pengyang County Northwest China’’, E-Journal of Chemistry, 2011.

Comment on “Assessment of groundwater recharge in a semi-arid groundwater system using water balance equation, southern Iran” by Mohammadi et al. (Journal of African Earth Sciences, vol. 95, pp. 1-8)

• Aquifer hydrodynamics and boundaries conditions are key factors in water balance evaluation.

Reply to G.A. El Bahariya’s Comments on: “Pillow form morphology of selected Neoproterozoic metavolcanics in the Egyptian Central Eastern Desert and their implications” [Journal of African Earth Sciences 57 (2010) 163–168

Through their ability to bind complex glycoconjugates, lectins have unique specificity and potential for biomedical and biotechnological applications. In particular, lectins with short repeated peptides forming carbohydrate-binding domains are not only of high interest for understanding protein evolution but can also be used as scaffold for engineering novel receptors. Synthetic glycobiology now provides the tools for engineering the specificity of lectins as well as their structure, multivalency and topologies. This review focuses on the structure and diversity of two families of tandem-repeat lectins, that is, β-trefoils and β-propellers, demonstrated as the most promising scaffold for engineering novel lectins.

Comment on “Pillow form morphology of selected Neoproterozoic meta-volcanics in the Egyptian Central Eastern Desert and their implications” by E.S. Farahat, M.M. El Mahallawi, G. Hoinkes, A.Y. Abdel Aal, C.A. Hauzenberger [Journal of African Earth Sciences 57 (2010) 163–168

Self-reported antibiotic allergies are common among hospitalized adults and children. However, there is a paucity of studies investigating the impact of an antibiotic allergy label in childhood.To investigate the impact of antibiotic allergy labeling on clinical outcomes in children.A retrospective study was conducted in a major pediatric tertiary hospital to capture inpatient admissions (N = 1672) in April 2014 and April 2015. Data, collected by chart review, included documented antibiotic allergy labels, antibiotic prescriptions, admitting specialty, hospital length of stay, and hospital readmissions.Of the 1672 pediatric patients surveyed, 58.1% were male and 44.8% were prescribed antibiotics. Antibiotic allergy labels were recorded in 5.3% of patients; most were β-lactam allergy labels (85%), mostly to unspecified penicillins. There was an increasing incidence of antibiotic allergy label with age, which was statistically significant (P < .001); no sex effect was seen. Patients with antibiotic allergy labels received more macrolide (P = .045), quinolones (P = .01), lincosamide (P < .001), and metronidazole (P = .009) antibiotics than did patients without an antibiotic allergy label. After adjusting for patient age, sex, principal diagnosis, and admitting specialty, children with any antibiotic or β-lactam allergy label had longer hospital stays (odds ratio, 1.62; 95% CI, 1.05-2.50; P = .03) with a mean length of hospital stay of 3.8 days for those without a label and 5.2 days for those with a β-lactam allergy label.This is the first study demonstrating the negative impact of antibiotic allergy labels on clinical outcomes in children, as evidenced by significant alternate antibiotic use and longer hospital stays.

Succession of structural events in the Goren greenstone belt (Burkina Faso): Implications for West African tectonics

Ten years after field investigations in the SE Goren greenstone belt (GGB) of Burkina Faso by the Sanmatenga J.V., sponsored field studies conducted in 2007 have significantly enhanced structural datasets. The studies in 2007 were conducted across an expanded area of the GGB that included both southwestern and northeastern domains, and portions of the Pissila batholith to the west of the GGB. A revision of tectonic models proposed by Hein et al. [Hein, K.A.A., Morel, V., Kagoné, O., Kiemde, F., Mayes, K., 2004. Birimian lithological succession and structural evolution in the Goren Segment of the Boromo-Goren Greenstone Belt, Burkina Faso. Journal of African Earth Sciences 39, 1–23] is now possible. Three deformation events characterise the Goren greenstone belt. The deformation, D1 (previously D3) resulted in the formation of NW to NNW-trending steeply-dipping dextral-reverse shear zones folds and a penetrative S1-C schistosity that formed during a period of NE–SW shortening. The event is termed the Tangaean Event because it can be correlated across NE Burkina Faso in the Boromo, Bouroum, Yalago and Oudalan-Gorouol greenstone belts. The deformation, D2 (previously D2) resulted in the progressive development of NNE to NE-trending macroscopic to mesoscopic folds and a penetrative axial planar cleavage (S2), which was followed by the formation of dextral- and sinistral-reverse shears and a pervasive schistosity (S2-C). The first-order crustal-scale Sabce Shear Zone, which traverses the northern portion of the study area, is associated with macroscopic anticlockwise drag rotation of NW to NNW-trending D1 shears and folds: (the macroscopic fold was previously classified as D1). D2 in the GGB corresponds with the Eburnean Orogeny at 2130–1980 Ma, as described by [Feybesse, J.-L., Billa, M., Guerrot, C., Duguey, E., Lescuyer, J.-L, Milesi, J.-P., Bouchot, V., 2006, The paleoproterozoic Ghanian province: geodynamic model and ore controls, including regional stress modelling. Precambrian Research, 149–196]. The deformation D3 (previously D4) is recognised throughout the GGB. It is characterised by the formation of kinks and chevron folds (F3), or crenulation cleavage (S3) that are hosted by narrow WNW-trending shear zones. These formed during a period of north–south shortening termed the Wabo-Tampelse Event that post-dates the Eburnean Orogeny.

Geochemistry of the Neoarchaean mafic volcanic rocks of the Geita area, NW Tanzania: Implications for stratigraphical relationships in the Sukumaland greenstone belt

Geochemical data are presented for a suite of mafic volcanic rocks from the Geita area in the Sukumaland greenstone belt (SGB) of northwestern Tanzania with the aim of constraining their petrogenesis, tectonic setting and to assess a possible genetic link with mafic volcanic rocks from the Rwamagaza area also from the SGB previously reported by [Manya, S., Maboko, M.A.H., 2003. Dating basaltic volcanism in the Neoarchaean Sukumaland greenstone belt of the Tanzania Craton using the Sm–Nd method: implications for the geological evolution of the Tanzania Craton. Precambrian Research 121, 35–45] and [Manya, S., 2004. Geochemistry and petrogenesis of volcanic rocks of the Neoarchaean Sukumaland greenstone belt, northwestern Tanzania. Journal of African Earth Sciences 40, 269–279]. Mafic volcanic rocks from the two locations in the SGB show similar geochemical and Nd-isotopic compositions. Trace element and Nd-isotope compositions are consistent with their generation from a depleted MORB mantle (DMM) source which had been metasomatised by a subduction component in a late Archaean back arc setting at ∼2823 Ma. These findings are at variance with the previously proposed lithostratigraphical framework in the SGB which postulated an inner arcuate belt dominated by lower Nyanzian mafic volcanic rocks and an outer belt dominated by upper Nyanzian chemical sedimentary rocks, rare felsic flows and shales. The presence of mafic volcanic rocks flanking the outer belt which are of similar composition and age as those of the inner belt suggests that mafic volcanics in the SGB form discontinuous patches of rock distributed throughout the belt and separated by intervening granites. Furthermore, they corroborate previous evidence that both the rocks of the inner and outer belt formed more or less coevally and the subdivision of the volcano-sedimentary package of the SGB (and other greenstone belts of the Tanzania Craton) into a lower mafic volcanic dominated unit and an upper felsic volcanic and BIF dominated unit is not stratigraphically valid.

Erratum

Previous article No AccessErratumOriginal articleThe Irrawaddy River Sediment Flux to the Indian Ocean: The Original Nineteenth‐Century Data RevisitedPDFPDF PLUSFull Text Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The Journal of Geology Volume 116, Number 1January 2008 Article DOIhttps://doi.org/10.1086/524755 Views: 15Total views on this site Citations: 1Citations are reported from Crossref © 2008 by The University of Chicago. All rights reserved.PDF download Crossref reports the following articles citing this article:I.C.W. Fitzsimons A review of tectonic events in the East Antarctic Shield and their implications for Gondwana and earlier supercontinents, Journal of African Earth Sciences 31, no.11 (Jul 2000): 3–23.https://doi.org/10.1016/S0899-5362(00)00069-5Related articlesThe Irrawaddy River Sediment Flux to the Indian Ocean: The Original Nineteenth‐Century Data Revisited18 Jul 2015The Journal of Geology

Comment on “U–Pb dating of plutonic rocks involved in the nappe tectonic in southern Cameroon: Consequence for the Pan-African orogenic evolution of the central African fold belt” by Toteu et al. (Journal of African Earth Sciences 44 (2006) 479–493)

Comment on “U–Pb dating of plutonic rocks involved in the nappe tectonic in southern Cameroon: Consequence for the Pan-African orogenic evolution of the central African fold belt” by Toteu et al. (Journal of African Earth Sciences 44 (2006) 479–493)

Comment on “The Moroccan Hercynides” by Hoepffner et al. (Journal of African Earth Sciences, vol. 43, pp. 144–165)

Comment on “The Moroccan Hercynides” by Hoepffner et al. (Journal of African Earth Sciences, vol. 43, pp. 144–165)