Metal sources for the Katanga Copperbelt deposits (DRC) insights from Sr and Nd isotope ratios

The ore deposits of the Central African Copperbelt formed during a multiphase mineralisation process. The basement underlying the Neoproterozoic Katanga Supergroup that hosts the ore, demonstrates the largest potential as metal source. Various ore deposits that formed during different mineralisation phases are taken as case studies, i.e. Kamoto, Luiswishi, Kambove West, Dikulushi and Kipushi (Democratic Republic of Congo, DRC). The Sr and Nd isotopic compositions of gangue carbonates associated with these deposits is determined and compared with those of rocks from several basement units, bordering or underlying the Copperbelt, to infer the metal sources. The mineralising fluid of diagenetic stratiform Cu-Co mineralisation interacted with felsic basement rocks underlying the region. The Co from these deposits is most likely derived from mafic rocks, but this is not observed in the isotopic signatures. Syn-orogenic, stratabound Cu-Co mineralisation resulted mainly from remobilisation of diagenetic sulphides. A limited, renewed contribution of metals from felsic basement rocks might be indicated by the isotope ratios in the western part of the Copperbelt, where the metamorphic grade is the lowest. The mineralising fluid of syn- and post-orogenic, vein-type mineralisations interacted with local mafic rocks, and with felsic basement or siliciclastic host rocks

Enhanced transformer long short-term memory framework for datastream prediction

In machine learning, datastream prediction is a challenging issue, particularly when dealing with enormous amounts of continuous data. The dynamic nature of data makes it difficult for traditional models to handle and sustain real-time prediction accuracy. This research uses a multi-processor long short-term memory (MPLSTM) architecture to present a unique framework for datastream regression. By employing several central processing units (CPUs) to divide the datastream into multiple parallel chunks, the MPLSTM framework illustrates the intrinsic parallelism of long short-term memory (LSTM) networks. The MPLSTM framework ensures accurate predictions by skillfully learning and adapting to changing data distributions. Extensive experimental assessments on real-world datasets have demonstrated the clear superiority of the MPLSTM architecture over previous methods. This study uses the transformer, the most recent deep learning breakthrough technology, to demonstrate how well it can handle challenging tasks and emphasizes its critical role as a cutting-edge approach to raising the bar for machine learning

Metallogenesis of stratiform copper deposits in the Lufilian orogen, Democratic Republic Congo.

Acknowledgments I Table of contents V List of figures IX List of tables XIII Summary XV 1. Introduction 1 1.1. Sediment-hosted stratiform copper deposits 1 1.2. Stratiform copper mineralization of the Lufilian Orogen 1 1.3. Previous metallogenic models in the Central African Copperbelt 2 1.4. Problem definition 3 1.5. Scope and objectives 3 1.6. Thesis overview 4 2. Regional tectonic and geologic setting 7 2.1. Tectonic setting 7 2.2. Katanga Supergroup 9 2.3. Lufilian Orogeny 13 2.4. Evaporites and breccia 14 3. Methodology 17 3.1. Remote sensing 17 3.1.1. Satellite imagery and pre-processing 17 3.1.1.1. ASTER 17 3.1.1.2. ETM+ 17 3.1.2. Lineament analysis 18 3.2. Sampling, petrography and point counting 19 3.2.1. Lufukwe and Mwitapile 19 3.2.2. Luiswishi and Kamoto 19 3.2.3. Fluid inclusions 20 3.3. Isotope geochemistry 21 3.3.1. Stable S, C, and O isotope analysis 21 3.3.2. Rb-Sr analysis 22 4. Genesis of stratiform Cu mineralization at Lufukwe 23 4.1. Study area and mineralization 23 4.2. Results of remote sensing analysis 24 4.3. Petrography and paragenesis 35 4.4. Point counting 37 4.5. Fluid inclusions 41 4.5.1. Petrography 41 4.5.2. Microthermometry 44 4.6. Discussion 44 4.6.1. Nature of the ore-forming fluids 44 4.6.2. Controls on mineralization and timing 46 4.6.2.1. Structural controls 48 4.6.2.2. Diagenetic controls 48 4.6.2.3. Lithological controls 50 4.6.2.4. Relative timing of mineralization 51 4.6.3. Implications for exploration 52 4.7. Mineralization model 52 5. Genesis of stratiform Cu mineralization at Mwitapile and its relation to Lufukwe 57 5.1. Study area and mineralization 57 5.2. Results of remote sensing analysis 57 5.3. Petrography and paragenesis 60 5.4. Point counting 67 5.5. Fluid inclusion microthermometry 67 5.6. Discussion on the Mwitapile mineralization 71 5.6.1. Fluid evolution 71 5.6.2. Porosity and permeability controls on mineralization 73 5.6.3. Timing of mineralization 73 5.7. Discussion on the sandstone-hosted stratiform Cu mineralizations of the Lufilian Foreland 74 5.7.1. Lufukwe mineralization 74 5.7.2. Comparison between Lufukwe and Mwitapile mineralization 75 5.8. Implications for exploration 77 6. Luiswishi and Kamoto: geology, petrography and fluid evolution 79 6.1. Cu-Co mineralization 79 6.2. Petrography and paragenesis 80 6.3. Fluid inclusions 89 6.3.1. Petrography 92 6.3.2. Microthermometry 93 6.3.2.1. Type-I fluid inclusions 93 6.3.2.2. Type-II and type-III fluid inclusions 96 6.4. Discussion 99 6.4.1. Fluid inclusion microthermometry 99 6.4.2. Cu-Co ore phases 107 6.4.2.1. Hypogene Cu-Co phases 107 6.4.2.2. Supergene mineralization 107 6.4.3. Comparison with earlier microthermometric studies 108 6.4.4. Timing of mineralization 109 6.4.5. Origin of mineralizing/remobilizing fluids 111 6.4.5.1. Pressure–temperature of fluid entrapment 112 6.4.6. Hydrothermal versus syn-sedimentary origin of mineralization 112 7. Luiswishi and Kamoto: isotope geochemistry 115 7.1. Results of stable (S, C, O) and radiogenic (Rb-Sr) isotope analyses 115 7.1.1. Sulfur 115 7.1.2. Carbon and oxygen 115 7.1.3. Rb-Sr 118 7.2. Interpretation and discussion 119 7.2.1. Sources of sulfur 119 7.2.2. Carbon and oxygen isotopes 122 7.2.3. Rb-Sr isotopes 128 8. Comparison with vein-type deposits 135 8.1. Kipushi deposit 135 8.2. Dikulushi deposit 137 8.3. Main mineralization/remobilization phases in the Lufilian Orogen 138 8.3.1. Lufilian Arc 138 8.3.2. Lufilian Foreland 138 9. Conclusions, mineralization models and future perspectives 141 9.1. Conclusions and mineralization models 141 9.1.1. Lufilian Foreland 141 9.1.2. Lufilian Arc (Katanga Copperbelt) 142 9.1.3. Evolution of copper mineralization in the Lufilian Orogen 147 9.2. Future perspectives 147 9.2.1. Geochronology 148 9.2.2. Chemical analysis of fluid inclusions 148 9.2.3. Stable and radiogenic isotope geochemistry 148 9.2.4. Palaeothermometry 149 9.2.5. Remote sensing 149 Appendix A: Results of fluid inclusion microthermometry 151 References 161 Publication list of Hamdy A. El Desouky 181nrpages: 210status: publishe

Two Cu–Co sulfide phases and contrasting fluid systems in the Katanga Copperbelt, Democratic Republic of Congo

The Katanga Copperbelt is the Congolese part of the well-known Central African Copperbelt, the largest sediment-hosted stratiform Cu–Co province on Earth. Petrographic examination of borehole samples from the Kamoto and Luiswishi mines in the Katanga Copperbelt recognized two generations of hypogene Cu–Co sulfides and associated gangue minerals (dolomite and quartz). The first generation is characterized by fine-grained Cu–Co sulfides and quartz replacing dolomite. The second generation is paragenetically later and characterized by coarse-grained Cu–Co sulfides and quartz overgrown and partly replaced by dolomite. Fluid inclusion microthermometric data were collected from two different types of fluid inclusions: type-I fluid inclusions (liquid + vapor) in the quartz of the first generation and type-II fluid inclusions (liquid + vapor + halite) in the quartz of the second generation. The microthermometric analyses indicate that the fluids represented by type-I and type-II fluid inclusions had very different temperatures and salinities and were not in thermal equilibrium with the host rock. Petrographic and microthermometric data indicate the presence of at least two main hypogene Cu–Co sulfide phases in the Katanga Copperbelt. The first is an early diagenetic typical stratiform phase, which produced fine-grained sulfides that are disseminated in the host rock and frequently concentrated in nodules and lenticular layers. This phase is related to a hydrothermal fluid with a moderate temperature (115 to 220 °C, or less if reequilibration of inclusions has occurred) and salinity (11.3 to 20.9 wt.% NaCl equiv.). The second hypogene Cu–Co phase produced syn-orogenic coarse-grained sulfides, which also occur disseminated in the host rock but mainly concentrated in a distinct type of stratiform nodules and layers and in stratabound veins and tectonic breccia cement. This second phase is related to a hydrothermal fluid with high temperature (270 to 385 °C) and salinity (35 to 45.5 wt.% NaCl equiv.). A review of available microthermometric and ore geochronological data of the Copperbelt in both the Democratic Republic of Congo and Zambia supports the regional presence of the two Cu–Co phases proposed in our study. Future geochemical analyses in the Copperbelt should take into account the presence of, at least, these two Cu–Co phases, their contrasting fluid systems and the possible overprint of the first phase by the second one.status: publishe

The sandstone-hosted stratiform copper mineralization at Mwitapile and its relation to the mineralization at Lufukwe, Lufilian foreland, Democratic Republic of Congo

The Lufilian foreland is a triangular-shaped area located in the SE of the Democratic Republic of Congo and to the NE of the Lufilian arc, which hosts the well-known Central African Copperbelt. The Lufilian foreland recently became an interesting area with several vein-type (e.g.. Dikulushi) and stratiform (e.g., Lufukwe and Mwitapile) copper occurrences. The Lufilian foreland stratiform Cu mineralization is, to date, observed in sandstone rock units belonging to the Nguba and Kundelungu Groups (Katanga Supergroup).status: publishe

Stable (C-O) and radiogenic (Sr) isotope geochemistry of the Luiswishi and Kamoto Cu-Co ore deposits, Katanga Copperbelt, Democratic Republic of Congo

Stable and radiogenic isotope geochemistry on carbonates allowed better understanding of the genesis of two main hypogene Cu-Co phases in the Katanga Copperbelt. δ13C and δ18O of dolomites associated with stratiform, early diagenetic, sulphides, belong to the first Cu-Co phase, provide evidence for carbonate precipitation during BSR just before mineralization. Whereas δ13C and δ18O of dolomites associated with stratiform/stratabound, syn-orogenic, sulphides belong to the second Cu-Co phase, indicate carbonate precipitation from a high temperature, host-rock buffered, fluid, possibly under the influence of TSR. Sr isotopes indicate that the mineralizing fluid of the first Cu-Co phase has leached radiogenic Sr and possibly metals by interaction with the granitic basement. However, the fluid responsible for the second Cu-Co phase is most likely a remobilizing fluid that has significantly interacted with the sediments of the Roan Group and possibly did not mobilize additional metals from the granitic basement.status: publishe

Genesis of the Eugui sparry Magnesite deposit (Western Pyrenees, Spain): Evidence from fluid inclusions and isotope geochemistry

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From Pixels to Deposits: Porphyry Mineralization With Multispectral Convolutional Neural Networks

Mineral exploration is essential to ensure a sustainable supply of raw materials for modern living and the transition to green. It implies a series of expensive operations that aim to identify areas with natural mineral concentration in the crust of the Earth. The rapid advances in artificial intelligence and remote sensing techniques can help in significantly reducing the cost of these operations. Here, we produce a robust intelligent mineral exploration model that can fingerprint potential locations of porphyry deposits, which are the world's most important source of copper and molybdenum and major source of gold, silver, and tin. We present a deep learning pipeline for assessing multispectral imagery from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) with the objective of identifying hydrothermal alterations. Our approach leverages a convolutional neural network (CNN) to analyze the high-resolution images, overcoming computational challenges through a patch-based strategy that involves an overlapping window for partitioning the images into fixed-size patches. Through the utilization of manually labeled patches for image classification and identification of hydrothermal alteration areas, our results demonstrate the remarkable ability of CNN to accurately detect hydrothermal alterations. The technique is adaptable for other ore deposit models and satellite imagery types, providing a revolution in satellite image interpretation and mineral exploration

Diagenetic origin of the stratiform Cu-Co deposit at Kamoto in the Central African Copperbelt

International audienceSediment-hosted stratiform ore deposits that underwent metamorphism and orogenesis are interpreted either to have a multiphase origin that might in part predate these events or to be exclusively related to fluid migration during the orogeny. This controversy concerns the formation of many world-class sediment-hosted ore deposits such as in the Central African Copperbelt. Here we present Re-Os dating results for disseminated and stratiform Cu-Co sulfide pseudomorphs after anhydrite in nodules and layers from the Copperbelt. Results demonstrate that at least some of the ores formed at around 800 Ma during rifting and basin development, and thus predate the Pan-African Lufilian orogeny. Younger Re-Os ages, i.e., between 682 +/- 28 and 230 +/- 36 Ma, may be due to the replacement of the early Cu-Co sulfides by younger sulfide phases. Alternatively, these younger ages may result from the disturbance or resetting of the Re-Os system during recrystallization/metamorphism or the transition of chalcocite from its high- to its low-temperature polymorph

Clinical and laboratory characteristics of short-term mortality in Egyptian patients with acute heart failure

Objective: To identify the clinical and laboratory predictors of short-term mortality in patients with acute heart failure (AHF). Subjects and methods: We conducted a prospective, single center study on 120 consecutive patients presented with acute heart failure to the emergency department. All patients had clinical, laboratory, electrocardiographic and echocardiographic evaluation. Short-term mortality was reported within 30 days of presentation. Results: Mean age was 59.29 ± 10.1 years, 55.8% were males and 50.8% were smokers. The common AHF presentations were dyspnea (91.7%), chest tightness (62.5%) and lower limb edema (54.2%). Ischemic heart disease, diabetes and hypertension were present in 72.5%, 43.3% and 35% of patients, respectively. Short-term mortality was reported in 29 patients (24.16%); most of them died in-hospital (19 patients, 65.52%). The following parameters were significantly associated with short-term mortality: hypoxia (P < 0.001), tachycardia (P < 0.01), raised jugular venous pressure (JVP) (P < 0.001), low systolic blood pressure (P < 0.01), prolonged PR interval (P < 0.007), atrial fibrillation (AF) (P < 0.038), left bundle branch block (LBBB) (P < 0.04), impaired kidney function (P < 0.007), anemia (P < 0.029), hyponatremia (P < 0.006), hypoalbuminemia (P < 0.005), dilated left ventricle (LV) (P < 0.001), low LV ejection fraction (LVEF) (P < 0.001), and dilated left atrium (LA) (P < 0.002). ROC curve analysis showed that low LVEF (≤24%), dilated LV end diastolic diameter (LVESD) ≥ 66.5 mm, dilated LV end systolic diameter (LVESD) ≥ 53.5 mm, dilated LA diameter ≥ 48 mm, increased serum creatinine ≥ 1.6 mg/dl, and decreased serum albumin ≤ 3 g/dl can significantly predict short-term mortality in patients with acute heart failure. Conclusion: Variable clinical, laboratory, electrocardiographic and echocardiographic parameters were associated with short-term mortality. Our study showed that low LVEF, dilated LV diameter, dilated LA diameter, impaired kidney function and low serum albumin can predict short-term mortality in patients with acute heart failure