In the ternary system CsCl – NaCl – H2O, at a temperature of 298.15 K, a double salt with the stoichiometric formula CsCl∙2NaCl∙2H2O(cr) is known to be formed. This double salt and the anhydrous CsCl(cr) are the end-members of a solid solution. For the pure double salt, the solubility constant was determined. The obtained value was applied to calculate the solubility diagram also of the quaternary system CsCl – NaCl – KCl – H2O and the quaternary-reciprocal system Cs+, Na+ || Cl−, SO42− – H2O. The solubility constant together with a solid solution between CsCl·2NaCl·2H2O(cr) and CsCl(cr) were implemented in THEREDA, which extends the applicability of the existing cesium dataset.

Driven by the need to use mineral resources more sustainably, and the increasing complexity of ore deposits still available for commercial exploitation, the acquisition of quantitative data on mineralogy and microfabric has become an important need in the execution of exploration and geometallurgical test programmes. Hyperspectral drill-core scanning has the potential to be an excellent tool for providing such data in a fast, non- destructive and reproducible manner. However, there is a distinct lack of integrated methodologies to make use of these data through-out the exploration and mining chain. This thesis presents a first framework for the use of hyperspectral drill-core scanning as a pillar in exploration and geometallurgical programmes. This is achieved through the development of methods for (1) the automated mapping of alteration minerals and assemblages, (2) the extraction of quantitative mineralogical data with high resolution over the drill-cores, (3) the evaluation of the suitability of hyperspectral sensors for the pre-concentration of ores and (4) the use of hyperspectral drill- core imaging as a basis for geometallurgical domain definition and the population of these domains with mineralogical and microfabric information.:Introduction Materials and methods Assessment of alteration mineralogy and vein types using hyperspectral data Hyperspectral imaging for quasi-quantitative mineralogical studies Hyperspectral sensors for ore beneficiation 3D integration of hyperspectral data for deposit modelling Concluding remarks References

For the polythermal Pitzer dataset of the hexary system of oceanic salts (Na+, K+, Mg+2, Ca+2, Cl-, SO4-2 - H2O) including acids and hydroxides the data selection is documented in detail in the report “THEREDA - Thermodynamische Referenzdatenbasis” (Altmaier et al. 2011, https://www.grs.de/de/aktuelles/publikationen/grs-265-thereda-thermodynamische-referenzdatenbasis-abschlussbericht). The present short communication supplements this report by the numerical values of all temperature coefficients.

The Marine Isotope Stage (MIS) 2 is considered the coldest, driest and stormiest period during the last Glacial-Interglacial cycle in large parts of Eurasia. This resulted from strongly decreased northern hemisphere temperature and related maximum extension of northern ice sheets that strongly reinforced large-scale circulation modes such as westerlies and East Asian Winter Monsoon driven by the Siberian High. Normally, this intensified circulation is reflected by maximum loess deposition in numerous loess regions spanning Europe and Asia. However, here we present a new loess record from the Caucasus region in NE-Armenia providing evidence in support of heavily reduced or even lacking loess formation during the MIS-2. Owing to implementations of comprehensible luminescence dating work and a provenance survey using rock magnetic and geochemical data, we are able to define distinct loess formation phases and to retrace sediment transport pathways. By comparing our results to other Eurasian palaeo-records, we unveil general atmospheric circulation modes that are most likely responsible for loess formation in the Southern Caucasus. Moreover, we try to test different scenarios to explain lacking loess formation during MIS-2. In line with other archive information, we suggest that loess formation was hampered by higher regional moisture conditions caused by a southward-shift of westerlies and renewed moisture absorption over the Black Sea. Our results show that modifications of MIS-2 circulation modes induced a very heterogeneous moisture distribution, particularly in the lower mid-latitudes of Eurasia producing a juxtaposition of very dry (morphodynamically active) and moderately dry (morphodynamically stable) areas.

The THEREDA model has been extended by phases and species formed within the title system. A temperature range of 0 °C to 100 °C is considered. Most of the solubility products, Pitzer parameters and association constants were adapted from the model of Königsberger et al. (Königsberger, E., Königsberger, L.-C., Gamsjäger, H.: Low-temperature thermodynamic model for the system Na2CO3−MgCO3−CaCO3−H2O. Geochim. Cosmochim. Acta, 63, (1999), pp. 3105–3119, DOI 10.1016/S0016-7037(99)00238-0). Literature on solubility data of carbonates of magnesium and calcium is critically evaluated. As far as experimental solubility data were available, they were compared with model calculations. The data comprise the minerals magnesite (MgCO3), nesquehonite (MgCO3∙3H2O), lansfordite (MgCO3∙5H2O), hydromagnesite (4MgCO3∙Mg(OH)2∙4H2O), dypingite (4MgCO3∙Mg(OH)2∙5H2O), calcite (CaCO3), aragonite (CaCO3), vaterite (CaCO3), ikaite (CaCO3∙6H2O), dolomite (MgCO3∙CaCO3), huntite (3MgCO3∙CaCO3), magnesian calcite (solid solution between CaCO3 and MgCO3), eitelite (Na2CO3·MgCO3), pirssonite (Na2CO3·CaCO3·2H2O), gaylussite (Na2CO3·CaCO3·5H2O), natrite (Na2CO3), thermonatrite (Na2CO3·H2O), Na2CO3·7H2O, natron (Na2CO3·10H2O), nahcolite (NaHCO3), wegscheiderite (Na2CO3·3NaHCO3) and trona (Na2CO3·NaHCO3·2H2O). There are minerals known as artinite (MgCO3∙Mg(OH)2∙3H2O) or barringtonite (MgCO3·2H2O), for which no solubility data exist. The literature survey also covers geochemical observations on the existence of carbonate minerals, laboratory investigations on the decomposition, formation and conversion as well as spectral and XRD characterization of carbonate phases. For important minerals, such as magnesite or hydromagnesite, the uncertainty of the solubility constants is large. The added Pitzer parameters, concern the binary cation - carbonate, cation - hydrogen carbonate and the ternary interactions, including mixing parameters of the anions HCO3-, CO32- and OH-. Mixing parameters of these anions with chloride or sulfate are not considered in this work. From the data situation and the modelling results, conclusions are drawn with respect to future experimental work to obtain more reliable equilibrium data.

Within the framework of this research, the complex geological history of the Pan African-Volta basin has been systematically reconstructed. Based on a broad review of literature and new data, 5 stages of geological-tectonic development have been identified. For the first time a systematic review of the mineral potential of the Pan-African Volta Basin was executed. Known and potentially existing mineralization have been related to the geotectonic history and metallogenetic conclusions have been drawn. Based on the findings of this research, the folded thrust belt located at the eastern rim of the Volta basin has been identified as the most prospective area for the ultramafic rocks with chromite, nickel mineralization and PGEs, hydrothermal gold and banded iron formation (BIF) but this will require further work.

Um Hinweise auf die geodynamische Entwicklung und zur Rekonstruktion der magmatischen und tektono-metamorphen Geschichte der Västervik-Region (SE-Schweden) und dem Kamanjab Inlier (NW-Namibia) zu erhalten, wurden isotopengeochemische Untersuchungen (Rb-Sr, Sm-Nd, K-Ar, U-Pb) in Kombination mit Haupt- und Spurenelementanalytik sowie Untersuchungen zu den P-T-Bedingungen an metamorphen Gesteinen durchgeführt. Beide Gebiete vereint eine gemeinsame Entwicklung innerhalb des Superkontinentes Columbia. Sowohl die Västervik-Region als auch der Kamanjab Inlier sind durch ihre Lage entlang eines aktiven Kontinentalrandes geprägt. In beiden Arbeitsgebieten konnte eine mehrphasige Entwicklung erkannt werden. Die Untersuchungen zeigen, dass der granitoide Magmatismus entlang des südlichen Randes des Laurentia-Baltika Systems durch zwei paläoproterozoische Phasen charakterisiert ist. So konnten fünf granitoide Einheiten unterschieden werden, die in ihrer Zusammensetzung von Tonaliten bis Syenograniten variieren. Geochemische Klassifikationen haben für drei der fünf Einheiten einen „magnesian“, metaluminösen Cordillerancharakter gezeigt, der in Verbindung mit einem aktiven Kontinentalrand steht (2. Phase 1.81-1.77 Ga). Die übrigen zwei Einheiten zeigen einen Wechsel zu „ferroan“, peraluminösen Granitoiden mit einem A-Typ-Charakter, die während einer Extensionsphase gebildet wurden (1. Phase 1.87-1.84 Ga). Während die Ältere der beiden A-Typ-Gruppen mit der ersten Phase korreliert werden kann, zeigt die Jüngere Affinitäten zur sogenannten Granit-Pegmatit-Einheit. Das bestehende tektonische Modell für die Bergslagen-Region (N‘ Västervik) setzt eine Verlagerung der Subduktionszone in SW‘ Richtung voraus, die einhergeht mit einem Wechsel des geodynamischen Regimes. Die für die Västervik-Region definierten fünf granitoiden Einheiten passen gut in dieses Modell und liefern Argumente für einen neuen tektonischen Zyklus im Süden der Bergslagen-Region. Der Kamanjab Inlier zeigt eine ähnliche Entwicklung, wie sie in der Västervik-Region beobachtet werden konnte. Der granitoide Magmatismus wurde auf ein paläoproterozoisches Alter von 1.88-1.81 Ga datiert und fällt vermutlich mit einem ersten tektono-metamorphen Ereignis zusammen, in dem es unter anderem zur Ausbildung von Migmatiten kam. Die ermittelten Sm-Nd-Modellalter der Amphibolite zeigen eine systematische Zunahme von tiefen zu höheren Krustenstockwerken (Rooikop/Aandgloed[S]: TDM 2.10-1.96 Ga; Suiderkruis/Aandgloed [N]: TDM 2.40-2.12 Ga; Ehobib: TDM 2.74-2.30 Ga). Das Einsetzen der Kibarischen Orogenese bzw. des kibarischen Riftereignisses im Mesoproterozoikum (~1.6 Ga) wird als Auslöser für eine großräumige Überprägung des südlichen Randes des Kongo-Kraton gesehen. Sowohl K-Ar-Datierungen (1.3-1.4 Ga) als auch die Ergebnisse der Rb-Sr-Isotopenanalyse (~1.5 Ga) deutet auf eine solche Überprägung hin und können mit einem zweiten tektono-metamorphen Ereignis sowie dem bimodalen Magmatismus entlang des Kontinentalrandes korreliert werden. Untersuchungen der P-T-Bedingungen zeigen eine Unterteilung in eine nördliche (T=650-750 °C; P=8-11 kbar) und eine südliche (T=500-600 °C; P=5-9 kbar) Domäne. Ausgehend von zwei diskreten Metamorphoseereignissen scheinen die Geländebeobachtungen (Ausbildung der Migmatite) die Bedingungen des ersten tektono-metamorphen Ereignisses widerzuspiegeln. Wohingegen die durch Laborbefunde ermittelten, das zweite Ereignis zeigen.

Within the framework of this research, the complex geological history of the Pan African-Volta basin has been systematically reconstructed. Based on a broad review of literature and new data, 5 stages of geological-tectonic development have been identified. For the first time a systematic review of the mineral potential of the Pan-African Volta Basin was executed. Known and potentially existing mineralization have been related to the geotectonic history and metallogenetic conclusions have been drawn. Based on the findings of this research, the folded thrust belt located at the eastern rim of the Volta basin has been identified as the most prospective area for the ultramafic rocks with chromite, nickel mineralization and PGEs, hydrothermal gold and banded iron formation (BIF) but this will require further work.:Table of contents Table of contents iii List of tables v List of figures 1 Introduction 5 Summary of work done 6 Acknowledgements 6 1 In the Geology and regional geotectonic development of the West African Shield 7 1.1 Introduction 7 1.2 The basement of the Proterozoic sedimentary platform cover 9 1.3 Connection of West African Shield to Brazil 10 1.4 The Neoproterozoic sedimentary sequence and the extent of the Volta Basin 13 1.4.1 Introduction 13 1.4.2 The Neoproterozoic Sedimentary Sequence 15 1.5 The Pan-African Mobile Belt 23 1.5.1 The Buem Fold and thrust belt 23 1.5.2 New defined units 30 1.6 Interpretation of the deep structure of the Volta Basin 35 1.7 Metallic Minerals 37 1.7.1 Introduction 37 1.7.2 Iron (Fe) 39 1.7.3 Aluminium (Al) 46 1.7.4 Manganese (Mn) 50 1.7.5 Lead (Pb) 52 1.7.6 Copper (Cu) 55 1.7.7 Mineralisation related to ultramafic rocks 57 1.7.8 Gold (Au) 69 1.7.9 Tantalum (Ta) 72 1.7.10 Zirconium (Zr) 73 1.7.11 Heavy minerals in sands of Paleochannels 76 1.8 Non-metallic minerals 83 1.8.1 Introduction 83 1.8.2 Limestone (CaCO3) 84 1.8.3 Magnesite (MgCO3) 91 1.8.4 Barite (BaSO4) 93 1.8.5 Diamonds 97 1.8.6 Bitumen 100 1.9 Mineral Prediction with advangeo® Prediction Software 102 2 Minerogeny 109 2.1 Mineralisation controls and indicators 109 2.1.1 Geochemical Properties of selected stratigraphic units 109 2.1.2 Intrusive rocks 114 2.1.3 Volcanic rocks 118 2.1.4 Fault structural controls 119 2.1.5 Reactive Rocks 121 2.1.6 Other sedimentary controls: placers and paleoplacers 122 2.1.7 Laterites 122 2.1.8 Control of diamond occurrences 132 2.2 Key stages of metallogenic development 132 3 Discussion and recommendations 136 3.1 Recommendations 138 4 List of References 139 5 Appendices 144 5.1.1 Sample G113RK1 144 5.1.2 Sample G109RK1 145 5.1.3 Sample G116RK1 147 5.1.4 Sample G121RK1 149 5.1.5 Sample G121RK2 151 5.1.6 Sample G121RK3 152 5.1.7 Sample G131RK1 154 5.1.8 Sample G144RK2 155 5.1.9 Sample G145RK1 156 5.1.10 Sample G147RK1 157 5.2 Thin Sections 159 5.3 Deep drilling Data 174 5.4 Geophysical Datasets 176 5.5 Geochemical properties of volcanic rocks 181 5.6 Regional Geochemical Datasets (MSSP) 186 5.6.1 Methodology of data processing 188 5.7 Geochemical analysis – Electronic Dump 190 5.8 Geochemical properties of selected geo-tectonic units 190 5.8.1 Epicratonic basin 190 5.8.2 Foreland Basin 195 5.8.3 Thrusted continental margin 202

This report documents the selection of thermodynamic data for lead and lead compounds. Except for elemental lead, it is restricted to lead in the oxidation state +II (plumbous lead). Besides formation constants and, in part, enthalpies of formation and standard entropies, interaction coefficients for the correction of activity coefficients following the Pitzer formalism are provided. Aqueous complexes of lead with chloride, sulphate, and hydroxide are explicitly accounted for in the Pitzer model. Wherever possible, the validity of selected data is tested by recalculating experimental data. The presented data set is valid for 298.15K only.

Considering the ever-growing global demand for raw materials and the complexity of the geological deposits that are still to be found, high-quality extensive mineralogical information is required. Mineral exploration remains a risk-prone process, with empirical approaches prevailing over data-driven strategy. Amongst the many ways to innovate, hyperspectral imaging sensors for drill-core mineral mapping are one of the disruptive technologies. This potential could be multiplied by implementing machine learning. This dissertation introduces a workflow that allows the use of supervised learning to map minerals by means of ancillary data commonly acquired during exploration campaigns (i.e., mineralogy, geochemistry and core photography). The fusion of hyperspectral with such ancillary data allows not only to upscale to complete boreholes information acquired locally, but also to enhance the spatial resolution of the mineral maps. Thus, the proposed approaches provide digitally archived objective maps that serve as vectors for exploration and support geologists in their decision making.:List of Figures xviii List of Tables xix List of Acronyms xxi 1 Introduction 1 1.1 Mineral resources and the need for innovation . . . . . . . . . . . . . 2 1.2 Spectroscopy and hyperspectral imaging . . . . . . . . . . . . . . . . 5 1.2.1 Imaging spectroscopy ....................... 6 1.2.2 Spectroscopy of minerals ..................... 8 1.2.3 Mineral mapping.......................... 12 1.2.4 Mineral mapping in exploration ................. 15 1.2.5 Drill-core mineral mapping.................... 16 1.3 Machine learning .............................. 19 1.3.1 Supervised learning for drill-core hyperspectral data . . . . . 20 1.4 Motivation and approach ......................... 22 2 Hyperspectral mineral mapping using supervised learning and mineralogical data 25 Preface ....................................... 25 Abstract....................................... 26 2.1 Introduction ................................. 27 2.2 Data acquisition............................... 30 2.2.1 Hyperspectral data......................... 30 2.2.2 High-resolution mineralogica ldata . . . . . . . . . . . . . . . 31 2.3 Proposed system architecture ....................... 33 2.3.1 Re-sampling and co-registration ................. 33 2.3.2 Classification ............................ 35 2.4 Experimental results ............................ 36 2.4.1 Data description .......................... 36 2.4.2 Experimental setup......................... 37 2.4.3 Quantitative and qualitative assessment . . . . . . . . . . . . . 37 2.5 Discussion.................................. 40 2.6 Conclusion.................................. 42 3 Geochemical and hyperspectral data integration 45 Preface ....................................... 45 Abstract....................................... 46 3.1 Introduction ................................. 47 3.2 Basis for the integration of geochemical and hyperspectral data . . . 50 3.3 Proposed approach ............................. 51 3.3.1 Geochemical data labeling..................... 51 3.3.2 Superpixel segmentation ..................... 53 3.3.3 Classification ............................ 53 3.4 Experimental results ............................ 54 3.4.1 Data description .......................... 54 3.4.2 Data acquisition........................... 55 3.4.3 Experimental setup......................... 55 3.4.4 Assessment of the geochemical data labeling . . . . . . . . . . 58 3.4.5 Quantitative and Qualitative Assessment . . . . . . . . . . . . 58 3.5 Discussion.................................. 61 3.6 Conclusion.................................. 63 4 Improved spatial resolution for mineral mapping 65 Preface ....................................... 65 Abstract....................................... 66 4.1 Introduction ................................. 67 4.2 Methods: Resolution Enhancement for Mineral Mapping . . . . . . . 69 4.2.1 Hyperspectral Resolution Enhancement . . . . . . . . . . . . . 69 4.2.2 Mineral Mapping.......................... 71 4.2.3 Supervised Classification ..................... 71 4.3 Case Study.................................. 72 4.3.1 Data Acquisition .......................... 72 4.3.2 Resolution Enhancement Application . . . . . . . . . . . . . . 74 4.3.3 Evaluation of the Resolution Enhancement . . . . . . . . . . . 75 4.4 Results .................................... 76 4.4.1 Mineral Mapping.......................... 76 4.4.2 Supervised Classification ..................... 77 4.4.3 Validation .............................. 80 4.5 Discussion.................................. 82 4.6 Conclusions ................................. 84 5 Bibliography 92