Understanding of clayey materials properties continues to elude brick manufacturers, hence unsure of their application for brick making purposes. The raw materials were assessed geochemically, mineralogically, physically and technologically. The geochemical result showed that the fluxing oxides K 2 O, N 2 O, CaO, MgO and MnO are generally low in content with average abundance ranging from 0.06% to 1.78%. The Fe 2 O 3 content varies (4.8-25.5%) thus reflects heterogenous stability in tonality. Most of the studied samples have relatively high Al 2 O 3 content which suggest the bauxitic composition from which kaolinite minerals might have resulted from. The XRD analysis revealed the presence of kaolinite and chlorite as the major clay minerals while quartz, feldspar, talc and hornblende were present as non-clay minerals. For DTA, the threshold of new crystallization processes were attained at 1000 C. The SEM analysis revealed the presence of some stroma in all samples although with sizes >50 nm. These pores were suggested to constitute a capillary system where molten mineral occupy as temperature increases. The Atterberg's limit indicated that the studied materials are inorganic silts with high compressibility and organic clays properties since it plotted below the A-line of plasticity chart. The compressive strength (CS) for brick specimens made from kaolinite-rich material are relatively higher than chlorite-rich specimens. This was attributed to the ineffective pore connection within the kaolinite interstitial particles compared to the chlorite-rich specimen, hence increasing the density. The water absorption (WA) test on twenty brick specimens showed that the pore volume and capillarity for bricks which are chlorite-dominated were comparatively higher, thus absorbing more water molecules. These results revealed that majority of the studied clayey material are not suitable for double storey construction bricks but meet the requirements for single-storey construction when compared with SANS standards.

Carbonaceous shale is more topical than ever before due to the associated unconventional resources of methane. The use of FTIR, SEM-EDX, and mineralogical analyses has demonstrated a promising approach to assess methanogenesis potentials in a more rapid and reliable manner for preliminary prospecting. Representative core samples from the borehole that penetrated the carbonaceous Mikambeni shale Formations were investigated for methanogenesis potentials. The absorption band stretches from 1650 cm−1 to 1220 cm−1 in wavenumber, corresponding to C-O stretching and OH deformation of acetic and phenolic groups in all studied samples, thereby suggesting biogenic methanogenesis. The CO2 was produced by decarboxylation of organic matter around 2000 cm−1 and 2300 cm−1 and served as a source of the carboxylic acid that dissolved the feldspar. This dissolution process tended to release K+ ions, which facilitated the illitization of the smectite minerals. The SEM-EDX spectroscopy depicted a polyframboidal pyrite structure, which indicated a sulfate reduction of pyrite minerals resulting from microbial activities in an anoxic milieu and causes an increase in alkalinity medium that favors precipitation of dolomite in the presence of Ca and Mg as burial depth increases. The contact diagenesis from the proximity of Sagole geothermal spring via Tshipise fault is suggested to have enhanced the transformation of smectite to chlorite via a mixed layer corrensite in a solid-state gradual replacement reaction pathway. The presence of diagenetic chlorite mineral is characteristic of low-grade metamorphism or high diagenetic zone at a temperature around 200 °C to 230 °C and corresponds to thermal breakdown of kerogen to methane at strong absorption band around 2850 cm−1 and 3000 cm−1, indicating thermal methanogenesis.

South Africa has many artisanal and small-scale mining (ASM) activities that some are registered and others informal and illegal. This paper presents an overview of ASM operations in the vicinity of abandoned mine sites found in Giyani and Musina areas, Limpopo Provine of South Africa. It looks at the mining processes, environmental problems, and health and safety risks of ASM in the area. It also provideds a discussion of practical ways of dealing with the problems of artisanal and small-scale mining operations in a harmonized way with the rehabilitation of the abandoned mine sites. The exploitation of waste rock dumps for aggregate production in Musina demonstrated that formalized ASM activities can be the best alternative uses of the abandoned mine sites. However, artisanal gold mining around Giyani revealed the health and safety risks and environmental problems of these operations. The artisanal gold mining activities worsened the health and safety and the environmental problems of the abandoned mine sites. Therefore, this paper recommends that the efforts of coming up with strategies to formalize and regulate artisanal mining in South Africa be deepened for these activities to be accepteble as sustainable as post-mining land-uses in abandoned mines.

Pan African pegmatites occurring as near vertical dykes and striking mainly in the NNW-SSE direction have been studied in Apomu area with a view to evaluate their petrochemical features and possible economic potentials. These pegmatites intrude into the older lithology of granite around Apomu area Southwestern Nigeria. Petrographic determinations show they are composed of microcline, quartz and to a lesser extent plagioclase albite with interstitial muscovite, biotite and accessory minerals under transmitted light.

A total of eleven samples comprising whole rock pegmatites were analyzed for major and trace elements using Inductively Coupled Plasma-Atomic Emission Spectrometry analytical technique (ICP-AES).

From the geochemical results, the whole rock pegmatite is considerably siliceous, with an average value of 69.31%, while, MnO with a range of (0.01-0.23%), TiO₂ with a range of (0.01-0.69%), P₂O₅ with a range of (0.02-0.23%) has values that are generally low. Mean contents of major oxides, Al₂O₃ (14.34% ), Na₂O (3.31%), Fe₂O₃ (2.61%), MgO (0.78%), CaO (1.63%), and K₂O (4.80%) for the Apomu pegmatites compare favorably with the Ipetu Ijesha barren pegmatites , Kafin Maiyaki barren pegmatites and Ago-Iwoye barren pegmatites. Apomu pegmatites are fairly enriched in Rb, Sr, Zr but comparatively, poor in the rare metals Ta, Nb, Cs and Sn. Rare metal mineralization enrichment indices mainly, Ta vs Nb, Ta vs K/Cs, plots, suggests the Apomu pegmatites to be barren in rare-metal mineralization when compared with other rare-metal pegmatites across the world.

The rise in demand for natural gas has spurred the need to investigate the inland sedimentary basin for more potential sources. In response, the petrophysical parameters of the carbonaceous shale samples from two deep boreholes of Anambra Basin were evaluated. The gas-prone nature of Nkporo shale showed a thermal evolution of a Type III kerogen with initial HI value between 650 and 800 mgHC/gTOC, S2/S3 < 1, a maximum Tmax value of 488°C and have a low hydrocarbon generation potential ranging from 0.07 to 0.15. However, the average TOC content (2.21 wt%) indicated a good source rocks for hydrocarbon since it exceeds threshold limit of 0.5%. The plot of HI against Tmax shows that the organic matter belongs to the Type-III kerogen which reflects the capability of the Npkoro Formation to generate more natural gas than oil compared to Type-II kerogen. The high values (>3) of pristane/phytane ratio in both wells indicated that the organic matter belongs to terrigenous source deposited under anoxic condition which is typical of non-marine shale. The presence of Oleanane content in the Cretaceous shale sediments indicated the contribution of cell wall and woody plant tissues from the terrestrial higher plant. The low concentrations of extractable organic matter (EOM) present in form of isoprenoid and aliphatic hydrocarbon indicated little or no bitumen extract from the studied shale. Considering the high carbon preference indices (CPI) value greater than 1, the preponderance of vitrinite organic macerals and other favourable aforementioned petrophysical parameters, the non-marine Npkoro Shale Basin has significant potential to generate and expel natural gas apart from the current marine basins.