Journal of Mines and Geosciences

The Role of Minerals on Petroleum Generation: An implication for the pyrolysis of Asphaltene from Bitumen

2024-11-26T23:58:50-05:00

This laboratory study replicates natural petroleum generation processes using analytical pyrolysis techniques applied to sedimentary organic matter. We focus on assessing pyrite and silica's roles in petroleum formation by analyzing changes in pyrolysate during analytical pyrolysis. We vary temperature (750°C to 1000°C) and heating time (8 to 15 seconds) as key factors to relate with the natural petroleum generation processes which consider the duration or time of decomposition of organic matter with temperature. Asphaltene is employed as a primary component to simulate petroleum product generation. We investigate asphaltene's thermal degradation behavior and physical characteristics, extracting it from bitumen samples using n-hexane. Pyrite (FeS2) and silica (SiO2) minerals are matrix feedstock or adsorbent. A pyrolysis gas chromatography-mass spectrometry (PyGC/MS) is an essential tool for identifying pyrolysates. Our study highlights significant aliphatic chain products such as n-alkanes and n-alkenes up to C32 in asphaltene from an Iraq bitumen sample. Notable, the heavy hydrocarbons in the pyrolysate are aromatic.

Spatial distribution of petroleum system elements in the Pangani rift basin of north-eastern Tanzania based on interpretation of gravity and magnetic datasets

2024-03-15T03:38:51-04:00

There are limited studies on the occurrence and spatial distribution of petroleum system elements in the Pangani Rift Basin (PRB) of northeastern Tanzania. The elements include magmatic intrusions, sediment thickness, and faults and fold structures. This study aimed at assessing the petroleum potential of the PRB based on distributions of these elements. To meet the focus of this work, interpretation of gravity and magnetic datasets was employed. Results show that the basin contains thin and thick sedimentary covers ranging from 0.25 to 2.5 km, respectively. Thick sedimentary successions are found in the northern and southern parts of the basin; the central part contains thin sedimentary cover. Overall, sedimentary fills are thickening westward, toward the NNW-SSE trending master fault. Other mapped faults have the N-S and NNE-SSW trends. Results of magnetic data interpretation also show that igneous intrusions are present in the PRB and they have produced several fold structures; are dominantly increasing toward the northern part of the basin. The locations of these intrusions conform to locations of different faults suggesting tectonic influence in magmatism. The mapped and estimated features (faults, igneous intrusions, and sediment thickness) indicate possible presence of petroleum accumulations in the PRB.

The Investigations of Ore and Tailing Samples for Improving Extracting Methods and Enhancing Gold Recovery of Artisanal and Small-Scale Miners

2024-03-05T03:01:09-05:00

The Artisanal and Small-Scale Miners (ASSM) are engaged in gold mining activities across various regions in Tanzania, yet their production rates have been consistently subpar. This research aims to determine deficiencies in recovery techniques and the overall mineral extraction process, emphasizing the necessity of improving mineralized zone discovery and extraction methods through collaborative efforts among geologists, mining and mineral processing engineers, and ASSM. Leveraging geophysical and geological data, tailings, and ore studies using geostatistical software packages, this study evaluated mineralization in the Singida area to comprehend the mineralization controls and reasons for low gold metal recovery at different sites. Primary mineralization suites include As, Pb, and Sb, with Hg, Ag, and Te indicating potential pathfinders. The presence of Au-Cu-Zn polymetallic mineralization is evident. Structurally, the mineralization is predominantly governed by NE – SW first-generational structures and to some extent by NNW – SSE second-generational structures. The mineral extraction methodology targets Au recovery, yet it proves ineffective, as significant Au content remains in the tailings. This research highlights the necessity of conducting ore characterization and metallurgical tests before commencing mineral extraction processes, aiming to enhance processing and recovery methods, thus facilitating the efficient extraction of Au, Cu, and Zn in the Singida area to strengthen the economic prospects of ASSM and the country. This is a creditable practice worth emulating by other African countries to ASSM activities.

The Mafic related Metallic Mineral Deposits in the Msangano Trough, Mbozi Terrane, Tanzania: Insights from Apparent Density Mapping

2025-02-18T16:52:29-05:00

This study reports the occurrence of mafic-related metallic mineral deposits in the Msangano Trough of the Mbozi terrane, Tanzania. The study investigated the Msangano Trough by applying apparent density mapping and edge detection methods to TOPEX gravity data of the study area, utilizing Oasis Montaj software. The edge detectors were used to locate contacts, and faults, and, to calculate depths to the gravity anomalies. The apparent density values were utilized to distinguish metallic mineral deposits from non-mineralized intrusions. The results from these methods were combined to construct the structural map of the study area. The results show that the area is structurally controlled by major faults predominantly trending in the northwest-southeast direction. The area has two metallic mineral deposits, A and B, with density values ranging from 3.62 to 4.30 g/cm3. These deposits, A and B, span 109.8 and 62.2 km2, respectively. The Euler deconvolution and Direct Source Parameter Imaging indicate that the deposits are situated at an average depth of 950 m below the surface. The age of the basalts in the Mbozi terrane correlates well with the age of the Bushveld Igneous Complex in South Africa and the Sudbury Complex in Ontario, Canada. This indicates that the Msangano deposits, the Bushveld Igneous Complex, and the Sudbury Complex were all emplaced during the same era of magmatic events. This suggests that the Msangano trough is a promising area for the exploration and prospecting of metallic minerals such as chromium, platinum group metals, or nickel, which are also enriched in the Bushveld Igneous Complex and the Sudbury Complex. Additionally, the findings provide crucial information that can guide further exploration of metallic mineral deposits in the Msangano Trough and adjacent areas.