Time filter

Source Type

Pereira Z.,National Laboratory of Energy and Geology | Fernandes P.,University of Algarve | Lopes G.,University of Bergen | Marques J.,Gondwana Empreendimentos e Consultorias Limitada | Vasconcelos L.,Eduardo Mondlane University
Review of Palaeobotany and Palynology | Year: 2016

The Permian-Triassic transition has been identified for the first time in the Karoo Supergroup of the Moatize-Minjova Basin in Mozambique. This transition was identified in the subsurface in deep (ca. 500 m) coal exploration boreholes that penetrated the Matinde Formation. Two palynomorph assemblages (assemblage 1 and assemblage 2) assigned to the latest Permian were defined for the Matinde Formation. These assemblages are both dominated by taeniate pollen, cavate trilete spores of Kraeuselisporites spp., associated with conifer (Lueckisporites virkkiae) and pteridosperm pollen (Guttulapollenites hannonicus and Weylandites lucifer). Assemblage 3 represents a microfloral turnover. For the first time specimens of Lunatisporites pellucidus appear in an assemblage dominated by lycopod spore taxa such as Lundbladisporites spp. This assemblage was assigned to the Early Triassic and occurs at the top of borehole DW 132 within the Matinde Formation. The palynostratigraphic signature obtained for the Permian-Triassic transition puts the Moatize-Minjova Basin in the central Gondwana palaeobiogeographic province with strong affinities with the Karoo basins of Madagascar and the Salt Range Basin in Pakistan. These new data indicate that coal deposits accumulated in the Moatize-Minjova Basin until the latest Permian and that these are possibly more extensive temporally than previously described, opening new perspectives for coal and unconventional hydrocarbon exploration in this basin. © 2015 Elsevier B.V. Source

Two coal exploration boreholes (DW123 – T.D. 489 m and DW132 – T.D. 516 m) drilled in the Moatize – Minjova Coal Basin (Tete Province, Mozambique) were studied by means of vitrinite reflectance (VR) and apatite fission track analysis (AFTA), in order to assess their burial and uplift histories. VR shows a linear increase in the two borehole sections indicating medium to low volatile coal rank. Modelled VR data indicate palaeogeothermal gradients between 40 and 56ºC/km. Inverse modelling of both VR and fission track data indicate that samples have been heated to a maximum temperature of 150 to 180°C following deposition. Maximum temperature was reached at 260 Ma, then a first phase of cooling occurred between 255 and 230 Ma. The sections subsequently cooled very slowly until Neogene time. At 7 Ma, a second, fast cooling episode reduced rock temperatures from 50 – 60°C to present day temperature. This second cooling episode is possibly related to exhumation caused by the uplift and erosion of the East-African Rift shoulders. © 2014 LNEG – Laboratório Nacional de Geologia e Energia IP. Source

The lower Permian Moatize Formation is an important stratigraphic unit of the Karoo Supergroup of the Moatize – Minjova Coal Basin, Tete Province, Mozambique. The shales from this formation yielded type II - III kerogen, high TOC values (1.3 – 31 wt.%) and Hydrogen Index (HI) low to moderate (70 – 270 mg HC/g TOC) and can be regarded as an important gas prone source rock. The Vúzi Formation, the older stratigraphic unit of the Karoo Supergroup, has no hydrocarbons source rock potential. © 2014 LNEG – Laboratório Nacional de Geologia e Energia IP. Source

Pereira Z.,National Laboratory of Energy and Geology | Lopes G.,National Laboratory of Energy and Geology | Lopes G.,University of Algarve | Fernandes P.,University of Algarve | Marques J.,Gondwana Empreendimentos e Consultorias Limitada
Comunicacoes Geologicas | Year: 2014

The first palynostratigraphical data collected from borehole ETA 72 of the Lower Karoo of the Moatize-Minjova Coal Basin are here presented. Two palynological assemblages were collected from the upper glacial sediments of Vúzi Tillite Formation and lower post-glacial sediments of Moatize Sandstone Formation, respectively, both yielding a Kungurian/Roadian (Lower - Middle Permian) age. The main objectives of this palynostratigraphical study which also involves the study of several other boreholes drilled in this part of the basin, is to constrain the age of the end of the Late Palaeozoic Gondwana glaciation in Mozambique and to better understand the subsurface geology and structure of the Moatize- Minjova Coal Basin, especially the correlation of the exploited coal seams. New data are expected during the course of this study. © 2014 LNEG – Laboratório Nacional de Geologia e Energia IP. Source

Discover hidden collaborations