Por favor, use este identificador para citar o enlazar a este item:
http://hdl.handle.net/10261/348368
COMPARTIR / EXPORTAR:
SHARE BASE | |
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL | DATACITE | |
Título: | Paleoenvironmental and diagenetic evolution of the Aptian Pre-Salt succession in Namibe Basin (Onshore Angola) |
Autor: | Moragas, Mar CSIC ORCID ; Baqués, Vinyet CSIC ORCID; Martín-Martín, J. D.; Sharp, Ian; Lapponi, F.; Hunt, David; Zeller, Michael; Vergés, Jaume CSIC ORCID ; Messager, G.; Gindre-Chanu, L.; Swart, Roger; Machado, Vladamir | Palabras clave: | Diagenesis Namibe basin Onshore Angola Palaeovalley Pre-salt Sedimentology |
Fecha de publicación: | 2023 | Editor: | Elsevier BV | Citación: | Marine and Petroleum Geology, 150: 106153 (2023) | Resumen: | The Aptian Pre-Salt sedimentary succession cropping out in Cangulo palaeovalley onshore Namibe Basin (Angola) was studied by a combination of field and analytical techniques to constrain the sedimentary and diagenetic evolution of the uppermost sag sequence of the South Atlantic passive margin. Field observations allows definition of four transgressive-regressive cycles characterised by fluvial to tidal-influenced mixed clastic-carbonate and carbonate-dominated deposits, that locally show evidence of evaporite dissolution; highlighting that evaporite deposition started earlier than deposition of the regional South Atlantic Loeme-Bambata evaporite formations. Two separate pre-salt carbonate units have been differentiated within the Cangulo Fm; i) a lower transitional to marginal marine, and ii) a younger upper non-marine freshwater travertine system, that is documented for the first time in the west African margin. Transgressive-regressive cycles control the early diagenesis of the tidal carbonates that include dolomitization due to mixing fluids during transgressions, and karstification due to evaporite dissolution by meteoric water circulation during regressive events. Clastic supply appears to have been completely shut down during carbonate deposition, suggesting major climatic change associated with carbonate deposition. During the lowstand between the two carbonate units, fluid flow through Cangulo palaeovalley was re-established resulting in extensive karstification and formation of a large-scale erosional unconformity that is interpreted to be time equivalent to an intra Chela-Cuvo Fm. event. The top of the studied succession corresponds to the transgressive deposits of the Bambata evaporites that are not preserved in the Cangulo palaeovalley due to its erosion but are regionally developed. The results of this study can be directly linked to along strike age equivalent Pre-Salt successions cropping out in the Namibe, Benguela and Kwanza basins, and directly offshore Angola and Brazil using well and seismic data. These new data shed important new light and constraints on the depositional and diagenetic evolution of the complex Pre-Salt reservoir systems of the South Atlantic, and the depositional and bathymetric setting at the time of onset of the main south Atlantic evaporite deposition. | Versión del editor: | http://dx.doi.org/10.1016/j.marpetgeo.2023.106153 | URI: | http://hdl.handle.net/10261/348368 | Identificadores: | doi: 10.1016/j.marpetgeo.2023.106153 issn: 0264-8172 |
Aparece en las colecciones: | (Geo3Bcn) Artículos |
Ficheros en este ítem:
Fichero | Descripción | Tamaño | Formato | |
---|---|---|---|---|
Marine and Petroleum Geology_150_106153_2023.pdf | 47,96 MB | Adobe PDF | Visualizar/Abrir |
CORE Recommender
Este item está licenciado bajo una Licencia Creative Commons