This project investigates the deep crustal structure, the sedimentary section and sediment dynamics, the tectonic control and the detailed geometry of the fluid escape pathways in an area of active mud volcanism in the Gulf of Cadiz, from where gas hydrates have been recovered. It joins the efforts of a multidisciplinary and multi-national team of scientists conducting active research in the Gulf of Cadiz, with expertise in various complementary research fields relevant to this investigation. An innovative multiscale approach to the imaging of the mud volcanic edifices, fluid conduits and largescale tectonic control on gas escape features will be applied, acquiring both deep seismic profiles, and high resolution, closely spaced, 2-D seismic surveys (pseudo-3D, using for the first time in this area two recently developed high-resolution deep-tow seismic systems: DTAGS and the new RCMG’s deep-tow system). The deep crustal structure of the area will be investigated with seismic reflection profiles and new refraction and wideangle data, acquired along existing deep multichannel seismic lines. Particular attention will be put into unravelling the links between the deep faulting in the accretionary complex/olistostrome and the mud volcanism. Active faults in the Gulf of Cadiz and off SW Portugal will be targets of further investigation and sedimentary coring, in order to determine the age of their most recent activity, which will allow constraining the recent stress field in the study area and to unravel its relationship with the mud volcanism. The transition between focused flow and diffuse flow patterns in shallow horizons, the intrinsic facies of diffuse flow pathways and the role of stratigraphic controls on flow deflection and shallow migration pathways will also be investigated. One other topic that will be investigated is the possible methane-related origin of some carbonate mound build-ups and chimneys, focussing on any potential relationship with subtle underlying structural deformations such as polygonal faulting. Also, the relative role of climate-controlled oceanographic variability versus tectonics in the episodic formation and activity of fluid venting structures will be investigated. Particular emphasis will be put into unravelling the effect of the periodic variability of the Mediterranean Outflow Water (MOW) on the dissociation of gas hydrates, particularly in the northern sector of the Gulf of Cadiz, and the contribution of the release of the methane stored in the oceanic sediments to the formation of carbonate crusts and chimneys and to the greenhouse gas effect. Using heat-flow data and high resolution bathymetry, attempts will be made to estimate the volume of gas hydrates and methane Gulf of Cadiz. Finally this project will contribute to the understanding of the role of methanotrophic and sulphide-reducing bacteria (SRB) in the building up of chemosynthetic ecosystems and "reefs" and the biomineralisation processes related to biochemical transfer between methane and organisms in the Gulf of Cadiz.
Other information
A Workshop on Margin Geofluids: the Aveiro Forum took place in Aveiro, Portugal, 1-3 April 2004, and was organised by Dr. Luis Menezes Pinheiro.
This workshop involved the MVSEIS, MOUNDFORCE and MEDIFLUX projects with representatives from WESTMED and SWIM projects. The workshop focused on Rationale for cross-project cooperations: key problems; EUROMARGINS cross-project cooperation: lines of action; shiptime and joint cruises; opportunities; publication strategy.
Project Leader:
- LuisPinheiroE-Mail
- Universidade de AveiroDep. GeosciênciasAveiroPortugal
Principal Investigators:
- JoanGardnerE-Mail
- Naval Research LaboratoryWashingtonUnited States
- Marc-AndréGutscherE-Mail
- Université de Bretagne occidentaleInstitut Universitaire Europeen de la Mer (IUEM)UMR 6538 Domaines OceaniquesPlouzanéFrance
- Jean-PierreHenrietE-Mail
- Universiteit GentFaculty of SciencesDepartment of Geology and Soil ScienceRenard Centre of Marine Geology (RCMG)GentBelgium
- LuisSomoza LosadaE-Mail
- Geological Survey of Spain (IGME)MceMEC Science and Technology MinistryMarine Geology DivisionMadridSpain
- PieterVan RensbergenE-Mail
- Universiteit GentRenard Centre of Marine Geology (RCMG)Department of Geology and Soil ScienceGentBelgium
