HR: 1340h
AN: T43B-1327 [Abstracts]
TI: Relationships between heat flow, thermal and pressure fields in the Gulf of Mexico
AU: * husson, l
EM: husson@cdf.u-3mrs.fr
AF: College de France, Chaire de G‚odynamique
Europole de l'Arbois
Bat Laennec - Hall D - BP 80
, Aix en Provence, 13545
France
AU: henry, p
EM: henry@cdf.u-3mrs.fr
AF: College de France, Chaire de G‚odynamique
Europole de l'Arbois
Bat Laennec - Hall D - BP 80
, Aix en Provence, 13545
France
AU: le pichon, x
EM: lepichon@cdf.u-3mrs.fr
AF: College de France, Chaire de G‚odynamique
Europole de l'Arbois
Bat Laennec - Hall D - BP 80
, Aix en Provence, 13545
France
AB:
The thermal field of the Gulf of Mexico (GoM) is restored from a comprehensive temperature-depth database. A striking feature
is the systematic sharp gradient increase between 2500 and 4000 m. The analysis of the pressure (fracturation tests and mud
weights) indicates a systematic correlation between the pressure and temperature fields, as well as with the thickness of
Plio-Pleistocene sedimentary layer, and is interpreted as the fact of cooling from fluid flow in the upper, almost
hydrostatically pressured layer. The Nusselt number, that we characterize by the ratio between the near high-P gradient over
low-P gradient varies spatially and is correlated to the structural pattern of the GoM; this observation outlines the complex
relationships between heat and fluid flows, structure and sedimentation. The deep thermal signal is restored in terms of
gradient and heat flow density from a statistical analysis of the thermal data combined to the thermal modelling of about 175
wells. At a regional scale, although the sedimentary cover is warmer in Texas than in Louisiana in terms of temperature, the
steady state basal heat flow is higher in Louisiana. In addition, beneath the Corsair Fault, which lay offshore parallel to
the Texan coast, the high heat flow suggests a zone of Tertiary lithospheric thinning.
DE: 8105 Continental margins and sedimentary basins
DE: 8109 Continental tectonics--extensional (0905)
DE: 8120 Dynamics of lithosphere and mantle--general
DE: 8130 Heat generation and transport
DE: 8135 Hydrothermal systems (8424)
SC: Tectonophysics [T]
MN: 2004 AGU Fall Meeting