The results of a combined geophysical and geochemical research program
are presented that focused on Grimsey hydrothermal field (GHF) which
is located at 66 degrees 35'30"N, 17 degrees 39'30"W east of the
island of Grimsey in the Tjornes Fracture Zone. The vent field is
situated at the sourthernmost tip of a submarine ridge which is connected
to the offshore part of the Theistareykir Fissure Swarm. Reflection
seismic recordings were interpreted in conjunction with Earthquake
catalogue data to detect active fault structures and potential heat
sources in the subsurface. An inter-linked fracture network forming
a downwards converging system of faults connected to a deep-reaching
normal fault is assumed to provide the preferential pathways for
gases (He-3, CO2, CH4 etc.) migrating from a possible deep-seated
gas source (lower crust/upper mantle) to the surface. The location
of hydrothermal vents was detected by concentration measurements
of dissolved methane in the water column, which coincide with polarity
reversals in the seismic seafloor reflection. Both the molecular
composition of the gas and the isotopic composition of methane at
GHF indicate a predominating abiogenic source (Fischer-Tropsch reactions
at 250-500 degreesC) mixed with thermogenic hydrocarbons. New seismic
data from the GHF were compared with gas geochemical data which indicate
that the thermogenic hydrocarbons are related to (up to 60 m thick)
sediments deposited in a basin located east of the ridge. (C) 2001
Elsevier Science B.V. All rights reserved.
%0 Journal Article
%1 Riedel2001
%A Riedel, C.
%A Schmidt, M.
%A Botz, R.
%A Theilen, F.
%D 2001
%J Earth and Planetary Science Letters
%K imported
%N 3-4
%P 409--421
%T The Grimsey hydrothermal field offshore North Iceland: crustal structure, faulting and related gas venting
%V 193
%X The results of a combined geophysical and geochemical research program
are presented that focused on Grimsey hydrothermal field (GHF) which
is located at 66 degrees 35'30"N, 17 degrees 39'30"W east of the
island of Grimsey in the Tjornes Fracture Zone. The vent field is
situated at the sourthernmost tip of a submarine ridge which is connected
to the offshore part of the Theistareykir Fissure Swarm. Reflection
seismic recordings were interpreted in conjunction with Earthquake
catalogue data to detect active fault structures and potential heat
sources in the subsurface. An inter-linked fracture network forming
a downwards converging system of faults connected to a deep-reaching
normal fault is assumed to provide the preferential pathways for
gases (He-3, CO2, CH4 etc.) migrating from a possible deep-seated
gas source (lower crust/upper mantle) to the surface. The location
of hydrothermal vents was detected by concentration measurements
of dissolved methane in the water column, which coincide with polarity
reversals in the seismic seafloor reflection. Both the molecular
composition of the gas and the isotopic composition of methane at
GHF indicate a predominating abiogenic source (Fischer-Tropsch reactions
at 250-500 degreesC) mixed with thermogenic hydrocarbons. New seismic
data from the GHF were compared with gas geochemical data which indicate
that the thermogenic hydrocarbons are related to (up to 60 m thick)
sediments deposited in a basin located east of the ridge. (C) 2001
Elsevier Science B.V. All rights reserved.
@article{Riedel2001,
abstract = {The results of a combined geophysical and geochemical research program
are presented that focused on Grimsey hydrothermal field (GHF) which
is located at 66 degrees 35'30"N, 17 degrees 39'30"W east of the
island of Grimsey in the Tjornes Fracture Zone. The vent field is
situated at the sourthernmost tip of a submarine ridge which is connected
to the offshore part of the Theistareykir Fissure Swarm. Reflection
seismic recordings were interpreted in conjunction with Earthquake
catalogue data to detect active fault structures and potential heat
sources in the subsurface. An inter-linked fracture network forming
a downwards converging system of faults connected to a deep-reaching
normal fault is assumed to provide the preferential pathways for
gases (He-3, CO2, CH4 etc.) migrating from a possible deep-seated
gas source (lower crust/upper mantle) to the surface. The location
of hydrothermal vents was detected by concentration measurements
of dissolved methane in the water column, which coincide with polarity
reversals in the seismic seafloor reflection. Both the molecular
composition of the gas and the isotopic composition of methane at
GHF indicate a predominating abiogenic source (Fischer-Tropsch reactions
at 250-500 degreesC) mixed with thermogenic hydrocarbons. New seismic
data from the GHF were compared with gas geochemical data which indicate
that the thermogenic hydrocarbons are related to (up to 60 m thick)
sediments deposited in a basin located east of the ridge. (C) 2001
Elsevier Science B.V. All rights reserved.},
added-at = {2009-11-03T20:21:25.000+0100},
author = {Riedel, C. and Schmidt, M. and Botz, R. and Theilen, F.},
biburl = {https://www.bibsonomy.org/bibtex/28a5e7ae274b14c185dbe576eee10b432/svance},
interhash = {36c6650703f0d8b64b03c209baf55648},
intrahash = {8a5e7ae274b14c185dbe576eee10b432},
journal = {Earth and Planetary Science Letters},
keywords = {imported},
number = {3-4},
owner = {svance},
pages = {409--421},
timestamp = {2009-11-03T20:22:12.000+0100},
title = {The Grimsey hydrothermal field offshore North Iceland: crustal structure, faulting and related gas venting},
volume = 193,
year = 2001
}