TY - JOUR

T1 - Characterizing ancient and modern hydrothermal venting systems

AU - Manton, Ben

AU - Müller, Philipp

AU - Mazzini, Adriano

AU - Zastrozhnov, Dmitry

AU - Jerram, Dougal A.

AU - Millett, John M.

AU - Schmid, Daniel W.

AU - Berndt, Christian

AU - Myklebust, Reidun

AU - Planke, Sverre

N1 - Publisher Copyright: © 2022 Elsevier B.V.

PY - 2022/5

Y1 - 2022/5

N2 - Ancient hydrothermal vent complexes have released large volumes of greenhouse gases in the past causing global warming, and similar modern vent structures are potential geohazards. In the NE Atlantic, thousands of hydrothermal vent complexes were formed during the Paleocene-Eocene Thermal Maximum. In Java, Indonesia, the erupting Lusi sediment-hosted geothermal system caused the displacement of 40,000 people. In order to determine how ancient and modern hydrothermal venting systems are related, we map a well-defined buried hydrothermal vent complex offshore mid-Norway using 3D seismic reflection data and then compare it to the active Lusi eruption (since 2006) and the neighboring inactive Porong Structure. These are characterized using 2D seismic reflection data, borehole data and field observations. The venting structures are subcircular in plan-view and a few kilometers in diameter. They are funnel-shaped in profiles, with inward-dipping beds surrounding the conduits. The hydrothermal vent complex offshore mid-Norway reveals five seismically-distinct vent fill facies units. Importantly, two of the facies units are separated by an angular unconformity, clearly indicating that the depositional events within the vent fill were distinct. Hydrothermal fluids are interpreted to have led to the fluidization of mud-rich sediments which were erupted and deposited in and around the vent complex. Interpretation of a seismically transparent body along the conduit of the Norwegian venting structure, and the abrupt widening of the conduit at the Porong Structure, are interpreted to be caused by changes in fluid-flow dynamics as the fluids rise and get released from the host-rock. The hydrothermal venting systems in Java and offshore mid-Norway are found to be morphologically similar and are interpreted to form as the result of the transport and eruption of fluidized sediments.

AB - Ancient hydrothermal vent complexes have released large volumes of greenhouse gases in the past causing global warming, and similar modern vent structures are potential geohazards. In the NE Atlantic, thousands of hydrothermal vent complexes were formed during the Paleocene-Eocene Thermal Maximum. In Java, Indonesia, the erupting Lusi sediment-hosted geothermal system caused the displacement of 40,000 people. In order to determine how ancient and modern hydrothermal venting systems are related, we map a well-defined buried hydrothermal vent complex offshore mid-Norway using 3D seismic reflection data and then compare it to the active Lusi eruption (since 2006) and the neighboring inactive Porong Structure. These are characterized using 2D seismic reflection data, borehole data and field observations. The venting structures are subcircular in plan-view and a few kilometers in diameter. They are funnel-shaped in profiles, with inward-dipping beds surrounding the conduits. The hydrothermal vent complex offshore mid-Norway reveals five seismically-distinct vent fill facies units. Importantly, two of the facies units are separated by an angular unconformity, clearly indicating that the depositional events within the vent fill were distinct. Hydrothermal fluids are interpreted to have led to the fluidization of mud-rich sediments which were erupted and deposited in and around the vent complex. Interpretation of a seismically transparent body along the conduit of the Norwegian venting structure, and the abrupt widening of the conduit at the Porong Structure, are interpreted to be caused by changes in fluid-flow dynamics as the fluids rise and get released from the host-rock. The hydrothermal venting systems in Java and offshore mid-Norway are found to be morphologically similar and are interpreted to form as the result of the transport and eruption of fluidized sediments.

KW - Geophysics (seismic)

KW - Geothermal systems

KW - Hydrothermal vents

KW - Java Indonesia

KW - NE Atlantic

KW - Volcanic continental margins

UR - http://www.scopus.com/inward/record.url?scp=85127329445&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/0bbff559-706f-3c23-9b4e-8e3ea8014ee2/

U2 - 10.1016/j.margeo.2022.106781

DO - 10.1016/j.margeo.2022.106781

M3 - Article

VL - 447

JO - Marine Geology

JF - Marine Geology

SN - 0025-3227

M1 - 106781

ER -