Hydrothermal vent complexes associated with sill intrusions in sedimentary basins

Author:

Jamtveit Bjørn1,Svensen Henrik1,Podladchikov Yuri Y.1,Planke Sverre12

Affiliation:

1. Physics of Geological Processes (PGP), University of Oslo PO Box 1048 Blindern, 0316 Oslo, Norway bjorn.jamtveit@geo.uio.no

2. Volcanic Basin Petroleum Research, Oslo Research Park Gaustadalleen 21, 0349 Oslo, Norway

Abstract

AbstractSubvolcanic intrusions in sedimentary basins cause strong thermal perturbations and frequently cause extensive hydrothermal activity. Hydrothermal vent complexes emanating from the tips of transgressive sills are observed in seismic profiles from the Northeast Atlantic margin, and geometrically similar complexes occur in the Stormberg Group within the Late Carboniferous-Middle Jurassic Karoo Basin in South Africa. Distinct features include inward-dipping sedimentary strata surrounding a central vent complex, comprising multiple sandstone dykes, pipes, and hydrothermal breccias. Theoretical arguments reveal that the extent of fluid-pressure build-up depends largely on a single dimensionless number (Ve) that reflects the relative rates of heat and fluid transport. For Ve >> 1, ‘explosive’ release of fluids from the area near the upper sill surface triggers hydrothermal venting shortly after sill emplacement. In the Karoo Basin, the formation of shallow (< 1 km) sandstone-hosted vents was initially associated with extensive brecciation, followed by emplacement of sandstone dykes and pipes in the central parts of the vent complexes. High fluid fluxes towards the surface were sustained by boiling of aqueous fluids near the sill. Both the sill bodies and the hydrothermal vent complexes represent major perturbations of the permeability structure of the sedimentary basin, and are likely to have long time-scale effects on its hydrogeological evolution.

Publisher

Geological Society of London

Subject

Geology,Ocean Engineering,Water Science and Technology

Reference31 articles.

1. Reciprocal flexural behaviour and contrasting stratigraphies: a new basin development model for the Karoo retroarc foreland system, South Africa;Catuneaunu;Basin Research,1998

2. Morphotectonics and mechanism of emplacement of the dolerite rings and sills of the western Karoo, South Africa;Chevallier;South African Journal of Geology,1999

3. Rapid intrusion of magma into wet rock: Groundwater flow due to pore pressure increases

4. Dingle R.V. Siesser W.G. Newton A.R. (1983) Mesozoic and Tertiary Geology of Southern Africa (A.A. Balkema, Rotterdam).

5. The timing and duration of the Karoo igneous event, southern Gondwana

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3