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Implications of palaeomagnetic data from the Tortworth Silurian inlier (southern Britain) to palaeogeography and Variscan tectonism

dc.contributor.authorTorsvik, Trond H.en_US
dc.contributor.authorTrench, Allanen_US
dc.contributor.authorMckerrow, W. S.en_US
dc.date.accessioned2010-06-01T22:11:18Z
dc.date.available2010-06-01T22:11:18Z
dc.date.issued1994-10en_US
dc.identifier.citationTorsvik, T. H.; Trench, A.; Mckerrow, W. S. (1994). "Implications of palaeomagnetic data from the Tortworth Silurian inlier (southern Britain) to palaeogeography and Variscan tectonism." Geophysical Journal International 119(1): 91-100. <http://hdl.handle.net/2027.42/75207>en_US
dc.identifier.issn0956-540Xen_US
dc.identifier.issn1365-246Xen_US
dc.identifier.urihttps://hdl.handle.net/2027.42/75207
dc.description.abstractPalaeomagnetic data are presented from early Silurian (Upper Llandovery) lavas from the Tortworth Silurian inlier of south-west England. Two magnetization components are recognized on the basis of contrasting demagnetization characteristics. A lower unblocking-temperature component (<350°C) is oriented parallel to the Earth's present magnetic field at the sampling site ( N = 46, declination = 352°, inclination = 69°, k = 52.1, Α 95 = 2.9°). A higher unblocking-temperature component (350–600°C) is inferred to be primary on the basis of a stratigraphy-parallel reversal pattern (combined tilt-corrected mean: N = 42, declination = 056°, inclination = -30°, k = 22.6, Α 95 = 4.7°). Geological implications of these new data are as follows. (1) the calculated Upper Llandovery ( c. 430 Ma) palaeolatitude for the site (16°S) is consistent with tectonic models invoking pre-Wenlock closure of the Iapetus Ocean across Britain. (2) the declination of the primary magnetization indicates substantial clockwise rotation within this sector of the Variscan thrust belt. Rotation is most likely to be linked to early Variscan northward thrust transport with components of dextral transpression. the amount of clockwise rotation is approximately 85° in the south (Mendips) and decreases to 33-63° in the north (Tortworth). (3) the polarity of the primary magnetization (Lower Trap lava: reversely polarized; Upper Trap lava: normally polarized is consistent with that expected from a preliminary analysis of the Silurian magnetic-field reversal pattern.en_US
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dc.format.extent3109 bytes
dc.format.mimetypeapplication/pdf
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dc.publisherBlackwell Publishing Ltden_US
dc.rights1994 Royal Astronomical Societyen_US
dc.subject.otherPalaeogeographyen_US
dc.subject.otherPalaeomagnetismen_US
dc.subject.otherUKen_US
dc.titleImplications of palaeomagnetic data from the Tortworth Silurian inlier (southern Britain) to palaeogeography and Variscan tectonismen_US
dc.typeArticleen_US
dc.subject.hlbsecondlevelGeology and Earth Sciencesen_US
dc.subject.hlbtoplevelScienceen_US
dc.description.peerreviewedPeer Revieweden_US
dc.contributor.affiliationumDepartment of Geological Sciences, University of Michigan, Ann Arbor, MI 48109, USAen_US
dc.contributor.affiliationotherExploration Department, Western Mining Corporation, Kambalda, WA 6442, Australiaen_US
dc.contributor.affiliationotherDepartment of Earth Sciences, University of Oxford, Parks Road, Oxford, OX1 3PR, UKen_US
dc.description.bitstreamurlhttp://deepblue.lib.umich.edu/bitstream/2027.42/75207/1/j.1365-246X.1994.tb00915.x.pdf
dc.identifier.doi10.1111/j.1365-246X.1994.tb00915.xen_US
dc.identifier.sourceGeophysical Journal Internationalen_US
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dc.owningcollnameInterdisciplinary and Peer-Reviewed


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