Space-time variations in British Caledonian Granites: some geophysical correlations

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

8

Scientific paper

The characteristics of 30 ``granites'' from the postulated Caledonian (Iapetus Ocean) suture zone of mainland Britain are discussed. Geophysical (gravity, aeromagnetic), geochemical (U/Pb and initial 87Sr/86Sr) and isotopic age data indicate that these British Caledonian intrusions (390-600 Ma) can be divided into two distinct groups temporally, each of which is further subdivided spatially. The temporal division applies throughout the British province and separates a pre-Silurian (group 1) suite of low-volume, low-mobility magmas, which were intruded under compressive conditions, from a Siluro-Devonian (group 2) suite of large volume, mobile magmas intruded under tensional conditions. The spatial subdivisions of groups 1 and 2 are made between intrusions emplaced to either side of the postulated ENE-WSW Iapetus Ocean suture which runs through the Solway Firth. First, the group 1 granites northwest of the suture probably were produced by partial fusion involving Proterozoic continental crust (group 1N) whereas those to the southeast have isotopic characteristics simply indicating a mantle or ocean crustal source (group 1S). Second, the Siluro-Devonian granites, which were all derived largely at the expense of Caledonian mantle, have different aeromagnetic expressions depending on their position in the northwest (2N) or southeast (2S) Caledonides. These aeromagnetic characteristics are probably related to the differences in basement structure recently identified by seismic surveys and they provide further evidence for the former existence and Siluro-Devonian closure of Iapetus. Another significant implication may be that Proterozoic basement is lacking from beneath the region immediately adjacent to and southeast of the suture - southern Scotland and most of England.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Space-time variations in British Caledonian Granites: some geophysical correlations does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Space-time variations in British Caledonian Granites: some geophysical correlations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Space-time variations in British Caledonian Granites: some geophysical correlations will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1387787

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.