Along-strike segmentation and architecture of the southeast Greenland volcanic passive margin from both gravity and aeromagnetism data
Abstract
During the early Tertiary, the East Greenland volcanic passive margin developed whereas the Atlantic opened between Greenland and Eurasia. As a typical volcanic margin, the East Greenland margin is characterised by an anomalously thick crust including 1) thick wedges of seaward-dipping volcanic and volcano-sedimentary formations continuing offshore as seaward-dipping reflector sequences (SDRSs) and extending at least 2600 km along-strike, 2) an intense plumbing of the onshore crust by mafic intrusions, comprising an extensive margin-parallel mafic dyke swarm, and 3) a high P-wave velocity body within the lower crust, interpreted as underplated igneous material. In recent studies, the along-strike architecture of the exposed E Greenland volcanic margin has been examined in terms of along-strike distributions of magmatism, structural and geological features. Here, we have investigated the along-strike structure of the SE-Greenland margin through an integrated analysis of satellite-derived gravity and aeromagnetic anomalies. Aims of this study were to reveal the existence or absence of an along-strike segmentation, define its characteristic wavelenghts and compare them that of the adjacent Mid Atlantic spreading ridge. Various scales of segmentation along the Greenland margin were revealed, with an intermediate scale (~100 km) and a smaller scale (25-50 km). These characteristic wavelenghts are in good agreement to segmentation observed at other volcanic passive margins and suggest that common processes acted during the continental break-up. We also present preliminary results of the magnetic modeling of the crustal structure across and along the SE-Greenland volcanic margin, interpreting the observed magnetic anomalies as semi-periodic variations in space of the dimensions of the magma bodies (high P-wave velocity body and SDRSs) constituting the margin.
- Publication:
-
EGS - AGU - EUG Joint Assembly
- Pub Date:
- April 2003
- Bibcode:
- 2003EAEJA....11723P