Astronomy and Astrophysics – Astronomy
Scientific paper
Dec 2006
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006geoji.167.1148m&link_type=abstract
Geophysical Journal International, Volume 167, Issue 3, pp. 1148-1159.
Astronomy and Astrophysics
Astronomy
2
Palaeomagnetism, Periadriatic Intrusion, Pohorje, Tectonics, Tertiary
Scientific paper
The Periadriatic lineament is a 700-km-long, first-order tectonic boundary in the Alps, along which several Tertiary intrusions are located that were emplaced while tectonic processes were active. The Pohorje pluton is one of the Periadriatic magmatic suites and comprises a pluton and a dacite stock that were emplaced at depths of about 10 and 2 km, respectively. Oriented samples were collected from 33 sites in the magmatic, and three in the surrounding metamorphic rocks and subjected them to standard palaeomagnetic and magnetic susceptibility anisotropy processing. There is extreme variation in susceptibility (although the magnetic mineral are always magnetite) and in its anisotropy within the pluton. Lowest values are in the mafic members (in the gabbro, the oldest and in some lamprophyres, the youngest member of the plutonic suite), while the tonalite (granodiorite) exhibits extreme variation, far exceeding those observed for other Periadriatic plutons. The `abnormality' of the Pohorje pluton is attributed to the complex history that involves assimilation, fractional crystallization, stratification in the magma chamber, incorporation of wall rocks, variable degree of K-metasomatism and hydrothermal alteration. Despite the above-described heterogenities and sometimes very high degree of susceptibility anisotropy (much higher that in the metamorphic samples) in the acid member, the palaeomagnetic directions observed for the pluton define three clear-cut groups. The directions show no dependence on the degree of magnetic susceptibility anisotropy. In the order of crystallization, they exhibit decreasing degree of clockwise declination deviation from north. The dacite stock is characterized by counter-clockwise rotated declinations. As the Pohorje pluton was uplifted very fast within the right-lateral Periadriatic shear zone system, it is interpreted that the palaeomagnetic directions observed for the pluton are evidence for a clockwise rotation during exhumation. The palaeomagnetic directions for the dacite, which formed after the climax of the external forces, fits the regional pattern of counter-clockwise rotation observed in the Neogene sediments around the Pohorje pluton. This shows that by the time of the dacite intrusion, the Pohorje pluton was already incorporated into the `block' that was driven by counter-clockwise rotated Adriatic microplate.
Jelen Bogomir
Márton Emö
Trajanova Mirka
Zupancic Nina
No associations
LandOfFree
Formation, uplift and tectonic integration of a Periadriatic intrusive complex (Pohorje, Slovenia) as reflected in magnetic parameters and palaeomagnetic directions 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 Formation, uplift and tectonic integration of a Periadriatic intrusive complex (Pohorje, Slovenia) as reflected in magnetic parameters and palaeomagnetic directions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Formation, uplift and tectonic integration of a Periadriatic intrusive complex (Pohorje, Slovenia) as reflected in magnetic parameters and palaeomagnetic directions will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1544334