The structure of the ophiolitic beltin Albania inferred from geomagnetic anomalies

I. Kane, A. Stampolidis, N. G. Tsokas, S. Bushati, D. Kondopoulou, P. Tsourlos

Abstract


The ground magnetic measurements in Albania were used for the compilation of the Total Magnetic Field (TMF)
anomaly map of Albania. The magnetic data were processed and interpreted in order to study the structure of the
ophiolitic belts of Albania. The ophiolites of Albania are placed at the Mirdita zone and are divided into two parallel
alignments which are called the eastern and western ophiolitic belts. They are associated with strong potential
field anomalies and their characteristics are considered crucial for a better understanding of the tectonic settings
of Albania. The ground TMF data used in this study were acquired over various campaigns (1990-1994) and
cover most of Albania's territory. The data were compiled to a map after reduction to the epoch 1990.4. The
strongest magnetic anomalies in Albania appear along the known ophiolitic belts which trend NE-SW to the north
and NW-SE to the south. Several processing steps were applied to the unified and gridded data in order to obtain
information on the distribution of the magnetic sources. The magnetic sources were subsequently modeled using
a 2.5D inversion technique. The magnetic properties of the ophiolites determined from laboratory measurements
on rock samples, while their lateral extent was calculated from the processing of the magnetic data and used as
constraints to the inversion procedure. The bottom of the ophiolitic belts is considered to be predominated by
harzburgites. They exhibit lower magnetization than other rocks of the complex, i.e. gabbros, basalt. In fact gabbros
are associated with the observed high frequency magnetic anomalies. The modeling results indicate that the
thickness of the ophiolites is reduced from east to west. The eastern ophiolitic belt has a maximum thickness of
approximately 12 km at its northern section (Kukesi and Lura massifs). The magnetic sources appear with relatively
small thickness at the western ophiolitic belt. Boundaries of the eastern ophiolites are characterized by vertical
contacts.

Keywords


Total Magnetic Field;ophioltic belt;2.5D modelling

Full Text:

PDF

References


DOI: https://doi.org/10.4401/ag-3198
We use cookies to ensure that we give you the best experience on our website. If you continue to use this site we will assume that you are happy with it (Read more).
Ok


Published by INGV, Istituto Nazionale di Geofisica e Vulcanologia - ISSN: 2037-416X