Abstract
Hyperextended margins are very heterogeneous along the entire length of the margin, so the definition of tectonic domains made exclusively from 2D seismic sections presents serious limitations. In this work we present an approach of the 3D crustal-scale structure of the West Iberia margin (WIM) by modelling eight lithospheric sections, using seismic, wells and gravity data. The continuous nature of gravity data allowed us to propose a new map of tectonic domains within the WIM. Maps of total horizontal (THD) and vertical gradients (dZ) of Bouguer anomaly have been calculated and compared with other criteria such as the crustal structure and thinning factor. This comparative analysis has been carried out on a section proposed as a model for the Western Iberian Margin (Tugend et al. in Tectonics, 2014; Cadenas et al. in Tectonics 37:758–785, 2018), and on four 2 + 1/2D gravimetric models transversal to the margin. The results point out a significant variation in the absolute values of Bouguer anomaly, thinning factor and crustal structure along the margin and, therefore, of the position of the different domain boundaries. Clear patterns that correlating the Bouguer anomaly signal and its derivatives to the tectonic domain are evidenced. Most significantly, the necking-zone and its transition to the hyperextended domain are characterized by high values of the THD of the Bouguer anomaly. The observed patterns in Bouguer anomaly and its derivatives provide a solid constraint for mapping the boundaries between different tectonic domains along the margin, even in those areas where limited deep seismic information could lead to uncertain interpretations. The results of this work can also inform on the general kinematics of the WIM.
Original language | English |
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Article number | 10 |
Number of pages | 30 |
Journal | Marine Geophysical Researches |
Volume | 42 |
Issue number | 2 |
DOIs | |
Publication status | Published - Jun 2021 |
Austrian Fields of Science 2012
- 105111 Gravimetry
- 105124 Tectonics
- 105102 General geophysics
Keywords
- ATLANTIC
- DEEP-STRUCTURE
- EVOLUTION
- GALICIA CONTINENTAL-MARGIN
- Gravity modelling
- Hyperextended margin
- INTERIOR BASIN
- Integrated structural characterization
- MAGNETIC-ANOMALIES
- NONVOLCANIC MARGINS
- OCEAN
- RIFTED MARGINS
- SEISMIC VELOCITY STRUCTURE
- Tectonic domains
- West Iberian margin