Updated Bouguer anomalies of the Iberian Peninsula: a new perspective to interpret the regional geology

Abstract

Bouguer anomaly maps are powerful cartographic tools used mainly by geoscientists and natural resources' companies (oil, mining, etc.) since they reflect rock density distribution at different depths, allowing the identification of different tectonic features. At upper crustal levels, Bouguer anomaly maps can help, for instance, in characterizing possible ore deposits, ground water reservoirs, petroleum resources, CO 2 storage sites and sedimentary basins; at deeper crustal levels they can help to further refine seismic velocity models or other integrated geophysical models and thus help in deciphering the lateral density variations within the crust and the geometry of the base of the crust. This new Bouguer anomaly map at a 1:1,500,000 scale is based on the compilation of 210,283 gravity stations covering the Iberian Peninsula (c. 583,254 km 2 ). The new map upgrades previous maps in two ways: (1) it is built up from a database with a 15% more spatial coverage than previous compilations and (2) it is freely available. This map show shorter wavelengths than previous published maps thus allowing investigation of smaller geological features. ARTICLE HISTORY

Heat Flow, Geotherms, Density and Lithosphere Thickness in SW of Iberia (South of Portugal)

“…Gravity data were obtained from the gravity maps of the Iberian Peninsula (Ayala et al, 2016;Torné et al, 2015). The maps show a gravity high located in the SW part of the Iberian Peninsula.…”

Crustal structure of the SW Iberian passive margin: The westernmost remnant of the Ligurian Tethys?

“…Onshore Bouguer gravity anomalies have been taken from a recent compilation of gravity data on Iberia (Ayala et al, 2016). Offshore, free-air gravity anomalies come from the global satellite altimetry data model V16.1 Sandwell, 1997, updated 2007) (Fig.…”

Basin filling evolution of the central basins of Mallorca since the Pliocene

“…In this work, 3,523 gravity measurement points were available from Ayala et al. () for Mallorca, covering 3,549 km 2 . Because the grid is not homogeneous, the resulting mean data density is 0.78 points per km 2 .…”

“…Our geophysical observations are based on an analysis of gravity anomalies. The scale of the map presented by Ayala et al (2016) is 1:1,500,000, although the use of a weighted average grid space between TIN nodes of 2,000 m can theoretically resolve structures with wavelengths twice the size of the grid space (Ayala, 2013), which is 4,000 m in this case. This resolution is a mean for the entirety of Spain and the Balearic Islands, and there are zones with higher point densities.…”