Welcome to LithoFLEX
LithoFLEX is a working tool, that is indispensable for the interpretation of gravity data in oceanic and continental areas. The tool combines gravity forward and inverse calculation with an investigation of the isostatic state. Density models derived from the gravity field are ambiguous if external geological or geophysical constraints are scarce or unavailable. However, because isostasy is a physical condition , some of the native ambiguity can be reduced by checking the compatibility of the density model with the isostatic state. We demonstrated the usefulness of our tool in the analysis of the basement in the Barents Sea and in the South China Sea, where the basement characterization is accomplished by the high-resolution analysis of the equivalent elastic thickness. Other situations for which our tool could be useful include the recovery of depth-to-basement by the inversion of the gravity field, the identification of distinctive terrains by their variation in elastic thickness, or, given a comprehensive gravity field, the interpolation of crustal thickness between seismic lines.
The first routines included in the software package made all calculation on a flat Earth. Dut to our involvement in the satellite GOCE, the development of new routines that allowed spherical calculations was necessary. The satellite GOCE measured gravity gradients along tracks, so it was also necessary to calculate gravity gradients, and not only the gravity field. The new routines were developed in cooperation with Leonardo Uieda, in the frame of the GOCE Italy project and an ESA AO-GOCE proposal in cooperation with the University of Sao Paulo (Brazil). The spherical calculations are done discretizing the Earth into tesseroids, which is the spherical equivalent of a rectangular prism.
The following achievements have been obtained with the LithoFLEX tool:
Continental Areas
Alps:
Alpine crustal structure, distinction of orogen and foreland in terms of flexural rigidity.Tibet: crustal thickness model. Identification of Tarim craton as high rigidity block explaining the seismicity pattern.
Andes:
crustal structure.
West Siberian Basin:
preliminary estimate of the volume of basalts associated with the end Permian extensive basalt flows.
Oceanic Areas
East Barents Sea:
basin characterisation and identification of lower crustal and upper mantle increased density.
South China Sea:
morphology of extinct rift buried presently below a thick blanket of sediments.
The tool is used presently at the following institutions: University of Trieste, Geological Survey of Norway, University of Trondheim, StatoilHydro, Dokuz Eylül University, San Juan University, Argentina.
The tool runs on Windows and is accompanied with an exhaustive tutorial and a Help file.
Personnel involved in the past or presently in the LithoFLEX project are:
Wolfgang Born, Carla
Braitenberg, Jörg Ebbing, Patrizia Mariani, Tim Redfield, Susann Wienecke, Yushan Yang, Leonardo Uieda.
Software development:
Carla Braitenberg, Susann Wienecke, Wolfgang Born, Yushan Yang, Leonardo Uieda
Reference:
Braitenberg C., Wienecke S., Ebbing J., Born W., Redfield T.(2007) JOINT GRAVITY AND ISOSTATIC ANALYSIS FOR BASEMENT STUDIES - A NOVEL TOOL
Extendended Abstracts, EGM 2007 International Workshop, Innovation in EM, Grav and Mag Methods: a new Perspective for Exploration, Villa Orlandi, Capri - Italy , 15-18 April 2007
For more information please contact info@lithoflex.org