ITERATIVE GEOLOGICAL MAPPING AND 3D STRUCTURAL MODELING TO IDENTIFY SPATIAL INCONSISTENCIES AND CREATE ACCURATE VISUALIZATION FRAMEWORK FOR GEOARCHAEOLOGICAL INTERPRETATIONS: MT. LYKAION (GREECE) SANCTUARY OF ZEUS CASE STUDY: PART 2, MODELING

The detailed geological mapping initiated in 2004 at the Sanctuary of Zeus at Mt. Lykaion (Peloponessos, Greece) lends itself to 3D structural modeling, given quality of exposures, significant topographic relief, distinctive stratigraphy, variety of classic large-scale geologic structures, and density and coverage of map data. Applying MOVE software to field data provided in digital form, Midland Valley Exploration Ltd (MVE) created a 2.5D geological map draped onto a DEM so that visualization of the relationship between geology and topography became more obvious. First, a deep 3D model was constructed by drawing cross sections trying to honor all field data projected along the section planes; and correlating horizons and faults between adjacent cross sections. Second, a shallow skeletal 3D model was created, highlighting “ribbon surfaces”, which represent the shallowest portions of the 3D-forms of stratigraphic and fault contacts. The orientations of each segment of ribbon surfaces were compared (and, if necessary, adjusted) with respect to floating “attitude patches” based upon relevant strike-and-dip control. The final preliminary model, completed before the 2009 mapping season, represented the integration of the deep and shallow 3D models.

Following the 2009 mapping season, the MOVE modeling was repeated based upon new field data including updates on bedding readings, geological contacts, fold axial traces and landscape photos displaying the expression of bedding and structure. The new data were collected specifically to address issues of coherence and ambiguity recognized during the first pass modeling. The direct comparison of the results of modeling before and after the 2009 field season highlights the value of such interaction between mapping and modeling. The modeling component enables the use of rigorous techniques to build a valid 3D model of the sub-surface. Furthermore, it aids in the visualizing of 3D structures mapped in the field. By displaying structural and stratigraphical relationships in 3D, geologists can communicate more effectively to other professionals in other fields, for which the geology component is essential for planning and/or management of use of land, water, and natural resources.