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Another Advantage of 3D Model Building: Communicating Geological Research Results to Non-Geologist Colleagues and Project Directors

George H. Davis¹, Alan Gibbs², and David G. Romano³
¹Department of Geosciences, The University of Arizona, Tucson, AZ
²Midland Valley Exploration, Ltd., Glasgow, Scotland, UK
³School of Anthropology, The University of Arizona, Tucson, AZ

Abstract

Cross-disciplinary research has become a way of life in accomplishing mission-based research goals (both applied and basic) in academia and the private sector. Success in such research is predicated on the capacity of interdisciplinary colleagues to communicate effectively with one another. A number of factors favor communication across disciplinary boundaries, especially the consuming 'drive' of a team to be successful, thus applying effort strenuously to common purpose. Some factors work against requisite communication, especially barriers borne of discipline-specialized taxonomies, methodologies, and idiosyncratic work products. For geoscientists collaborating with non-geologist colleagues in team-based efforts, communicating the meaning and significance of geologic map products can be the supreme challenge, primarily because geological maps appear to be two-dimensional, when in fact they are four-dimensional in character. Thus non-geologists normally will not be able to visualize the structural geometries, let alone the geological history that emerges from 'seeing' the 3D and 4D nature of geological contacts (faults, unconformities, welds, and intrusive contacts). In this contribution we emphasize that this problem can be surmounted when basic geological map products are transformed into 3D structural models, and presented through animations.

The example we present here is one that has emerged from a University of Arizona and Midland Valley Exploration partnership centered on the Mt. Lykaion Survey and Excavation Project, Arcadia, Greece (Romano, Co-Director). The (ongoing) Mt. Lykaion Project began in 2004 with the goal of understanding all aspects of the human and cultural history of the Sanctuary of Zeus, Mt. Lykaion. On the summit of the mountain is a Late Bronze-Age (through Hellenistic) mountaintop sanctuary, containing an ash altar, temenos, stadium, and column bases. A lower sanctuary (mainly Hellenistic) contains the only visible and extant hippodrome in the Greek world, along with a bath, fountains, stoa, xenon, stadium, and processional way. The high relief and steep topographic landscape of Mt. Lykaion reflects contemporary active-tectonic extensional stretching of Greece. This is clear from seismicity and from the presence of active normal faults. The bedrock geology of the Sanctuary of Zeus conforms to the characteristics of Pindos Belt folding and thrusting, and features large upright to overturned anticlines and synclines as well as stacked thrust sheets. The strata (Neotethyan) range from Jurassic through Paleocene and are deformed as a result of inversion tectonics during latest Cretaceous and early Tertiary. The intimacy of interrelationships of geology and archaeology is immediately apparent to geologists, for the upper sanctuary occupies a thrust klippe, and the master thrust surface (planar and dipping 10°) sharply separates the upper and lower sanctuaries. Fountains (springs) emanate along the thrust trace, and ancient built structures (such as the stoa and hippodrome) occupy the immediate footwall of the thrust.

In 2008 the first author (Davis) was completing his mapping of the Sanctuary of Zeus, and he anticipated the challenge of communicating the geological map relationships to the ~50 team members (professionals and students) drawn from a broad range of disciplines: archaeology, classics, architecture, design, art, history, conservation, landscape ecology, paleobotany, geochronology, philosophy, and more. It was with this communication challenge in mind, as well as testing the efficacy of the geologic map, that Davis sought help from Gibbs, CEO, Midland Valley Exploration (MVE). A partnership was established through which MVE applied its MOVE software to Davis' field data, which Davis provided to MVE in ARCmap shapefiles. MVE created a 2.5D geological map draped onto a DEM so that visualization of the relationships between geology and topography became more obvious. Then, again using its MOVE technology, MVE built virtual cross-sections in ways that conformed as tightly as possible to all surface data, including mapped locations and measurements of contacts, bedding, and formation thicknesses. Furthermore MVE, through trial-and-error testing, applied isogonal best fit solutions to macroscopic fold shapes in ways consistent with map relationships, inferred mechanical stratigraphy, and well chosen panoramic photographs of fold styles viewed in normal profile. Where the virtual cross sections and geological map data were not solidly compatible, Davis and MVE modelers would together create check-lists of relationships to be field tested by Davis. In this way the geological mapping was completed in 2010, not for the normal reasons ('no more time or money'), but through the achieving of a tight correspondence between the virtual cross sections and the geological map. The virtual cross sections then became the skeleton for expanding the 3D model into a volume containing all of the formations and faults as coherent surfaces.

The final iteration, prepared for this conference, is the addition of archaeological information to the DEM. In particular the final model contains the locations of all built structures and activity areas. We believe that this 3D combining of topography, geology, and archaeology will permit a relative ease in communicating the tripartite relationships. Moreover, the built structures and activity areas may no longer be viewed by non-geologists as simply 'placed' on Earth's surface, but instead as 'attached' meaningfully to alluvium, colluvium, bedrock, structure, and geomorphology. Using visualization and dynamic models to communicate across disciplines and critically to carry the technical conversation to the general public in a meaningful way is a key objective of initiatives such as this.

 

AAPG Search and Discovery Article #120140© 2014 AAPG Hedberg Conference 3D Structural Geologic Interpretation: Earth, Mind and Machine, June 23-27, 2013, Reno, Nevada