The flag studies below were adapted from mapping symbols from the United States Geologic Survey included in Elements of Topographic Drawing, by R. C. Sloane, 1943, research in historical and contemporary geologic literature and maps, and consultation with professional geologists. Contemporary geologic mapping primarily uses a color-text notational system, visual patterns representing rock types is from an earlier era of map making and has, unfortunately, been somewhat lost as a practice. One intention of this project is to revive and re-invent this visual practice to generate visually rich and informative flags flown over any given site - the flags representing the hidden landscapes and materials below. Multiple flag poles over an extended area would be the ideal configuration of this system, facies change (generally a lateral shift in material or depositional environment along one strata) and similar horizontal changes would be more visually and experientially apparent than from a single pole.
The materials represented here schematically represent most major rock types, however, the richness and variability of just this part of the geologic spectrum that might represent a given site can only be hinted at by the selection shown. In practice, like the multiple flag poles, hybrid flags that combine, interpret and extend the different categories indicted here are more likely the norm - see some of the examples in the ÒAssemblage/FaciesÓ group on the lower left of this page. R. W. LeMaitre, 1976, compiled over 26,000 averaged rock analyses that have been given a rock-type name by the original author.
The basic rock types/structures of this page are the core assemblies of a larger taxonomy that the flags could represent in describing and understanding a site or sites. Cross-correlated with this group would be systems of representation that range in scale from atomic structure to global processes like plate tectonics. Additional layers to the hidden picture of a site include: mineralogy, local and regional tectonic structures, geologic time scale, geochemical, magnetic anomaly and gravity data, paleontological profiles, contemporary bio-regimes (bacteria living in the earth), active processes, hydrologic systems, other anthroturational information besides architecture, etc.. All these systems are overlapping and inform each other in different ways, are generally hidden from view but constitute the landscape we live upon and in.
The inclusion of the ÔanthroturbationalÕ flag images, represents the concept that the human-built environment using earth materials is a geologic stratum (Holocene era) in its own right and should be represented in this system. Architectural Graphic Standards, by Charles Ramsey, 1956, was used (along with other books and materials from the architectural field) for confirming the flag imagery. The term Òanthroturbation was developed in conversation with the geophysicist, Paul Spudich.
John Roloff, 2004