THE STATE OF GEOLOGIC MAPPING IN AFGHANISTAN

Prior to the fall of the Taliban, the last regional geologic mapping to have taken place in Afghanistan was in the late 1960's by Russian and Afghan geologists. They compiled a countrywide geologic map that was published in 1977 at 1: 500,000-scale. That map is no longer widely available, but the USGS acquired digital versions and has re-published the mapping in both countrywide and quad-tiled formats at 1:1,000,000-, 1:500,000-, and 1:250,000-scales. The tiled quadrangles are augmented by corresponding topographic maps, based on Shuttle-Radar-Mission-90-meter digital topography. Each tile is also covered at the same scale by two image maps, natural and false-color, based on Landsat-7 - 14.28-meter, pan-sharpened data. These maps are available for download in pdf format at http://pubs.usgs.gov/of/afghan/ and the original digital data can be acquired on request. Comparison of the published geology and geographic features with modern image data of high spatial resolution (e.g. Digital Globe data at 0.65 to 2.5 meters) reveals serious shortcomings at all levels. Mapped linear features such as contacts, faults, and roads are either not real or are typically mis-located by as much as a kilometer, and polygonal areas commonly show little or no relation to actual rock bodies on the ground. Available rock descriptions are limited in scope and highly generalized. It is self-evident that the Afghan government needs new maps of all types to facilitate the rebuilding of the country. To this end the USGS has initiated a program of geologic and cultural mapping, based primarily on modern remote-sensing techniques. Since ground-truth is hard to come by in a country still plagued by insurgency and land mines, USGS has started to train a new generation of Afghan geologists in the Afghan Geological Survey in modern mapping techniques. It is hoped that Afghans can refine the remotely sensed geology in the near future.