Preliminary Investigations of the Hydrologic Properties of Diatremes in the Hopi Buttes, Arizona

From the Proceedings of the 1974 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 19-20, 1974, Flagstaff, ArizonaDiatremes of Late Pliocene age in the Hopi Buttes area of Arizona are becoming increasingly important sources of groundwater to the Indian nations. These volcanic vent structures are prime sources of groundwater because sedimentary formations in the Hopi Buttes area yield only limited amounts of water or yield poor quality water. Diatremes act as traps for groundwater and some have yielded moderate amounts of good quality water to wells. Surface geologic investigations and analysis of drillers' logs indicate that structural relationships and diatreme lithology provide a means to project the hydrologic properties of the vent. Diatremes most suitable for groundwater development should have a diameter greater than one half mile, should contain volcanic tuff and breccia at its center, and should be fractured from collapse. Lava flows covering diatremes reduce recharge from sheet wash or from ephemeral stream flow. Data from geomagnetic and gravity surveys will be analyzed to determine its suitability for predicting subsurface size, shape, and lithology of the diatreme. The integration of geophysical and surface geologic data will reveal the total geometry of the structure enabling the most accurate appraisal of the hydrologic properties of the diatreme.This article is part of the Hydrology and Water Resources in Arizona and the Southwest collections. Digital access to this material is made possible by the Arizona-Nevada Academy of Science and the University of Arizona Libraries. For more information about items in this collection, contact anashydrology@gmail.com