The objective of the integrated Surveys and Analysis (S&A) projects is to develop national digital datasets categorized in four major themes: geology, mineral deposits, geochemistry, and geophysics, and to integrate, analyze, and interpret these data in order to assess mineral resources, determine regional background values for chemical elements with known environmental impact, characterize regional mineral districts, define metallogenic provinces, and study the relationship between toxic commodities or mining practices and human health. These interpretive studies involve contributions from a wide variety of disciplines and partners.
The strategy for coordinating this data acquistion, compilation, and interpretation has been to form an S&A steering group, comprised of regional S&A project chiefs and the chief of the Spatial Data Delivery Project. This group has undertaken the development of minimum goals for each data theme and the prioritization of S&A activities on a nationwide basis.
- The minimum goal for the geology theme is to compile digital versions of all state geologic maps, using a common data structure and a common data model that will make the maps useful for mineral resource and environmental assessment at scales of 1:500,000, 1:1,000,000, and smaller. The first stage of this work, the acquisition of digital maps for all the states, is nearly complete, including a multi-year effort in Alaska to create a digital state map at 1:500,000 scale. The second stage, attribution of the maps and creation of digital databases, has been initiated, using a common data model for Alaska, Hawaii, and the conterminous States.
- The minimum goal for the mineral deposits theme is to assure that, for all 50 states, the Nation's significant mineral deposits will have comprehensive MRDS records (in Alaska, ARDF and MRDS records), and that major inconsistencies in the MRDS database are eliminated. In addition to metallic records, we will include records for selected industrial minerals. The work is being done primarily through contracts and cooperative agreements with State geological surveys and similar entities, and with individuals.
- The minimum goal for the geochemistry theme is to provide, for the 50 states, a national stream-sediment and soil geochemical database that includes information for a number of elements, including the important toxic elements, arsenic, selenium, and mercury. We will accomplish this using a combination of existing NURE and other USGS sampling and data, reanalysis of existing samples, and collection of new samples, at an average grid spacing of 17 km or better. New samples will be collected in cooperation with State Geological surveys and other partners, using consistent protocols. Currently about 50,000 samples have been analyzed, drawan both from NURE reanalyses and some new collecting. An additional 10,000 new samples are needed to complete nationally distributed coverage.
- The minimum goal for the geophysics theme is to provide, for the 50 states, gravity, aeromagnetic, and aeroradiometric data on land that are adequate to support grids at 1-2 km spacing. A large proportion of this data is already in-hand, and, except for Alaska, this goal can be met with a minimum of new data collection. In Alaska, a major effort is starting to collect additional data to fill existing gaps in the geophysical coverage. At present, large areas of the state lack aeromagnetic and gravity data of sufficient quality for regional use