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  2. United States Geological Survey - Wikipedia

    en.wikipedia.org/wiki/United_States_Geological...

    www.usgs.gov. The United States Geological Survey (USGS), founded as the Geological Survey, is an agency of the U.S. Department of the Interior whose work spans the disciplines of biology, geography, geology, and hydrology. The agency was founded on March 3, 1879, to study the landscape of the United States, its natural resources, and the ...

  3. McKelvey diagram - Wikipedia

    en.wikipedia.org/wiki/McKelvey_diagram

    Diagram as published by McKelvey in 1976 [2] A McKelvey diagram or McKelvey box is a visual representation used to describe a natural resource such as a mineral or fossil fuel, based on the geologic certainty of its presence and its economic potential for recovery. The diagram is used to estimate the uncertainty and risk associated with ...

  4. Mineral resource classification - Wikipedia

    en.wikipedia.org/wiki/Mineral_resource...

    Mineral resources. A 'Mineral Resource' is a concentration or occurrence of material of intrinsic economic interest in or on the Earth's crust in such form, quality and quantity that there are reasonable prospects for eventual economic extraction. [7] Mineral Resources are further sub-divided, in order of increasing geological confidence, into ...

  5. Mineral resource estimation - Wikipedia

    en.wikipedia.org/wiki/Mineral_resource_estimation

    Mineral resource estimation. Mineral resource estimation is used to determine and define the ore tonnage and grade of a geological deposit, from the developed block model. There are different estimation methods used for different scenarios dependent upon the ore boundaries, geological deposit geometry, grade variability and the amount of time ...

  6. World Reference Base for Soil Resources - Wikipedia

    en.wikipedia.org/wiki/World_Reference_Base_for...

    The World Reference Base for Soil Resources (WRB) is an international soil classification system for naming soils and creating legends for soil maps. The currently valid version is the fourth edition 2022. [1] It is edited by a working group of the International Union of Soil Sciences (IUSS). WRB, 4th edition (2022)

  7. Unified Soil Classification System - Wikipedia

    en.wikipedia.org/wiki/Unified_Soil...

    The Unified Soil Classification System (USCS) is a soil classification system used in engineering and geology to describe the texture and grain size of a soil. The classification system can be applied to most unconsolidated materials, and is represented by a two-letter symbol. Each letter is described below (with the exception of Pt): If the ...

  8. United States Geological Survey Library - Wikipedia

    en.wikipedia.org/wiki/United_States_Geological...

    The USGS headquarters in Reston, VA. Today, the United States Geological Survey Library's users have access to over 1.7 million items: over 980,000 books and journals, over 600,000 maps, over 8,000 electronic media items (DVDs, CDs), and subscribes to over 113,000 electronic journal titles and eBooks.

  9. List of GIS data sources - Wikipedia

    en.wikipedia.org/wiki/List_of_GIS_data_sources

    List of GIS data sources. This is a list of GIS data sources (including some geoportals) that provide information sets that can be used in geographic information systems (GIS) and spatial databases for purposes of geospatial analysis and cartographic mapping. This list categorizes the sources of interest.