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Geochemical Database (Major and Trace Element) of Permian to Jurassic Igneous Samples from Central Mongolia, South Russia, and NE China

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In the element database, major elements are reported in weight percent oxide (wt%). Trace element concentrations are reported in parts per million (ppm). Available lithologic information (“lithology” column) and the type of igneous sample (intrusive or extrusive in the “Sample-Type” column) were included. The name of the area or of the corresponding igneous body were included when available (“Location/Body-Name” column). The location of the samples is reported in decimal degrees (WGS84), however, uncertainties explained below must be considered. Coordinates were obtained from three different ways of presenting the information about the location. The three scenarios are distinguished as “GPS”, “Figure-Point”, and “Figure-Polygon” in the “Location-Type” column. Samples with a location in a coordinate system were transformed to decimal degrees (WGS84) and classified as “GPS”. Samples individually identified in a georeferenced geologic map were approximately located after georeferencing the map in Google Earth or ArcGis (“Figure-Point”). Samples identified with a polygon in a georeferenced map (through age, body name or unidentified sample locations), but without more detailed information were approximately located in the middle of the corresponding polygon after georeferencing the map in Google Earth or ArcGis (“Figure-Polygon”). Precise “GPS” locations were obtained for 358 analyses, and approximate locations were obtained for 428 analyses. The age information was organized using three categories: “Age-Approximation”, “Age-number”, and “Age-Error”. “Age-approximation” corresponds to the age information from original paper or from an additional reference detailed in the “Reference-Age” column. “Age-number” corresponds to the age reported in the original paper or previous compilation, or to the average age calculated from a given age range. “Age-Error” corresponds to the error presented in the original paper or previous compilation, or to half of the age range. Information about the methods, analyzed material and laboratory name was included when available. Lastly, the original data sources are available in the “Reference” column. References from previous compilations incorporated in this database are specified as “Compilation-Reference”. Additional references used for constraining the age are detailed in “Reference-Age” column. Data that were incorrectly reported (e.g., reporting average compositions instead of sample composition) or with anomalous trace element concentrations were filtered-out from the element database. Analyses from weathered or altered samples producing high total volatile content (LOI> 5 wt%) were removed. Samples with no available information to approximately locate them or to constrain their age were eliminated. Despite this screening process, the database suffers from uncertainties related to approximated ages and locations and variable information regarding the lithology, and availability of trace elements The inhomogeneity in this database is explicit and uncertainties related to the age and location should be carefully considered in any interpretation. The final compilation contains 787 geochemical analyses (major, minor and trace elements) and includes data from 36 studies.

Last modified
  • 02/28/2024
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  • Mongolia, , Mongolia
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  • USGS
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