Geochemical data

Jurassic—Cretaceous Besshi-type and Mn-Fe strata-bound deposits are present in Hidaka, Hokkaido (Fig. 1.2). Geochemical data and geological evidence all point to a midoceanic ridge environment of ore formation. values of Shimokawa Besshi-type... 

The summary of the bulk chemical compositions (major elements, minor elements, rare earth elements), Sr/ Sr (Farrell et al., 1978 Farrell and Holland, 1983), microscopic observation, and chemistry of spinel of unaltered basalt clarifies the tectonic setting of Kuroko deposits. Based on the geochemical data on the selected basalt samples which suffered very weak alteration, it can be pointed out that the basalt that erupted almost contemporaneously with the Kuroko mineralization was BABB (back-arc basin basalt) with geochemical features of which are intermediate between Island arc tholeiite and N-type MORE. This clearly supports the theory that Kuroko deposits formed at back-arc basin at middle Miocene age. 

Numerous geochemical data (fluid inclusions, stable isotopes, minor elements) on the epithermal vein-type deposits in Japan are available and these data can be used to constrain geochemical environment of ore deposition (gas fugacity, temperature, chemical compositions of ore fluids, etc.) and origin of ore deposits. 

I am indebted to Roger Powell for a constructive review and trenchant observations from a real expert in statistical examination of geochemical data, and to Pyramo Marianelli for pointing out the relevance of prior constraints in Monte Carlo simulations of °Th/U ages. 

Wollenberg, H.A., Naturally Occurring Radioelements and Terrestrial Gamma-ray Exposure Rates An Assessment Based on Recent Geochemical Data, Report LBL-18714, Lawrence Berkeley Laboratory, Berkeley CA (1984). 

Sinclair, A. 1974. Selection of threshold values in geochemical data using probability graphs. Journal of Geochemical Exploration, 3,129-149. 

Fig. 2. Shiko Lake bedrock geology and soil sample locations. Geochemical data described here were compiled from BC Geological Survey studies by Lett Doyle (2009) and a Novagold Resources till survey (Petsel 2006).

Reimann, C., Filzmoser, P. Garrett, G. 2002. Factor analysis applied to regional geochemical data problems and... 

In 2002, the North American Soil Geochemical Landscapes Project, a trinational initiative among the United States, Canada, and Mexico, was initiated with the goals to (1) develop a continental-scale framework for generating soil geochemical data and (2) provide soil geochemical data that are useful for a wide range of applications and disciplines. 

Fig. 2. Percent quartz in C horizon (dashed trend line) and weight percent Al (filled boxes) in C horizon soils along the W-E transect (truncated box plot boxes include 50% of data, extent of lines include 80% of data solid line is the median). Geochemical data shown by the box plots were grouped into 10 areas (vertical dashed lines, numbers at top of plot) defined by commonalities of physiographic features.

Lessons learned from the field sampling for the transects and recognized in the geochemical data lead to the following ... 

Fig. 1. Aqueous geochemical data from the Lake George Antimony Mine tailings. The x-axis represents concentrations in mg/L unless otherwise stated.

Presentation of regional geochemical data via Internet Earth browsers Stephen W. Adcock1, Wendy A. Spirito1, Eric C. Grunsky1... 

This paper outlines one approach that is being developed at the Geological Survey of Canada (GSC), where data are extracted from the database and re-cast as KML files that can be displayed in Google Earth or any other KML-aware application. Examples are presented for a recently-completed compilation of till geochemical data from New Brunswick (Adcock et al. 2009). 

Bjorklund, A. Gustavsson, N. 1987. Visualization of geochemical data on maps New options. Journal of Geochemical Exploration, 29, 89-103. 

The current distribution of geochemical data available through the national repository (OZCHEM database) is shown in Figure 1. The map shows that there are vast areas of the country (>60%) that lack any geochemical information. Also, where geochemical data are available, they are often not comparable as a result of incompatible sampling media, inconsistent sample preparation and analysis methods, incomplete quality assessment metadata and/or different analyte suites being reported. 

Fig. 1. Distribution of whole rock geochemical data in Australia (plus signs) extracted from the OZCHEM national database as at June 2006, overlain on bedrock (pink) and regolith (green) coverages.

A national-scale geochemical survey of Australia is under way. It applies ultra low sampling density to transported and well-mixed outlet sediments, which are expected to represent the average composition of large catchments. The NGSA will provide the first complete, internally consistent geochemical data layer for Australia and is expected to find applications in energy and mineral resources exploration. 

The value of government-generated geochemical data, and an example... 

Geological Survey of Western Australia has combined its regional geochemical data with other lithogeochemical information in a corporate database, and delivered the data via a customised web application which combines... 

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