The research is analyzing different lithostratigraphic units of chert bedrock from the Mid-Lower Devonian Period. CaCO3 is dominant within the chert, including Si. Chert lithostratigraphic units alternate with limestone bedrock.

Analytical results have shown that when Ca, C, and Si increased in Wt% or ppm, major trace elements and REE's decreased in ppm

The chert bedrock was formed in a sea west of the Acadian Orogen in the USA and Canada.

Chert samples were collected from geologic sources and archaeological sites.

The research avoids major oxides and trace elements that can be substituted, replaced or impacted due to calcium carbonates.

The goal of the research is to determine geochemical differences for each lithostratigraphic unit to chemically connect chert samples from archaeological sites to a chert source.

I have used two different statistical preparation methods.

I reduced the impact of Si, by doing a ratio of Si Wt% to each element to determine how element ppm were altered or changed.

A second preparation method normalized all elements to LOI before analyzing and comparing the chemical results of each element.

After each method, elements were re-examined and results compared to determine how each method impacted the comparison of elements in chert samples.

All analytical results were compared to determine distinct elements that could be used to separate each chert lithostratigraphic unit based and connect chert samples from archaeological sites back to a chert source.

I am using multidimensional Scaling, PCA, and discriminant analysis to compare the elements.

I am asking for suggestions whether there is another method that can be used to remove the impact of CaCO3 and/or Si, in chert samples, from elements in chert samples determined with ICP-MS/ES.

Lorenz Bruechert

Doctoral Candidate