Principal component analysis of the geochemistry of soil developed on till in Northern Ireland

Abstract

This paper presents results from the first regional statistical analysis of soils developed on till in Northern Ireland, using the Geological Survey of Northern Ireland's Tellus geochemical database. Till geochemistry is largely determined by its parent bedrock and soils developed on tills are known to inherit this geochemical signature. Soil geochemistry from areas of till can therefore be used to establish sediment provenance which in turn provides information on palaeo ice flow directions and ice sheet history. In this study, we use Principal Component Analysis to establish geochemical groupings that can be related back to likely bedrock parent material for the tills in the region. The maps, presented here at 1:445,000 scale, show the results of the first regional investigation of soil geochemistry of part of the northern sector of the Irish Ice Sheet. The results indicate that the upper surface of the majority of tills in the study area have a close relationship to local bedrock with rapid geochemical changes observed at lithological boundaries. This suggests that tills in this sector of the Irish Ice Sheet are primarily local in origin, indicating rapid entrainment of bedrock and low rates of evacuation of debris to the ice margin.

The silicon isotopic composition of fine-grained river sediments and its relation to climate and lithology

“…At present, the entire area is mainly covered by glacial tills left behind the retreat of the British-Irish ice-sheet during the last deglaciation period (e.g. Dempster et al, 2013). A substantial fraction of the fine-grained particles transported by Northern Irish rivers is expected to derive from erosion of late glacial deposits and/or post-glacial soil sequences that developed after ca.…”

Catenas of Grain Size and Chemical Forest Soil Properties in Outer Western Carpathians of the Czech Republic Characterized by Principal Component Analysis

“…The soil environment characteristics were used for demarcation of soil catenas. Exploratory analysis of the soil properties contained overlay and multivariate analysis of point field from sampled pits (Dempster et al, 2013). The sampled forest soil pits were characterized by statistical selection of potentially most significantly correlating soil properties.…”

“…The using of geomorphology does not enough itself for survey on catena development, but the development can be derived through using of similarities in chemical composition between soil and bedrock. The comparison of chemical composition similarities between soil and bedrock suggests, if soil could be developed in-situ, or if it could be a sediment (Dempster et al, 2013).…”

“…This study is focused on statistical distinction of terrain or bedrock effects on soil catenas between lowland and mountain systems. Geological environment inprints signatures into soils, so that soil properties are organized into clusters of similar spatial relationships (Dempster et al, 2013). Soil grain size and chemical properties are basic signatures of the geological environment (Filzmoser et al, 2009).…”

Zonation of the Newry Igneous Complex, Northern Ireland, based on geochemical and geophysical data

“…Airbourne radiometric data usually record proportions of common isotopes of potassium, uranium and thorium ( 40 K, 238 U and 232 Th), which can be assumed to represent total proportions of the respective elements in the bedrock (e.g., Grasty 1975;Cook et al, 1996;Schetselaar et al, 2000;Martelet et al, 2006;Dempster et al, 2013;Keaney et al, 2013).…”