Geochemistry of recent lacustrine sediments from Fildes Peninsula, King George Island, maritime Antarctica

Abstract

Comprehensive geochemical analyses (bulk parameters, major and trace elements, organic matter, mineralogy and particle analysis) were carried out on sediments from seven lakes on Fildes Peninsula, King George Island. The resulting compositional dataset was subjected to principal component analysis and cluster analysis. The results showed that four different lacustrine sedimentary environments can be distinguished: i) lakes 1 and 2 with relatively high values of secondary aluminous clay minerals, ii) lake 4 with anthropogenic enrichment of Co, Cu and Zn, iii) lake 7 with relatively high values of Ba and P and a high zeolite content, and iv) all the other studied lakes. Our results indicate moderate chemical weathering in all lacustrine sediments and that the distance to the glacial ice margin is one of the most important factors influencing the chemical weathering in the area. Furthermore, depositional processes have little influence on the geochemistry of the investigated elements and that local bedrock is the main source of sediments in the lakes on Fildes Peninsula.

Provenance, transport and diagenesis of sediment in polar areas: a case study in Profound Lake, King George Island, Antarctica

“…Minerals such as quartz, zeolite, plagioclase and magnetite present solution pits, precipitation coatings and dissolution etching, all comprising alteration products of chemical weathering of source rock during contact with external factors, presumably present at the time of ice withdrawal when source rock was exposed to the atmosphere and biosphere. This type of chemical alteration of minerals was previously reported in lacustrine sediment from the Fildes Peninsula by Alfonso et al (2015). Alternatively, such weathering may be linked to one or more interglacial periods of the Pleistocene prior to ice readvance, bedrock release, entrainment and transport, with grain overprinting to the lake.…”

“…In the Canadian Soil Classification System, these pedons would key out as Regosols (Soi1 Classification Working Group 1998). In addition, geochemical studies of lacustrine sediment from Fildes Peninsula indicate that local bedrock is probably the main source of sediment in Profound Lake, which contrasts with other nearby lakes that have high concentrations of some elements (Ba, Sr, P) and zeolites (Alfonso et al 2015). Using geochemical data from local bedrock of King George Island, Monien et al (2011) showed that short-term alterations in the regional climate during the last ca.…”

Sedimentary analysis and magnetic properties of Lake Anónima, Vega Island

“…Lacustrine sediments carry a strong signal originating from minerogenic and chemical weathering products of the catchment areas (i.e. solutes and particulate material) and can be considered to be representatives of sedimentological and biogeochemical processes taking place in the watershed (Alfonso et al 2015).…”

Analysis of Shallow Lake Sediments in the Fildes Peninsula, King George Island, Maritime Antarctica

“…In the cluster analysis, Ward, Simple and Paired methods were employed. Euclidean distance was used for the distance measure (ALFONSO et al, 2015). For the Principal Component Analysis, the correlation coeffi cient was used as the initial matrix of similarities, to eliminate the eff ect of scale.…”