Mineralogical, Chemical, and Isotopic (Sr, Pb) Composition of Atmospheric Mineral Dusts in an Ombrotrophic Peat Bog, Southern South America
type: CreativeWork
description: Peat bogs are excellent environmental archives of atmospheric deposition of many major and trace elements and of mineral dusts. Geochemical studies of major and trace elements, mineralogy of atmospheric dust and their radiogenic isotope compositions in the peat, provide important information about the mineralogical host phases of major and trace elements transported through the atmosphere, grain size fractionation during transport, and their possible source areas (PSAs). To date, no peat bog records of atmospheric dust depositions in southern South America have been reported. Therefore, the major and trace elements, and mineralogical and radiogenic isotopic compositions of inorganic fraction in a peat bog from southern South America were investigated. The main goal was to characterize the atmospheric dust deposition in southern South America, and to identify their PSA. For this purpose, a 542 cm long core from the Oreste bog in southern Chile, Isla Navarino (55º13’13’’S, 67º37’28’’W), was used. The peat formation at the Oreste bog began at ~ 11160 14C yr before present (BP) (13 ka cal. BP). Because of the limited amount of mineral material available from thinly sliced cores (~ 2 – 3 mg from a 2 cm slice), an analytical method was developed to extract, isolate, and chemically characterize atmospheric dusts from ombrotrophic peat. About 2 g of dried peat was combusted overnight at 550 °C that on ashing yielded ca. 20 mg. 1M HCl was allowed to react for 15 min to dissolve soluble minerals such as carbonates, sulphates, and oxides which were mainly formed during combustion. Acid insoluble ash (AIA) was then separated from the solution (acid soluble ash: ASA) by using polycarbonate filters of pore size 0.2 µm. The analytical procedure effectively extracted and isolated the AIA fraction which was composed of silicates and refractory oxides derived from crustal weathering, as well as volcanic ash and glass particles. The residue obtained was analyzed directly on the filter…
abstract: Peat bogs are excellent environmental archives of atmospheric deposition of many major and trace elements and of mineral dusts. Geochemical studies of major and trace elements, mineralogy of atmospheric dust and their radiogenic isotope compositions in the peat, provide important information about the mineralogical host phases of major and trace elements transported through the atmosphere, grain size fractionation during transport, and their possible source areas (PSAs). To date, no peat bog records of atmospheric dust depositions in southern South America have been reported. Therefore, the major and trace elements, and mineralogical and radiogenic isotopic compositions of inorganic fraction in a peat bog from southern South America were investigated. The main goal was to characterize the atmospheric dust deposition in southern South America, and to identify their PSA. For this purpose, a 542 cm long core from the Oreste bog in southern Chile, Isla Navarino (55º13’13’’S, 67º37’28’’W), was used. The peat formation at the Oreste bog began at ~ 11160 14C yr before present (BP) (13 ka cal. BP). Because of the limited amount of mineral material available from thinly sliced cores (~ 2 – 3 mg from a 2 cm slice), an analytical method was developed to extract, isolate, and chemically characterize atmospheric dusts from ombrotrophic peat. About 2 g of dried peat was combusted overnight at 550 °C that on ashing yielded ca. 20 mg. 1M HCl was allowed to react for 15 min to dissolve soluble minerals such as carbonates, sulphates, and oxides which were mainly formed during combustion. Acid insoluble ash (AIA) was then separated from the solution (acid soluble ash: ASA) by using polycarbonate filters of pore size 0.2 µm. The analytical procedure effectively extracted and isolated the AIA fraction which was composed of silicates and refractory oxides derived from crustal weathering, as well as volcanic ash and glass particles. The residue obtained was analyzed directly on the filter…
author: Sapkota, Atindra
date published: 2006-12-08
date modified: 2026-07-24T02:30:34Z
provider: Universität Heidelberg
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Universität Heidelberg