Improved Paleopedological Reconstruction of Vertic Paleosols at Novaya Etuliya, Moldova Via Integration of Soil Micromo
The integration of micromorphology, environmental magnetism and Mössbauer spectroscopy along with identification of pedogeomorphic classes of paleosols may improve the quality of Pleistocene paleopedological reconstructions and their applicability to loes
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Abstract The integration of micromorphology, environmental magnetism and Mössbauer spectroscopy along with identification of pedogeomorphic classes of paleosols may improve the quality of Pleistocene paleopedological reconstructions and their applicability to loess stratigraphy. Our case study from the SW Black Sea area demonstrates that microfabrics, mineralogy and magnetism of paleosols older than 0.5 Ma are comparable with certain types of Mediterranean soils from Israel and Turkey. The diversity of paleosols in terms of pedogeomorphic, genetic, and diagenetic typology is prominent. Two welded accretionary paleosols, i.e. pedocomplexes PK4 (~0.5 Ma) and PK8 (~0.9–1.0 Ma), have a distinct rubefied A (AB) horizon with micromorphological features of high biological activity, quasi-isotropic humus-clayey groundmass and compacted excremental fabric. Vertic micromorphological features, more intense in the older PK8, are superposed upon bio-related microstructures. Both paleosols show magnetic enhancement in a topsoil due to increased concentration of pedogenic ⬍20 nm superparamagnetic (SP) and stable single domain magnetite which is partly oxidized. In these PKs the concentration of ferrimagnetics is correlated with antiferromagnetic SP hematite/goethite and paramagnetic Fe(III)-clay content. In contrast, other ⬎0.5 Ma old paleosols which are related to a transformational welded type, show a small magnetic susceptibility signal, a high concentration of paramagnetic clays and SP Fe oxyhydroxides. Fe/ Mn impregnations are juxtaposed in the microfabric with abundant soft masses of micritic calcite and aggregates of stress coatings. The latter may have originated from decay of clay coatings under intermittent waterlogged conditions. In the time
A. Tsatskin Zinman Institute of Archaeology, University of Haifa, Haifa 31905, Israel, e-mail: [email protected] T.S. Gendler Institute of Physics of the Earth, Russian Academy of Sciences, Bolshaya Gruzinskaya 10, Moscow 123810, Russia, e-mail: [email protected] F. Heller Institut für Geophysik, ETH Hönggerberg, CH-8093 Zürich, Switzerland, e-mail: [email protected]
S. Kapur et al. (eds.), New Trends in Soil Micromorphology, © Springer-Verlag Berlin Heidelberg 2008
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interval ~0.5–~1.5 Ma the rubefied and magnetically enhanced pedocomplexes PK4 and PK8 are proposed as key stratigraphic markers in South Eastern Europe. Keywords Paleopedology · pleistocene · vertic soils · micromorphology · magnetism · mössbauer effect
1 Introduction Soil micromorphology along with macro- and mesomorphological investigations of soil profile organization are essential tools in paleopedology (Courty et al. 1989, Retallack 1990, Bronger 2003, Holliday 2004). In Pleistocene loess/paleosol sequences, the best terrestrial records of long-term global change, micromorphology aids in identifying specific soil-forming and sedimentary processes, and is increasingly complemented with other climatic proxies, e.g. magnetic susceptibility (Kemp 1998 and reference
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