Interdisciplinary Quaternary Research

Interdisciplinary Quaternary Research

Quaternary International 95–96 (2002) 139–140 Editorial Interdisciplinary Quaternary Research The second part of this volume of Quaternary Internati...

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Quaternary International 95–96 (2002) 139–140

Editorial

Interdisciplinary Quaternary Research The second part of this volume of Quaternary International brings together papers from a variety of areas. Although differing in subject matter, all involve interdisciplinary research and represent the expanding horizons opening to Quaternarists. The diversity of knowledge useful to any analysis of a Quaternary problem is well illustrated by considering these papers. DeRita, Fabbri, Mazzini, Paccara, Sposato, and Trigari have investigated the interplay between volcanism and modern sea level changes in coastal Italy, an area of relative recent tectonic stability. In a coastal sector of northern Latium, products from three different Quaternary volcanoes reached the coast between 0.45 and 0.1 Ma. Lateral facies relationships between marine and volcaniclastic sediments are analysed using volcanic horizons, pyroclastic flow deposits, and fallout deposits as stratigraphic markers. The successions have been organized in Unconformity Bounded Stratigraphic Units, and the Synthems are bounded by primary order unconformities recognized throughout the continental area down to the coast. The analysis of the components and of the lithofacies of each Synthem has proven to be a powerful tool to correlate marine and volcanosedimentary successions in areas affected by the interaction between volcanic activity and sea level changes, and to the marine oxygen isotope stratigraphy. This study has important implications for other researchers working in volcanically active areas. The use of the volcanic deposits in conjunction with sea level changes, and the indications that volcanic and sea level stratigraphy are linked, is indicative of the importance of working simultaneously with both these areas of Quaternary study. Novothny, Horva! th, and Frechen have investigated the detailed Upper Pleistocene record exposed in a loess/ palaeosol sequence at Albertirsa, Hungary. Luminescence dating was carried out to establish a more reliable chronological framework for the Hungarian loess record. The lowermost palaeosol of the section, probably an equivalent of the MF2 horizon at the Mende key section, is superimposed on penultimate glacial loess. An IRSL age estimate of about 65 ka BP was determined for the lower part of this palaeosol, indicating soil formation late in oxygen isotope stage 5 or early in OIS 3. The loess between the upper and and lower palaeosol yielded a mean luminescence age of about 50 ka BP. The upper

palaeosol is probably an equivalent of the MF1 horizon at the Mende type section, formed between 37 and 25 ka BP, and represents the Hengelo and/or Denekamp interstadial of northwestern European stratigraphy. This study highlights the importance of combining advances in geochronology, pedology, and loess sedimentology. ! Krystyna Szeroczynska has analysed the human impact on lakes, as recorded in the remains of Cladocera. Subfossil Cladocera analysis allows discussion of the influence of human activity on lake environments from Neolithic times up to the present. Three lakes were chosen for the analysis: two in northern Poland and the third on Cres Island, Adriatic Sea (Croatia). During the Holocene the species composition and the specimen abundance often changed, resulting mainly from climate changes, but also from human activity. Phases of increased lake eutrophication, distinguished on the basis of Cladocera species preferring nutrient-rich water, are correlated with the periods of human activity beginning in Neolithic times. The most distinct changes in the species composition of Cladocera have been noted in the lake sediment from the Medieval Period. The intensity of the expressed abundance of index species in sediments is dependent on the size (area and depth) of the lake, with small lakes marked by large changes in species composition of zooplankton. The smaller water bodies react faster to an excessive supply of eutrophic compounds, and therefore the change is more clearly evident in the sediment ! record. Szeroczynska’s work illustrates the importance of considering the spatial dimension in analysis of palaeoecological data, as well as considering potential human impacts. Vogt and Larque! have analyzed the utility of clays and secondary minerals from the circum-Baikal region as permafrost indicators. The structural and mineralogical changes induced by permafrost are commonly irreversible and affect the present soils, so that it is important to be able to recognize them. However, regions such as southeastern Siberia that suffered severe, but dry periglacial conditions during cold Quaternary periods commonly show few periglacial features. Five exposures investigated in the circum-Baikal area show permafrost features, although the same phenomena occur throughout southeastern Siberia. These exposures

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Editorial / Quaternary International 95–96 (2002) 139–140

demonstrate that, even though evidence of permafrost may be lacking or equivocal, thorough analysis can reveal indicators of permafrost such as neoformed clays, secondary precipitates of iron, calcite, and sulphates with peculiar crystalline features. In combination with sedimentary structures and the geomorphic environment, these indicators affirm the definite existence of permafrost. Investigation of suspected palaeo-permafrost areas has long been hampered by the absence of the diagnostic cryoturbation and ice wedge features associated with some active periglacial areas, and separation of seasonal frost influence from true periglacial activity has also presented problems in some localities. Analysis of clay minerals and precipitates provides a

way to establish the former existence of periglacial conditions. This volume also includes the Compte Rendues, and the Minutes from the International Council and the General Assembly of INQUA, from the highly successful INQUA XV Congress, held in Durban, South Africa, in August 1999. All of us look back fondly on the Durban meeting, and are also looking forward to the upcoming XVI Congress meeting in Reno, USA, in 2003. Norm Catto Department of Geography, Science Building, Memorial University of Newfoundland, St. John’s NF, Canada A1BX9 E-mail address: [email protected]