Search results for "Process"
showing 10 items of 22310 documents
A 2000-year record of lake ontogeny and climate variability from the north-eastern European Russian Arctic
2016
A lake sediment record from the north-eastern European Russian Arctic was examined using palaeolimnological methods, including subfossil chironomid and diatom analysis. The objective of this study is to disentangle environmental history of the lake and climate variability during the past 2000 years. The sediment profile was divided into two main sections following changes in the lithology, separating the limno-telmatic phase between ~2000 and 1200 cal. yr BP and the lacustrine phase between ~1200 cal. yr BP and the present. Owing to the large proportion of semi-terrestrial chironomids and poor modern analogues, a reliable chironomid-based temperature reconstruction for the limno-telmatic p…
Meteorological validation of chironomids as a paleotemperature proxy using varved lake sediments
2016
In order to improve the reliability of climate models in their projections for the future, spatially and temporally detailed paleoclimate proxy data are needed. In this study, we examined annually laminated sediments from Lake Nurmijärvi (Finland) for their fossil Chironomidae assemblages over a time period with available meteorological observational data (since 1830s). In doing so, we correlated chironomid-based inferences of summer air temperatures against instrumentally measured values using two different reconstruction approaches, namely, calibration-in-space (CiS, multilake training set) and calibration-in-time (CiT, calibration of time series data against meteorological data). The re…
Palaeoenvironmental evidence for the impact of the crusades on the local and regional environment of medieval (13th–16th century) northern Latvia, ea…
2015
This paper evaluates the impact of the crusades on the landscape and environment of northern Latvia between the 13th–16th centuries (medieval Livonia). The crusades replaced tribal societies in the eastern Baltic with a religious state (Ordenstaat) run by the military orders and their allies, accompanied by significant social, cultural and economic developments. These changes have previously received little consideration in palaeoenvironmental studies of past land use in the eastern Baltic region, but are fundamental to understanding the development and expansion of a European Christian identity. Sediment cores from Lake Trikāta, located adjacent to a medieval castle and settlement, were s…
Rapid climate change during the early Holocene in western Europe and Greenland
2006
Based on microfacies analyses of seasonally laminated varved sediments from lake Holzmaar, Germany, we report evidence of decadal-to century-scale climate variability during the early Holocene. The shifts in climate are documented in the thickness variations and changes in the composition of the varves in response to subtle shifts in limnological conditions. The close similarity between the Holzmaar varve record and the GRIP oxygen isotope record during 7.4-9.0 calendar (cal.) ka suggests that the high frequency climatic variations in both regions were controlled by the same mechanism. Our more detailed studies covering the central 409-yr period (∼7.846-8.255 cal. ka, encompassing the 8.2 …
Luminescence dating of aeolian–coastal events on the Kristianstad plain, SE Sweden
2016
Aeolian–coastal sediments and landforms are excellent palaeoenvironmental archives, but chronological studies of coastal records are scarce in Sweden. In this study, we provide luminescence and radiocarbon ages of aeolian activity and coastal landscape evolution on the Kristianstad plain, SE Sweden, based on the investigations of two foredunes and two inland dunes at Åhus and Vittskövle. Additionally, we do a laboratory intercomparison of five young luminescence samples. The comparison shows a significant age difference most likely due to an instrumental difference. The equivalent dose cannot be determined accurately with the low irradiation times, and therefore, the results obtained from …
Ceramic productions and human interactions during the Early Bronze Age in northern Iberia
2021
The Early Bronze Age ceramic collection found into the caves of La Llana and El Toral III in Asturias (Spain) presents common decoration such as that found in the centre of Cantabrian Spain from the same period, which resembles others found in the Ebro Valley and Atlantic Europe. Therefore, the main objective of this study it is to identify the raw material origin and understand the pottery production process during the Early Bronze Age in the Cantabrian region. A methodological approach based on the chemical and mineralogical analysis of vessels and experimentally fired clay samples collected all over the centre of this region was developed. Furthermore, the post-depositional processes aff…
Late Quaternary coastal uplift of southwestern Sicily, central Mediterranean sea
2021
Abstract Mapping and luminescence aging of raised marine terraces and aeolian ridges along an ∼90 km coastal stretch in southwestern Sicily provide the first quantitative assessment of vertical tectonic deformation in this region, which spans the frontal part of an active thrust belt. We recognized a staircase of eleven terraces and nine related aeolian ridges. The elevation profile of terraces parallel to the coast shows a >90 km long bell-shaped pattern, onto which shorter-wavelength (∼10 km long) undulations are superimposed. Luminescence ages from terraced beach deposits and aeolian sediments constrain the position of paleoshorelines formed during MIS 5e, 7a and 7c, with a maximum uplif…
Copper quality and sources in Middle Bronze Age I Byblos and Tell Arqa (Lebanon)
2013
Abstract Forty-four Middle Bronze Age I weapons discovered at the sites of Byblos and Tell Arqa in Lebanon were investigated in order to study their copper quality and provenance. The evaluation of copper qualities is based on quantifying permanent inclusions such as copper sulfide and lead globules. The provenance of copper was studied using lead isotope analyses. For further discrimination between copper groups and sources elemental analyses by PIXE were performed on some of the weapons investigated. The results revealed two copper groups that could be qualified as “dirty” copper and “clean” copper. The former was used in most of the weapon types whereas the latter was reserved for items …
Geomeasure: GIS and Scripting for Measuring Morphometric Variability
2019
This paper presents Geomeasure, a methodological tool developed to recover typometric information with a twofold objective. First, to speed up the process of gathering data by automatizing the way in which it is recovered. Second, it adds higher accuracy and the possibility of re-measuring archeological items without further directly interacting with the piece. Based on a combination of R scripting with GIS features, Geomeasure is at the time able to automatically gather 125–130 typometric variables per archaeological item, with the only input of vectorized photographs. It can be used as a reliable methodological aid to extract detailed information on patterns and trends of shape variabilit…
Early Middle Ages Houses of Gien (France) from the Inside: Geoarchaeology and Archaeobotany of 9th–11th c. Floors
2018
International audience; At Gien (France), indoor floors from early Middle Ages occupation (8th–10th c. AD) are very well preserved, providing a new reference for archaeological investigation in northern France. This site is located on an outcrop, 20 m above the Loire valley, where a 15th c. castle stands now. The medieval occupation combines high-status houses with crafting and agricultural areas. They constitute a new urban nucleus, which grew 2 km east from an ancient Roman settlement. During the rescue excavation, four buildings of different status were sampled and studied using an integrated approach, combining stratigraphy, micromorphology, chemical, macro-remain and phytolith analyses…