A late Eemian aridity pulse in central Europe during the last glacial inception.

Investigating the processes that led to the end of the last interglacial period is relevant for understanding how our ongoing interglacial will end, which has been a matter of much debate (see, for example, refs 1, 2). A recent ice core from Greenland demonstrates climate cooling from 122,000 years ago driven by orbitally controlled insolation, with glacial inception at 118,000 years ago. Here we present an annually resolved, layer-counted record of varve thickness, quartz grain size and pollen assemblages from a maar lake in the Eifel (Germany), which documents a late Eemian aridity pulse lasting 468 years with dust storms, aridity, bushfire and a decline of thermophilous trees at the time of glacial inception. We interpret the decrease in both precipitation and temperature as an indication of a close link of this extreme climate event to a sudden southward shift of the position of the North Atlantic drift, the ocean current that brings warm surface waters to the northern European region. The late Eemian aridity pulse occurred at a 65 degrees N July insolation of 416 W m(-2), close to today's value of 428 W m(-2) (ref. 9), and may therefore be relevant for the interpretation of present-day climate variability.

Red thermoluminescence of quartz and its application in dating archaeometallurgical slag.

Slag is often the only relic of early pyrometallurgical processes. In archaeological research information about the age of slag deposits is needed and diflicult to obtain with traditional methods. Thermoluminescence has a great potential in this field, because the smelting process leads to a well defined resetting of the 'Luminescence Clock'. Metallurgical slag generally consists of many components, artificial secondary minerals, e.g. fayalite and glass phases usually being the dominant parts. Primary minerals, called relics, are also components or slag. Such a complex composition leads to large difficulties in palaeodose determation if the bulk slag is used. To overcome these problems defined phases of the slag have been separated. Palaeodose determination has been carried out on separated quartz fractions by 'Single Aliquot Regeneration' procedures using the 620 nm emission. The dose rate was determined by high-resolution gamma spectrometry. Alpha autoradiography was carried out to get information about the distribution of radionuclides. The study includes first dating results.

A radioluminescence study of spectral and dose characteristics of common luminophors.

Many synthetic materials are used as thermoluminescence dosemeters for the measurement of the absorbed dose from ionising radiation sources. A part of the absorbed energy leads to a prompt luminescence (radioluminescence, abbreviated RL) which dose behaviour mainly corresponds with the densitity of charge carriers in the respective traps or recombination sites. The RL reported in this study was stimulated using two 137Cs sources with activities of 3.7 MBq (spectral measurements) or 5 MBq (dosimetry studies), respectively, and was recorded steadily during stimulation. This presentation gives a comprehensive survey of the spectral and dose dependent RL properties of a number of luminescent materials like LiF:Mg,Ti, Al2O3:C, CaSO4:Dy, CaF2:Mn, Li2B4O7:Mn, BeO and ZnS:Ag. The spectral and dose dependent results were compared with thermoluminescence as well as other RL studies.