The chemical composition including the Rare Earth Elements of the three major glass types of Europe and the Orient used in late antiquity and the Middle Ages

Sets of 20 soda ash glasses, 16 soda lime glasses and 23 wood ash glasses mainly from excavations in Europe (additional soda ash glasses from Egypt) were analysed on 61 chemical elements. Average SiO₂ is about 62% in soda glasses and 50% in wood ash glasses. The three groups of glasses contain on average 13% Na₂O, 18% Na₂O and 13% K₂O as fluxes to lower the melting temperature of quartz at their production. The starting materials beside quartz were halophytic plant ash for soda ash glass, trona (Na₃H(CO₃)₂·2H₂O) and lime (clamshells) for soda lime glass and beech ash for wood ash glass. Each of the three major glass types contains specific Rare Earth Element (REE) concentrations mainly contained in quartz and its intergrown minerals. 50 Paleozoic and Mesozoic sandstones from Central Europe represent the quartz composition. The REE pattern of these glasses apparently indicates major compositional stages of the Continental Earth's Crust. The boron to lithium and sodium to potassium ratios as in seawater suggest reactions of materials for soda glass with seawater. Negative Ce anomalies in the three glasses are caused by reactions of quartz with seawater.     

Changes in the water regime of the caspian sea

The article deals with issues of structure and dynamics of the Caspian Sea water balance. On the base of historical, paleogeomorphological and other data the evolution history of the Caspian Sea and its basin has been observed for different time intervals down to 400 thous. years ago. Presented are computerized data on water balance components in the current centenary obtained from instrumental observations, revealed are causes of the sea-level fluctuations within that time interval and anthropogenic factor contribution to this process. Based on the analysis of this material, an attempt has been undertaken to present a scenarion of a possible sea-level position of the Caspian Sea with the expected versions of climatic changes at the end of the XX and beginning of the XXI centuries.     

Paleo- and Neoproterozoic magmatic and tectonometamorphic evolution of the Isla Cristalina de Rivera (Nico Pérez Terrane, Uruguay)

The Isla Cristalina de Rivera crystalline complex in northeastern Uruguay underwent a multistage magmatic and metamorphic evolution. Based on SHRIMP U–Pb zircon, Th–U–Pb monazite (CHIME-EPMA method) and K–Ar age data from key units several events can be recognized: (1) multistage magmatism at 2,171–2,114?Ma, recorded on zircon of the granulitic orthogneisses and their 2,093–2,077?Ma overgrowths; (2) a distinct amphibolite facies metamorphism at ~1,980?Ma, recorded by monazite; (3) greenschist facies reworking and shearing at ca. 606?Ma (monazite and K–Ar on muscovite) along the Rivera Shear Zone, and finally (4) intrusion of the post-tectonic Sobresaliente and Las Flores granites at around 585?Ma. Lithological similarities, geographic proximity and coeval magmatic and metamorphic events indicate a similar tectonometamorphic evolution for the Isla Cristalina de Rivera, the Valentines Block in Uruguay and the Santa María Chico Granulitic Complex in southern Brazil, since at least 2.1?Ga.     

Über stratigraphische Untersuchungsmethoden in rezenten Tiefseesedimenten

Zusammenfassung Durch Bestimmung der Foraminiferenanzahl in I g Sediment wird die biostratigraphische Untersuchungsmethode, die mittels einer qualitativen und quantitativen Erfassung der Foraminiferenfauna in den Tiefseekernen der deutschen Meteor-Expedition und schwedischen Albatroß-Expedition durchgeführt werden ist, auf ihre Richtigkeit hin geprüft. Die Untersuchung hat die Anwendbarkeit dieser stratigraphischen Methode bestätigt. Sie hat daneben wiederum gezeigt, daß die Verbreitung und Entwicklung der einzelnen Foraminiferenarten vor allem von der Temperatur des Meerwassers abhängig sind; andere Faktoren wie Phosphatgehalt des Wassers usw. scheinen in dieser Hinsicht eine mehr untergeordnete Rolle zu spielen. Unter gewissen Voraussetzungen können Tiefseekerne durch Bestimmung der Foraminiferenanzahl je 1 g Sediment in groben Zügen stratigraphisch gegliedert werden; auch kann die Individuenanzahl der einzelnen Foraminiferenarten aus der Foraminiferenanzahl in 1 g Sediment und aus der prozentualen Zusammensetzung der Gesamtfauna errechnet werden. Mit den hier gewonnenen Erkenntnissen wird versucht, die engen Bezichungen zwischen dem prozentualen Anteil der Warmwasserforaminiferen in der Gesamtfauna und dem CO₂-Gehalt des Sedimentes, dieOvey im Kern 241 der schwedischen Albatroß-Expedition beobachtet hat, zu deuten.Herrn Professor Dr.Carl W. Correns zum 60. Geburtstag gewidmet.     

The Fayette County,Texas, meteorites

Abstract— We report the first petrologic examination of all stone meteorites of Fayette County, Texas. The 10 stones represent four or five different fall events. The three recovered Bluff stones represent two falls. Bluff (a), which includes the 145.5-kg Bluff #1 stone, is classified as L5(S4), whereas Bluff (b) is classified as L4(S3) and is represented by a single stone. The studied Cedar stones are classified as H4(S3), and all four Cedar stones appear to define a strewnfield. Round Top (a), classified as L5(S3) and represented by two stones, is unrelated to either Bluff or Cedar. Round Top (b) [H4(S3); 1 stone], whose exact provenance is unknown, might be a transported fragment of the Cedar shower.     

Spatial variations in the progress of land reform in Romania

Romania's socialist agricultural sector has been transformed by a series of measures taken after the revolution of 1989. A new farm structure is emerging out of the restitution provided for under the Land Law of 1991. There are striking spatial variations in different aspects of the privatisation process, especially the contrasting situations between the hill country (with heavy pressure on land) and the plains (where there is much better supply in relation to demand). Very small units of land ownership are being grouped into larger functional units for management by associations which are especially prominent in the main cropping zones. Meanwhile individual smallholdings are predominant in the hill and mountain zones. Despite a desire for owner-occupation, association is often advantageous through efficient deployment of machinery and some 40 percent of land allocated to individual peasants is being worked by some 20,000 associations. However, the situation has not yet stabilised and it is emphasised that small farms should be regarded not simply as agricultural units but as the cores of diversified enterprises characterised increasingly by pluriactivity     

Quantitative C NMR of whole and fractionated Iowa Mollisols for assessment of organic matter composition

Both the concentrations and the stocks of soil organic carbon vary across the landscape. Do the amounts of recalcitrant components of soil organic matter (SOM) vary with landscape position? To address this question, we studied four Mollisols in central Iowa, two developed in till and two developed in loess. Two of the soils were well drained and two were poorly drained. We collected surface-horizon samples and studied organic matter in the particulate organic matter (POM) fraction, the clay fractions, and the whole, unfractionated samples. We treated the soil samples with 5 M HF at ambient temperature or at 60 °C for 30 min to concentrate the SOM. To assess the composition of the SOM, we used solid-state nuclear magnetic resonance (NMR) spectroscopy, in particular, quantitative ¹³C DP/MAS (direct-polarization/magic-angle spinning), with and without recoupled dipolar dephasing. Spin counting by correlation of the integral NMR intensity with the C concentration by elemental analysis showed that NMR was ?85% quantitative for the majority of the samples studied. For untreated whole-soil samples with <2.5 wt.% C, which is considerably less than in most previous quantitative NMR analyses of SOM, useful spectra that reflected ?65% of all C were obtained. The NMR analyses allowed us to conclude (1) that the HF treatment (with or without heat) had low impact on the organic C composition in the samples, except for protonating carboxylate anions to carboxylic acids, (2) that most organic C was observable by NMR even in untreated soil materials, (3) that esters were likely to compose only a minor fraction of SOM in these Mollisols, and (4) that the aromatic components of SOM were enriched to ∼53% in the poorly drained soils, compared with ∼48% in the well drained soils; in plant tissue and particulate organic matter (POM) the aromaticities were ∼18% and ∼32%, respectively. Nonpolar, nonprotonated aromatic C, interpreted as a proxy for charcoal C, dominated the aromatic C in all soil samples, composing 69-78% of aromatic C and 27-36% of total organic C in the whole-soil and clay-fraction samples.