Der Membran-Salzfühler als geignetes Gerät zur Registrierung der Schichtung im Meere

An Hand von erzielten Resultaten mit dem Membran-Salzfühler wird die Genauigkeit dieser Methode zur Registrierung der Salzschichtung diskutiert. Die Reproduzierbarkeit der Meßergebnisse wird besprochen. Einige Messungen in der Ostsee werden als Beispiele angeführt. With the aid of some results the accuracy of the membrane salinity sensor is discussed. The reproducibility of the measurements is determined. Some recordings in the Baltic Sea demonstrate the usefulness of the method

Some investigations intothe sensitivity of the membrane salinometer for various ions

The sensitivity of the membrane salinometer to the various ionic species that constitute the dissolved salts in sea water is investigated. Mixtures of various salts with sodium chloride are investigated with regards to changes in the electromotive force upon dilution with water, and also with regards to changes in the composition of the mixed electrolyte. The results are expressed in terms of changes in the activity of sodium chloride. Also sea water is investigated upon a similar basis. Die Empfindlichkeit des Membransalinometers für die verschiedenen Ionensorten, welche im Meersalz vorhanden sind, wird untersucht. Mischlösungen von verschiedenen Salzen mit Natriumchlorid werden im Zusammenhang mit Veränderungen in der elektromotorischcn Kraft sowohl bei Verdünnung mit Wasser, als auch bei Änderung der Zusammensetzung, untersucht. Mit der Aktivität von Natriumchlorid als Referenz werden die Resultate von modifizierten Nernst-Gleichungen beschrieben

A study of the variability in the hydrochemical factors in the Baltic Sea on the basis of two anchor stations September 1967 and May 1968

The present study was undertaken to investigate the physical and chemical variability in the eastern Gotland Basin. This can serve as an example for the variability in the inner part of an adjacent sea with small tidal influence. Two anchor stations of about four days duration were made, with R.V. "Alkor" in September 1967 and with F.R.V. "Anton Dohrn" in May 1968. On the basis of variations in the physical parameters, and also from continuous recordings of salinity and temperature, c.f., of oxygen and temperature, the presence of internal waves is demonstrated. The variability in the chemical data not only indicate internal waves but also proves the patchlike structure of the water masses with regard to biochemical parameters. The two anchor stations were made during periods of partial and of total stagnation in the deeper parts of the Gotland Basin. Ziel dieser Arbeit ist eine Beschreibung der physikalisch chemischen Veränderlichkeit im östlichen Gotland-Becken, und zwar als Beispiel für die Veränderlichkeit im inneren Teil eines gezeitenarmen Nebenmeeres. Zwei viertägige Ankerstationen wurden durchgeführt, im September 1967 und Mai 1968, mit "Alkor" und "Anton Dohr". Auf Grund der Variationen in den physikalischen Parametern und auch von den kontinuierlichen Registrierungen von Salzgehalt und Temperatur, bzw. von Sauerstoff und Temperatur, werden interne Wellen nachgewiesen. Von der Veränderlichkeit der chemischen Parameter werden neben internen Wellen auch wolkenartige Strukturen der Wassermassen im Bezug auf biochemische Eigenschaften demonstriert. Beide Dauerstationen fielen in einer Periode von teilweiser und von voller Stagnation im Gotland-Becken

10Be and 9Be concentrations and ratios of hydroxylamine leachable and residual phases of DSDP Site 64-477 (Table 1)

Profiles of both10Be and9Be concentrations have been measured in sediments from the DSDP, Leg 64, Site 477 core. Established in the deep Guaymas Basin, in an area of high heat flow, this site offers the opportunity of studying hydrothermal alteration induced by two distinct hydrothermal systems, those caused (I) by the intrusion of hot sills into porous sediments and (I) by heat associated with a magma chamber. The results show that the distribution of both beryllium isotopes between two operationally defined sedimentary phases (material susceptible to hydroxylamine leaching and residual material) changes with the degree of hydrothermal alteration. A decrease in10Be/9Be in the leachable phase of altered sediments relative to unaltered sediments indicates that hydrothermal alteration is not limited to a simple chemical leaching but involves redistribution of the beryllium isotopes between metamorphosed sedimentary phases. In addition, the similarity of the mean10Be/9Be ratios associated with the leachable and the residual phases in the part of the core which has experienced greenschist facies metamorphism suggests that this process leads in the prevailing geophysical conditions to isotopic homogenization. A close relationship exists between10Be and MgO concentrations in altered sediments from this core. This supports earlier observations that beryllium is not easily removed from the sedimentary column and indicates that this remains the case even under the conditions encountered in submarine hydrothermal systems

(Table 1) Clay mineralogy for hemipelagic mud samples of ODP Site 131-808

This paper presents a synthesis of data from X-ray diffraction analyses of clay minerals and X-ray fluorescence analyses of bulk mudstones from Ocean Drilling Program Site 808. The samples come from three closely spaced holes drilled through the toe of the Nankai accretionary prism offshore Shikoku, Japan. Detrital assemblages of clay minerals are unusually uniform throughout the Nankai trench-wedge facies. Illite is the most abundant detrital clay mineral, followed by chlorite, smectite, and traces of kaolinite. Relative percentages of smectite increase within the upper subunit of the Shikoku Basin stratigraphy. This subunit contains abundant layers of volcanic ash, and the corresponding change in clay mineralogy probably was caused by synvolcanic weathering in source areas during the Pliocene, together with in-situ alteration of disseminated glass shards within the Shikoku Basin. At a depth of ~555 mbsf, the detrital and/or authigenic smectite component begins its transformation to illite/smectite mixed-layer clay. With increasing depth below this horizon there is a monotonic increase in illite interlayers. The onset of illitization occurs at an estimated temperature of ~65°C. Ordered (R = 1) illite/smectite interlayering first appears at depths of ~1220 mbsf (<2-µm size fraction) and ~1100 mbsf (<0.2-µm size fraction). The depth interval of the smectite-to-illite transformation coincides with a reduction in pore-water chlorinity; however, the absolute abundance of smectite appears to be insufficient to account for the changes in aqueous chemistry via in-situ dehydration reactions. Instead, significant volumes of diluted pore water probably were transported to Site 808, either from sources located deeper in the accretionary prism (where bulk mudstone porosities are lower) or from lateral sources where mudstones originally deposited in the Shikoku Basin may contain higher percentages of smectite. Significantly, we did not detect any anomalies in clay mineralogy or clay-mineral diagenesis within or near the décollement zone (945-964 mbsf). X-ray fluorescence analyses show that hemipelagic muds and mudstones at Site 808 are chemically uniform throughout most of the section. There are no geochemical perturbations, for example, within the décollement zone. Data from interbeds of volcanic ash demonstrate that the chemical effects of mud/ash dissemination and/or in-situ alteration of pyroclastic material are limited. In addition, ash layers are chemically heterogeneous within Unit III and Subunit IVa, which indicates that tephra was transported from a variety of andesitic to rhyolitic sources on the Japanese Islands during the Pliocene. In contrast, Miocene rocks of Unit V display a clear chemical divergence (little mixing) between rhyolitic tuffs and interbeds of multicolored mudstone. The most significant geochemical anomaly at Site 808 occurs well below the décollement zone between 1087 and 1111 mbsf. Variegated mudstones in this interval contain unusually high ratios of MgO/Al2O3, Fetotal/Al2O3, MnO/Al2O3, and CaO/Al2O3, together with high concentrations of Ba, Y, Sr, La, and Ce. We attribute this anomaly to hydrothermal alteration and/or precipitation of Ca-carbonate, siderite, barite, and related minerals, but we do not know when the event occurred. Fluid migration may have taken place during late Miocene time early in the depositional history of Shikoku Basin (i.e., above newly formed oceanic lithosphere) or during the Holocene as fluids advected through the Nankai accretionary prism

Geochemistry of shallow sediments in Guaymas Basin

Offset of prograde hydrothermal alterations by retrograde reactions is evident in sediments from a piston core (PC6, 8 m long) from the Guaymas Basin, Gulf of California. Geochemical and mineralogical analyses of sediments and pore fluids show superimposed geochemical signals that indicate currently active reactions are modifying previously formed secondary solids. Hydrothermal barite was formed in a previously active flow channel between 150 and 250 cm depth. Hydrothermal gypsum is presently dissolving at depths >780 cm, below which hydrothermal fluid flow is channeled by a secondary dolomite layer. Thermal stress of organic matter generates hydrothermal gas and petroleum having wide ranges of compositions and maturities. A significant amount of hydrothermally generated oil has been transported laterally through a porous debris flow (approx. 240 cm subbottom), overwhelming the indigenous bituminous matter. Water soluble petroleum constituents have disseminated throughout the cored sediments. From 400 to 700 cm depth the immature organic matter continues to experience thermally-enhanced diagenesis, and an even higher thermal stress has occurred at the bottom of the core. Enhanced bacterial degradation of organic matter has led to depletion of pore water sulfate and enrichment of ammonium (NH4+) in both pore fluid and sediment, resulting in formation of NH4+ bearing secondary clay minerals at depths below 780 cm