Hydrocarbon distribution in coals and in dispersed organic matter of different maceral compositions and maturities

More than 60 samples from 5 coal seams and adjacent siltstones and sandstones were selected from a well through Westphalian B sediments from Northern Germany in order to study bitumen generation and migration. The cores were drilled between 1200 und 1530 metres depth. In this interval, vitrinite reflectance (Rr) is increasing from 0.70 to 0.92%. Results reveal high hydrocarbon generation potentials for all coal samples, but not for adjacent clastic rocks, although maceral compositions of both are quite similar. Yields and compositions of thermal extracts from the coals depend on maceral compositions and rank. However, the bulk of the already generated bitumen has not been removed during natural coalification and is not easily releasable by thermovaporisation. A mass balance based on elemental composition of dull coals indicates that in the rather narrow rank interval (0.70–0.92% Rr) a total mass loss of 20% may have occurred by migration. This is evidenced by a loss of about 20% of the original hydrogen, the rest being stored in the coals.

---

Zusammenfassung Um die Entstehung und Migration von Bitumen zu untersuchen wurden in Norddeutschland mehr als 60 Proben aus 5 Kohleflözen und benachbarten Silt- und Sandsteinen aus einer Bohrung durch Westphal B-Sedimente bearbeitet. Die Entnahmetiefe der Bohrkerne liegt zwischen 1200 und 1530 Metern. Innerhalb dieses Intervales steigt die Vitrinit-Reflexion (Rr) von 0,70 auf 0,92%. Für alle Proben aus den Flözen ergeben sich hohe Kohlenwasserstoff-Bildungspotentiale, nicht aber für die benachbarten klastischen Gesteine, obwohl die Mazeral-Zusammensetzungen in beiden ähnlich sind. Die Ausbeute und Zusammensetzung thermaler Extrakte aus den Flözen hängen von Mazeral-Zusammensetzung und Reife ab. Allerdings wurden weder während der Inkohlung größere Mengen des Bitumens abtransportiert, noch ist dieses durch Thermovaporisation leicht freisetzbar. Eine Massenbalanzierung auf der Basis der Elementzusammensetzung ergibt für das relativ schmale Interval von C,70-0,92% Rr ein Massenverlust von 20% durch Migration. Diese Angabe basiert auf einer 20%igen Reduzierung der ursprünglichen Wasserstoffmenge, wobei die restlichen 80% in der Kohle gespeichert bleiben.

---

Résumé Dans un forage pratiqué à travers le Westphalien B du nord de l'Allemagne, on a sélectionné plus de 60 échantillons provenant de 5 couches de charbon ainsi que des siltites et grès adjacents, dans le but d'étudier la formation et la migration du bitume. Les carottes proviennent de profondeurs situées entre 1200 et 1530 m. Dans cet intervalle, le pouvoir réflecteur de la vitrinite (Rr) passe de 0,70 à 0,92%. L'étude révèle des potentiels élevés en hydrocarbure pour tous les échantillons de charbon, mais pas pour les roches détritiques voisines, bien que les compositions «macérales» soient analogues dans les deux cas. L'importance et la composition des extrait athermiques des charbons dépendent de la composition «macérale» et du degré d'évolution. Toutefois, la plus grande partie du bitume engendré est restée sur place au cours de la houillification naturelle et elle est difficile à extraire avex la methode de thermovaporisation. Une balance des masses d'éléments indique pour cet intervalle relativement étroit (0,7–0,92% Rr) une perte totale de masse de 20% due à la migration. Ce résultat correspond à une perte d'environ 20% de l'hydrogène originel, les 80% restants étant demeurés dans le charbon.

---

60 5 , , . 1200 1530 . /Rr/ 0,7 0,92. , , . , , . , , . , , 20% 0,7 0,92 %. 20%; , 80%, .

     

Influence of the surface microlayer on the flux of nonconservative trace gases (CO,H2, CH4, N2O) across the ocean-atmosphere interface

Gas exchange experiments were conducted in the tropical Atlantic Ocean during a ship expedition with FS Meteor using a small rubber raft. The temporal change of the mixing ratios of CO, H₂, CH₄ and N₂O in the headspace of a floating glass box and the concentrations of these gases in the water phase were measured to determine their transfer velocities across the ocean-atmosphere interface. The ocean acted as a sink for these gases when the water was undersaturated with respect to the mixing ratio in the headspace. The transfer velocities were different for the individual gases and showed still large differences even when normalized for diffusivity. Applying the laminar film model, film thicknesses of 20 to 70 m were calculated for the observed flux rates of the different gas species. When the water was supersaturated with respect to atmospheric CO, H₂, CH₄ and N₂O, the transfer velocities of the emission process were smaller than those determined for the deposition process. In case of H₂ and CH₄, emission was even not calculable although, based on the observed gradient, the laminar film model predicted significant fluxes at the air-sea interface. The results are interpreted by destruction processes active within the surface microlayer.     

The Transiometer: An Alternative Method of Soil Moisture Measurement in Slowly Permeable Soils

The union of a piezoresistive pressure transducer and a porous ceramic cup was termed "transiometer." The transiometer was constructed from economical and readily available materials. It could be used to measure soil water potentials in both saturated and unsaturated conditions, and was well suited to continuous monitoring with data acquisition equipment.
Transiometer testing was conducted at two sites, one of moderate permeability and the other of slow permeability. The slowly permeable site was instrumented with four replications of the following: (1) transiometers installed at four depths, (2) a transi-ometerwithout the ceramic cup, (3) apiezometer, and (4) access tubes for monitoring soil moisture with a neutron probe. The moderately permeable site was instrumented with a transiometer, two piezometers, and an access tube for monitoring with a neutron probe.
In saturated conditions the transiometer had a faster response time after installation than the piezometer. Faster response makes the transiometer more desirable for use in slowly permeable soils, especially when monitoring dynamic soil water.
Calculated random error of the transiometer measuring system, including a digital voltmeter and a scanner, was typically 0.09 feet (2.8cm), with a maximum calculated to be 0.38 feet (11.5cm). The two most significant components were imprecision of the scanner card and calibration shift. The transiometer was sensitive to atmospheric pressure fluctuations, with sensitivity to atmospheric pressure change increasing with installation depth.     

Strontium-calcium ratios in Cenozoic planktonic foraminifera

The $\text{Sr}\text{Ca}$ ratio and other parameters have been measured in fossil planktonic foraminifera from the Atlantic and Pacific Ocean basins in order to evaluate the $\text{Sr}\text{Ca}$ ratio of seawater during the last 75 million years. Results on well-preserved samples indicate that the ratio has increased to its present value by 10–15% during the Cenozoic, and that minima occurred between 55-45 Ma and 10-5 Ma, when the ratio was 15–25% less than at present. The long-term increase may reflect either decreasing deposition of aragonite with a high $\text{Sr}\text{Ca}$ ratio in shallow seas, or decreasing seafloor spreading rates and consequently decreasing hydrothermal supply of Ca during the Cenozoic. Other geologic evidence suggests that the Eocene minimum (near 50 Ma) may have resulted from increased aragonite sedimentation, while the Late Miocene minimum (between 10-5 Ma) may have been caused by an increased rate of seawater-basalt exchange when seafloor spreading rates increased on the East Pacific Rise near 10 Ma.     

Tracer methods used to verify the hypothesis of Cvijić about the underground connection between Prespa and Ohrid Lake

Prespa Lake and Ohrid Lake constitute a hydraulic system shared between Albania, FYR of Macedonia and Greece. Karst rocks separate both lakes. The elevation of Prespa Lake is about 150 m higher than that of Ohrid Lake. Considering these facts, Cvijić formulated in 1906 the hypothesis that Prespa Lake recharges the St. Naum and Tushemisht springs at Ohrid lakeside. Environmental isotopes demonstrated that Prespa Lake recharges about 37–42 and 52–54% of water emerging in St. Naum, and Tushemisht springs, respectively. An artificial tracer experiment carried out in 2002 physically demonstrated the underground connection between both lakes. This experiment confirmed the supposed underground connection and brought important information about the groundwater velocity, transit time, and karst water conduits development.     

Freshwater snail communities and lake classification. An example from the Åland Islands, southwestern Finland

The freshwater snail fauna in 51 lakes on the Åland Islands was investigated. By means of cluster analysis it appears that lakes may be divided into four groups on the basis of snail species composition. The lakes of the four groups show a spatial distribution which is related to topographical differences, terrestrial vegetation and land use. Snails may be divided on the basis of water hardness into hard water species and calcium indifferent species or into demanding and modest/indifferent species when clustering is based on presence/absence.     

A novel ozone sensor for direct eddy flux measurements

A small, lightweight (1.5 kg) and fast-response ozone sensor for direct eddy flux measurements has been built. The basis for detection is the chemiluminescence of an organic dye adsorbed on dry silica gel in the reaction with ozone. The chemiluminescence is monitored with a cheap and small blue-sensitive photomultiplier. At a flow rate of 100 l min^-1 the ozone sensor has a 90% response time of significantly better than 0.1 s with a detection limit lower than 50 ppt at S/N=3. There are no interferences from other atmospheric trace gases like NO_x, H₂O₂ and PAN. Water vapour and SO₂ enhance the chemiluminescence efficiency of the ozone sensor. Since their response times are 22 seconds and 30 minutes, respectively, no correlation between rapid ozone fluctuations and those of these two trace gases is noticed by the ozone sensor when operating at a frequency of 10 Hz.The ozone sensor was tested for several weeks in continuous measurements of ozone fluxes and deposition velocities over different croplands using the eddy correlation technique. Good agreement was found between ozone dry deposition velocities derived from profile measurements and by eddy correlation.     

Computation of 5-day temperature normals in western Europe and the Mediterranean area

Summary UsingCraddock's method of representing the annual temperature variation by a two-term harmonic form fitted to monthly means, the harmonic coefficients of 63 stations in western Europe and around the Mediterranean Sea, as well as the 5-day normals for 24 Mediterranean stations, were computed and tabulated. In addition, some of the harmonic coefficients were charted and isoplethed, showing very distinctly the influence of continentality and topography. These charts, together withCraddock's charts for northern and northwestern Europe, provide fairly complete coverage of Europe and the Mediterranean area.This paper was prepared in the offices of the Technical Support Division of the 2d Weather Wing, United States Air Force, as a matter of routine business. The information contained herein was presented at the 5th Meeting of the Italian Society of Geophysics and Meteorology by Dr.Ingrid Weiss (Genoa: 23–25 April 1957). Since the paper is of general interest to all meteorologists of the Mediterranean area, it is published here with the permission of the originating agency as «Mémoire No. 3 du Centre International de Recherches sur la Météorologie de la Méditerranée (CIRMM)».     

Helium-uranium dating of corals from Middle Pleistocene Barbados reef tracts

By He-U dating of corals from elevated Pleistocene reef tracts on Barbados, we have extended back to the Middle Pleistocene the high sea stand chronology previously deduced by Th²³⁰-U dating. Six samples from the first major reef tract complex older than the 200,000-yr complex gave ages of 350,000 ± 25,000 yr B.P. Two corals from the crest of Second High Cliff, an unusually large escarpment occurring approximately midway in the terrace sequence, gave concordant ages of 480,000 and 500,000 yr. Unrecrystallized corals from older reefs gave ages ranging back to 650,000 yr.The results date episodes of high sea stands at 350,000 and 500,000 yr B.P.