Verteilung von Fe,Mn, Ca und Mg im Karbonspati der Blei-Zink-Erzgänge des Südlichen Rheinischen Schiefergebirges

The statistical study of the chemical composition of the carbonates I in the lead-zinc ore district belonging to the southern ?Rheinisches Schiefergebirge“ represents a suitable method for characterising the ore veins and their types in this district. It allows to find out and to confirm the genetic relationships. In a detailed study (Hannak, 1965) the iron-manganese ratio in the carbonates I of the veins has been investigated and it has been shown that the Fe-Mn quotient can be employed as a typological factor for the types of the ore veins. Supplementary to this, the calcium-magnesium distribution has been followed up and compared with that of iron-manganese. The investigation led to the conclusion that calcium and magnesium also show a distribution which is characteristic of the veins and of different vein types. Investigations concerning the conditions of formation as well as the possibility of solid solutions in the above treated system will be made in some later studies.     

Field measurement of air-sea gas transfer: A methodical search

In order to obtain field data of ocean-atmosphere gas transfer coefficients, it is preferable to measure the interfacial gas flux in the air rather than in the water. This approach has been reported in the literature for CO₂. However, it is shown here that ²²²Rn and methyliodide, CH₃I, may be more suitable gases for air-side flux measurements.     

Application of a forest succession model to a continentality gradient through Central Europe

The forest succession model FORSKA was applied to a west-east transect across Central Europe using points from a global climate data set. Climate change experiments were undertaken for two general circulation model scenarios and two different site classes. The simulated climate changes lead to reduced forest productivity and a changed species composition on most sites. Under current climate, the broad scale pattern of the climatically driven distribution of forest communities is quite realistically reproduced. However, the resolution of climate data imposes limitations on the simulation of forest dynamics in subcontinental climate, because climate variability and extreme events are not well represented.     

Identification of cryovolcanism on Titan using fuzzy cognitive maps

Future planetary exploration of Titan will require higher degrees of on-board automation, including autonomous determination of sites where the probability of significant scientific findings is the highest. In this paper, a novel Artificial Intelligence (AI) method for the identification and interpretation of sites that yield the highest potential of cryovolcanic activity is presented. We introduce the theory of fuzzy cognitive maps (FCM) as a tool for the analysis of remotely collected data in planetary exploration. A cognitive model embedded in a fuzzy logic framework is constructed via the synergistic interaction of planetary scientists and AI experts. As an application example, we show how FCM can be employed to solve the challenging problem of recognizing cryovolcanism from Synthetic Aperture Radar (SAR) Cassini data. The fuzzy cognitive map is constructed using what is currently known about cryovolcanism on Titan and relies on geological mapping performed by planetary scientists to interpret different locales as cryovolcanic in nature. The system is not conceived to replace the human scientific interpretation, but to enhance the scientists’ ability to deal with large amounts of data, and it is a first step in designing AI systems that will be able, in the future, to autonomously make decisions in situations where human analysis and interpretation is not readily available or could not be sufficiently timely. The proposed FCM is tested on Cassini radar data to show the effectiveness of the system in reaching conclusions put forward by human experts and published in the literature. Four tests are performed using the Ta SAR image (October 2004 fly-by). Two regions (i.e. Ganesa Macula and the lobate high backscattering region East of Ganesa) are interpreted by the designed FCM as exhibiting cryovolcanism in agreement with the initial interpretation of the regions by Stofan et al. (2006). Importantly, the proposed FCM is shown to be flexible and adaptive as new data and knowledge are acquired during the course of exploration. Subsequently, the FCM has been modified to include topographic information derived from SAR stereo data. With this additional information, the map concludes that Ganesa Macula is not a cryovolcanic region. In conclusion, the FCM methodology is shown to be a critical and powerful component of future autonomous robotic spacecraft (e.g., orbiter(s), balloon(s), surface/lake lander(s), rover(s)) that will be deployed for the exploration of Titan.     

Source-rock identification by isotope analyses of natural gases from fields in the Val Verde and Delaware basins,west Texas

Methane, ethane and propane carbon-isotope ratios are controlled by the maturity of the organic material in their source rocks. Isotope data of natural gases can be used in some instances to identify their source rocks. Migration seems to cause no essential changes in the carbon-isotopic composition of the gas components. Under certain circumstances the isotope-maturity relationship can be used in approximating displacement along fault systems or in determining the direction of gas migration.