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Abstract
The present cycle-stratigraphic study is based on four main alternating lithofacies of the Boda Claystone Formation (sandstone, siltstone, claystone and dolomite). The statistical analysis of cycles/rhythms identified from the main rock types of the sequence showed that the theoretical cycle is a succession made up of all layer types and contains the entire sandstone-dolomite row. The definition of the modal cycles that are closer to reality and to practical applications was carried out in several steps. Because of changes within the formation, the modal cycle was identified separately within the major lithostratigraphic units. The more detailed analysis using seven rock types gave similar results, with the dominance of rhythms. Markov chain analysis indicates the arrangement of the Boda Formation in the form of fining-upward cycles. A complete cycle consists of sandstone or siltstone at the base sequentially succeeded by claystone and dolomite at the top. As a result two major facies transition successions can be identified from the facies relationships diagram, which are sandstone to claystone and dolomite to claystone transition. Unit One is represented by sandstone (a, b) and siltstone (c, d), mainly occurring in the basal sequence. Unit Two is dominated by transition from sandstone (a) to silty sandstone (b) and (clayey) dolomite (g, f) to siltstone (b) and/or claystone (e) facies transition successions.
Abstract
Risk assessments and remediation plans of hydrocarbon-contaminated sites usually have been managed based on total petroleum hydrocarbon (TPH) content. Gasoline is one of the most mobile pollution agents, which consist mainly of light hydrocarbons. Measuring of TPH does not give enough information about the individual compounds. Another problem is using solvents such as n-hexane for extraction. In some cases we would like to know about the hydrocarbon-adsorption properties of contaminated samples. The article describes a laboratory model for hydrocarbon contamination modeling, and measuring hydrocarbon sorption properties. For modeling the authors have chosen gasoline type hydrocarbon, homogeneous sand and clay samples from the Kiscell Clay Formation. Results of the modeling indicate that the referenced ATD-GC/MS method can be a very effective tool in the risk assessment of hydrocarbon-contaminated areas.
Abstract
Remains of Triassic vertebrates discovered in the Villány Hills (SW Hungary) are described here. After the well-documented Late Cretaceous Iharkút locality, this material represents the second systematically collected assemblage of Mesozoic vertebrates from Hungary. Fossils were collected from both the classical abandoned road-cut at Templom Hill (Templom-hegy) and a newly discovered site at a construction zone located 200 meters west of the road-cut. Macrofossils of the construction site are mainly isolated bones and teeth of nothosaurs from the Templomhegy Dolomite, including a fragmentary mandible referred to as Nothosaurus sp. and placodont teeth tentatively assigned here to cf. Cyamodus sp. Affinities of these fossils suggest a Middle Triassic (Ladinian) age of these shallow marine deposits.
New palynological data prove for the first time a Late Triassic (Carnian) age of the lower part of the Mészhegy Sandstone Formation. Vertebrate remains discovered in this formation clearly represent a typical Late Triassic shallow-marine fauna including both chondrichthyan (Lissodus, Palaeobates, Hybodus) and osteichthyan (cf. Saurichthys, ?Sphaerodus sp.) fish fossils. The presence of reworked nothosaur and placodont tooth fragments as well as of possible archosauriform teeth, suggest an increase of terrestrial influence and the erosion of underlying Triassic deposits during the Late Triassic.
A belemnite rostrum collected from the lowermost beds of the Somssichhegy Limestone Formation proves that this Lower Jurassic (Pliensbachian) layer was deposited in a marine environment. Most of the vertebrate remains (nothosaurs, placodonts, hybodont shark teeth, perhaps Palaeobates, Lissodus) recovered from these beds are also reworked Triassic elements strongly supporting an erosive, nearshore depositional environment.
