Early Cretaceous foraminifera from atoll environment (Márévár Valley, Mecsek Mountains, Hungary)

This paper presents the microfaunal examination of the Márévár (Eastern Mecsek) occurrence of the Hidasivölgy Marl Formation. The foraminifera-dominated microfauna clearly indicates the type of palaeoenvironment. The foraminiferal assemblage is composed of 35 taxa (frequent genera: Trocholina, Neotrocholina, Lenticulina, Dentalina, Nodosaria, Spirillina). The benthic foraminifera fauna is divided into four (A, B, C, D) morphogroups in relation to microhabitat depth in the sediments. Morphogroup A: epifaunal foraminifera (Neotrocholina, Trocholina, Patellina, Spirillina, Ammodiscus) live in up to 1 cm depth in the sediment. Morphogroup B: shallow infaunal foraminifera (Dentalina, Nodosaria, Pseudonodosaria) live in depth of less than 5 cm. Morphogroup C: shallow to deep infaunal foraminifers (Dorothia, Tritaxia, Reophax) live deeper than 5 cm depth in the sediments. Morphogroup D: epifaunal to deep infaunal foraminifers (lenticulinids) distribute within a wide range of depths in the substrate. The foraminifera assemblage of the Márévár occurrence can be characterized with low diversity and abundance but with significant ratio of morphogroup A (dominance of the trocholinids, neotrocholinids). The results of the microfauna and macrofauna observations indicate normal salinity, warm water, shallow marine environment in lagoon region. In addition, an input of large amount of volcanic material could be reconstructed for the time. Involving these facts into the presently accepted formation model, the Márévár occurrence of the Hidasivölgy Marl represents an outer part of the lagoon in between the basalt volcano and the atoll situated at the rim of the volcanic build-up during the Early Valanginian. Because of repeated volcanic activity, it is most probable that the lagoon filled up and mixture of volcanic material and sediments redeposited into the deeper slope around the volcanic cone

Micropaleontological observations on the Lower Cretaceous iron ore-related formations of the Mecsek Mts. (Upper Valanginian–Lower Hauterivian, South Hungary)

The Late Valanginian–Early Hauterivian iron ore deposit and related formations at Zengővárkony (Mecsek Mts., South Hungary) provided a relatively rich microfauna of foraminifera, crustacean microcoprolites, and sponge spicules. Benthic foraminifera are recognized in decreasing abundance: Glomospira cf. gordialis (Jones and Parker 1860), Lenticulina sp., Spirillina sp., Nodosaria sp., Epistomina sp., and Trocholina sp. A Hedbergella sp. indicates the presence of planktonic foraminifera around the ore deposit. Besides this microfauna, sponge spicules (diactine-type criccorhabds and anactine-type rhax forms) are first recorded from this environment. Rock-forming quantities of various ichnospecies of crustacean microcoprolites are recorded. Favreina hexaochetarius, Palaxius tetraochetarius, and Palaxius decaochetarius isp. provided statistically evaluated quantities in thin sections, which point to a complete crustacean ichnofauna from juveniles to adults. Four different microfossil assemblages are recognized from the Apátvarasd Limestone Fm: (a) Glomospira-dominated foraminifer assemblage, (b) diverse crustacean microcoprolite assemblage dominated by Palaxius, (c) monotypic Favreina assemblage, and (d) diverse sponge-dominated assemblage. These assemblages are similar to that of the Recent Aegean Sea hydrothermal field communities. The remains of an undetermined crinoid from dissolved rock sample may indicate a vivid sea-bottom environment

Albian Foraminifera from Vértessomló Vst-8 borehole, Vértes Mountains (Hungary)

The subject of this research is a rich and well-preserved foraminifera fauna of Albian age from Vértessomló Vst-8 borehole of Vértes Foreland (Transdanubian Range, Hungary). A fifty-meter section of the sequence contains a quantity of this diversified microfauna within the ~100 m thick Vértessomló Siltstone excavated by the borehole. The microfauna is dominated by foraminifera. The samples were dissolved in hydrogene peroxide and concentrated acetic acid. The fauna indicates Albian age but most of the species have wide stratigraphical distribution. Tritaxia, Gavelinella, Favusella are the dominant genera. Determination of 40 taxa, their statistical evaluation and their classification into morphogroups are given. The investigated sequence can be divided into three parts according to the ratio of calcareous/agglutinated forms, planktonic/benthic forms, inbenthic/ epibenthic forms and diversity. The lower part of the sequence was deposited in a weakly dysaerobic off-shore marine environment which contains Orbitolina redeposited from the platform of the Környe Limestone. The middle part of the sequence was formed in a planktonic foraminifera-rich (Hedbergella, Favusella), low energy offshore environment with limited amount of nutrient and low/moderate degree of oxygen depletion (dysaerobic environment). On these results the upper part of the sequence can be described as a formation sedimented in a nutrient-rich dysaerobic (moderate degree of oxygen depletion) environment

A Mecseki- és a Villány-Bihari-zóna ősföldrajzi viszonyainak feltárása a felső-triász - középső-kréta képződmények sokoldalú elemzése alapján = Palaeogeographic connections of the Mecsek and Villány-Bihar Zones based on multilateral analyses and studies of the Upper Triassic - Middle Cretaceous formations

Az irodalmi előkészítéssel kiválasztott felső-triász – alsó-kréta előfordulások rajzos és fényképi dokumentálása, anyagvizsgálati mintázása alapján kezdődtek meg a csiszolatos szöveti és mikrofácies vizsgálatok. Ezzel egyidőben folyt a nagy számú fúrási rétegsor áttekintő, ill., részletes értékelése. Újravizsgáltuk több tucat fúrás raktári maganyagát. Az anyagvizsgálati keret jelentős része önálló alcím alatt az MTA GKL-ben, más része a MÁFI-ban, ill., több kutatóhelyen került felhasználásra különböző szakirányokban. Néhány konkrétum A Villányi-hegység szerkezetföldtani felmérése során 6 szerkezeti fázis elkülönítésére került sor. A hegység arculatát alapvetően a transzpressziós tenzortér szabta meg. A komlói szénkutatási területen elkészült az alsó-jura formációk vastagsági és kavics (breccsa) tartalmú rétegeinek fajlagos vastagsági térképe. A vastagsági maximumok egybeesése jelzi, hogy a medencén belül hosszú ideig léteztek gyorsabban, illetve lassabban süllyedő területek. Az ásványkőzettani és paleontológiai adatok alapján meghatározásra került a nagy szervesanyagtartalmú toarci rétegek képződési ideje és a rétegsor rövid ciklusú változékonysága. Hasonló alapokon klimaváltozási ciklusokat állapítottak meg a kora-jurától a középső-juráig terjedően. Modell szinten alapvetően átértékeltük a Tiszai-egység fejlődéstörténetét. E szerint a leszakadási folyamat a középső-triász végén kezdődött el, konszolidációja a kora-kréta végén a takaróképződés megindulásával vette kezdetét. | Figures, photographs and rock sampling of Upper Triassic to Lower Cretaceous surface outcrops were the base for starting textural and microfacies studies of surveying character. Documentation of many wells and boreholes were revised in varied details. It is followed by studies of cores of dozens of boreholes. A significant part of the mount for lab studies were dedicated for MTA GKL in a contract, the rest was used by MÁFI and other research places for varied scientific directions. Major achievements: Based on microtectonic studies Villány Hills 6 tectonic phases were distinguished in the Villány Hills. The character of the Villány Range is determined by transpressional stress fields. Thickness maps of the Lower Jurassic formations and their pebble–bearing beds of the Komló coalfield have been prepared. The coincidences of the maximum thicknesses of the map sets gave evidences for the long existence of both the quickly and the slowly sinking areas of the basin. The formation time and the short-cyclic variability of the organic-rich Toarcian beds were established on recently gained data set. In a similar way cycles of climatic changes were appointed for the Early Jurassic epochs. Using basic geological data the model of the palaeogeographic history of the Tisza unit is reassessed fundamentally. According to this the process of separation started at the end of the Middle Triassic and the consolidation begun with the formation of nappe system at the end of the Early Cretaceous

Hantken Miksa hagyatéka

Hantken Miksa tárgyi hagyatéka, mely magába foglalja az általa gyűjtött ősmaradványokat és a hátra maradt munkáit is, egyben egy igen jelentős, máig ható szellemi hagyaték is. Sokrétű munkásságának fennmaradt emlékei a jelenkor kutatóinak is segítségül és útmutatásul szolgálnak munkájuk során. A Koch által 1894-ben összeállított, eddig legteljesebb Hantken bibliográfiát pontosítottuk és 22 munkával egészítettük ki. Közreadjuk Hantken által leírt és a róla elnevezett taxonok listáját