36 research outputs found
KözĂ©psĆ-triĂĄsz karbonĂĄtplatformok fejlĆdĂ©se az Aggteleki-hegysĂ©gben, az Ăszaki-MĂ©szkĆalpokban Ă©s a Cirkum-Pannon-tĂ©rsĂ©gben
ANISIAN TERRESTRIAL SEDIMENTS IN THE BĂKK MOUNTAINS (NE HUNGARY) AND THEIR ROLE IN THE TRIASSIC RIFTING OF THEVARDAR-MELIATA BRANCH OF THE NEO-TETHYS OCEAN
In recent years detailed sedimentological and biostratigraphical investigations have revealed Anisian terrestrial sediments in three sections of the BĂŒkk Mountains. In the northern part of the mountains fluviatile sediments were recognised while in the southern part lake deposits were observed. Based on the stratigraphical position and microfacies analyses of the resedimented grains, two terrestrial events can be reconstructed. The age of the younger is late Pelsonian-early Illyrian?. This can be correlated with the Richthofen Conglomerate in the Dolomites. The age of the older terrestrial event could not be established exactly but it must have happened either in the Pelsonian or in the Aegean-Bithynian; consequently it may correlate either with the Voltago or with the Piz de Peres Conglomerate in the Dolomites. The terrestrial sediments in the BĂŒkk Mountains are parts of a volcano-sedimentary succession, which is characteristic of the updoming part of a rifting area. Terrestrial sediments in the southern part of the mountains represent the deepest part of the half-grabens, which originated during the course of the rifting. The present paper gives an overview of the Anisian-Lower Ladinian terrestrial sediments in the Southern Alps-Dinarides and considers their formation during the Triassic rifting of the Vardar-Meliata branch of the Neo-Tethys.
Re-evaluation of the Triassic sequence in the subsurface of the Little Plain Basin Hungary: A case study from the GyĆrszemere-2 well
The Little Plain Basin is one of the largest units in the Pannonian Basin System. Its continuation in Slovakia is called the Danube Basin. The Little Plain Basin is one of the most underexplored areas in Hungary. Based on archival geologic and geophysical data the lithostratigraphic composition of the area is controversial. The significance of the area is increased by the known Neogene and the supposed basement (Paleozoic and Mesozoic) hydrocarbon systems in Hungary and in Slovakia.
The purpose of this study is to identify the exact age, facies, geologic formations and possible source rocks of the Triassic section penetrated by the GyÔrszemere-2 well in the Little Plain Basin.
Based on new facies and paleontological results it can be stated that two Triassic sequences are identified in the well, separated by fault breccia. A carbonate sequence was deposited between the Induan and Early Anisian and above that a homogeneous recrystallized dolomite appears, the age of which is unknown.
The following formations were encountered, from base upward:
ArĂĄcs Marl Fm. (3,249.5â3,030 m), silty marl with ooids, bivalves, gastropods and ostracode shells. Occasionally layers of angular quartz grains in large quantities appear. Postcladella kahlori and Spirobis phlyctaena indicates Induan (Early Triassic) age.
KöveskĂĄl Dolomite Fm. (3,030â2,790 m), rich in ooids and also containing anhydrite. The Glomospira and Glomospirella dominance indicates an age interval between Olenekian and earliest Anisian age.
Fault breccia (2,790â2,690 m) separating the KöveskĂĄl and overlying dolomites.
Upper dolomite (2,690â2,200 m): homogeneous, saccharoidal, and totally recrystallized. The age is unknown.
The low TOC values of the supposed source rock interval (marl between 3,249.5 and 3,030 m) indicate poor hydrocarbon potential
A triĂĄsz zĂĄtonyok fejlĆdĂ©se a Tethys Ă©szaki peremĂ©n = Evolution of the Triassic Reefs on the Northern Part of the Tethys
ElkĂ©szĂtettĂŒk az Aggteleki platform 10 000-es tĂ©rkĂ©pĂ©t. KĂ©t zĂĄtonyt kĂŒlönĂtettĂŒnk el. LeĂrtuk faunĂĄjukat Ă©s flĂłrĂĄjukat, összesen 98 fajt. Egy Ășj fajt (Aggtecella hungarica) Ă©s egy Ășj ĂĄsvĂĄnyt (nonstrandit) Ărtunk le. RekonstruĂĄltuk a platform fejlĆdĂ©sĂ©t az anisusi-ladin-ban. EgĂ©sz pontosan meghatĂĄroztuk a zĂĄtony kialakulĂĄs korĂĄt: Trinodosus subzona. Az elsĆ zĂĄtony a Trinososus subzĂłna kezdetĂ©tĆl a Curionii subzĂłnĂĄig lĂ©tezett, majd a zĂĄtony ĂK-re progradĂĄlt. BebizonyĂtottuk, hogy a Neotethys riftesedĂ©se Ă©s az Aggteleki zĂĄtony kialakulĂĄsa között ok-okozati összefĂŒggĂ©s van. Kimutattuk, hogy minden neptĂșni telĂ©r hĂĄrom idĆszakban keletkezett: Binodosus-, Trinodosus-, Avisianum subzone. | We finished the 1:10 000 map about the Aggtelek platform. We distinguished two reefs, described their fauna and flora, all together 98 species. We described a new species (Aggtecella hungarica) and a new mineral (nonstrandit). We reconstructed the evolution of the platform during the Anisian-Ladinian. We determined the exact age of the reef forming: Trinodosus subzone. The first reef existed from the beginning of the Trinososus subzone until the Curionii subzone, than the reef prograded to the NE. We proved, that there is a causal relation between the rifting of the Neotethys and the forming of the Aggtelek reef. We justified, that every neptunian dykes originated during three interval: Binodosus-, Trinodosus-, Avisianum subzone
CT Based Analysis Of Pore Network Of Reservoir Rocks
High-resolution X-ray Computed Tomography (CT) is a novel technique suited to a wide range of geological investigations. It is a quick and non-destructive method to produce images that correspond closely to serial sections through an object. Sequential contiguous images are compiled to create three-dimensional representations that can be manipulated digitally to perform efficiently a large array of measurements and visualizations. In this study we combined conventional core analysis technique with micro-scale Computed Tomography imaging technique to extract pore network properties of carbonate rocks. In order to detect pore properties from the CT images different filtering algorithms and various segmentation techniques were applied to obtain robust data, which were compared with those of mercury injection texts carried out in the laboratory on the same samples. The methodology is applied to a set of real porous media and the resulting pore network statistics showed great variability compared to lab results due to limitations in voxel resolution. Despite this, useful information about the pore constituents could be extracted
Contribution of microbial processes to the enrichment of Middle Permian manganese deposits in northern Guizhou, South China
Stratigraphy, facies and geodynamic settings of Jurassic formations in the BĂŒkk Mountains, North Hungary: its relations with the other areas of the Neotethyan realm.
Jurassic mélange complexes related to the subduction of the Neotethys Ocean occur
in the BĂŒkk Mountains, North Hungary. This paper characterizes the sedimentary sequence of
basin and slope facies that occur in the southwestern part of the BĂŒkk Mountains, placing special
emphasis on the redeposited sedimentary rocks (olistostromes, olistoliths: Mónosbél Group) in order
to obtain information on the provenance of the clasts, and the mode and time of their redeposition.
The series of formations studied shows a general coarsening-upwards trend. Based on radiolarians
and foraminifera, the Mónosbél Group formed in Early to Late Bathonian time. The lower part
of the complex is typified by a predominance of pelagic carbonates, shale and radiolarite with
andesitic volcaniclastic intercalations. The higher part of the succession is characterized by polymictic
olistostromes. Large olistoliths that are predominantly blocks of Bathonian shallow marine limestone
(BĂŒkkzsĂ©rc Limestone) appear in the upper part of the sequence. Based on the biostratigraphic and
sedimentological data, results of analyses of the redeposited clasts and taking into consideration
the concepts of the development of the western Neotethys domain, the evolutionary stages of the
sedimentary basins were defined. The onset of the compressional stage led to initiation of nappe
stacking that led to the formation of polymict olistostromes and then to the redeposition of large
blocks derived from out-of-sequence nappes of the former platform foreland
AXOPORA AGGTELEKENSIS SCHOLZ, 1972, ORIGINALLY DESCRIBED AS HYDROZOA, IS ATTRIBUTED TO THE NEW GENUS ANISOPHYTES (CYANOPHYTA?)
Examination of the calcareous microfossil from the Anisian reef limestones of the Aggtelek Mountains, northern Hungary, described as Axopora aggtelekensis by Scholz, supports the cyanobacterian nature of this organism. It is not a Hydrozoa as originally thought by Scholz. For this microfossils, occuring in Triassic shallow water carbonates the new genus Anisophytes is proposed. The differences between Anisophytes, as gregarious microfossil composed of tubes, and other similar looking organisms, like Tubiphytes, Aeolisaccus kotori Radoicic, Koivaella Tchuvashov or Proaulopora Vologdin is discussed. Anisophytes is attributed tentatively to Cyanophyceans.