Entity

Time filter

Source Type


Kullmer O.,Senckenberg Institute | Benazzi S.,Max Planck Institute for Evolutionary Anthropology | Schulz D.,Research and Methods | Gunz P.,Max Planck Institute for Evolutionary Anthropology | And 2 more authors.
Journal of Human Evolution | Year: 2013

Dental arch reconstructions present as much of a challenge in paleoanthropology as in orthodontics and maxillo-facial surgery. Dentists and dental technicians know that it is very difficult to find the precise physiological crown positions that will yield individually correct occlusal kinematics in living individuals, and this difficulty is compounded by damage and deformation in fossil specimens. Typically, dental arch reconstructions of fossils are not validated, although a functionally correct reconstruction is of undoubted importance for accurate morphological descriptions and comparative studies of fossil dentitions.Here we describe a new method for functional dental arch reconstruction derived from detailed wear facet mapping (Occlusal Fingerprint Analysis, OFA) and dental-technical approaches. OFA was used to restore the entire dental arches of the most complete late Miocene fossil great ape dentition, that of Rudapithecus hungaricus, from Rudabánya in Hungary. Dental stone casts of the maxillary and mandibular dentition were repositioned in a dental articulator. The correct alignment of the tooth crowns was monitored by physically and virtually testing the tooth contacts during occlusal movements.The characteristic distribution pattern of the individual macrowear facets strongly constrains the antagonistic crown relationships in the Rudabánya specimen. We propose that the method used to reconstruct the functional dental arches of R. hungaricus, derived from kinematic evidence encoded in macrowear patterns, can be used as a reliable foundation for dental and facial restorations in fossils, and for individual occlusal crown morphology and dental arch reconstructions in modern dentistry and prosthetics. © 2012 Elsevier Ltd.


Nemeth K.,Massey University | Risso C.,University of Buenos Aires | Nullo F.,CONICET | Kereszturi G.,Massey University | Kereszturi G.,Geological Institute of Hungary
Central European Journal of Geosciences | Year: 2011

Payún Matru Volcanic Field is a Quaternary monogenetic volcanic field that hosts scoria cones with perfect to breached morphologies. Los Morados complex is a group of at least four closely spaced scoria cones (Los Morados main cone and the older Cones A, B, and C). Los Morados main cone was formed by a long lived eruption of months to years. After an initial Hawaiian-style stage, the eruption changed to a normal Strombolian, conebuilding style, forming a cone over 150 metres high on a northward dipping (∼4°) surface. An initial cone gradually grew until a lava flow breached the cone's base and rafted an estimated 10% of the total volume. A sudden sector collapse initiated a dramatic decompression in the upper part of the feeding conduit and triggered violent a Strombolian style eruptive stage. Subsequently, the eruption became more stable, and changed to a regular Strombolian style that partially rebuilt the cone. A likely increase in magma flux coupled with the gradual growth of a new cone caused another lava flow outbreak at the structurally weakened earlier breach site. For a second time, the unstable flank of the cone was rafted, triggering a second violent Strombolian eruptive stage which was followed by a Hawaiian style lava fountain stage. The lava fountaining was accompanied by a steady outpour of voluminous lava emission accompanied by constant rafting of the cone flank, preventing the healing of the cone. Santa Maria is another scoria cone built on a nearly flat pre-eruption surface. Despite this it went through similar stages as Los Morados main cone, but probably not in as dramatic a manner as Los Morados. In contrast to these examples of large breached cones, volumetrically smaller cones, associated to less extensive lava flows, were able to heal raft/collapse events, due to the smaller magma output and flux rates. Our evidence shows that scoria cone growth is a complex process, and is a consequence of the magma internal parameters (e.g. volatile content, magma flux, recharge, output volume) and external conditions such as inclination of the pre-eruptive surface where they grew and thus gravitational instability. © 2011 © Versita Warsaw and Springer-Verlag Wien.


Uhrin A.,Geological Institute of Hungary | Sztano O.,Eotvos Lorand University
International Journal of Earth Sciences | Year: 2012

Major deepwater sand accumulations are known to be connected to sea-level lowstands in marine basins, due to the relative lack of accommodation space on the shelf. This model was tested for the Late Miocene Lake Pannon, a large endorheic lake depositing a sedimentary succession up to 3-4 km thick. The progradation of the shelf between 9. 7 and 6 Ma was tracked along a 2D seismic network. The shelf-edge trajectory indicates continuous, moderate lake-level rise between 9. 7 and 9 Ma. This is followed by alternating intervals of quasi-steady and rapidly rising relative lake level with a period of ca. 250 ky. However, due to the lack of significant lake-level drops, no third-order sequence boundary was identified in the studied time span (9. 7-6 Ma). The sand ratio of the deepwater deposits does not show strong correlation with these lake-level changes; moreover, the units deposited under rising lake-level conditions generally contain slightly larger proportion of sand. These features can be explained by the climatic origin of water-level rises: increasing precipitation enhances not only water inflow, but also sediment influx, which can overwhelm the well-known effect of accommodation space on the sand transport toward the deep water. The results suggest that shelf-margin trajectory might not be an efficient tool for predicting deepwater accumulations of sand in endorheic lacustrine basins. © 2011 Springer-Verlag.


Jordan G.,Geological Institute of Hungary | Szucs A.,Uppsala University
Landscape Research | Year: 2011

Acid mine drainage containing toxic contaminants is a major cause of landscape degradation at numerous historic mine sites in Europe. Risk assessment of acid mine drainage and related polluted lands requires an approach that is able to study the complexity of pollution emissions and impacted landscapes. The objective of this paper is to link geochemical contaminant fate modelling and landscape analysis for the risk assessment of acid mine drainage along the source-pathway-receptor chain. A simple geochemical landscape analysis tool is developed using landscape ecology spatial analysis and geochemical modelling methods. A case study is presented for the analysis of geochemical landscapes in central Sweden. Results show that the method can be used efficiently for the risk assessment of toxic mine contaminants in the complex wetland landscape in the study area. © 2011 Landscape Research Group Ltd.


Kereszturi G.,University of Miskolc | Nemeth K.,Massey University | Csillag G.,Geological Institute of Hungary | Balogh K.,Hungarian Academy of Sciences | Kovacs J.,University of Pecs
Journal of Volcanology and Geothermal Research | Year: 2011

The occurrence, shape, structure and eruption style of monogenetic volcanoes, such as maars, tuff rings, tuff cones and scoria cones, are generally governed by several internal (composition of the magma, magmatic flux, ascent rate, viscosity, volatile contents) and external conditions (regional and local tectonics, topography, and the presence of surfacial, ground and meteoric water). These controlling factors are together responsible for the eruption style, distribution pattern, volcanic facies architecture and morphology of the monogenetic volcanic landforms. The Late Miocene to Pleistocene Bakony-Balaton Highland Volcanic Field (BBHVF) in western Hungary is a typical small sized (< 50 eruption centres), basaltic, intraplate "monogenetic" volcanic field. Generally, initial eruptions of the BBHVF were phreatomagmatic (n = ~. 28); however, a lesser number (n = ~. 14) of predominantly scoria cone forming eruptions are also inferred. The temporal distribution of the Strombolian style scoria cones was concentrated mostly between 3 and 2.5. Ma. A detailed study of the changes in eruption styles recorded in the pyroclastic sequences suggested a change from a conventional phreatomagmatic to a magmatic fragmentation style during the activity of the volcanic field. A clear correlation has been identified between the long-term environmental changes of the region that resulted in a gradual shift from a more phreatomagmatic eruption style to a more magmatic eruption style. Detailed examination of the temporal distribution of K-Ar and Ar-Ar radiometric data, Digital Elevation Model and Dense Rock Equivalent-based volume calculations of eruptive products and origin of pyroclastic rocks (e.g. phreatomagmatic or magmatic) preserved in variously eroded monogenetic volcanoes were utilized to integrate available volcanological and climatological data to identify potential links between external and internal controlling parameters that responsible for long-term eruption style changes. At least 6 volcanic cycles have been identified by cluster analysis. Time gap between the cycles were vary from 1.66 up to 0.06Ma, while the average eruption recurrence rate was ~0.1078Ma/event. The time-volume diagram of the volcanism of BBHVF have shown time-predictive behavior combined with low magma-flux (total preserved volume ~2.867km3) and output rates (0.53km3/Ma for the entire volcanic field and 0.90km3/Ma for the last 5cycles), suggesting that volcanism was largely tectonically-controlled and not magmatically-controlled.Furthermore, the topographic differences between the northern ("elevated") and southern ("basin-like") parts of the volcanic field, are also important in local differences in dominant fragmentation style, because the elevated part of the field was prone to host large, more magmatically-evolved volcanoes, than on the lower, water-saturated, unconsolidated sediments, which favored to the magma/water interaction driven phreatomagmatic fragmentation. The third controlling parameter, which seems to play an important role in controlling the eruptive style of monogenetic volcanism at BBHVF, was the paleoclimate fluctuation, especially during the time interval of 3.0 to 2.5. Ma. Thus, mainly the long-term environmental changes (e.g. aridification) have been response the shifting fragmentation style from phreatomagmatic to more magmatic ones. © 2010 Elsevier B.V.

Discover hidden collaborations