Microfacies Analysis of Upper Eocene Shallow-water Carbonates from the Rodnei Mountains (N Romania)

Sahy, Diana; Săsăran, Emanoil; Tămaș, Tudor

doi:10.5038/1937-8602.53.2.2

Cited by 8 publications

(7 citation statements)

References 31 publications

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“…The quantity of precipitation is highest in the summer and lowest in winter. From the geological point of view, the surroundings are comprised of crystalline rocks such as mica schists, conglomerates, limestones, black shales and sandstones (Sahy et al, 2008;Tămaş et al, 2011). The regional vegetation is composed of compact spruce (Picea abies) forest (Feurdean et al, 2015a).…”

Section: Study Areamentioning

confidence: 99%

How warm? How wet? Hydroclimate reconstruction of the past 7500 years in northern Carpathians, Romania

Diaconu

Tóth

Lamentowicz

et al. 2017

Palaeogeography, Palaeoclimatology, Palaeoecology

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As natural and anthropogenic ecosystems are dependent on the local water availability, understanding past changes in hydroclimate represents a priority in research concerning past climate variability. Here, we used testate amoebae (TA) and chironomid analysis on a radiocarbon dated complex of small pond and peat bog sediment profiles from an ombrotrophic bog (Tăul Muced, northern Carpathians, Romania) to quantitatively determine major hydrological changes and July air temperature over the last 7500 years.Wet mire surface conditions with a pH between 2.3 and 4.5 were inferred for the periods 4500-2700 and 1300-400 cal yr BP by the occurrence of Archerella flavum, Amphitrema wrightianum and Hyalosphenia papilio. Dry phases in mire surface conditions and a pH between 3 2.5 and 5 were inferred for 7550-4500, 2750-1300 and 0 cal yr BP-present by the dominance of Nebela militaris, Difflugia pulex and Phryganella acropodia. The quantitative reconstruction of mean July temperature based on the chironomid communities suggests low summer temperatures for the periods 6550-5600, 4500-3150 and 1550-600 cal yr BP, while periods of slightly higher summer temperatures were observed for 5600-4500, 3150-1550 and 100 cal yr BP-present.There is a general good agreement between drier phases of the peat surface conditions with higher July temperature, suggesting that temperature may have been a controlling factor for water table fluctuation.Our quantitative reconstructions, among the first for central eastern Europe, show a relatively good agreement with other palaeohydrological studies from central eastern Europe, but contrast with others estimates from north-west Europe. Another important aspect of our study is that it provides valuable information on changes in local hydrology and the potential effect of the mean summer temperature over these changes.

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Section: Study Areamentioning

confidence: 99%

How warm? How wet? Hydroclimate reconstruction of the past 7500 years in northern Carpathians, Romania

Diaconu

Tóth

Lamentowicz

et al. 2017

Palaeogeography, Palaeoclimatology, Palaeoecology

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“…3) deposited in sag basins (Krézsek & Bally 2006). Platform carbonates are preserved in the Rodna horst and in the southern and eastern parts of the study area (Iza limestone - Dicea et al 1980;De Brouker et al 1998;Sahy et al 2008). Deepening towards the northwest is indicated by a change from platform carbonates towards marls and distal turbidites (Vaser and Viseu Formations - Săndulescu et al 1991).…”

Section: Geological Settingmentioning

confidence: 96%

Thermal history of the Maramureş area (Northern Romania) constrained by zircon fission track analysis: Cretaceous metamorphism and Late Cretaceous to Paleocene exhumation

Gröger¹,

Tischler²,

Fügenschuh³

et al. 2013

Geologica Carpathica

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This study presents zircon fission track data from the Bucovinian nappe stack (northern part of the Inner Eastern Carpathians, Rodna Mountains) and a neighbouring part of the Biharia nappe system (Preluca massif) in order to unravel the thermal history of the area and its structural evolution by integrating the fission track data with published data on the tectonic and sedimentary evolution of the area. The increase of metamorphic temperatures towards the SW detected by the zircon fission track data suggests SW-wards increasing tectonic overburden (up to at least 15 km) and hence top NE thrusting. Sub-greenschist facies conditions during the Alpine metamorphic overprint only caused partial annealing of fission tracks in zircon in the external main chain of the Central Eastern Carpathians. Full annealing of zircon points to at least 300 °C in the more internal elements (Rodna Mountains and Preluca massif). The zircon fission track central and single grain ages largely reflect Late Cretaceous cooling and exhumation. A combination of fission track data and stratigraphic constraints points to predominantly tectonic differential exhumation by some 7-11 km, connected to massive Late Cretaceous extension not yet detected in the area. Later events such as the latest Cretaceous ("Laramian") juxtaposition of the nappe pile with the internal Moldavides, causing exhumation by erosion, re-burial by sedimentation and tectonic loading during the Cenozoic had no impact on the zircon fission track data; unfortunately it prevented a study of the low temperature part of the Late Cretaceous exhumation history.

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“…At the advanced stage of transgression, these rhodolith-bearing deposits would be covered by fine-grained subneritic facies (Nalin et al 2008) or buried by shoreline progradation during normal regression (Catuneanu 2006). For example, most of the Eocene shallow-water carbonates, including rhodolith facies, in the Alpine-Pannonian region were deposited with a major basal unconformity over Mesozoic rocks and overlain by deeper-water siliciclastic sediments (Sahy et al 2008).…”

Section: Depositional Modelmentioning

confidence: 99%

Origin and resedimentation of rhodoliths in the Late Paleocene flysch of the Polish Outer Carpathians

Leszczyński

Kołodziej

Bassi

et al. 2012

Facies

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This study analyses the rhodolith-bearing deposits in the largest and most rhodolith-rich outcrop of the Polish Outer Carpathian flysch, located in the Silesian Nappe, at the village of Melsztyn. The rhodoliths and sparse associated biota occur as resedimented components in a deep-marine succession of siliciclastic conglomerates and coarse-grained sandstones, deposited by high-density turbidity currents and debris flows. The sediment was derived from a fan-delta system located at the southern margin of the Silesian flysch basin. Stratigraphic data indicate that the succession represents the Upper Istebna Sandstone deposited during the Late Paleocene. The rhodoliths are composed mostly of coralline red algae with seven genera and eight species representing the family Sporolithaceae and the subfamilies Mastophoroideae and Melobesioideae. Rhodoliths show sub-spheroidal and subellipsoidal shapes with encrusting, warty and lumpy growth forms. Lumpy growth forms show massive inner arrangements, whereas the encrusting growth forms are usually made of thin thalli and show more loosely packed inner arrangements. The rhodoliths grew on a moderately mobile siliciclastic substrate in a shallow-marine environment with a low net sedimentation rate. It is inferred that the growth of rhodoliths was favored during a relative sea-level rise. During the subsequent sea-level fall, the rhodoliths and associated siliciclastic deposits were resedimented by gravity flows into the deep-sea setting. The analyzed deposits, like other Paleocene-Eocene deposits of the Polish Outer Carpathians, provide no evidence of coeval widespread shallow-marine carbonate sedimentation along the margins of the Outer Carpathian flysch basins.

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Microfacies Analysis of Upper Eocene Shallow-water Carbonates from the Rodnei Mountains (N Romania)

Cited by 8 publications

References 31 publications

How warm? How wet? Hydroclimate reconstruction of the past 7500 years in northern Carpathians, Romania

How warm? How wet? Hydroclimate reconstruction of the past 7500 years in northern Carpathians, Romania

Thermal history of the Maramureş area (Northern Romania) constrained by zircon fission track analysis: Cretaceous metamorphism and Late Cretaceous to Paleocene exhumation

Origin and resedimentation of rhodoliths in the Late Paleocene flysch of the Polish Outer Carpathians

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