Première identification en subsurface de calcaires d'eaux peu profondes attribués au Crétacé basal dans la Dépression de Transylvanie (Roumanie)

Triassic, Upper Jurassic and upper Lower Cretaceous sedimentary formations were previously studied from the Transylvanian Depression basement, but the presence of lowermost Cretaceous (Berriasian-Valanginian) has not been confirmed paleontologically. The carbonate sequence cored from a borehole drilled in the central part of the Transylvanian Depression yields microfossil assemblages dominated by benthic foraminifera. These new data unequivocally document the presence of characteristic Berriasian-Valanginian taxa in these deposits

Microbiostratigraphie (foraminifères) et reconstitution paléoenvironnementale de la Formation marine de Chechiș (Miocène inférieur) dans le Bassin Transylvanien

Planktonic and benthic foraminiferal assemblages were used for biostratigraphy and paleoenvironmental reconstruction of the marine lower Miocene Chechiș Formation from the Gălpâia section (Sălaj county, Romania) in the northwestern Transylvanian Basin. Planktonic foraminifera suggest an Eggenburgian (Burdigalian) age for the deposits studied and reveal episodes of high primary productivity and mostly cool surface waters. Benthic foraminiferal assemblages indicate paleoenvironmental deepening from outer shelf to upper bathyal settings. Deltaic influences may be observed at the base of the studied section in outer shelf (possibly upper bathyal) environments with oxygenated bottom water and episodic high primary productivity, as a consequence of nutrient input from the land. Changes in paleobathymetry resulted in reduction of primary productivity. The benthic assemblages from the uppermost part of the section are dominated by tubular agglutinated foraminifera and indicate an upper bathyal setting with low organic flux to the sea floor. The sediments of the studied section were deposited during the late stage of the first early Miocene relative sea-level rise in the Transylvanian Basin.Les associations de foraminifères planctoniques et benthiques sont exploitées à des fins biostratigraphiques et de reconstitution des paléoenvironnements de la Formation Chechiș du Miocène inférieur marin dans la coupe de Gălpâia (district de Sălaj, Roumanie, NW du Bassin transylvanien). Les foraminifères planctoniques suggèrent un âge eggenburgien (Burdigalien) pour les dépôts objets de cette étude. Ils révèlent en outre l'existence d'épisodes de forte productivité primaire et la présence d'eaux de surface généralement froides. Les associations de foraminifères benthiques indiquent un approfondissement des paléoenvironnements depuis le bord externe du plateau continental à la partie supérieure de l'étage bathyal. Des influences deltaïques peuvent être observées à la base de la coupe au sein des environnements du bord externe du plateau continental (peut-être même dans la partie supérieure de l'étage bathyal) avec des eaux de fond oxygénées et des épisodes de forte productivité primaire en raison d'apports de nutriments en provenance des terres émergées. Des variations paléobathymétriques ont entraîné une diminution de la productivité primaire. Les associations de formes benthiques de la partie sommitale de la coupe sont dominées par des foraminifères tubulaires à test agglutinant, marqueurs de la partie supérieure de l'étage bathyal, avec un faible flux de matière organique vers les fonds marins. Les sédiments de la coupe étudiée se sont déposés au cours du stade ultime de la première montée relative du niveau de la mer enregistrée au Miocène inférieur dans le Bassin transylvanien

Безопасное захоронение бокситовых отходов и возможности дальнейшего применения. Часть 1. Рекультивация кислотных почв

This paper is presenting the investigations concerning a new approach in acid soil remediation by deep reshaping the land surface layer, in order to change its agrochemical composition and properties. Three property control adjuvant were used for this purpose: the bauxite residue for pH control, the organic compost as source of organic carbon and better control of the soil properties, and the NPK mineral fertilizers as source of main macronutrients. Doses of 15, 30 and 75 t bauxite residue/ha associated with 40 t/ha organic compost and 120 Kg N/ha + 60 Kg P2O5/ha + 40 Kg/ha K2O mineral fertilizers have generated reshaped acid soils with agrochemical properties close to average fertile soils. These new soils have promoted intensive vegetative growth in maize plants (waist, green mass and dried mass), as well as the high productions in cobs and grains. Harvested green mass, and cobs and grains contain macronutrients, micronutrients and heavy metals at normal concentration, usually found in maizeСтатья представляет исследования, касающиеся нового подхода в рекультивации кислотных почв путем восстановления поверхностного слоя земли для изменения его агрохимического состава и свойств. Для этого были использованы три вспомогательных вещества при контроле качества земли: отходы бокситов для контроля рН, органический компост как источник органического углерода и лучшего контроля свойств почв и минеральные удобрения NPK как источник основных макроэлементов. Значения 15, 30 и 75 т отходов бокситов на 1 га соответствуют 40 т/га органического компоста и 120 кг N/га + 60 кг P2O5/Га + 40 кг/Га K2O минеральных удобрений, сформировавших восстановленную кислотную почву, с агрохимическими свойствами, близкими к средним свойствам плодородной почвы. Эта новая почва способствовала интенсивному росту кукурузы (оценивали параметры: узкая часть початка, зеленая масса и высушенная масса), а также высокая продуктивность початка и зерен. Собранные зеленая масса, початки и зерна содержат макроэлементы, микроэлементы и тяжелые металлы, соответствующие нормальной концентрации, содержащейся в обычной кукуруз

Badenian evolution of the Central Paratethys Sea : paleogeography, climate and eustatic sea-level changes

The Miocene Central Paratethys Sea covered wide areas of the Pannonian Basin System, bordered by the mountain chains of the Alps, Carpathians and Dinarides. The epicontinental sea spread not only in the back-arc basin area, but flooded even the Alpine-Carpathian Foredeep, situated along the front of gradually uplifting mountains. The Early Badenian (early Langhian) transgressions from the Mediterranean toward the Central Paratethys realm, via Slovenia and northern Croatia (Transtethyan Trench Corridor or Trans Dinaride Corridor) flooded the Pannonian Basin and continued along straits in the Carpathian Chain into the Carpathian Foredeep. The isolation of eastern parts of the Central Paratethys at the end of this period (late Langhian) resulted in the "Middle Badenian" salinity crisis. Thick evaporite sediments, above all halite and gypsum were deposited in the Transcarpathian Basin, Transylvanian Basin and Carpathian Foredeep. During the Late Badenian (early Serravallian), the latest full marine flooding covered the whole back-arc basin and a great part of the foredeep. The main problem is to create a model of sea connections during that time, because some authors consider the western Transtethyan Trench Corridor (Trans Dinaride Corridor) closed and there is no evidence to prove a supposed strait towards the Eastern Mediterranean. A proposed possibility is a connection towards the Konkian Sea of the Eastern Paratethys. The Badenian climate of the Central Paratethys realm can be characterized as fairly uniform, reflecting the stable subtropical conditions of the Miocene Climatic Optimum. No considerable changes in terrestrial ecosystems were documented. Nevertheless, evolution of steep landscape associated with rapid uplift of the East Alpine and Western Carpathian mountain chains (including high stratovolcanoes) caused development of vertical zonation of dry land and consequently close occurrence of different vegetation zones in a relatively small distance during this time. In the Central Paratethys Sea a slight N-S climatic gradient seems to be expressed already from the Early Badenian, but a biogeographic differentiation between basins in the North and South starts to become more prominent first during the Late Badenian, when a moderate cooling of the seawater can also be documented. The Late Badenian sea-level highstand coincides with the appearance of stress factors such as stratification of the water column and hypoxic conditions at the basin bottom in the whole area. Taking into account all bioevents and changes of paleogeography in the Central Paratethys realm, we can very roughly correlate the Early (and "Middle") Badenian with the eustatic sea-level changes of TB 2.3, TB 2.4 or Bur5/Lan1, Lan2/Ser1 and the Late Badenian with TB 2.5 or Ser2 cycles (sensu Haq et al. 1988; Hardenbol et al. 1998). Generally, we can assign the Early Badenian transgressions to be controlled by both, tectonics (induced mainly by back-arc basin rifting) and eustacy, followed by forced regression. The Late Badenian transgression and regression were dominantly controlled by sea-level changes inside the Central Paratethys realm

New data on the Early - Middle Badenian transition in the NW Transylvanian Basin (Romania) revealed by the planktonic foraminifera assemblages

The planktonic foraminifera assemblages recovered from two cores drilled in Cluj-Napoca (NW Transylvanian Basin) demonstrate connections of the basin to the open seas before the middle Badenian evaporite deposition. Assemblages suggest clear changes in the environments, with an initial transgressive trend, followed by a decrease in the rate of sea-level rise, and finally a sea-level fall. The occurrence of planktonic foraminifera (mainly Globorotalia) offers a good potential for correlation of the pre-evaporitic interval with the uppermost Langhian and can be used for tracing the early-middle Badenian boundary

New data on the Early - Middle Badenian transition in the NW Transylvanian Basin (Romania) revealed by the planktonic foraminifera assemblages

The planktonic foraminifera assemblages recovered from two cores drilled in Cluj-Napoca (NW Transylvanian Basin) demonstrate connections of the basin to the open seas before the middle Badenian evaporite deposition. Assemblages suggest clear changes in the environments, with an initial transgressive trend, followed by a decrease in the rate of sea-level rise, and finally a sea-level fall. The occurrence of planktonic foraminifera (mainly Globorotalia) offers a good potential for correlation of the pre-evaporitic interval with the uppermost Langhian and can be used for tracing the early-middle Badenian boundary

Anomalinoides dividens bioevent at the Badenian/Sarmatioan boundary – a response to paleogeographic and paleoenvironmental chnages

Recent investigations on the microfauna at the Badenian / Sarmatian boundary (Middle Miocene) showed interesting characters of the Anomalinoides dividens foraminifera assemblages. Several taxonomic aspects are considered in order to clarify the meaning of different stratigraphic approaches. A possible planktonic or pseudo-planktonic life of the species is suggested by micropaleontologic, paleogeographic and paleoenvironmental data

Anomalinoides dividens bioevent at the Badenian/Sarmatioan boundary – a response to paleogeographic and paleoenvironmental chnages

Recent investigations on the microfauna at the Badenian / Sarmatian boundary (Middle Miocene) showed interesting characters of the Anomalinoides dividens foraminifera assemblages. Several taxonomic aspects are considered in order to clarify the meaning of different stratigraphic approaches. A possible planktonic or pseudo-planktonic life of the species is suggested by micropaleontologic, paleogeographic and paleoenvironmental data

Wielician foraminifera at the western border of the Transylvanian Basin

Marine Middle Miocene deposits at the top of Gârbova de Sus Formation preserve a particular foraminifera assemblage, with both benthic and planktonic taxa. Presence of several biostratigraphic significant species allowed an extension of the known age of the formation, up to Wielician. The morphogroups also suggest a deeper environment, compared to the rest of the formation. The change of fauna type at this level might be correlated to the start of a new global cycle