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Kosmos
Astronomia Astrofizyka
Inne

Kultura
Sztuka dawna i współczesna, muzea i kolekcje

Metoda
Metodologia nauk, Matematyka, Filozofia, Miary i wagi, Pomiary

Materia
Substancje, reakcje, energia
Fizyka, chemia i inżynieria materiałowa

Człowiek
Antropologia kulturowa Socjologia Psychologia Zdrowie i medycyna

Wizje
Przewidywania Kosmologia Religie Ideologia Polityka

Ziemia
Geologia, geofizyka, geochemia, środowisko przyrodnicze

Życie
Biologia, biologia molekularna i genetyka

Cyberprzestrzeń
Technologia cyberprzestrzeni, cyberkultura, media i komunikacja

Działalność
Wiadomości | Gospodarka, biznes, zarządzanie, ekonomia

Technologie
Budownictwo, energetyka, transport, wytwarzanie, technologie informacyjne

Studia Universitatis Babes-Bolyai, Geologia

The Mesozoic limestones of Piatra Craiului Massif were deposited in the Dâmbovicioara sedimentary area, at the eastermost part of the Getic carbonate platform. In order to study the microfacies and to provide a more detailed biostratigraphy, we sampled the carbonate succession from Piatra Craiului Massif along several sections. The identified microfacies point to reef slope, carbonate platform margin or restrictive, lagoon-type internal depositional environments. Some of the identified microfossils are biostratigraphic markers for the Tithonian-Lower Valanginian. The calcareous algae form associations typical for reef slopes and internal platforms. The latter can be subdivided into: (1) restrictive environments (low-energy subtidal-intertidal), dominated by rivulariacean-type cyanobacteria, and (2) open-marine environments (moderate to high-energy subtidal) where dasycladalean algae are more frequent.

http://scholarcommons.usf.edu/geologia/vol59/iss1/art1 2014/06/17 - 21:08

The Mesozoic limestones of Piatra Craiului Massif were deposited in the Dâmbovicioara sedimentary area, at the eastermost part of the Getic carbonate platform. In order to study the microfacies and to provide a more detailed biostratigraphy, we sampled the carbonate succession from Piatra Craiului Massif along several sections. The identified microfacies point to reef slope, carbonate platform margin or restrictive, lagoon-type internal depositional environments. Some of the identified microfossils are biostratigraphic markers for the Tithonian-Lower Valanginian. The calcareous algae form associations typical for reef slopes and internal platforms. The latter can be subdivided into: (1) restrictive environments (low-energy subtidal-intertidal), dominated by rivulariacean-type cyanobacteria, and (2) open-marine environments (moderate to high-energy subtidal) where dasycladalean algae are more frequent.

http://scholarcommons.usf.edu/geologia/vol59/iss1/art1 2014/06/17 - 21:08

With its more than 50,000 valid official and provisory meteorite entries, the online catalogue of The Meteoritical Society, i.e., the Meteoritical Bulletin Database (MBDB) represents the most authorized and primary source of information in the field. Unfortunately, this official reference contains some erroneous geographical information in the case of five historical Romanian meteorites. For Zsadany, the current country information is “Hungary, Bekes county” instead of Romania, Timiş County. For Mezö-Madaras and Tauti, the county affiliations “Harghita” and respectively “Cluj” have to be corrected into Mureş and Arad, respectively. Geographical coordinates for Kakowa and Ohaba require minor corrections, only.
The source of these errors resides in changes of names and administrative affiliations of the localities of the fall/find, while the formal nomenclature protocol requires the meteorite name in the original description to be preserved. The example of the historical Romanian meteorites illustrates the challenges that a researcher unfamiliar with a region faces when locating old specimens, in general. This requires knowledge of regional history and geography, and sometimes access to the original references - usually not written in English, or having a somehow limited circulation.
Additionally, in the last two decades several new publications provided more detailed classification information on Sopot, Ohaba, Tauti and Mocs meteorites. Sopot was classified as H5, with shock stage S3. The studied Ohaba and Tauti samples also attested S3 shock stages. Variable shock stages (S3-5) were identified in Mocs samples, the most well-known Romanian meteorite. This new information should be added to the corresponding MBDB entries.

http://scholarcommons.usf.edu/geologia/vol58/iss2/art5 2014/01/17 - 20:35

In order to establish the age of the Bozeş Formation, which crops out in the SE Apuseni Mts., calcareous nannofossils investigations and U-Pb detrital zircon dating were performed on Stăuinii Valley deposits. The results were correlated, and further compared with previous fossil age data. The U-Pb detrital zircon age spectrum reveals a consistent Upper Cretaceous grain population, which yielded an age of 83 Ma (concordia age of 82.87±0.59 Ma), interpreted as the maximum deposition age, thus, marking the Lower Campanian as the initiation of sediment deposition. Based on the presence of some important taxa in the calcareous nannofossils assemblage, the age of studied deposits were assigned to Upper Santonian? – upper Upper Campanian. The Upper Santonianage is presumed by the presence of curved Lucianorhabdus cauyeuxii, reworked from older deposits. The Campanian stage is confirmed by the presence of Broinsonia parca parca, Broinsonia parca constricta and rare specimens of Ceratolithoides aculeus and Uniplanarius sissinghii. Both Reinhardtites anthophorus and Eiffelithus eximius indicate that the upper part of the Stăuinii section is ending in CC22 / UC15dTP – UC15eTP Subzones, thus in upper Upper Campanian. FO of Eiffellithus parallelus points to the same age. The calcareous nannofossils assemblages do not sustain the presence of the Lower Maastrichtian deposits on Stăuinii Valley, as mentioned by few previous studies based on Pachydiscus neubergicus.

http://scholarcommons.usf.edu/geologia/vol58/iss2/art4 2014/01/17 - 20:35

Three Late Cretaceous lineages of heterohelicid planktic foraminifera, which evolved in the proximity of the Cenomanian/Turonian boundary, bring new data in understanding the group evolutionary history. Lunatriella Eicher and Worstell 1970a is a directional lineage of late Cenomanian-early Turonian age, which gradually develops peripheral backward extensions in the last-formed chambers. Steineckia Georgescu 2009a of the Turonian is the earliest heterohelicid lineage that evolved ornamentation consisting of pore mounds; a gap spanning the latest Turonian-early Santonian separates it from Laeviheterohelix Nederbragt 1991 of the late Santonian-Campanian, the second lineage that developed ornamentation consisting of pore mounds. Pseudoplanoglobulina Aliyulla 1977 evolved in the early Turonian and is the first heterohelicid lineage that developed multichamber growth in the adult stage; it became extinct in the Santonian. The three directional lineages show that the iterative and convergent evolution patterns occur extensively in the early heterohelicid history.

http://scholarcommons.usf.edu/geologia/vol58/iss2/art3 2013/10/29 - 17:33

Mineralogical studies performed on crusts, nodules and earthy masses from the Romanian caves Gaura cu Muscă, Gaura Haiducească and Peștera Zidită have revealed the presence of three different phosphate associations. The minerals have been identified by means of X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. Five phosphates have been identified in the samples, with hydroxylapatite the only common mineral in all the three caves. Brushite, taranakite, leucophosphite and variscite are the other phosphates identified. Associated minerals include gypsum, calcite, quartz and illite-group minerals. Aside from differences in the lithology, the occurrences of the different phosphate minerals indicate variable pH and humidity conditions near or within the guano accumulations.

http://scholarcommons.usf.edu/geologia/vol58/iss2/art2 2013/10/17 - 23:44

Lower Cretaceous orbitolinid assemblages from Central Iran yield various bioerosional structures. The omnipresent traces of different boring taxa and groups (e.g., sponges, calcimicrobes, incertae sedis) represent a characteristic feature of the investigated thin-section material. The assemblage can be attributed to the Entobia ichnofacies dominated by borings assigned to the activity of sponges. The boring galleries are often concentrated in a plane parallel to the test surface, along the boundary of the marginal and the central zone of the orbitolinid tests. The borings are observed in foraminiferan-dasycladalean wackestones to poorly washed-out packstones, which can be referred to a subtidal palaeoenvironment.

http://scholarcommons.usf.edu/geologia/vol58/iss2/art1 2013/10/04 - 10:17

The Early - Middle Miocene transition can be studied in several sections from the north-western Transylvanian Basin, across the boundary between the Hida and Dej Formations. The Pâglişa and Râpa Dracului (Dej locally outcrop) sections offer a very good record of the changes in the sedimentary facies and micropaleontological content across the boundary. The lower parts of the sections display the upper Hida Formation with prodelta fine grained sediments covered by coarser grained sediments related to a delta front progradation. Four sedimentary facies associations have been separated based on grain size and associated sedimentary structures. Micropaleontological assemblages are moderately to poorly preserved, with a low abundance and diversity. Planktonic Streptochilus pristinum is the main taxon associated with rare (< 10%) calcareous benthic foraminifera (Bulimina, Bolivina, Cibibicidoides). The Dej Formation consists of stacked channel lag deposits associated with lateral accretion bars and crevasse splays followed by fall-out tuffs and redeposited low density tuffites interbedded with low density fine siliciclastics. The deposits of Dej Formation from the investigated areas were separated in four facies associations based on grain size/petrography and primary sedimentary structures. Micropaleontological assemblages contain typical early Badenian planktonic foraminifera (species of Orbulina, Praeorbulina, Globigerinoides, and Globorotalia) associated to the main phase of the marine transgresion from the beginning of the Middle Miocene.

http://scholarcommons.usf.edu/geologia/vol58/iss1/art5 2013/08/06 - 21:32

This paper concerns the sequence stratigraphy of the Oligocene (Rupelian–Chattian)–Early Miocene (Burdigalian) Asmari Formation based on microfacies analysis of the sediments in the Ghale Nar Oilfield, central area of Zagros fold-thrust belt. Fourteen facies types typical for upward shallowing trend from open marine (MF 1–3), to shoal (MF 4-5), semi-restricted and restricted lagoon (MF 6–12) and finally to near-shore lagoon (MF 13-14) depositional environments were identified. Based on the environmental interpretations, we reconstructed a homoclinal ramp mainly represented by its inner and middle sectors. Facies types MF 4–14 are characterized by the occurrence of large and small porcelaneous benthic foraminifera representing a shallow-water setting of an inner ramp influenced by wave and tide processes. MF1 (Pabdeh Formation), and 2 -3 with planktonic, large and small hyaline benthic foraminifera represent between FWWB and SWB. Four third-order depositional sequences were recognized. In this study, in order to better correlate the identified sequences with pre-defined sequences of the Asmari Formation in the Dezful Embayment and the Izeh zone that are chronologically well-defined, we use their number instead of their name. Sequence 2 mainly consists of an open marine environment in the base, followed by semi-restricted to restricted lagoonal facies. Sequences 36 are characterized by semi-restricted to restricted lagoonal facies. Moreover, the regional relative sea-level change curves correlate well with the global sea-level change curves.

http://scholarcommons.usf.edu/geologia/vol58/iss1/art4 2013/08/06 - 21:32

The paper is focused on new micropalaeontological data from the Triassic succession of Krížna and High-Tatric units in the Tatra Mts. Benthic foraminifera species were determined from the Anisian−Norian succession of the Krížna Unit and the Anisian succession of the High-Tatric Unit. In the later, calcareous algae species were also found. In mentioned Triassic successions, most of genera were described for the first time, while the others were found in new locations. A few of them belong to index fossils. Based on the assemblage containing calcareous algae Oligoporella species, characteristic for the Oligoporella pilosaPhisoporella pauciforata zone, as well as the foraminifera Meandrospira dinarica, and the presence of Diplopora annulatissima, the age of the upper part of the Stoły pod Ciemniakiem section (High-Tatric Unit) is most probably Lower Illyrian. The establishment of the foraminifera species Pilamminella semiplana, Glomospirella triphonensis and Nodosaria skyphica, within the limestone of the Łysanki section and accompanying species Ophthalmidium cf. exiguum, Hoyenella gr. sinensis, Agathammina sp. and Gaudryina sp. from Żleb pod Czerwieniec and Skoruśniak sections (Krížna Unit): suggest early Anisian age. Ladinian age is indicated by the Turriglomina mesotriasicaGlomospirella kuthani/gemericaAulotortus gaschei praegaschei assemblage present in the dolostones of the Skupniów Upłaz and Hlúpy sections (Krížna Unit). The assemblage from dolostones of the Żleb pod Czerwoną Przełęcz (Krížna Unit) includes ?Triasina hantkeni species, which is a zone marker for the upper Norian (Sevatian) to Rhaetian succession.

http://scholarcommons.usf.edu/geologia/vol58/iss1/art3 2013/03/01 - 08:19

Physicochemical parameters have been studied in the water column of Inkwell, Church, and Watling’s Blue Holes (San Salvador Island, Bahamas). Water samples were collected from multiple depths at the three blue holes to identify and characterize changes of physical and chemical parameters. The values were compared to the average ocean concentrations in order to assess how connectivity to the ocean, evaporation, freshwater input, and bacterial activity influence water rock interactions. The salinity concentrations vary between the surface and ~ -4 m in each blue hole before stabilizing to rather similar values (~19.6‰). Mixing processes in the water column at Inkwell and Church blue holes are inferred from changes in the concentration of chloride. The degree of variation is a mixed signal resulting from changes of the precipitation/evaporation balance and tidal driven water-rock interaction. Inkwell is strongly influenced by tidal pumping, which causes ample value fluctuations, most notably salinity (1.01 to 21.8‰), chloride (Cl-) from 300 to 9591.8 mg/L, and total hardness (9 to 293 mg/L) within the mixing zone. This location is the only site that may have a true halocline. Watlings’s geochemical parameters have the smallest range (i.e., salinity 30.19 - 34.30‰) due to a lack of mixing that suggests that this site has a direct conduit connection to the ocean. The furthest inland blue hole (Church) lacks significant geochemical fluctuations with the exception of Cl-, which changes from 19600 mg/L to 1800 mg/L between the depths of 1 and 2 m. The abrupt modification of Cl- values between surface and -2 m suggests mixing is occurring. The lack of other parameter variations within the water column suggests restricted flow via narrow conduits or more likely matrix flow. Salinity values decrease from the surface (21.47‰) to ~ -1 m (17.78‰) whereas, sulfate (SO42-) concentration at the same depth reach its maximum value (4009 mg/L). The high sulfate values throughout the column (2634 to 4009 mg/L) are characteristic of seawater (>2700 mg/L), thus indicating seawater seepage into the blue hole. We assume the elevated salinity values at the surface and -1 m are pointing towards evaporative processes.

http://scholarcommons.usf.edu/geologia/vol58/iss1/art2 2013/02/05 - 18:08

Thaumatoporella (incertae sedis) represents a widespread constituent in Middle Triassic–Cretaceous shallow-marine carbonates of the Tethyan realm and exhibit a wide morphological variability. Seemingly monostromatic cell-layers intermingled with and incorporated into bacinellid crusts (“Bacinella irregularis”) were described as Thaumatoporella bridges or ladders in the literature. This appearance of Thaumatoporella also accounted for the creation of the genus Polygonella ELLIOTT and its misleading comparison with single-layered crustose corallinacean alga, e.g., genus Lithoporella. In fact, these “ladders” belong to the roof part of thaumatoporellaceans encrusting microbial crusts that subsequently became overgrown and thus incorporated. Often a rudimentary thin basal layer and an elongated sparitic void corresponding to the former body of Thaumatoporella, are present evidencing that its morphology is that of a variously shaped body (free or attaching) enclosed by an all-round wall. Irregular lobate and thin-walled thaumatoporellacens occurring in “bacinellid” fabrics might be interpreted as crust-dwellers.

http://scholarcommons.usf.edu/geologia/vol58/iss1/art1 2012/11/27 - 16:25

The central idea of this article is the obligation of a micropaleontologist to respect without any doubt the rules and demands stipulated by the International Commission on Zoological Nomenclature (ICZN), in order to avoid taxonomical mistakes. An unusual example of confusion generated by disregard for the ICZN Code rules is the case of Rosalina marginata REUSS. The species Rosalina marginata REUSS, 1845 emend. REUSS, 1854 is here transferred to the genus Dicarinella. Other specimens illustrated as “Marginotruncana marginata” for example the “neotype” established by Jirova (1956) are placed in the new species Marginotruncana pseudomarginata nom. novum.

http://scholarcommons.usf.edu/geologia/vol57/iss2/art4 2012/06/02 - 11:40

The Cotumba-Sita-Tǎtaru Sandstones of Teleajen Unit (Upper Aptian – Albian) are relatively well exposed in the Teleajen Valley (Prahova County, Romania), as predominantly thick and massive sandstone beds. Other facies occurring in the study area include sandstones with several sedimentary structures (e.g., parallel lami- nation, ripples, convolution), siltstones and mudstones. Almost 200 m long outcrop gives great opportunity for sedimentological study focusing on deep-marine facies and interpretation of exposed deposits. A sedimentological study of the facies and stacking patters suggest that these rocks were deposited in relatively shallow depositional channels with levees and interchannel areas.

http://scholarcommons.usf.edu/geologia/vol57/iss2/art3 2012/06/02 - 11:40

New data about the highly variable test morphology of the benthic foraminifer Troglotella incrustans WERNLI & FOOKES (Oxfordian-Lower Cenomanian) are presented, permitting an emended species/genus diagnosis. This concerns mainly the existence of a large final chamber with fistulose extensions that may follow the uniserial or the irregular-branching test part. The way of life of T. incrustans (cryptoendolithic vs. euendolithic) is discussed against the background of different existing models in the literature. The study is based on material (thin-sections and provided photographs) mainly from the Upper Jurassic of Austria, Italy, Romania, Ukraine, and also the type-locality of France.

http://scholarcommons.usf.edu/geologia/vol57/iss2/art2 2012/05/24 - 23:36

Taxonomic revision of the genus Bollitruncana O.A. Korchagin, 2001 shows that it accommodates a directional lineage, which consists of two species: B. carpathica (Scheibnerová, 1963) and B. posthelvetica (Hanzliková, 1963). Bollitruncana directional lineage is restricted to Turonian. A new planktic foraminiferal biozone is recognized in the Turonian, namely the Bollitruncana carpathica Biozone.

http://scholarcommons.usf.edu/geologia/vol57/iss2/art1 2012/05/24 - 23:36

Underground gas storages from Romania are located in south Romania (in the Moesian Platform) and in Transylvanian Basin. They are converted from depleted gas reservoirs. Those from south have bigger capacity because the reservoirs are thick and stratiform, consisting of unconsolidated sand, with high porosity and permeability. The Transylvanian storages have smaller capacity because the layers are thinner, consisting of interbedded sandstones, silts and marls, with many lithological and facies variations, lower porosities and permeabilities. Geology of the reservoir has to be well known before constructing a deposit. Most important parameters are: depth of the reservoir, thickness, porosity, permeability, pore volume, structural model, tectonics, stratigraphic and lithological variations, type of aquifer, etc.

http://scholarcommons.usf.edu/geologia/vol51/iss1/art11 2012/03/11 - 22:19

The Padeş suite from the Poiana Ruscă Mountains is a component of the Padeş Paleozoic terrane. The Padeş terrane evolved as an island arc between the Cadomian Sebeş-Lotru and Făgăraş terranes, the main parts of the Getic crystalline in the Southern Carpathians. Evaporated single zircon grains offered 394±20 Ma, 546±20 Ma, 655±19 Ma, 1305±17 Ma, and 1538±17 Ma ages. The 394 Ma age has been interpreted as an early Variscan collision age, 546 Ma as the protolith age and the other ages as signifying Cadomian and Saharan detrital zircons. Similar to the terranes in the Apuseni Mountains, the Padeş terrane has a North African-Gondwanan provenance.

http://scholarcommons.usf.edu/geologia/vol51/iss1/art10 2012/03/11 - 22:19

The Biharia sequence from the Apuseni Mountains is a component of the Biharia Paleozoic terrane. The Biharia terrane probably evolved as an island arc between the Cadomian Someş and Baia de Arieş terranes. A gneissic metagranodiorite associated with metabasites from the Valea Ierţii creek, was sampled for U/Pb and Pb/Pb zircon age determination. The zircons extracted out of the sampled rock were subjected both to dilution and evaporation methods. Dilution method offered Concordia intercepts at 227±23 Ma, 312±13 Ma, 465.7+8.4/-8.0 Ma, 703±21 Ma and 1604±45 Ma. Evaporated zircon grains gave 450±20 Ma and 543±17 Ma. The 227±23 Ma age and 312±13 Ma age have been interpreted as Pb loss due to the final effect of the Permian widespread magmatism and late Variscan anatexis respectively. The 465.7+8.4/-8.0 Ma and 450±50 Ma ages probably represent the protolith generation time. The 543±17 Ma is viewed as an inherited Cadomian age and the 703±21 and 1604±45 Ma might represent Cadomian and Saharan detrital zircon ages.

http://scholarcommons.usf.edu/geologia/vol51/iss1/art9 2012/03/11 - 22:19

In order to clarify some of the issues regarding the mineralogical content and the source area of the Cretaceous deposits from Ampoi Valley basin (Southern Apuseni Mountains) fourteen lithologic logs were drawn from the Ampoi Valley both side tributaries (Slatinii, Ruzi, Vâltori, Valea lui Paul, Feneş, Călineasa, Fierului Brook, Bobului, Satului, Tăuţi, Galaţi, Presaca Ampoiului, Valea Mică and Valea Mare brooks). The main sedimentary rock types were identified (conglomerates, wacke and lithic sandstones, clays, and marls). The sandstones were classified according to the ternary diagrams. Their petrographic features revealed both a magmatic and a metamorphic source area for them.

http://scholarcommons.usf.edu/geologia/vol51/iss1/art8 2012/03/11 - 22:19

A new Hybodus site from Romania is located at Anina, in the Pliensbachian – Middle Toarcian succession from Ponor quarry (Caraş-Severin district). The paper refers to a short description of the Hybodus teeth recently collected, followed by some considerations on hybodonts phylogeny and palaeoecology.

http://scholarcommons.usf.edu/geologia/vol51/iss1/art7 2012/03/11 - 22:19

Volcanic tuffs out cropping in Măcicaş area (Cluj County) have been investigated and tested for their ammonium removal capacity. The zeolitic volcanic tuffs from Măcicaş are mainly represented by vitric and vitric crystal tuffs. In this region, significant amounts of volcanic glass in the pyroclastic sequence have been replaced by zeolites (between 50-80 %). The main zeolite species identified in volcanic tuffs from Măcicaş is clinoptilolite and subordinately mordenite. The zeolitic tuff samples considered in zeolitic sodium form (labeled M1-Na and M2-Na) are tested in ammonium removal experiments. The ammonium ions were completely removed from 0.0716g/dm3 NH4+ solution onto 10g of zeolitic material in static regime. In dynamic regime, the ammonium ions were completely removed after 250 ml and 500 ml solution passed on M1-Na and M2-Na sample respectively. Also the zeolite exhaustion takes place after more than 1500 ml solution is processed in both cases. The ionic exchange properties suggest that the zeolitic tuff of the Măcicaş region can be used as a final stage (following the biological process) in wastewater treatment plants in order to assure compliance with environmental standards.

http://scholarcommons.usf.edu/geologia/vol51/iss1/art6 2012/03/11 - 22:19

The investigated clay fraction was separated from salt samples recovered from three boreholes located in the Praid salt deposit area. For comparison, samples collected from Turda deposit (Franz Josef adit, the Rudolf and Ghizele chambers) and from the salt massif from Sărăţel were also analyzed. The qualitative investigations evidenced a clay minerals association dominated by illite and chlorite accompanied by subordinate amounts of kaolinite, smectite, fibrous clays (sepiolite, palygorskite), and in minor amounts, by 14/14 chlorite/vermiculite and chlorite/smectite interstratifications. A quantitative evaluation (%) including a standard graphical representation was performed only for the borehole samples (Praid), according to the vertical distribution. The genetical interpretation of the identified clay minerals association took into account the influence of the sedimentation mechanisms and the climate control on the mineral phases. The environment of formation for the salt in the Transylvanian Basin was defined by the presence of specific climatic factors, also suggested by the palynological investigations.

http://scholarcommons.usf.edu/geologia/vol51/iss1/art5 2012/03/11 - 22:19

The middle Badenian Ocnele Mari evaporitic formation from Slănic Prahova represents one of the most important salt deposits from the outer Carpathians (Prahova district). The salt deposit is located in the sedimentary succession of the Slanic syncline belonging to the post-tectogenetic cover of Tarcău Nappe. The sedimentary environment of the Ocnele Mari Formation was dominated by evaporitic condition covering the interval from the last stage of carbonates precipitation to halite, however, without reaching the stage of K and Mg salt precipitation. During evaporitic condition, authigenic minerals precipitated: carbonates, sulfates (anhydrite, gypsum and polyhalite) and halite (predominant). Simultaneously with the precipitation processes, an important input of sediments from the adjacent areas into the basin took place. Thus, minerals of allogenic origin (quartz, plagioclase feldspars, and clay minerals) are also present, sometime as interbedded layers in the salt formation.

http://scholarcommons.usf.edu/geologia/vol51/iss1/art4 2012/03/11 - 22:19

The loose jamesonite felted masses found in several vein-type Miocene ore deposits in Romania, at Herja in particular, host a very rich and peculiar mineral assemblage. This study concerns a novel morphological type of loose siderite crystals identified in this paragenesis. Additional to their macroscopic and microscopic investigation, powder X-ray diffraction (XRPD) analysis was carried out. Based on XRPD patterns, some pseudoxehagonal prisms, up to 10 mm in size, black to dark brown in color, with rugged surfaces and microscopic mosaic-like structures, were proved to be siderite. The described morphological type of siderite represents a novelty for Herja ore deposits, possibly also for Romania and for the entire Carpathian region.

http://scholarcommons.usf.edu/geologia/vol51/iss1/art3 2012/03/11 - 22:19

More than 600 radiometric K-Ar ages on rocks from the metamorphic basement of the Romanian Carpathians are statistically treated and discussed. The data suggest that the most pervasive Alpine rejuvenation occurred in a belt of about 100-120 km width, within which crystalline rocks were intensely reworked, undergoing a metamorphic remobilisation of Barrovian type before Middle – Late Cretaceous. This Eo-Alpine metamorphic belt outcrops on the flanks of the Mureş Zone, i.e., in the Rodna massif to the NE, and in the Northern Apuseni to the west. Away from it, ages get progressively older and outline a broad Variscan metamorphic province. In the most external part of the South Carpathians preserved pre-Variscan ages point to the former extension of the Moesian Plate. Within the study area radiometric K-Ar ages, as well as recently reported fission-track data, do not support reheating above 300°C and corresponding regional metamorphic events during meso- and neo-Alpine times.

http://scholarcommons.usf.edu/geologia/vol51/iss1/art2 2012/03/11 - 22:19

The Sarmatian deposits from the Şimleu basin are developed in two facies: terrigenous and calcareous. An attempt to distinguish the main types of Sarmatian limestone microfacies was made by Bucur et al. (1992). The present study provides more detail of the sedimentary facies and fabrics of these limestones, emphasizing the essential contribution of microbialites to their formation. The following types of microbialite and microbial structure were found: (1) thrombolites with clotted fabric and fenestral structures; (2) microbial crusts on bioclasts; (3) peloidal microbialites (4) agglutinated microbialites; (5) stromatolites and laminoid-fenestral structures. All these structures played an important role in the accretion of the Sarmatian carbonate deposits in the area studied.

http://scholarcommons.usf.edu/geologia/vol51/iss1/art1 2012/03/11 - 22:19

The examination of pollen and charcoal from the Gutâiului Mountains in northwestern Romania and the archaeological evidence from surroundings provides some information on how past human activities have changed the vegetation in this region. The first evidence of potential human influence upon the woodlands is manifested by fire clearance recorded at approximately 7900 cal. yr BP coinciding with the Early Neolithic. The charcoal peaks at ca. 5750, 3300, 2700, 1500, 1000 cal. yr BP, and during the last 300 years are associated with episodes of decline of main woodland constituents (Ulmus, Tilia, Fraxinus, and Corylus), and the expansion of fire-precursors (Betula, Alnus, and Corylus), and of herb species that indicate an anthropogenic disturbance. The small openings created within the woodlands were probably used as grazing areas. The first signs of agriculture appear at ca. 1500 cal. yr BP. Only during the last 300 years does pollen of the cereals e.g. Secale, Hordeum-group, Poaceae >40 μm, suggest the spread of arable field in the lowlands (Oaş Depression), but not in the proximity of the study basins.

http://scholarcommons.usf.edu/geologia/vol50/iss1/art7 2012/03/11 - 22:19

Early Triassic carbonate outcrops were studied in the central sector of the Hăghimaş Syncline with regard to stratigraphy, microfacies and facies interpretation.This is the first microfacies study of these deposits. Early Triassic carbonates in the Hăghimaş Syncline are represented by two stratified successions: limestones and dolomites. The limestones overlie very rarely the detritic basal deposits (Induan) which marks the beginning of the alpine transgression. The stratified dolomites underlie frequently the Early Anisian massive dolomites. The contact between the stratified limestones and stratified dolomites is only exposed on Calu brook outcrop (the western flank of the Hăghimaş Syncline). The age of the investigated carbonates is Olenekian, based on the occurrence of Meandrospira pusilla biozone (in limestones). The foraminifera are very scarce in dolomites, represented mostly by Earlandia taxa. Microfacies data indicate the existence of a carbonate platform. The Olenekian carbonates yield a broad spectrum of microfacies types, predominantly micrites and biomicrites with foraminifera associated with echinoderms, ostracods, radiolarians, calcitized gastropods etc. These facies types are also known from the carbonate platforms in other parts of the Tethys.

http://scholarcommons.usf.edu/geologia/vol50/iss1/art6 2012/03/11 - 22:19

Telephragmoxylon transsylvanicum, a new morphospecies of cheirolepidiaceous conifer wood, typical for the Latest Cretaceous from Sebeş Valley in Oarda-Sebeş sector (Alba district), coeval with the latest dinosaurs, is described. Geological and palaeobotanical settings for South Apuseni Mts. area are sketched and paleoclimatical remarks are suggested.

http://scholarcommons.usf.edu/geologia/vol50/iss1/art5 2012/03/11 - 22:19

The paper concerns the stages of evolution of the South Harghita area and of the adjacent mountainous basins. The focus is set on specific geological events and on their consequences upon the paleogeographical modeling. Based on field observations and on previous studies, the Pliocene-Pleistocene geological events from the Baraolt and Lower Ciuc basins, the Tuşnad – Malnaş Channel and Sfântu Gheorghe gulf were synchronised with those from the South Harghita volcanic area.

http://scholarcommons.usf.edu/geologia/vol50/iss1/art4 2012/03/11 - 22:19