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Speleology in Kazakhstan

Shakalov on 04 Jul, 2018
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

New publications on hypogene speleogenesis

Klimchouk on 26 Mar, 2012
Dear Colleagues, This is to draw your attention to several recent publications added to KarstBase, relevant to hypogenic karst/speleogenesis: Corrosion of limestone tablets in sulfidic ground-water: measurements and speleogenetic implications Galdenzi,

The deepest terrestrial animal

Klimchouk on 23 Feb, 2012
A recent publication of Spanish researchers describes the biology of Krubera Cave, including the deepest terrestrial animal ever found: Jordana, Rafael; Baquero, Enrique; Reboleira, Sofía and Sendra, Alberto. ...

Caves - landscapes without light

akop on 05 Feb, 2012
Exhibition dedicated to caves is taking place in the Vienna Natural History Museum   The exhibition at the Natural History Museum presents the surprising variety of caves and cave formations such as stalactites and various crystals. ...

Did you know?

That head, total is the total head of a liquid at a given point is the sum of three components: (a) the elevation head, which is equal to the elevation of the point above a datum, (b) the pressure head, which is the height of a column of static water that can be supported by the static pressure at the point, and (c) the velocity head, which is the height to which the kinetic energy of the liquid is capable of lifting the liquid [22].?

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Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
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Karst environment, Culver D.C.
Mushroom Speleothems: Stromatolites That Formed in the Absence of Phototrophs, Bontognali, Tomaso R.R.; D’Angeli Ilenia M.; Tisato, Nicola; Vasconcelos, Crisogono; Bernasconi, Stefano M.; Gonzales, Esteban R. G.; De Waele, Jo
Calculating flux to predict future cave radon concentrations, Rowberry, Matt; Marti, Xavi; Frontera, Carlos; Van De Wiel, Marco; Briestensky, Milos
Microbial mediation of complex subterranean mineral structures, Tirato, Nicola; Torriano, Stefano F.F;, Monteux, Sylvain; Sauro, Francesco; De Waele, Jo; Lavagna, Maria Luisa; D’Angeli, Ilenia Maria; Chailloux, Daniel; Renda, Michel; Eglinton, Timothy I.; Bontognali, Tomaso Renzo Rezio
Evidence of a plate-wide tectonic pressure pulse provided by extensometric monitoring in the Balkan Mountains (Bulgaria), Briestensky, Milos; Rowberry, Matt; Stemberk, Josef; Stefanov, Petar; Vozar, Jozef; Sebela, Stanka; Petro, Lubomir; Bella, Pavel; Gaal, Ludovit; Ormukov, Cholponbek;
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Your search for salinity crisis (Keyword) returned 26 results for the whole karstbase:
Showing 1 to 15 of 26
Messinian event in the black sea, 1979, Hsu Kenneth J. , Giovanoli Federico,
Three holes were drilled during the 1975 DSDP Leg 42B drilling the Black Sea. A section from Hole 380, at 2107 m water depth on the western edge of the abyssal plain, is 1074 m thick, and provides the most complete stratigraphic section. Dating of the sediments is based upon (1) fossil evidence from pollen, crustaceans, benthic foraminifera, and diatoms, (2) correlation with climatic changes and with unusual isochronous events that have been dated elsewhere, (3) paleomagnetic data, and (4) estimates of sedimentation rate.The history of Black Sea sedimentation recorded by the DSDP cores includes black shale sedimentation during the Late Miocene, followed by periodic chemical sedimentation from Late Miocene to Early Quaternary, and a change to dominantly terrigenous sedimentation from the Middle Quaternary. These hemipelagic and turbiditic sediments were deposited in lacustrine and brackish marine environments. The Messinian sediments, however, consist of stromatolitic dolomite, oolitic sands, and coarse gravels, deposited in supratidal and intertidal environments. The intercalation of the shallow-water sediments in a deep-water sequence suggests a drastic lowering of the water-level within the Black Sea basin during the Messinian so that the edge of the present abyssal plain was then the edge of a shallow lake.The Messinian draw-down phase of the Black Sea was in existence for about 100,000 years during the Lago-Mare stage of the salinity crisis. The evaporated waters formed an alkaline lake before it was drowned by a brackish marine transgression correlative to the Trubi transgression of the Mediterranean

Carbonate rocks in the Black Sea basin: indicators for shallow water and subaerial exposure during Miocene--Pliocene time, 1979, Stoffers P. , Muller G. ,
Drilling in the Black Sea in general revealed three types of sediments: terrigenous, chemical, and biogenic. Terrigenous muds predominate in the Pleistocene whereas chemical sediments are abundant in the lower Pleistocene--Pliocene to Late Miocene sedimentary section. Biogenic constituents play a minor role only. The chemical sediments include calcite (lake chalk), Mg-calcite, aragonite, siderite and dolomite. Among these, the dolomites of Pliocene to Late Miocene age are most interesting. They were encountered in the two drill sites close to the Bosporus drilled in 2115 to 1750 m water depth, respectively. The dolomites show a great variety of criteria (e.g. intraclasts, algae mats, crusts, pellets, oolites), indicating a shallow water environment with occasional subaerial exposure and supratidal evaporitic conditions. The formation of these shallow water carbonates in the Black Sea is supposed to correlate with the Messinian salinity crisis in the Mediterranean

Palokarsts et palo-gomorphologie nognes des Alpes occidentales et rgions adjacentes, 1984, Julian M. , Nicod J.
NEOGENE PALEOKARSTS AND PALEO-GEOMORPHOLOGY IN THE WESTERN ALPS, JURA AND PROVENCE - This text is an attempt to confront our knowledge about the karsts and the problems of landscape evolution (tectonics, paleo-climates, sea level changes). Three periods had been studied: 1/ Early and Middle Miocene, with the development of chemical erosional surfaces and a prevailing sub-superficial karstic solution; 2/ the revolution of the Upper Miocene ("Rhodanian" tectonical phase and the salinity crisis of the Messinian), that caused the deepening of the karstic systems; 3/ the Plio-Villafranchian phase, favoured the production of terra-rossa and the evolution of the karstic caves, except during some dry periods during the Villafranchian.

Chronology, causes and progression of the Messinian salinity crisis, 1999, Krijgsman W. , Hilgen F. J. , Raffi I. , Sierro F. J. , Wilson D. S. ,

La stratigraphie oligo-miocene et la surface d'erosion messinienne en mer Noire, stratigraphie sismique haute resolution: The Oligo-Miocene stratigraphy and the Messinian erosional surface in Black Se, 2003, Gillet H, Lericolais G, Rehault Jp, Dinu C,
ResumeLa stratigraphie des marges occidentales de la mer Noire est revisee a partir des donnees de sismique multitrace haute resolution des recentes missions franco-roumaines Blason 1 et 2. Les profils, cales par des forages petroliers et DSDP, revelent la presence de plusieurs discontinuites majeures, interpretees comme des surfaces d'erosion tertiaires. D'une part, la discontinuite sismique la plus marquee souligne la base des series miocenes et correspond a une surface dite composite qui integre plusieurs phases erosives successives de l'Oligocene au Pontien. D'autre part, une surface d'erosion messinienne est clairement mise en evidence en mer Noire. Nos resultats confortent l'hypothese de Hsu [Palaeogeogr. Palaeoclimatol. Palaeoecol. 29 (1979) 75-93], qui propose une chute majeure du niveau de la mer Noire au Messinien, parallelement a la crise messinienne en Mediterranee. Pour citer cet article : H.[no-break space]Gillet et[no-break space]al., C. R. Geoscience 335 (2003).AbstractThe stratigraphy of the Black Sea western margin is revisited through seismic data acquired during two French-Romanian surveys. These data are calibrated by industrial and DSDP drillings; they display several major discontinuities regarded as Tertiary erosional surfaces. The major seismic discontinuity underlines the base of Miocene formations and corresponds to a composite surface including at least three erosional phases ranging from Oligocene to Pontian times. Moreover, a Messinian erosional surface is clearly identified. This is in agreement with the Hsu's proposition [Palaeogeogr. Palaeoclimatol. Palaeoecol. 29 (1979) 75-93] suggesting a Messinian sea-level drop of Black Sea related to the Messinian Salinity Crisis described in the Mediterranean Sea. To cite this article: H.[no-break space]Gillet et[no-break space]al., C. R. Geoscience 335 (2003)

Temporal evolution of tertiary dolostones on Grand Cayman as determined by Sr-87/Sr-86, 2003, Jones B. , Luth R. W. ,
On the Cayman Islands, the Tertiary Bluff Group (Brac Formation, Cayman Formation, Pedro Castle Formation) is onlapped and overlain by the Pleistocene Ironshore Formation. On Grand Cayman, the Brac Formation and Cayman Formation are formed of finely crystalline dolostones; whereas the Pedro Castle Formation is formed of finely crystalline dolostones, dolomitized limestones, and limestones. No dolomite has been found in the Ironshore Formation. Dolostones in the Bluff Group, which retained their original depositional textures and lack evidence of any recrystallization, are formed of small (typically 5-15 mum long) interlocking, euhedral dolomite crystals. Dolomite cement is present in the Brac Formation and Cayman Formation but is very rare in the Pedro Castle Formation. Most of the dolomite crystals are characterized by oscillatory zoning with alternating zones of low-Ca calcian dolomite and high-Ca calcian dolomite. Grand Cayman is ideal for assessing the temporal evolution of Tertiary dolostones because the dolostones are young, have not been recrystallized, and are geographically isolated by the deep oceanic waters around the island. Interpretation of 158 new Sr-87/Sr-86 ratios from the dolostones in the Bluff Group indicate that the succession underwent three time-transgressive phases of dolomitization during the Late Miocene, the Late Pliocene, and Pleistocene. Petrographically similar dolomite was produced during each phase of dolomitization that was mediated by the same type of fluid and the same general conditions. Dolomitization was part of a dynamic cycle of processes that followed major lowstands. Karst development during the lowstands preconditioned the limestones for dolomitization by increasing their porosity and permeability. Thus, vast quantities of the dolomitizing fluids could freely circulate through the strata during the subsequent transgression. Dolomitization ceased once a stable highstand had been attained

The effect of the Messinian Deep Stage on karst development around the Mediterranean Sea. Examples from Southern France, 2004, Audra P, Mocochain L, Camus H, Gilli E, Clauzon G, Bigot Jy,
It is difficult to explain the position and behaviour of the main karst springs of southern France without calling on a drop in the water table below those encountered at the lowest levels of Pleistocene glacio-eustatic fluctuations. The principal karst features around the Mediterranean are probably inherited from the Messinian period ('Salinity crisis') when sea level dropped dramatically due to the closing of the Straight of Gibraltar and desiccation of the Mediterranean Sea. Important deep karst systems were formed because the regional ground water dropped and the main valleys were entrenched as canyons. Sea level rise during the Pliocene caused sedimentation in the Messinian canyons and water, under a low hydraulic head, entered the upper cave levels. The powerful submarine spring of Port-Miou is located south of Marseille in a drowned canyon of the Calanques massif. The main water flow comes from a vertical shaft that extends to a depth of more than 147 in bsl. The close shelf margin comprises a submarine karst plateau cut by a deep canyon whose bottom reaches 1,000 in bsl. The canyon ends upstream in a pocket valley without relation to any important continental valley. This canyon was probably excavated by the underground paleoriver of Port-Miou during the Messinian Salinity Crisis. Currently, seawater mixes with karst water at depth. The crisis also affected inland karst aquifers. The famous spring of Fontaine de Vaucluse was explored by a ROV (remote observation vehicle) to a depth of 308 in, 224 m below current sea level. Flutes observed on the wall of the shaft indicate the spring was formerly an air-filled shaft connected to a deep underground river flowing towards a deep valley. Outcroppings and seismic data confirm the presence of deep paleo-valleys filled with Pliocene sediments in the current Rhone and Durance valleys. In the Ardeche, several vauclusian springs may also be related to the Messinian Rhone canyon, located at about 200 in below present sea level. A Pliocene base level rise resulted in horizontal dry cave levels. In the hinterland of Gulf of Lion, the Cevennes karst margin was drained toward the hydrologic window opened by the Messinian erosional surface on the continental shelf

Etude des palokarsts des environs de Saint-Remze (Ardche, France) : mise en vidence dune rivire souterraine fossilise durant la crise de salinit messinienne, 2005, Martini, Jacques
Paleokarst investigation near Saint-Remze, Ardche, France discovery of an underground river fossilized during the Messinian salinity crisis - The paleokarst features studied in this paper are hosted in Lower Cretaceous limestone and generally appear as filled caves, subsequently de-roofed by denudation. The most important of them forms a sequence of segments developed at a relatively constant elevation of 360-380 m above sea level and can be traced over a length of 5.2 km. The ancient cave passages generally appear as soil covered bands, 5 to 20 m in width and limited on both sides by limestone outcrops. At surface the nature of the cave filling is revealed mainly by scattered blocks: calcite from speleothems and calcified clay, silt, sand and breccia. In the best preserved places, the earth band lies in a trench, where the walls may display a cave morphology and where the filling is often exposed in a undisturbed state. Three types of detrital cave filling have been identified, which in stratigraphical order are as follows: 1) Beige-grey silt, sand and microconglomerate of immature alluvials, with elements of Paleozoic granites and metamorphic rocks, and Upper Miocene volcanics, both originating from the Cvennes Mountains 30 km to the NW. The lithological composition is comparable to the recent alluvials of the Paleokarst investigation near Saint-Remze, Ardche, France discovery of an underground river fossilized during the Messinian salinity crisisArdche River, which is flowing a few kilometers to the SW and is deeply entrenched into a canyon at elevations of 40 to 80 m. The karst context, combined with the biostratigraphical data obtained from rodent molars in the alluvials, suggests an Uppermost Miocene age, comprised between ~5.8 and ~5.45 Ma. 2) Red mature alluvials and colluvials originating from local reworking of surficial karst residuals. At one spot they gave a paleontological age of 3.6 to 3.0 Ma, but from the local karst context one may expect ages from final Miocene to Pleistocene in other spots. 3) Monogenic breccia generated from wall gelifraction, which is Pleistocene after rodent molars found in two places. The paleocave is visualised as formed by an underground stream fed from swallow-holes on the bank of the Ardche River, when it was flowing more than 300 m higher than its actual bed. With regard to its relatively constant elevation and a discordant relationship with the country rock bedding, it is interpreted as a vadose cave controlled by a paleo-water-table. The other fillings (2 and 3) were deposited during subsequent vadose speleogenesis and after considerable water-table lowering. The elevation of this fossilised underground river coincides fairly well with the pre-salinity crisis abandonment surface (5.52 Ma), which is evidenced in the area by high perched gravel relics. The end of the speleogenesis could have taken place just before this event (~5.6 Ma) or at an age not younger than ~5.45 Ma. In the latter possibility, speleogenesis had to be working before the regressive erosion generated by the drastic lowering of the Mediterranean Sea [5.52 to 5.33 Ma, Clauzon et al, 2005 ] reached the area and de-watered the deep karst aquifer. This fossil underground river provides also information about the morphological evolution of the area. For instance the nature of the immature alluvials suggests that the torrential regime of the Ardche was about the same than today. It also indicates that the important and famous cave systems in the area (Grotte de Saint-Marcel, Aven dOrgnac, Systme de Foussoubie, Grotte Chauvet), which are developed at lower elevations, cannot be older than ~5.6 Ma and most likely formed mainly during the Plio-Pleistocene, although most of them have been initiated during the salinity crisis.

La grotte de Saint-Marcel (Ardche) : un rfrentiel pour lvolution des endokarsts mditerranens depuis 6 Ma, 2006, Mocochain Ludovic, Bigot Jeanyves, Clauzon Georges, Faverjon Marc Et Brunet Philippe
Saint Marcel Cave: an important site for the evolution of the mediterranean endokarst in the last 6 million years - The plateau of Saint-Remze is a mesozoic carbonate platform located close to the Rhne valley. This carbonate platform is intensely karstified, as proven by Saint-Marcel Cave, which is 53 km long. It displays several horizontal levels. The upper and middle levels are dry most of the time. They are composed of large horizontal conduits extending over several kilometers. The lowermost third level is active and partly drowned. Scuba divers have reached a depth of 65 m below the Ardche. The horizontal levels are not controlled by geological structure. Consequently, the distribution of the horizontal levels depends only on the base level which constrains the whole organisation of the Ardche karst. Around the Ardche Canyon and the Rhne Valley, the identification of the marks made by the messinian salinity crisis allows to reconstruct the evolution of the local base level. This reconstruction allowed us to study the Saint-Marcel Cave in a geodynamical and chronological frame over the last six million years. The morphological investigations in the cave, combined with the study of the base level change, have shown three main stages of speleogenesis and two main types of water flow. Following entrenchment of the deep messinian canyons during the salinity crisis, cave levels developed according to the very deep base level of that time. At the end of the crisis, at 5.35 Ma, the Pliocene transgression caused a sudden rise of the base level. The messinian valleys as well as the karst outflows were flooded. This hydraulic change produced a per ascensum genesis of some shafts that are called chimney-shafts. This per ascensum genesis of chimney-shafts repeated itself at each stage of the Pliocene base level rise. During the Pliocene (5.32 to 2 Ma), the infilling of the messinian canyons by fluvial sediments shows that the Ardche river had several long stages of base level stability, allowing the development of new cave levels. The karst system was fed by both local recharge from the Saint-Remze Plateau and large underground shortcuts through the Ardche river meanders. The detailed study of the main levels in Saint-Marcel Cave reveals the existence of intermediate stages in the evolution of the base level, allowing us to refine its knowledge.

The Ardeche endokarstic responses to the eustatic variations resulting from the Messinian salinity crisis, 2006, Mocochain L. , Clauzon G. , Bigot J. Y. ,
The Messinian salinity crisis is typically recorded by evaporites in the abyssal plains of the Mediterranean Sea and by canyons incised into the Mediterranean margins and their hinterlands. However, the impacts of crisis on geomorphology and surface dynamics lasted, until. canyons were filled by sediments in the Pliocene (fig. 2). In the mid-Rhone valley, the Ardeche Cretaceous carbonate platform is incised over 600 m by the Rhone Messinian canyon. The canyon thalweg is located - 236 m Lis) (below sea level) in the borehole of Pierrelatte [Demarcq, 1960; fig. 1]. During the Pliocene, this canyon was flooded as a ria and infilled by a Gilbert type fan delta [Clauzon and Rubino, 1992; Clauzon et al., 1995]. The whole Messinian-Pliocene third order cycle [Haq et al., 1987] generated four benchmark levels. The first two are [Clauzon, 1996]: (i) The pre-evaporitic abandonment Surface which is mapped around the belvedere of Saint-Restitut (fig. 1). This Surface is synchronous [Clauzon, 1996] of the crisis onset (5.95 Ma) [Gautier et al., 1994; Krigjsman et al., 1999] and, consequently, is an isochrounous benchmark. (ii) The Messinian erosional surface is also an isochronous benchmark due to the fast flooding [Blanc, 2002] of the Rhone canyon, becoming a ria at 5.32 Ma [Hilgen and Langereis, 1988]. These surfaces are the result of endoreic Mediterranean sea level fall more than a thousand meters below the Atlantic Ocean. A huge accommodation Space (up to more than 1000 in) was created as sea-level rose up to 80 in above its present-day level (asl) during (lie Pliocene highstand of cycle TB 3.4 (from 5.32 to 3.8 Ma). During the Lower Pliocene this accommodation space was filled by a Gilbert fan delta. This history yields two other benchmark levels: (i) the marine/non marine Pliocene transition which is an heterochronous surface produced by the Gilbert delta progradation. This surface recorded the Pliocene highstand sea level; (ii) the Pliocene abandonment Surface at the top of the Gilbert delta continental wedge. Close to the Rhone-Ardeche confluence, the present clay elevations Of file four reference levels are (evolution of base-level synthesized in fig. 4): (1) 3 12 in asl, (2) 236 in bsl, (3) 130 m asl, (4) 190 In A. The Ardeche carbonate platform underwent karstification both surficial and at depth. The endokarst is characterized by numerous cavities organised in networks. Saint-Marcel Cave is one of those networks providing the most coillplete record (fig. 5). It opens out on the northern side of the Ardeche canyon at an altitude of 100 m. It is made up by three superposed levels extending over 45 km in length. The lower level (1) is flooded and functionnal. It extends beneath the Ardeche thalweg down to the depth of 10 m bsl reached by divers. The observations collected in the galleries lead us to the conclusion that the karst originated in the vadose area [Brunet, 2000]. The coeval base-level was necessarily below those galleries. The two other levels (middle (2) and upper (3)) are today abandoned and perched. The middle level is about 115 m asl and the upper one is about 185 m A. They are horizontal and have morphologies specific to the phreatic and temporary phreatic zone of the karst (fig. 6). In literature, the terracing of the Saint-Marcel Cave had been systematically interpreted as the result of the lowering by steps of the Ardeche base-level [Guerin, 1973; Blanc, 1995; Gombert, 1988; Debard, 1997]. In this interpretation, each deepening phase of the base level induces the genesis of the gravitary shaft and the abandonment of the previous horizontal level. The next stillstand of base level leads to the elaboration of a new horizontal level (fig. 7). This explanation is valid for most of Quaternary karsts, that are related to glacio-eustatic falls of sea-level. However Our study on the Saint-Marcel Cave contests this interpretation because all the shafts show an upward digging dynamism and no hint of vadose sections. The same 'per ascensum' hydrodynamism was prevailing during the development of the whole network (figs. 8 and 9). We interpret the development of the Ardeche endokarst as related to the eustatic Messinian-Pliocene cycle TB 3.4/3.5 recorded by the Rhone river. The diving investigations in the flooded part of the Saint-Marcel Cave and also in the vaLlClusian springs of Bourg.-Saint-Andeol reached - 154 in bsl. Those depths are compatible only with the incision of the Messinian Rhone canyon at the same altitude (- 236 m bsl). The Saint-Marcel lower level would have develop at that time. The ascending shaping of levels 2 and 3 is thus likely to have formed during the ensuing sea-level rise and highstand during the Pliocene, in mainly two steps: (i) the ria stage controlled by the Mediterranean sea level rise and stillstand; (ii) the rhodanian Gilbert delta progradation, that controlled the genesis of the upper level (fig. 10)

How much did climate force the Messinian salinity crisis? Quantified climatic conditions from pollen records in the Mediterranean region, 2006, Fauquette S, Suc Jp, Bertini A, Popescu Sm, Warny S, Bachiri Taoufiq N, Perez Villa Mj, Chikhi H, Feddi N, Subally D,
The latest Miocene (5.96 to 5.33[no-break space]Ma) is characterised by an outstanding event: the desiccation of the Mediterranean Sea (Messinian salinity crisis). It has been suggested that this was caused by a tectonic event, with no climatic change playing a role in desiccation. Quantifying the climate of the region during this period will help support or refute this hypothesis. An effective method for reconstructing the climate from Neogene pollen data is the 'Climatic Amplitude Method' based on the modern climatic requirements of plants to interpret fossil data. It has been conceived especially for periods devoid of modern vegetation analogue.Twenty Messinian to Lower Zanclean pollen sequences are now available in the peri-Mediterranean region. Most of them do not cover the whole Messinian interval, particularly those along the Mediterranean shorelines where sedimentation was interrupted during the sea's desiccation. In contrast, sedimentation was almost continuous in such areas as the Atlantic side of Morocco, along the Adriatic coast (including the Po Valley), and to a lesser extent the Black Sea. The Mediterranean sites nonetheless provide a reliable if not a discontinuous record of vegetation variability in time and space.A first examination of the pollen diagrams reveals a high regional variability controlled by local conditions, and throughout the interval a southward increase in herb pollen frequency in contrast to the tree pollen frequency. This indicates that open and probably dry environments existed in the southern Mediterranean region prior to, during and after the salinity crisis. Trees developed in areas close to mountains such as in the Po Valley, in Cerdanya and in the Black Sea region. Most variations observed in the pollen diagrams are constrained by fluctuations of Pinus pollen amounts, indicating eustatic variations. Climatic quantification from pollen data does not show obvious climatic changes due to the desiccation of the Mediterranean Sea, especially in the dry and warm southwestern Mediterranean area (Sicily, southern Spain and North Africa). At Maccarone, along the Adriatic Sea, a decrease in temperatures of the coldest month and, less importantly, a decrease in mean annual temperatures, corresponding to a drastic vegetation change, are reconstructed. These temperature variations are assumed to be controlled by regional environmental changes (massive arrival of waters in this basin) rather than to reflect cooling, because some authors link the second phase of evaporite deposition to a period of global warming. Some migrations of plants probably occurred as a response to Mediterranean desiccation. But the climatic contrast which has probably existed at that time between the central Mediterranean and the peripheral areas might be amplified.Climatic reconstruction from pollen data in the western Mediterranean area shows that climate is not the direct cause of the Mediterranean desiccation, as the Mediterranean region had experienced continuously high evaporation long before the crisis. Therefore the main factor leading to this event seems to be the successive closures of the Betic and Rifian corridors, isolating the Mediterranean Sea from the Atlantic Ocean

Late Miocene and early Pliocene environments in the southwestern Black Sea region from high-resolution palynology of DSDP Site 380A (Leg 42B), 2006, Popescu Speranta Maria,
A high-resolution palynological study has been performed on late Miocene (Messinian) and early Pliocene (Zanclean) sediments cored at DSDP Site 380A (Leg 42B). A late Miocene coastal vegetation has been identified in association with a delta environment. The Pliocene is characterised by competition between the two most important vegetation components, namely humid thermophilous forests and dry steppes, with changes driven by large amplitude climatic variations. These variations are linked to other European reference pollen records and to the global temperature evolution for the early Pliocene, and result in climatostratigraphic relationships at large geographic scale. An orbital tuning is proposed with respect to new data clarifying time control on the section. The Black Sea appears to have dried up in response to the Messinian salinity crisis in the Mediterranean with which it might have been connected during periods of high sea level

The Messinian salinity crisis: Looking for a new paradigm?, 2006, Roveri M. , Manzi V. ,
The importance of the sedimentary record of Messinian events in the Apennines foredeep is due to its geological and structural settings, which allow the reconstruction of the relationships between marginal and basinal settings and provide fundamental insights into some important issues. A geologic-stratigraphic model of the Messinian Apennine foredeep indicating a possible solution for closing the last `Messinian gap' is here presented. Moreover, the establishment of a preliminary high-resolution stratigraphy for the terminal Lago Mare stage allows us to attempt Mediterranean-scale correlations across different structural settings.The Messinian evolution of the Apennine foredeep and some considerations of adjacent areas suggest the great importance of tectonic deformation in controlling Messinian events. The intra-Messinian unconformity is a common feature of the marginal basins of the Mediterranean, and it is associated in many cases to the collapse and resedimentation of primary evaporites. The genesis of such unconformity seems to be strictly related to a general tectonic reorganization of the Mediterranean area. Preliminary observation on the stratigraphy of the Lago Mare stage suggest that the high-frequency lithological cyclicity observed in the non-marine deposits of this stage, as well as the superimposed transgressive trend, are common to many Mediterranean basins. These characteristic features might reflect the interplay between a longer-term tectonic trend and higher-frequency, precession-related, climatic changes; this could represent a fundamental tool for establishing a high-resolution stratigraphic framework of the latest Messinian allowing long-distance correlations between terrestrial and marine ecosystems and hence more accurate palaeoenvironmental studies

Paratethyan-Mediterranean connectivity in the Sea of Marmara region (NW Turkey) during the Messinian, 2006, Cagatay Mn, Gorur N, Flecker R, Sakinc M, Tunoglu C, Ellam R, Krijgsman W, Vincent S, Dikbas A,
The Sea of Marmara region is thought to have been a gateway between Paratethys and the Mediterranean since the Middle Miocene, and is therefore an important control on water mass exchange between the two realms. The Miocene successions in the northeastern Aegean and northwestern Marmara regions indicate that the first Mediterranean marine transgression to affect these areas occurred during the late Serravallian.In the northeastern Aegean region, frequent marine incursions occurred during the Tortonian and Messinian stages. The Messinian stage in this area is represented by a package of brackish- to fresh-water carbonates with some marine sandstone-siltstone interbeds (Alcitepe Formation), which conformably overlies the Tortonian Kirazli Formation. The Messinian sequence is overlain with an erosional contact by a shallow marine siliciclastic sequence (Goztepe Formation) of Zanclean age. With its brackish- to fresh-water carbonates and broadly constrained age, the Messinian sequence is interpreted as being coeval with the Upper Evaporite-Lago Mare sequence observed in western Mediterranean basins.In the western Marmara region, the Pontian (Messinian) Alcitepe Formation consists of bioclastic and oolitic limestones with basal clastic rocks. It conformably overlies the fluvio-lacustrine siliciclastic sediments of the Middle to Upper Miocene Kirazli Formation and is overlain by fluvio-lacustrine sediments of the Kimmerian (5.5-3.2[no-break space]Ma) Truva and Tevfikiye formations with an erosional contact.The bioclastic limestones of the Alcitepe Formation in the western Marmara region contain a molluscan and ostracod fauna that are endemic to Paratethys. These fauna indicate deposition in a shallow, brackish- to fresh-water environment. Faunal and paleomagnetic analyses of a section of the Alcitepe Formation at Yenimahalle (Canakkale) confirm that the formation is of Pontian age and represents chron C3r (6.04-5.24[no-break space]Ma). The ostracod analysis indicates that during deposition of the Alcitepe Formation, salinity increased from brackish in the lower part to more saline conditions in the upper part. Ostracod valves have low 87Sr / 86Sr values relative to coeval Late Miocene ocean water. This indicates that exchange between the Sea of Marmara region and the global ocean was restricted throughout this period. Fossil and Sr-isotope evidence suggests, however, that there was a Paratethyan-Marmara connection during the deposition of the lower part of the Alcitepe Formation, with Paratethyan influence reaching the north Aegean. Connection via Marmara between Paratethys and the Mediterranean was not re-established until the late Aktchagylian (Late Pliocene). The re-connection was caused by both increased activity on the North Anatolian Fault and global sea level rise

Exhumation of Messinian evaporites in the deep-sea and creation of deep anoxic brine-filled collapsed basins, 2006, Cita Mb,
The first part of the paper summarizes some basic concepts concerning (a) the distribution of Messinian evaporites in the deepest parts of the Mediterranean Sea and (b) the Mediterranean Ridge accretionary wedge and its peculiar characteristics deriving from the presence of a substantial evaporitic body in the deforming sedimentary prism.Then five brine-filled anoxic collapsed basins (Tyro, Bannock, Urania, Atalante and Discovery), discovered from 1983 to 1994, are presented and discussed in their physiographic, geologic, hydrologic and geochemical characters. High density brines deriving from submarine dissolution of outcropping or subcropping evaporites accumulate at the bottom of collapsed basins, if they are not swept away by submarine currents. The interface separating normal sea-water from high density brines is sharp with a density contrast of about 20% and lies at 3200-3500[no-break space]m below sea level. Strong bacterial activity is developing at the interface and living bacteria have been recovered from the anoxic salty brines. Thickness of the brines may be up to 500[no-break space]m. Thermal stratification has been observed in three brine lakes. Exhumation and dissolution of Messinian evaporites in the Mediterranean Ridge occur in different tectonic settings: pull-apart basin (Tyro), subducting seamount close to the outer deformation front (Bannock Basin), top of a backstop (Urania, Atalante and Discovery Basins).Chemistry of the brines is strongly variable and suggests dissolution of different layers or levels of the Messinian suite. Discovery brines are the saltiest ever recorded in natural environment. Their saturation in Mg chloride (bischofite), the end product of sea-water evaporation, suggests that the deepest parts of the eastern Mediterranean were close to dryness at the end of the salinity crisis, strongly supporting the deep basin desiccation model

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