Strontium isotope ratios of the Eastern Paratethys during the Mio ...

Earth and Planetary Science Letters 292 (2010) 123–131 

Contents lists available at ScienceDirect 

Earth and Planetary Science Letters 

journal homepage: www.elsevier.com/locate/epsl 

Strontium isotope ratios of the Eastern Paratethys during the Mio-Pliocene 

transition; Implications for interbasinal connectivity 

Iuliana Vasiliev a, ⁎, Gert-Jan Reichart b , Gareth R. Davies c , Wout Krijgsman a , Marius Stoica d 

a Palaeomagnetic Laboratory ‘Fort Hoofddijk’, Budapestlaan 17, 3584 CD, Utrecht, The Netherlands 

b Department of Geochemistry, Faculty of Geosciences, Utrecht University, Budapestlaan 4, 3584 CD, Utrecht, The Netherlands 

c Department of Petrology, Faculty of Earth and Life Sciences, Vrije University, De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands 

d Department of Palaeontology, Faculty of Geology and Geophysics, University of Bucharest, Bălcescu Bd. 1, 010041, Romania 

article 

info 

abstract 

Article history: 

Received 4 August 2009 

Received in revised form 14 January 2010 

Accepted 19 January 2010 

Available online 6 February 2010 

Editor: M.L. Delaney 

Keywords: 

Paratethys 

87Sr/86Sr 

Pliocene 

Dacian basin 

Lago Mare 

Paratethys represents the large basin that extended from central Europe to inner Asia, comprising the North 

Alpine foreland, Pannonian and Dacian basins, the Black Sea and Caspian Sea. Connectivity between these 

subbasins and the connectivity of Paratethys with the open ocean varied drastically because of pervasive 

tectono-climatic processes affecting the region. Here, we investigate the biogenically produced carbonates of 

the Dacian basin for strontium analyses to monitor changes in connectivity, water geochemistry and 

palaeoenvironment during the Mio-Pliocene transition. Diagenetic evaluation showed that not all 

contamination could be removed, but that the strontium content of our samples was not affected by postdepositional 

processes. 87 Sr/ 86 Sr ratios of ostracods and molluscs are in good agreement and show relatively 

constant values of 0.70865–0.70885. These are much lower than coeval Mio-Pliocene ocean water (0.7089– 

0.7090), which indicates that no long-standing connection existed to the Mediterranean. The newly obtained 

strontium ratios for Paratethys are best explained by a mixture of Danube, Dnieper and Don river waters, 

implying connectivity between Dacian basin and Black Sea during the latest Miocene–earliest Pliocene. We 

observed no evidence for connectivity to the Caspian Sea during this period. The 87 Sr/ 86 Sr ratios of the Dacian 

basin are similar to the ones measured in the Mediterranean “Upper Evaporites/Lago Mare” facies. The major 

fresh water deluge at the end of the Messinian salinity crisis could thus have been caused by drowning of 

Eastern Paratethys waters into the Mediterranean. 

© 2010 Elsevier B.V. All rights reserved. 

1. Introduction 

The strontium isotope ratio of ocean waters is the same at any one 

time, regardless of where in the ocean it is measured, because the 

strontium residence time is considerably longer than the mixing time 

of ocean water. Oceanic 87 Sr/ 86 Sr ratios fluctuate through geological 

time, showing a general increase from ∼50 Ma to present, and can 

thus be used as stratigraphic tool (McKenzie et al., 1988; Hodell et al., 

1989a; Hodell et al., 1994; McArthur et al., 2001). Marine sedimentary 

records can be dated by measuring strontium ratios (e.g. from wellpreserved 

foraminifera), especially at time intervals where the 87 Sr/ 

86 Sr curve shows steep changes (Hodell et al., 1991; Miller et al., 

1991a,b; McArthur et al., 2001). 

In (semi)isolated inland basins strontium isotope dating is far 

more complicated because the 87 Sr/ 86 Sr ratio is controlled (in these 

geological settings) by mixing of ocean water and river water. The 

⁎ Corresponding author. Tel.: +31 30 253 1361; fax: +31 30 253 1677. 

E-mail addresses: vasiliev@geo.uu.nl (I. Vasiliev), reichart@geo.uu.nl (G.-J. Reichart), 

gareth.davies@falw.vu.nl (G.R. Davies), krijgsma@geo.uu.nl (W. Krijgsman), 

marius@geo.edu.ro (M. Stoica). 

87 Sr/ 86 Sr ratio of river water reflects the regional catchments geology 

and may differ substantially between drainage systems (Major et al., 

2006). Variations in input and mixing of different water sources will 

thus be reflected in the 87 Sr/ 86 Sr ratios, especially if these sources have 

markedly different isotope ratios. Consequently, the strontium 

isotope ratio can be used to quantitatively study the influx of river 

water and to determine connectivity. River input, however, needs to 

exceed ∼50% of the total inflow and needs to have strongly 

contrasting 87 Sr/ 86 Sr values and high strontium concentrations to be 

clearly identified (Flecker et al., 2002; Flecker and Ellam, 2006). 

The Black Sea, or its geological precursor Paratethys (Fig. 1), 

represents an inland basin that is very suitable to study regional 

hydrological patterns and interbasinal water exchange by determining 

the strontium isotope values. Connectivity to the Mediterranean 

would result in 87 Sr/ 86 Sr ratios that are extremely close to oceanic 

values (0.709155), while an exclusively fresh water supply would be 

reflected in values typical for the rivers feeding the Black Sea basin 

(0.708792; Palmer and Edmond, 1989). Additionally, ocean water has 

∼30 times more Sr dissolved than the rivers entering the Black Sea 

(Table 1). During the last glacial, when the Black Sea became a lake by 

complete isolation from the open ocean, 87 Sr/ 86 Sr values (Table 1; 

0012-821X/$ – see front matter © 2010 Elsevier B.V. All rights reserved. 

doi:10.1016/j.epsl.2010.01.027

124 I. Vasiliev et al. / Earth and Planetary Science Letters 292 (2010) 123–131 

Fig. 1. Schematic palaeogeographic map of Paratethys region, comprising Lake Pannon, the Dacian basin (DB), Black Sea and Caspian Sea. The star indicates the position of the 

Rîmnicu Sărat section in the Dacian basin as a Paratethys sub-basin. DS indicates the location of the Dobrogea sill and MS the position of the Marmara Sea. 

Major et al., 2006) were indeed close to a weighted average of the 

major rivers entering the basin (Major et al., 2006). It has also been 

suggested that the Paratethys was temporarily isolated from the open 

ocean during the Mio-Pliocene transition (Hsü and Giovanoli, 1979; 

Popov et al., 2006), especially when the Mediterranean water level 

dropped because of the Messinian salinity crisis (MSC). There is little 

information so far on strontium isotope changes in the Paratethys 

during this period. 

In this paper, 87 Sr/ 86 Sr analyses are applied to assess the changes in 

basin water geochemistry and palaeoenvironment of the Dacian basin 

(Romania) during the Mio-Pliocene transition. We selected the 

magnetostratigraphically well-dated successions of the Focşani 

Depression (Vasiliev et al., 2004; Vasiliev et al., 2007), and focussed 

on the interval between 6.3 and 4.1 Ma (Fig. 2), when Paratethys 

water level may have dropped because of the MSC. During this period, 

the Dacian basin formed, together with the Black Sea and Caspian Sea, 

the Eastern Paratethys (Fig. 1). The three subbasins were separated by 

shallow sills at Dobrogea and the Caucasus, and minor changes in 

tectonic uplift, sea level or hydrological budgets could have seriously 

influenced interbasinal connectivity. We selected both ostracod 

valves and mollusc shells for strontium analyses, because of their 

omnipresence throughout the succession and excellent state of 

preservation. Prior to Sr analyses we determined trace and minor 

elements to assess the preservation state of the biogenic carbonates. 

The results will be used to analyse the hydrological balance of the 

Dacian basin, and to determine the interbasinal connectivity within 

the Eastern Paratethys and the Mediterranean. The data will further 

serve as crucial constraints for ongoing strontium models of 

Messinian evaporites (Flecker et al., 2002) and may help to decipher 

the alleged Paratethys influx into the Mediterranean in the final (Lago 

Mare) stage of the MSC (Hsü et al., 1973; Orszag-Sperber, 2006). 

2. Geological setting 

The Paratethys has been a semi-enclosed basin since the beginning 

of the Oligocene, when it extended from central Europe to inner Asia 

(Rögl, 1996; Ramstein et al., 1997; Popov et al., 2006). Alpine 

continental collision during the Neogene caused restricted circulation 

and progressive rearrangement of individual subbasins. Paratethys 

gradually transformed into a restricted marine and finally into a giant 

Table 1 

87 Sr/ 86 Sr ratios of various rivers and open marine domains around the Paratethys. The Average Ocean Waters (AOW) is also reported. 

Water body Remarks Sr 

(ppm) 

87 Sr/ 86 Sr Reference 

Present-day ocean water 7.62 0.709155 Henderson et al. (1994) 

Global river water 0.712 Palmer and Edmond (1989) 

AOW during Lower Evaporites 0.708999 Howarth and McArthur (1997) 

AOW during Upper evaporites 0.709012 Howarth and McArthur (1997) 

Messinian sea water 0.708983–0.709028 Howarth and McArthur (1997) 

Marmara Sea (modern) 0.70915 Major et al. (2006) 

Aegean Sea (modern) 0.709157 Major et al. (2006) 

Black Sea (modern) 0.709133 Major et al. (2006) 

Black Sea (Last Glacial Maximum) 0.70865–0.70875 Major et al. (2006) 

Danube 53% of freshwater runoff to Black Sea 0.24 0.7089 Palmer and Edmond (1989), Major et al. (2006) 

Dnieper 14% of freshwater runoff to Black Sea 0.22 0.7085 Shimkus and Trimonis (1974), Palmer and Edmond (1989) 

Don ∼16% of freshwater runoff to Black Sea 0.22 0.7085 Shimkus and Trimonis (1974), Palmer and Edmond (1989) 

Sakarya ∼4% of freshwater runoff to Black Sea 0.7089 Major et al. (2006) 

River average Danube, Dnieper, Don and Sakarya 0.24 0.708792 Major et al. (2006) 

Caspian Sea (modern) 0.48 0.7082 Clauer et al. (2000), Page et al. (2003) 

Volga 82% of freshwater runoff to Caspian Sea 9.92 0.70802 Clauer et al. (2000), Page et al. (2003)

I. Vasiliev et al. / Earth and Planetary Science Letters 292 (2010) 123–131 

125 

marine nannofossils (Clauzon et al., 2005; Snel et al., 2006). 87 Sr/ 86 Sr 

analyses can determine the source of Paratethys waters and may 

elucidate the nature and timing of Mediterranean–Paratethys exchange. 

3. Analysed material and sample preparation 

3.1. Analysed material 

Fig. 2. Local stages, polarity zones, schematic lithological column and the position of the 

mollusc and ostracod samples used for trace elements and Sr isotopes; n.d. (no data) 

indicates the levels where the 87 Sr/ 86 Sr ratios were determined but, because of large Rb 

amounts found in the sample, interpreted as diagenetically affected. The dashed lines 

indicate the (interpretative) correlation of the polarity sequence to astronomically 

dated polarity time scale (APTS) (Vasiliev et al., 2004) and updated to new 

paleontological constraints (Stoica et al., 2007; Krijgsman et al., 2010). The age of the 

samples was calculated according to their position in the magnetostratigraphic record. 

The sampling gap between 1200 and 1800 m is mostly related to the coarser lithologies 

(silts and sandstones). The initial plan to obtain a monospecific record (Cyprideis sp.) in 

ostracods led to a major sampling gap between 1200 and 2300 m. To minimize it we 

selected a second specie (Thyrrenocythere filipescui) for 87 Sr/ 86 Sr analyses. In the time 

scale, Me 1 and Me 2 represent the lower and upper Meotian respectively; Odess. 

(Odessian), Portaf. (Portafferian) and Bosphorian are regional substages of Pontian 

Stage; Gt (Getian) and Pv (Parscovian) are substages of the Dacian Stage and Rm 1 

represents the lower Romanian. 

brackish–fresh water lake system during the upper Miocene–Pliocene 

(Fig. 1). The knowledge of its Mio-Pliocene palaeoenvironmental history 

relies mainly on palaeoecological assessment of aquatic and terrestrial 

organisms (e.g. Rögl and Daxner-Hock, 1996; Rögl, 1998), on the 

correlation to better time-constrained species from the Mediterranean 

realm (e.g. Harzhauser and Piller, 2004) and on several palynological 

studies (Popescu, 2001; Ivanov et al., 2007; Utescher et al., 2009). 

Marine connections between Paratethys and Mediterranean are 

commonly considered to have ended in the Late Miocene. Since then, 

the Paratethys was a brackish to fresh water basin, resulting in the 

complete loss of its marine fauna (e.g. foraminifera, calcareous 

nannoplankton and dinocysts) (Magyar et al., 1999), and its faunal 

content became dominated by a variety of ostracods and molluscs, 

endemic to the Paratethys. Short periods of Mediterranean–Paratethys 

connectivity are, however, suggested by some horizons containing 

Benthic organisms like ostracods and molluscs produce carbonate 

shells, which can be separated from the sedimentary rock and analysed 

for their isotopic composition. Twenty-five ostracod levels were selected 

from the Rîmnicu Sărat section, covering the interval between 6.3 and 

4.1 Ma. The section consists of cyclic alternations of sandstones and 

mudstones, deposited in a distal marine–brackish deltaic system 

(Panaiotu et al., 2007). The average duration (∼22 kyr) of the 

sedimentary cycles indicates deposition under the influence of precession 

(Vasiliev et al., 2004). Our biogenic carbonates were extracted from 

shales and siltstones because these fine-grained rocks ensured the best 

possible preservation of the shells. Single species records could not be 

used for the entire time interval, because the dynamically changing 

environments caused a faunal variation. The ostracod species Cyprideis 

sp. Jones, 1857 was chosen (Fig. 3a) because of its abundance within the 

selected time frame of the Romanian Carpathian foredeep (Fig. 2) and 

because this species was earlier successfully used for trace-elements and 

stable isotope studies (De Deckker et al., 1999; Anadon et al., 2002). 

Cyprideis is one of the most euryhaline ostracods that populate waters 

with salinity ranging from 0.4% to 150%. Cyprideis torosa is a typical 

shallow water species, which lives in permanent littoral marine 

environments as well as marginal marine environments such as deltas, 

estuaries and coastal lagoons. They have also been found in athalassic 

saline lakes and have been described as anomalohaline (Van Harten, 

1990). During the Late Miocene, the genus Cyprideis was affected by a 

great adaptive radiation in the Paratethys realm (Pipik et al., 2007), 

probably due to its adaptation to deeper waters (Van Harten, 1990; De 

Deckker, 2001, 2002). Twenty-two of the selected levels from the 

Romanian Carpathian foredeep contained sufficient shells of Cyprideis 

sp. for Sr isotope analysis (Fig. 2). Cyprideis is only scarcely present in the 

lower, middle and the first part of the upper Pontian at Rîmnicu Sărat 

(Krijgsman et al., 2010). To reduce the gap for that time period we 

analysed three levels with Tyrrhenocythere filipescui (Fig. 2). Tyrrhenocythere 

inhabits oligohaline to mesohaline waters, with the highest 

frequency between 0 and 30 m depth (Yassini and Ghahermann, 1979). 

Where possible, we also used mollusc shells at the same stratigraphic 

levels to compare the results with those obtained from ostracods (Fig. 2). 

The molluscs used in this study are unionids and cardiids and their 

seasonal growth is recorded throughout the entire year; therefore a 

complete shell records the variations in temperature, chemistry and 

isotopic signatures of water during the organism's lifetime. 

3.2. Sample preparation 

Specimens of Cyprideis sp. and T. filipescui were separated from 

bulk sediment by disaggregation in sodium carbonate solution, wet 

sieving to retain the >250 μm fraction and hand-picking under a 

microscope. The ostracods samples were cleaned to remove clay 

following the procedure of Barker et al. (2003), followed by washing 

twice in MilliQ®, five times in methanol (96%) and by 30 s cleaning in 

an ultrasonic bath. The washing procedure was then repeated. 

Cleaned samples were then evaluated for diagenetic alteration using 

trace element analysis and scanning electron microscopy (SEM). 

The mollusc specimens were handpicked and embedded in raisin. A 

slice from each mollusc was cut and finely polished. The fresh surface was 

sampled using laser ablation inductively coupled plasma-mass spectrometry 

(LA-ICP-MS). The specimens were subsequently re-sampled for 

the strontium isotope analysis using a Merchantek micro-drill or hand 

mini-drill avoiding contaminated external parts of the shell.


Fig. 3. (a) Scanning electron micrograph of a Cyprideis sp. from Rîmnicu Sărat Valley (from sample RMS116) with ablation craters. (b) High magnification of an ablation crater where 

the pristine structure of the ostracod shell can be observed. (c) Time resolved laser-ablation inductively coupled plasma-mass spectrometry data. Middle parts (marked by the 

shaded areas) represent the part of the measurement taken into consideration for the trace elements calculations (e.g. Sr/Ca ratios). Normalization to Ca was necessary to overcome 

the varying response (counts per second) during ablation that generates variable quantity of removed material. Important for 87 Sr/ 86 Sr ratios isotopes is that the Sr profiles record 

little variations indicating pristine preservation of this element within the shell structure. Other elements record higher values at the outside parts of the shells indicating that 

despite careful cleaning the outer part of the shells collected unremovable clay minerals/coating in the ornament pores. Therefore, for trace elements calculations only the middle 

(grey) parts of the profiles were used. 

4. Methods 

The ostracods and molluscs were ablated using a 193 nm 

wavelength laser. Such a short wave length is essential for the 

reproducible ablation of the fragile shells, because carbonates do not 

absorb laser radiation well at higher wavelengths (Mason and Kraan, 

2002; Reichart et al., 2003). The system employs a Lambda Physik 

excimer laser with GeoLas 200Q optics. Ablation was performed in a 

mixture of helium and argon atmosphere at a pulse repetition rate of 

6 Hz. Ablation craters were 80 μm in diameter (Fig. 3a and b). Ablated 

material was measured with respect to time (and hence depth) using 

a Micromass Platform quadrupole ICP-MS instrument (Figs. 3c and 4). 

Calibration was performed against U.S. National Institute of Standards 

and Technology SRM 610 glass using the concentration data of Pearce 

et al. (1997) with 44 Ca as an internal standard. A collision and 

reduction cell (Mason and Kraan, 2002) was used to give improved 

results by reducing spectral interferences on the minor isotopes of Ca 

( 42 Ca, 43 Ca and 44 Ca). Multiple isotopes were used where possible to 

confirm accurate concentration determinations (Fig. 3). 

The 87 Sr/ 86 Sr ratios were measured on both ostracods and mollusc 

carbonates. From each sample, 0.4 to 3 mg was dissolved in 0.5 ml of 5 N 

acetic acid. Any residue was separated by centrifugation and the 

remaining solution was evaporated to dryness. The resulting solid 

residue was dissolved in 2 drops of concentrated HNO 3 to remove 

organics, and again evaporated to dryness. The residue was completely 

redissolved at room temperature in 0.5 ml of 3 N HNO 3 and centrifuged 

for four minutes. 0.4 ml of the top-most part of the samples was 

introduced to chromatographic columns composed of “Elchrom Sr spec” 

ion exchange. The Sr fraction was dried and nitrated twice with one drop 

of concentrated HNO 3 . The isotopic analyses were carried out at the 

Isotopes Laboratory from Vrije Universiteit (Amsterdam). 

87 Sr/ 86 Sr 

ratios were analysed on Finningan MAT 261 and 262 mass spectrometers, 

running a triple-jump routine, applying exponential fractionation 

correction and normalizing to 87 Sr/ 86 Sr=0.1194. NBS 987 run 

during this study was within the long term average 0.710242± 

0.000012 (2σ), n>200. The blanks were less 30×10 −6 have 

the 87 Sr/ 86 Sr ratio marked as ‘not determined’ in Table 2 (although they 

were measured). 

5. Diagenetic evaluation; reliability of strontium measurements 

Contamination from clay minerals, iron and manganese (hydr) 

oxide coatings and possibly organic material can be a problem in 

microfossil trace element analysis. Most contamination is adhered to 

the outer surface of the shells post mortem and might accumulate in


127 

Ablation tracks were analysed perpendicular to the growth lines to 

investigate the possible diagenetic overprinting in the mollusc shells 

(Fig. 4). The excellently preserved pattern of changes in Ba/Ca, Sr/Ca 

and Mn/Ca ratios is interpreted to reflect ancient seasonal changes, 

providing strong evidence for good preservation of the mollusc shells 

from this valley. The cyclicity in the trace element ratios correlates to 

the growth lines (Fig. 4) comparable to modern shells (Vonhof et al., 

2003). 

Because of the constant Sr/Ca ratios through the LA-ICP-MS 

profiles from ostracods and the preserved seasonal patterns in the 

molluscs we concluded that the Sr content of the analysed shells was 

not affected by depositional processes. Therefore we used the LA-ICP- 

MS Sr content data (expressed as Sr molar ratios) by averaging the 

values obtained at each level (Table 2). For seven levels, the number of 

ostracods shells was limited to 3–4 valves and therefore we chose to 

not record the trace and minor elements. We used all the available 

material to measure the Sr isotope ratios. Based on the results of 

eighteen well-preserved sites we concluded that the Sr content was 

also not affected by post-depositional processes. Two ostracod levels 

out of seven gave ‘not determined’ Sr contents, but had timeequivalent 

molluscs data (RMS 48 M and RMS 45 M). Their Sr values 

are not deflecting from our other molluscs-based data (Table 2). 

6. 87 Sr/ 86 Sr values for the carbonates of the Dacian basin during 

the Mio-Pliocene transition 

Fig. 4. Trace elements ratio from a 5.5 mm profile in the mollusc shells. The profile is 

located in the lower half of the picture, just below the Mn/Ca record. The well resolved 

pattern of changes in Ba/Ca, Sr/Ca and Mn/Ca, most probably reflects ancient seasonal 

changes, from warm to cold season (or vice-versa), marked by the grey bands. 

pores and between the spines of the ostracods. Rigorous purification 

procedures have been developed to remove such extraneous phases 

(Boyle, 1981; Lea and Boyle, 1993). Analysis by LA-ICP-MS makes it 

possible to avoid such contamination during the integration of the 

data acquired during analysis of single valves. Al and U were 

monitored, to evaluate the surface contamination by clay particles 

(Fig. 3c). Mn was used as a proxy of secondary carbonate and 

manganese (hydr)oxides overgrowth. Those parts of the time 

integrated measurements having higher counts of Al, U and Mn 

were excluded from integration. Some of the specimens showed 

contamination throughout the profile and were excluded completely. 

We recorded at least two profiles for each specimen. SEM images of 

representative specimens were also used to examine the mineralogy 

of the ostracod valves. In contrast to molluscs, ostracods build their 

shells more or less instantaneous. This might explain why ablation 

profiles for ostracods show remarkably constant concentrations with 

thickness making the recognition of contamination relatively straightforward. 

The non-contaminated part of the ostracods shells are 

marked by the grey interval (Fig. 3). 

Ultimately, it is the heterogeneity between individual ostracod 

valves that sets the limit to the accuracy of ostracods trace metal 

based environmental reconstructions. Annual environmental and 

water composition changes would result in variations between 

individuals from the same sample. In view of the relatively fast shell 

building of the ostracods, changes in this growth rate could easily 

influence Sr and Mg incorporation, causing differences between 

ostracods shell from the same location. The ablation profiles for 

ostracods shows that even after the very thorough cleaning procedure 

not all the contamination present at the outer parts could be removed 

(Fig. 3c). However, the evaluation of these profiles enabled us to 

observe that the Sr/Ca ratio for the ostracods was constant through 

entire ablation profiles, indicating that the Sr content was not affected 

by post-deposition processes (Fig. 3c). 

Biological and inorganic precipitates record ambient water Sr 

isotope compositions. Unlike oxygen isotopes, the measurement 

techniques for strontium isotope ratios rule out measurable mass 

dependent fractionation from biological effects, temperature, or other 

physical environmental changes (Major et al., 2006). This potentially 

provides valuable information on the isotopic composition of the 

water, reflecting both connectivity of the basin to the open ocean, and 

changes in regional climate and hydrography. The resultant isotopic 

water composition depends on the Sr concentration of river water and 

on the isotopic contrast between oceans and rivers. Strontium isotope 

ratios can thus be used to test whether salinity fluctuations resulted 

from changes in fresh water supply (precipitation plus river runoff), 

from variations in evaporation, or from both. 

The Sr content in biogenic carbonates depends upon temperature 

and on the biological and physical environment, but these parameters 

do not influence 87 Sr/ 86 Sr (Faure, 1998). The values for Sr content of 

the Dacian basin, expressed as Sr molar ratio, are ∼2.2 times higher for 

the ostracods than for the molluscs (Table 2). The decreasing trend of 

Sr incorporated over time is similar for both ostracods and molluscs. 

Our results show that the 87 Sr/ 86 Sr ratios of ostracod valves from 

the Rîmnicu Sărat section (Fig. 5, Table 2) range from 0.708664 to 

0.708768. The 87 Sr/ 86 Sr ratios in mollusc carbonates range are in good 

agreement ranging from 0.708683 to 0.708882 (Table 2 and Fig. 5). 

Only at one level (RMS116, Table 2), the 87 Sr/ 86 Sr ratio obtained from 

molluscs (0.708865±26) differ substantially from the one obtained 

from the ostracod valves (0.708664±6). The latest Miocene–earliest 

Pliocene strontium values of the Dacian Basin carbonates are 

markedly different from coeval global ocean values (Henderson et 

al., 1994; McArthur et al., 2001) being significantly lower than the 

marine waters at that time (Fig. 5). 

Two samples show 87 Sr/ 86 Sr ratio that significantly differ from the 

mean values of the Dacian basin record. Sample RMS 96 O, located at 

the Portaferrian/Bosphorian boundary has a value of 0.708964±9, 

which is very close to the oceanic curve (Fig. 2). A possible 

explanation is that this level corresponds to a very short marine 

influx into the Dacian basin. It concerns one of the two measurements 

based on T. filipescui, but Rb content, monitored by default for all the 

analyses, is within the limits describing it as non-diagenetically 

affected. The second sample (RMS114 O) has the lowest strontium 

ratio of the dataset (0.708511±11). This low value may be related to


Table 2 

87 Sr/ 86 Sr ratios, 2σ error, stratigraphic position (in m), age (in Ma) and local stages from Rîmnicu Sărat Valley section. Sr concentrations (mmol/mol) are also reported; n.d. (no data) 

indicates the levels where the values were not determined. 

Sample name 

87 Sr/ 86 Sr 2 

(10 − 6 ) 

Ag 

(Ma) 

Level 

(m) 

Local stage 

Sr 

(mmol/mol) 

RMS116 O 0.708664 6 6.21 1099 Upper Meotian (Me2) 2.15 Cyprideis sp. 



RMS096 O 0.708964 9 5.52 1808 Bosphorian (Po3) n.d. Tyrrhenocythere filipescui 

RMS094 O n.d. n.d. 5.50 1815 Bosphorian (Po3) n.d. Tyrrhenocythere filipescui 

RMS088 O 0.708823 10 5.32 1993 Bosphorian (Po3) n.d. Tyrrhenocythere filipescui 

RMS084 O 0.708779 8 5.12 2243 Bosphorian (Po3) 1.95 Cyprideis sp. 

RMS074 O 0.708722 11 4.98 2483 Bosphorian (Po3) 1.26 Cyprideis sp. 

RMS067 O 0.708763 13 4.95 2739.5 Bosphorian (Po3) 1.09 Cyprideis sp. 

RMS065 O 0.708774 10 4.90 2841.5 Getian (Dc1) 1.59 Cyprideis sp. 

RMS060 O 0.708853 16 4.68 3001 Getian (Dc1) n.d. Cyprideis sp. 

RMS055 O 0.708821 10 4.60 3252 Getian (Dc1) 1.29 Cyprideis sp. 



RMS048 O n.d. n.d. 4.45 3441 Getian (Dc1) n.d. Cyprideis sp. 

RMS045 O n.d. n.d. 4.40 3561 Getian (Dc1) n.d. Cyprideis sp. 





RMS029 O 0.708804 10 4.32 3716 Getian/Parscovian 0.86 Cyprideis sp. 

RMS028 O 0.708810 10 4.31 3725.5 Getian/Parscovian 1.27 Cyprideis sp. 

RMS019 O 0.708844 15 4.17 3912 Parscovian (Dc2) n.d. Cyprideis sp. 

RMS018 O 0.708817 9 4.16 3914 Parscovian (Dc2) 0.88 Cyprideis sp. 

RMS007 O 0.708826 8 4.12 4011 Parscovian (Dc2) 1.17 Cyprideis sp. 

RMS116 M 0.708865 26 6.21 1099 Upper Meotian (Me2) 0.72 Unio (Psilunio) sp. 

RMS110 M 0.708776 9 6.13 1142 Upper Meotian (Me2) 1.23 Unio (Psilunio) sp. 

RMS1 styllo 0.708831 10 4.50 3395.5 Getian (Dc1) 0.59 Stylodacna stylodacna 

RMS3 styllo 0.708803 7 4.49 3410 Getian (Dc1) 0.73 Stylodacna heberti 

RMS048 M 0.708776 10 4.45 3441 Getian (Dc1) 0.64 Prosodacna sp. 

RMS045 M 0.708811 8 4.40 3561 Getian (Dc1) 0.65 Stylodacna heberti 

RMS043 M 0.708772 8 4.36 3579 Getian (Dc1) 0.54 Unio (Rumanounio) rumanus 

RMS039 M 0.708795 10 4.35 3594 Getian (Dc1) 0.67 Prosodacna (Psilodon) neumayri 



RMS2 proso 0.708815 5 4.21 3875 Parscovian (Dc2) 0.57 Prosodacna (Psilodon) neumayri 

RMS4 styllo 0.708834 8 4.20 3877 Parscovian (Dc2) 0.37 Stylodacna heberti 

RMS018 M 0.708743 9 4.16 3925 Parscovian (Dc2) 0.60 Prosodacna (Psilodon) neumayri 

Species 

diagenesis that can be evaluated from the trace elements record 

(Supplementary Fig. 1). 

7. Discussion 

7.1. The isolation of the Eastern Paratethys during the Mio-Pliocene 

boundary interval 

The present-day situation of the Black Sea, having only a very small 

connection to the Mediterranean through the Bosporus strait (2 km 

wide and 30 m deep), results in sufficient radiogenic Sr supply to 

induce oceanic 87 Sr/ 86 Sr ratios in the Black Sea, due to the high 

content of radiogenic Sr of sea water (Major et al., 2006). The major 

Paratethys rivers carry relatively low amounts of radiogenic Sr, 

ensuring a mean fluvial input with lower 87 Sr/ 86 Sr than ocean water 

(Palmer and Edmond, 1989; Muller and Mueller, 1991; Henderson et 

al., 1994; Flecker and Ellam, 1999). Paleoisolation of Paratethys would 

thus induce a tendency towards less radiogenic strontium, while an 

exclusively continental supply would be reflected in 87 Sr/ 86 Sr values 

typical for the rivers feeding the basin (Flecker and Ellam, 1999; Major 

et al., 2006). This has been observed during the last glacial period, 

when strontium values ( 87 Sr/ 86 Sr∼0.70879) were close to a weighted 

average of the major rivers entering the Black Sea (Table 1 and Fig. 5). 

The oceanic strontium ratios are well-determined for the Mio- 

Pliocene interval, showing a significant increase from 0.70895 to 

0.70904 (Hodell et al., 1991; Miller et al., 1991a,b; McArthur et al., 

2001). The 87 Sr/ 86 Sr ratios measured from the Dacian basin are 

significantly lower (ranging 0.708511 to 0.708768 in ostracods and 

0.708683 to 0.708882 in molluscs). These low 87 Sr/ 86 Sr ratios are 

compatible with very limited input or even with complete isolation 

from the open ocean waters. Our 87 Sr/ 86 Sr values are rather constant 

when compare to the noticeable globally increasing trend of the late 

Neogene seawater 87 Sr/ 86 Sr (Farrell et al., 1995), implying that the 

Dacian Basin was not connected to the Mediterranean during the 

latest Meotian (6.5–6.0 Ma). This is in good agreement with seismic 

sequence stratigraphic interpretations of the western Dacian basin 

(Leever et al., 2010) and the biochronological data from the Focşani 

Depression (Krijgsman et al., 2010) that suggested a major transgression 

in the Dacian basin at the Meotian–Pontian boundary in 

marine waters from the Mediterranean. Unfortunately, we have no 

strontium data of the lower Pontian (6.0–5.6 Ma), to evaluate the 

presence and the duration of this marine connection. 

Our data further indicate that the Dacian basin did not receive 

marine waters from the Mediterranean during the Bosphorian substage, 

which corresponds in time to the latest Messinian–early Pliocene 

(Krijgsman et al., 2010). Based on the strontium results, the only period 

that marine waters entered the Dacian basin was the Portaferrian/ 

Bosphorian boundary interval (Fig. 2). The relatively low resolution of 

our Paratethys data, however, still leaves room for other short marine 

incursions that are not yet resolved. Future work will therefore focus on 

obtaining a higher resolution Sr isotope ratio record to establish possible 

transient changes in sea level that cause marine incursions. The higher 

Sr concentrations of seawater compared to brackish water, makes the 

basin highly sensitive to such incursions.


129 

Fig. 5. 87 Sr/ 86 Sr ratios for the Miocene–Pliocene samples of Rîmnicu Sărat Valley plotted against the ocean Sr isotope curve in grey between 3.5 and 6.5 Ma (Farrell et al., 1995; 

McArthur et al., 2001). The values are listed in Table 1. The open circles (Hodell et al., 1991), open triangles (Hodell et al., 1989b), open squares (Beets, 1991) and × (Richter and 

DePaolo, 1988) are individual Sr isotope data used for construction of the reference Ocean Sr isotope curve. Filled circles (squares) indicate ostracods (molluscs) from this study. The 

error for individual Romanian samples is plotted and the age is derived from the magnetostratigraphic correlation of Rîmnicu Sărat magnetostratigraphy to the APTS (Vasiliev et al., 

2004). The other values represent all the published data for the 3.5–6.5 Myr time interval from the Mediterranean realm: Gavdos (Flecker et al., 2002), southern Turkey (Flecker and 

Ellam, 1999), Eastern Italy (Montanari et al., 1997), Sicily (Lower and Upper Evaporites) (McKenzie et al., 1988; Muller and Mueller, 1991; Keogh and Butler, 1999), the Tyrrhenian 

Sea (Muller et al., 1990; Muller and Mueller, 1991) and the Balearic, Levantine and Ionian basins (Muller and Mueller, 1991). Age data for this compilation is according to (Flecker 

et al., 2002). Blue dashed lines indicate the values from the four major rivers feeding the Black Sea (one of the remnants of the old Paratethys domain). The Caspian Sea (other 

remnant of the Paratethys) and the values for the main rivers (Volga and Ural) feeding it are much lower ( 87 Sr/ 86 Sr= 0.7082) than any of the values and are not included in the 

graphic representation. In the left hand side data for the last glacial times (Major et al., 2006) are very similar to those obtained for the Mio-Pliocene transition of the Dacian basin. 

Note the different scale of the time axes. 

7.2. Interbasinal connectivity during the Mio-Pliocene transition 

To investigate the interbasinal connectivity of the Eastern 

Paratethys domain we use the present day 87 Sr/ 86 Sr ratios of the 

dominant rivers that fed the Dacian, Black Sea and Caspian basins 

(Table 1). This assumption is justified because the palaeographic 

configuration of the source region had been relatively stable since the 

Mio-Pliocene. The most important mountain ranges surrounding the 

Paratethys, the Alps. Carpathians and Caucasus, were already formed 

and the drainage areas of the Danube, Don, Dniepr and Volga 

remained roughly the same (Popov et al., 2006). 

Present-day 87 Sr/ 86 Sr ratios of the major Paratethys rivers are 

between 0.7085 and 0.7089 (Table 1; Fig. 5). This range overlaps with 

the low Sr isotope ratios in the Rîmnicu Sărat section (Table 2; Fig. 5). 

We thus interpret these Mio-Pliocene Sr isotope ratios of the Dacian 

basin to be highly dominated by river input. The main river that drains 

into the basin, the Danube, has a 87 Sr/ 86 Sr ratio of 0.7089, much lower 

than the ocean water during the Mio-Pliocene transition time 

(Shimkus and Trimonis, 1974; Palmer and Edmond, 1989) but still 

higher than all our data. Hence, the Danube cannot account for the 

measured 87 Sr/ 86 Sr ratio on its own, indicating that an additional fresh 

water source should have been present. The best candidates for the 

source of lower 87 Sr/ 86 Sr are Dnieper and Don, rivers located to the 

east and draining now into the Black Sea. The Danube currently 

provides ∼60% of the freshwater runoff to the Black Sea, while the 

other ∼40% comes from the Dnieper and Don. The 87 Sr/ 86 Sr data from 

the Dacian basin are similar to the values obtained for the Black Sea in 

the last glacial times (Major et al., 2006) and suggests that the Dacian 

and the Black Sea basins were also connected during the latest 

Miocene–earliest Pliocene. Therefore, we conclude that the strontium 

isotope ratio of the Eastern Paratethys (comprising at least the Dacian 

Basin and Black Sea) during the Mio-Pliocene transition was 

dominated by a mixed inflow from the Danube, Dnieper and Don 

rivers, having a relatively constant value ranging 0.70865–0.70885. 

Similar to our Dacian basin data are the five 87 Sr/ 86 Sr values obtained 

from the lower part of the Alçıtepe Formation at Yenimahalle in the 

Marmara sea region (0.708656–0.708836) (Çagatay et al., 2006). The 

magneto-biostratigraphic data from Yenimahalle indicated that the 

Alçıtepe Formation was deposited during chron C3r (6.04–5.24 Ma), 

partly corresponding in time to our Dacian basin record. Thus, Sr 

isotope ratios from the Dacian basin are sustaining the conclusion of 

Çagatay et al. (2006) that during the deposition of the lower 

Yenimahalle section the area was connected to the Eastern Paratethys 

(Çagatay et al. 2006). 

When compared to the Danube, Don and Dnieper, the present-day 

Caspian Sea has even lower 87 Sr/ 86 Sr values (∼0.7082), similar to the 

Volga river (Clauer et al., 2000; Page et al., 2003) that supplies 82% of 

the total amount of fresh water into the Caspian basin (Table 1). 

Connectivity between Black Sea and Caspian Sea is thus expected to 

imprint a low 87 Sr/ 86 Sr ratio signature. We conclude that during the 

Mio-Pliocene transition the Caspian basin was probably isolated from 

the Black Sea, because we do not see any evidence for Volga signatures 

in our 87 Sr/ 86 Sr data. This is in agreement with the late Miocene 

paleogeographic reconstructions of the Eastern Paratethys that 

indicate a subdivision into a Dacian/Euxinian basin system and a 

Caspian basin (Popov et al., 2006). 

7.3. The possible Paratethys Sr signature in MSC waters 

An extensively studied, but still poorly understood, major episode 

of fresh water influx into a marine basin concerns the final phase of the 

Mediterranean MSC. A major deluge of low salinity waters was


proposed to have diluted the hypersaline environment of the 

Mediterranean, generating wide-spread brackish-water conditions in 

the latest Messinian and transforming the basin into a large Lago Mare 

(Lake Sea) (Hsü et al., 1973). 

87 Sr/ 86 Sr ratios measured in the 

Mediterranean domain for those times reached mean values of 

0.70874 (McKenzie et al., 1988; Muller and Mueller, 1991; Montanari 

et al., 1997; Flecker and Ellam, 1999; Flecker et al., 2002) while the 

ocean had a much higher 87 Sr/ 86 Sr ratio, of 0.709012 (Howarth and 

McArthur, 1997). These highly deflected values for the Lago Mare 

facies must have been generated by a massive water influx of very 

different Sr isotopic composition. Potential sources of distinctly 

different isotopic composition are the Rhône and Nile rivers. Another 

hypothesis infers that fresh–brackish waters came from Paratethys, in 

agreement with the common presence of caspo-brackish faunal 

elements (ostracods, molluscs and dinoflagellates) in the Lago Mare 

sediments (Hsü et al., 1973). The inflow from Paratethys into the 

Mediterranean is difficult to ascertain since there is little information 

on late Miocene connectivity (Çagatay et al., 2006). 

The newly obtained strontium isotope ratios from the Eastern 

Paratethys can be compared with data from the Mediterranean MSC 

facies (Fig. 5). The 87 Sr/ 86 Sr ratio of Paratethys waters are similar to the 

values measured in Upper Evaporites (McKenzie et al., 1988; Muller 

and Mueller, 1991; Keogh and Butler, 1999), and distinctly lower than 

the Lower Evaporites that still reflect the oceanic water ratios. This 

implies that a major dilution of the Mediterranean brine took place 

after the “Lower Evaporites” (after 5.55 Ma), when the Mediterranean 

became isolated from the Atlantic (Hilgen et al., 2007; Krijgsman and 

Meijer, 2008; Roveri et al., 2008). The similar Sr isotope ratios from the 

Dacian basin, make the Eastern Paratethys a reasonable candidate for 

the source of low Sr isotope waters of the Lago Mare facies (Fig. 5). 

However, an additional source is required to lower the Mediterranean 

ratios to the lowest 87 Sr/ 86 Sr values registered for the Upper Evaporites 

(0.70852). The best candidates for the low 87 Sr/ 86 Sr ratios, as proposed 

before (e.g. Muller et al., 1990; Muller and Mueller, 1991; Flecker and 

Ellam, 1999, 2006; Flecker et al., 2002), are the Rhône (0.7087) and 

especially the Nile (0.706). 

8. Conclusions 

We have observed a clear relation between the Sr concentrations 

incorporated in the biogenic carbonates from the Carpathians 

foredeep and 87 Sr/ 86 Sr. Different, but consistent, Sr partition coefficients 

for the two groups of organisms, implies a general decreasing 

basin water Sr/Ca ratio. The 87 Sr/ 86 Sr values are rather constant when 

compare to the noticeable globally increasing trend of the late 

Neogene seawater 87 Sr/ 86 Sr (Farrell et al., 1995). Both independent 

proxies show that relatively little Sr was supplied to the basin through 

weathering of the local mountains and that exchange with the open 

ocean was very limited or non-existent. Diagenetic evaluation showed 

that even after very thorough cleaning, not all the contamination at 

the outer parts of the ostracod shells could be removed. Nevertheless, 

the Sr/Ca ratio was constant in the ablation profiles, indicating that 

the Sr content was not affected by post-deposition processes. 

The first reported 87 Sr/ 86 Sr ratios record for the Eastern Paratethys 

during the Mio-Pliocene transition indicate much lower values than 

those in the coeval ocean waters. This indicates that the basin was 

isolated from the Mediterranean and mainly fed by riverine waters. 

The Sr isotope ratios are consistent with a mixture of Danube, Dnieper 

and Don rivers, indicating connectivity between the Dacian basin and 

Black Sea. The strongly contrasting 87 Sr/ 86 Sr signature of the Volga 

(0.70802) river, is not observed. Therefore, we suggest that the 

Caspian Sea was disconnected from the rest of Paratethys and 

behaved as a separate entity. We further conclude that during late 

Pontian–Dacian times (5.3–4.0 Ma) the Eastern Paratethys was 

disconnected from the Mediterranean. 

The newly obtained 87 Sr/ 86 Sr ratios from the Dacian basin can be 

used to unravel water exchange patterns in the circum-Mediterranean 

region during Pliocene times. The Sr ratios are similar to the ones 

measured in the Mediterranean “Upper Evaporites/Lago Mare”, 

indicating that the distinctly lower Sr isotope ratios of the latest MSC 

phase in the Mediterranean may have been caused by waters from the 

Eastern Paratethys. 

Acknowledgements 

I.V. thanks to Marin Waaijer and Richard Smeets (Vrije Universiteit) 

for help in the clean lab and during the 87 Sr/ 86 Sr measurements, to 

Martin Ziegler for help with ostracods cleaning procedures and to Paul 

Mason for facilitating the access in the LA-ICP-MS laboratory. This work 

was financially supported by the Netherlands Research Centre for 

Integrated Solid Earth Sciences (ISES) and the Netherlands Geosciences 

Foundation (ALW) with support from the Netherlands Organization for 

Scientific Research (NWO). We thank Rachel Flecker and two 

anonymous reviewers for their thorough and constructive reviews 

that significantly improved the manuscript. 

Appendix A. Supplementary Data 

Supplementary data associated with this article can be found, in 

the online version, at doi:10.1016/j.epsl.2010.01.027. 

References 

Anadon, P., Ghetti, P., Gliozzi, E., 2002. Sr/Ca, Mg/Ca ratios and Sr and stable isotopes of 

biogenic carbonates from the Late Miocene Velona Basin (central Apennines, Italy) 

provide evidence of unusual non-marine Messinian conditions. Geochem. Geol. 

187, 213–230. 

Barker, S., Greaves, M., Elderfiel, H., 2003. A study of cleaning procedures used for 

foraminiferal Mg/Ca paleothermometry. Geochem. Geophys. Geosyst. 4, 1–20. 

Beets, C.J., 1991. The late Neogene 87 Sr/ 86 Sr isotopic record in the western Arabian Sea. 

Site 722 (117), 459–464. 

Boyle, E.A., 1981. Cadmium, zinc, copper, and barium in foraminifera tests. Earth Planet. 

Sci. Lett. 53, 11–35. 

Çagatay, M.N., Görür, N., Flecker, R., Sakinc, M., Tünoglu, C., Ellam, R., Krijgsman, W., 

Vincent, S., Dikbas, A., 2006. Paratethyan–Mediterranean connectivity in the Sea of 

Marmara region (NW Turkey) during the Messinian. Sediment. Geol. 188–189, 

171–187. 

Clauer, N., Chaudhuri, S., Toulkeridis, T., Blanc, G., 2000. Fluctuations of Caspian Sea 

level: beyond climatic variations? Geology 28, 1015–1018. 

Clauzon, G., Suc, J.P., Popescu, S.-P., Marunteanu, M., Rubino, J.-L., Marinescu, F., Melinte, 

M.C., 2005. Influence of the Mediterranean sea-level changes on the Dacic Basin 

(Eastern Paratethys) during the late Neogene: the Mediterranean Lago Mare facies 

deciphered. Basin Res. 17, 437–462. 

De Deckker, P., 2001. Late quaternary cyclic aridity in tropical Australia. Palaeogeogr. 

Palaeoclimatol. Palaeoecol. 170, 1–9. 

De Deckker, P., 2002. Ostracode paleoecology. Ostracode: Applications in Quaternary 

Research, American Geophysical Union. 

De Deckker, P., Chivas, A.R., Shelley, J.M.G., 1999. Uptake of Mg and Sr in the euryhaline 

ostracod Cyprideis determined from in vitro experiments. Palaeogeogr. Palaeoclimatol. 

Palaeoecol. 148, 105–116. 

Farrell, J.W., Clemens, S.C., Gromet, L.P., 1995. Improved chronostratigraphic reference 

curve of late Neogene seawater 87 Sr/ 86 Sr. Geology 23, 403–406. 

Faure, G., 1998. Principles and Applications of Geochemistry. Upper Saddle River, New 

York. 

Flecker, R., Ellam, R., 1999. Distinguishing climatic and tectonic signals in the sedimentary 

succession of marginal basins using Sr isotopes: an exlample from the Messinian 

salinity crisis, Eastern Mediterranean. J. Geol. Soc. Lond. 156, 847–854. 

Flecker, R., Ellam, R.M., 2006. Identifying Late Miocene episodes of connection and 

isolation in the Mediterranean–Paratethyan realm using Sr isotopes. Sediment. 

Geol. 188–189, 189–203. 

Flecker, R., de Villiers, S., Ellam, R., 2002. Modelling the effect of evaporation on the 

salinity– 87 Sr/ 86 Sr relationship in modern and ancient marginal–marine systems: 

the Mediterranean Messinian Salinity Crisis. Earth Planet. Sci. Lett. 203, 221–233. 

Harzhauser, M., Piller, W.E., 2004. Integrated stratigraphy of the sarmatian (Upper 

Middle Miocene) in the western Central Paratethys. Stratigraphy 1, 65–86. 

Henderson, G.M., Martel, D.J., O'Nions, R.K., Shackleton, N.J., 1994. Evolution of seawater 

87 Sr/ 86 Sr over the last 400-ka: the absence of glacial interglacial cycles. Earth 

Planet. Sci. Lett. 128, 643–651. 

Hilgen, F.J., Kuiper, K.F., Krijgsman, W., Snel, E., Van der Laan, E., 2007. Astronomical 

tuning as the basis for high resolution chronostratigraphy: the intricate history of 

the Messinian Salinity Crisis. Stratigraphy 4, 231–238.


131 

Hodell, D.A., Benson, R.H., Kennett, J.P., Bied, K.R.E., 1989a. Stable isotope stratigraphy of 

latest Miocene sequences in northwest Morocco: the Bou Regreg section. 

Paleoceanography 4, 467–482. 

Hodell, D.A., McKenzie, J.A., Mead, G.A., 1989b. Strontium isotope stratigraphy and 

geochemistry of the late Neogene ocean. Earth Planet. Sci. Lett. 92, 165–178. 

Hodell, D.A., Mueller, P.A., Garrido, J.R., 1991. Variations in the strontium isotopic 

composition of seawater during the Neogene. Geology 19, 24–27. 

Hodell, D.A., Benson, R.H., Kent, D.V., Boersma, A., Bied, K.R.-E., 1994. Magnetostratigraphic, 

biostratigraphic, and stable isotope stratigraphy of an Upper Miocene drill 

core from the Salé Briqueterie (northwest Morocco): a high-resolution chronology 

for the Messinian stage. Paleoceanography 9, 835–855. 

Howarth, R., McArthur, J.M., 1997. Statistics for Strontium Isotope Stratigraphy: a 

robust LOWESS fit to the marine Sr-isotope curve for 0 to 206 Ma, with look-up 

table for derivation of numeric age. J. Geol. 105, 441–456. 

Hsü, K.J., Giovanoli, F., 1979. Messinian event in the Black Sea. Palaeogeogr. 

Palaeoclimatol. Palaeoecol. 29, 75–93. 

Hsü, K.J., Ryan, W.B.F., Cita, M.B., 1973. Late Miocene desiccation of the Mediterranean. 

Nature 242, 240–244. 

Ivanov, D.A., Ashraf, A.R., Mosbrugger, V., 2007. Late Oligocene and Miocene climate and 

vegetation in the Eastern Paratethys area (northeast Bulgaria), based on pollen 

data. Palaeogeogr. Palaeoclimatol. Palaeoecol. 255, 342–360. 

Keogh, S.M., Butler, R.W.H., 1999. The Mediterranean water body in the late Messinian: 

interpreting the record from the marginal basins of Sicily. J. Geol. Soc. Lond. 156, 

837–846. 

Krijgsman, W., Meijer, P.T., 2008. Depositional environments of the Mediterranean 

“Lower Evaporites” of the Messinian salinity crisis: constraints from quantitative 

analyses. Mar. Geol. 253, 73–81. 

Krijgsman, W., Stoica, M., Vasiliev, I., Popov, V.V., 2010. Rise and fall of the Paratethys 

Sea during the Messinian Salinity Crisis. Earth Planet. Sci. Lett. 290, 183–191. 

doi:10.1016/j.epsl.2009.12.020. 

Lea, D.W., Boyle, E.A., 1993. Determination of carbonate-bound barium in foraminifera 

and corals by isotope dilution plasma-mass spectrometry. Chem. Geol. 103, 73–84. 

Leever, K.A., Matenco, L., Rabagia, T., Cloetingh, S., Krijgsman, W., Stoica, M., 2010. 

Messinian sea level fall in the Dacic Basin (Eastern Paratethys): palaeogeographical 

implications from seismic sequence stratigraphy. Terra Nova 22, 12–17. 

Magyar, I., Geary, D.H., Muller, P., 1999. Paleogeographic evolution of the Late Miocene 

Lake Pannon in Central Europe. Palaeogeogr. Palaeoclimatol. Palaeoecol. 147, 

151–167. 

Major, C.O., Goldstein, S.L., Ryan, W.B.F., Lericolais, G., Piotrowski, A.M., Hajdas, I., 2006. 

The co-evolution of Black Sea level and composition through the last deglaciation 

and its paleoclimatic significance. Quat. Sci. Rev. 25, 2031–2047. 

Mason, P.R.D., Kraan, W.J., 2002. Attenuation of spectral interference during laser 

ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) using a rf 

only collision and reaction cell. J. Anal. At. Spectro. 17, 858–867. 

McArthur, J.M., Howarth, R.J., Baieley, T.R., 2001. Strontium isotope stratigraphy: 

LOWESS version 3: best fit to the marine Sr-isotope curve for 0–509 Ma and 

accompanying look-up table for deriving numerical age. J. Geol. 109, 155–170. 

McKenzie, J.A., Hodell, D.A., Mueller, P.A., Muller, D.W., 1988. Application of strontium 

isotopes to late Miocene–early Pliocene stratigraphy. Geology 16, 1022–1025. 

Miller, K.G., Feigenson, M.D., Wright, J.D., Clement, B.M., 1991a. Miocene isotope 

reference section, Deep Sea Drilling Project Site 608: an evaluation of isotope and 

biostratigraphic resolution. Paleoceanography 6, 33–52. 

Miller, K.G., Wright, J.D., Fairbanks, R.G., 1991b. Unlocking the Ice House: Oligocene– 

Miocene isotopes, eustacy and margin erosion. J. Geoph. Res. 96, 6829–6848. 

Montanari, A., Beaudoin, B., Chan, L.S., Coccioni, R., Deino, A., De Paolo, D.J., Emmanuel, 

L., Fornaciari, E., Kruge, M., Lundblad, S., Mozzato, C., Portier, E., Renard, M., Rio, D., 

Sandroni, P., Stankiewicz, A., 1997. Integrated stratigraphy of the Middle and Upper 

Miocene pelagic sequence of the Conero Riviera (Marche region, Italy). In: 

Montanari, A., Odin, G.S., Coccioni, R. (Eds.), Miocene Stratigraphy: An Integrated 

Approach. : Dev. Palaeontol. Stratigr., vol. 15. Elsevier, pp. 409–450. 

Muller, D.W., Mueller, P.A., 1991. Origin and age of the Mediterranean Messinian 

evaporites: implications from Sr isotopes. Earth Planet. Sci. Lett. 107, 1–12. 

Muller, D.W., Mueller, P.A., McKenzie, J.A., 1990. Strontium isotopic ratios as fluid 

tracers in Messinian evaporites of the Tyrrhenian sea (western Mediterranean sea). 

Proc. ODP Sci. Res. 107, 603–614. 

Orszag-Sperber, F., 2006. Changing perspectives in the concept of “Lago-Mare” in 

Mediterranean Late Miocene evolution. Sediment. Geol. 188–189, 259–277. 

Page, A., Vance, D., Fowler, M., Nisbet, E., 2003. Modern Sr isotopic mass balance and 

Quaternary variation in the Caspian Sea. In: EUG Joint Assembly, E.G.S.–.A.G.U.- (Ed.), 

Nice, France. 

Palmer, M.R., Edmond, J.M., 1989. The strontium isotope budget of the modern ocean. 

Earth Planet. Sci. Lett. 92, 11–26. 

Panaiotu, C.E., Vasiliev, I., Panaiotu, C.G., Krijgsman, W., Langereis, C.G., 2007. 

Provenance analysis as a key to orogenic exhumation: a case study from the East 

Carpathians (Romania). Terra Nova 19, 120–126. 

Pearce, N.J.G., Perkins, W.T., Westgate, J.A., Gorton, M.P., Jackson, S.E., Neal, C.R., 

Chenery, S.P., 1997. A compilation of new and published major and trace element 

data for NIST SRM 610 and NIST SRM 612 glass reference materials. Geostand. 

Newslett. 21, 115–144. 

Pipik, R., Minati, K., Buttinger, R., Gross, M., Knoblechner, J., 2007. Ecological radiation of 

Cyprideis in the Late Miocene Lake Pannon. In: Lord, A., Franz, C. (Eds.), European 

Ostracodologists' Meeting 6 (EOM VI): 19th International Senckenberg Conference. 

Popescu, S.M., 2001. Repetitive changes in Early Pliocene vegetation revealed by highresolution 

pollen analysis: revised cyclostratigraphy of southwestern Romania. 

Rev. Palaeobo. Palynol. 120, 181–202. 

Popov, S.V., Shcherba, I.G., Ilyina, L.B., Nevesskaya, L.A., Paramonova, N.P., Khondkarian, 

S.O., Magyar, I., 2006. Late Miocene to Pliocene palaeogeography of the Paratethys 

and its relation to the Mediterranean. Palaeogeogr. Palaeoclimatol. Palaeoecol. 238, 

91–106. 

Ramstein, G., Fluteau, F., Besse, J., Joussaume, S., 1997. Effect of orogeny, plate motion 

and land–sea distribution on Eurasian climate change over the past 30 million 

years. Nature 386, 788–795. 

Reichart, G.J., Jorissen, F., Anschutz, P., Mason, P.R.D., 2003. Single foraminiferal test 

chemistry records the marine environment. Geology 31, 355–358. 

Richter, F.M., DePaolo, D.J., 1988. Diagenesis and Sr isotopic evolution of seawater using 

data from DSDP 590B and 575. Earth Planet. Sci. Lett. 90, 382–394. 

Rögl, F., 1996. Stratigraphic correlation of the Paratethys Oligocene and Miocene. Mitt. 

Ges. Geol. Bergbaustud 41, 65–73. 

Rögl, F., 1998. Paleogeographic consideration for the Mediterranean and Paratethys 

seaways (Oligocene to Miocene). Ann. Naturhist. Mus. Wien 99A, 279–310. 

Rögl, F., Daxner-Hock, G., 1996. Late Miocene Paratethys correlation. The Evolution of 

the Western Eurasian Neogene Mammal Faunas, p. 487. 

Roveri, M., Lugli, S., Manzi, V., Schreiber, B.C., 2008. The Messinian Sicilian stratigraphy 

revisited: new insights for the Messinian salinity crisis. Terra Nova 20, 483–488. 

Shimkus, K.M., Trimonis, E.S., Degens, E.T., Ross, D.A., 1974. Modern sedimentation in 

Black Sea. The Black Sea—Geology, Chemistry and Biology: American Association of 

Petroleum Geologists, pp. 249–278. 

Snel, E., Marunteanu, M., Macalet, R., Meulenkamp, J.E., van Vugt, N., 2006. Late Miocene 

to Early Pliocene chronostratigraphic framework for the Dacic Basin, Romania. 

Palaeogeogr. Palaeoclimatol. Palaeoecol. 238, 107–124. 

Stoica, M., Lazar, I., Vasiliev, I., Krijgsman, W., 2007. Mollusc assemblages of the Pontian 

and Dacian deposits in the Topolog–Arges area (southern Carpathian foredeep — 

Romania). Geobios 40, 391–405. 

Utescher, T., Ivanov, D., Harzhauser, M., Bozukov, V., Ashraf, A.R., Rolf, C., Urbat, M., 

Mosbrugger, V., 2009. Cyclic climate and vegetation change in the late Miocene of 

western Bulgaria. Palaeogeogr. Palaeoclimatol. Palaeoecol. 272, 99–114. 

Van Harten, D., 1990. The Neogene evolutionary radiation in Cyprideis Jones (ostracoda: 

Cytheracea) in the Mediterranean area and the Paratethys. Cour. Forschungsinst. 

Senckenb. 123, 191–198. 

Vasiliev, I., Krijgsman, W., Langereis, C.G., Panaiotu, C.E., Matenco, L., Bertotti, G., 2004. 

Towards an astrochronological framework for the eastern Paratethys Mio-Pliocene 

sedimentary sequences of the Focsani basin (Romania). Earth Planet. Sci. Lett. 227, 

231–247. 

Vasiliev, I., Dekkers, M.J., Krijgsman, W., Franke, C., Langereis, C.G., Mullender, T., 2007. 

Early diagenetic greigite as a recorder of the palaeomagnetic signal in Miocene– 

Pliocene sedimentary rocks of the Carpathian foredeep (Romania). Geophys. J. Int. 

171, 613–629. 

Vonhof, H.B., Wesselingh, F.P., Kaandorp, R.J.G., Davies, G.R., van Hinte, J.E., Guererro, 

Rasanen, M., Romero-Pittman, L., Ranzi, A., 2003. Paleogeography of Miocene 

Western Amazonia: Isotopic composition of molluscan shells constrains the 

influence of marine incursions. GSA Bull. 115, 983–993. 

Yassini, I., Ghahermann, A., 1979. Recapitulation de la distribution des Ostracodes et des 

Foraminiferes du Lagon de Pahlavi, Province de Gilan, Iran du Nord. Rev. 

Micropaleontol. 19, 172–190.

Strontium isotope ratios of the Eastern Paratethys during the Mio ...

Create successful ePaper yourself

Delete template?

Save as template?