R. Utrilla - Academia.edu (original) (raw)

Papers by R. Utrilla

Research paper thumbnail of Formaciones salinas de las cuencas triásicas en la Península Ibérica: caracterización petrológica y geoquímica

Research paper thumbnail of Evolución tectonosedimentaria de la cuenca miocena de Bicorp (Macizo de Carroig, Valencia)

Research paper thumbnail of Paleohydrology of the Upper Miocene Bicorb Lake (eastern Spain) as inferred from stable isotopic data from inorganic carbonates

The hydrological evolution of the Upper Miocene Bicorb lake (eastern Spain) has been established ... more The hydrological evolution of the Upper Miocene Bicorb lake (eastern Spain) has been established based on sedimentology, carbonate mineralogy and stable isotopic data from inorganic carbonates from the upper lacustrine unit. Three main subunits have been recognized. In subunit A, the sedimentological features suggest a hydrologically closed lake although the isotopic data are not conclusive. The isotopic compositions of primary carbonates from subunit B display a distribution typical for a hydrologically closed lake, and allow the differentiation of four developmental stages. The first stage was defined by the deposition of gypsum, LMC, dolomite and aragonite, indicating large variations in the water Mg=Ca ratio. During the second and third stages only LMC was deposited suggesting only minor Mg=Ca fluctuations. The δ 13 C and δ 18 O pattern of the second stage shows a well-defined covariance .r D 0:8/, while in the third stage the isotopic data display a negative covariant relationship .r D 0:8/. Changes in dissolved inorganic carbon composition are considered the main factor to explain the variations from positive to negative covariance. In the fourth stage the lake waters underwent large Mg=Ca fluctuations, as indicated by the deposition of LMC, HMC and aragonite. The isotopic trend is also covariant. Finally, subunit C is characterized by LMC and minor amounts of HMC, suggesting minor changes in Mg=Ca ratio. The isotopic features of this subunit are more congruent with a hydrologically open lake. The lowest δ 13 C and δ 18 O values are very similar in the three subunits, reflecting the most dilute conditions of the lake water, and a uniform isotopic composition of the local meteoric water during these periods. The changes in water balance and solute inputs recorded in the mineralogy and isotopic signatures of carbonates were controlled by the diapiric evolution and changes in the E=P balance.

Research paper thumbnail of Sedimentology and isotopic composition of Upper Palaeocene to Eocene non-marine stromatolites, eastern Ebro Basin, NE Spain

Sedimentology, 1997

... include examples from France (Bertrand-Sarfati et al., 1966; Casanova & Nury, 1989; Durin... more ... include examples from France (Bertrand-Sarfati et al., 1966; Casanova & Nury, 1989; Duringer & Gall, 1994; Donsimoni & Giot, 1977; Freytet & Plaziat, 1965, 1972, 1982; Mouline, 1966; Plaziat, 1966), Germany (Leinfelder & Hartkopf-Froder, 1990; Reis, 1923; Rutte, 1954a,b ...

Research paper thumbnail of Sedimentology and isotope geochemistry of lacustrine carbonates of the Oligocene Campins Basin, north-east Spain

Sedimentology, 1993

The non-marine Campins Basin developed in the Oligocene, during a period of early rifting of the ... more The non-marine Campins Basin developed in the Oligocene, during a period of early rifting of the Catalan Coastal Ranges. Lacustrine deposits, interbedded between two alluvial units, comprise shallow and deep lacustrine facies. The lower, shallow lacustrine facies are made up of microbialite buildups and thin limestone beds. In the studied area, these facies are overlain by deep lacustrine facies which consist of alternations of several, metre-thick carbonate-and mudstone-dominated intervals. In addition to calcite, which is characteristic of the shallow lacustrine facies, aragonite and abundant dolomite are present in the deep lacustrine facies. This mineralogical change in the sequence reflects an overall increase in the Mg/Ca ratio of the lake waters. The deep lacustrine sequences are interpreted as having formed in a hydrologically closed basin that was subject to changes in the Mg/Ca ratio of the water, probably related to variations in the evaporation/precipitation rate.

Research paper thumbnail of Paleoenvironmental evolution of the Pliocene Villarroya Lake, northern Spain. A multidisciplinary approach

Sedimentary Geology, 2002

Research paper thumbnail of Use of charophyte carbonates as proxy indicators of subtle hydrological and chemical changes in marl lakes: example from the Miocene Bicorb Basin, eastern Spain

Sedimentary Geology, 2000

The lower, alluvial unit in the Miocene Bicorb Basin contains several metric-scale limestone inte... more The lower, alluvial unit in the Miocene Bicorb Basin contains several metric-scale limestone intervals which record episodic shallow lacustrine environments in an alluvial setting developed during the early stage of the basin's evolution. Five main carbonate facies have been differentiated in the lacustrine limestones, although calcite charophyte incrustations predominate and constitute the most striking features of these deposits. The thinnest limestone intervals correspond to deposits from charophyte meadows in ponded shallow depressions in floodplains. The thickest limestone intervals are mainly formed by banded limestones and usually correspond to diverse types of regressive sequences that have been interpreted as resulting from the infill of shallow lakes. The sedimentological features and sequences show noticeable differences in the gradient of the littoral zones and the amount of palustrine deposits with models proposed for marl lakes. Charophytic carbonates from the bestpreserved facies show similar microtextures to those from recent charophyte incrustations. The variations in stable isotopes (d 13 C, d 18 O) for these primary carbonates occur in parallel with luminescence variations and correspond to hydrological changes and variations in solute composition and Eh-pH status in the lake waters. The carbonates that display moderate to strong diagenetic modifications show a diverse degree of compaction, aggrading neomorphism, strong cementation and nodulization. The isotopic values for these are arranged in diverse clusters. There is a correlation between the degree of luminescence and the d 13 C. This suggests that hydrological and hydrochemical variations both in the lacustrine and diagenetic environments are being recorded in parallel. We emphasize the need for further comparative studies between recent and ancient charophytic carbonates. As these carbonates have been used in palaeoenvironmental reconstructions, special attention must be paid to the diagenetic changes in ancient charophytic marls. ᭧

Research paper thumbnail of Lacustrine sedimentation in the diapir-controlled Miocene Bicorb Basin, eastern Spain

Palaeogeography, Palaeoclimatology, Palaeoecology, 1998

The Miocene Bicorb Basin is a small elongated basin developed by normal faulting of a thick Juras... more The Miocene Bicorb Basin is a small elongated basin developed by normal faulting of a thick Jurassic-Cretaceous carbonate succession and subsequent diapirism of Upper Triassic mudstones and evaporites. The basin fill comprises a sequence over 650 m thick formed by two units. The lower, alluvial unit consists of a complex alternation of conglomerates, sandstones, mudstones, and minor lacustrine limestones. The upper unit comprises marginal alluvial and lacustrine deposits in which seven lacustrine facies associations have been distinguished. The inner lacustrine deposits comprise mudstones and carbonates with minor evaporitic deposits. At the northeast and southwest basin edges, alluvial inputs led to the development of delta and fan-delta environments where sandstone and conglomerate deposits dominate. The latter stages of the lake evolution are represented by an expansive thick limestone sequence which close to the NW fault-bounded margin pass laterally to breccias. The hierarchical arrangement of the upper unit shows five different orders of sequences. The first-order sequence defines a major vertical trend of lake expansion whereas three second-order sequences are linked to major flooding-expansion episodes. All these sequences are related to the tectonic evolution of the diapir. Metre-scale, third-and fourth-order sequences and fifth-order sequences, which consist of finely laminated rhythmite deposits probably record climatically forced processes. The diapir-graben system evolution and the climatic variations have exerted major controls on the sequential arrangement and evolution of the lacustrine system. Both factors have also strongly influenced the changes in the gastropod assemblages.

Research paper thumbnail of Precession-related sapropelites of the Messinian Sorbas Basin (South Spain): paleoenvironmental significance

Palaeogeography, Palaeoclimatology, Palaeoecology, 2000

Research paper thumbnail of Orbitally-controlled oscillations in planktic communities and cyclic changes in western Mediterranean hydrography during the Messinian

Palaeogeography, Palaeoclimatology, Palaeoecology, 2003

We use quantitative analyses of the planktic foraminiferal assemblages and stable isotope analyse... more We use quantitative analyses of the planktic foraminiferal assemblages and stable isotope analyses of the Sorbas section in the western Mediterranean to reconstruct the cyclical changes in surface and deep water hydrographic conditions during the Late Miocene prior to the Messinian salinity crisis. Oscillations in winter and summer temperatures linked to cyclical fluctuations in the hydrographic conditions and nutrient availability

Research paper thumbnail of A sediment–nutrient–oxygen feedback responsible for productivity variations in Late Miocene sapropel sequences of the western Mediterranean

Palaeogeography, Palaeoclimatology, Palaeoecology, 2003

Research paper thumbnail of Western versus eastern Mediterranean paleoceanographic response to astronomical forcing: a high-resolution microplankton study of precession-controlled sedimentary cycles during the Messinian

Palaeogeography, Palaeoclimatology, Palaeoecology, 2003

Planktic foraminifera and stable isotopes were analyzed in samples from four precession-controlle... more Planktic foraminifera and stable isotopes were analyzed in samples from four precession-controlled sedimentary cycles from southeastern Spain and the island of Gavdos (Greece) to reconstruct the paleobiologic and paleoceanographic response of the western and eastern Mediterranean to astronomically driven climate variability during the Messinian. Although the lithological succession in the western Mediterranean cycles (sapropelĥ omogeneous marl^diatomite^homogeneous marl) is different from that in the eastern Mediterranean (sapropeld iatomite^homogeneous marl), the pelagic biological succession is similar. Four stages were recognized in both environments, characterized by the dominance of warm-oligotrophic foraminifera (stage 1), Neogloboquadrinids and Globorotaliids (stage 2), Globigerina bulloides (stage 3) and Globigerinita glutinata (stage 4). The first stage occurs during deposition of the upper part of the sapropels in Spain, and the sapropels and part of the diatomites on Gavdos. This stage is inferred to relate to high summer insolation and strong surface water stratification with winter temperatures not high enough to allow eutrophic foraminifera growth. Stage 2 occurs during the deposition of the lower homogeneous marls in Spain and the middle^upper part of the diatomites in Greece, most likely indicating stratification, with colder winter temperatures and a nutricline above the euphotic layer. The end of surface water stratification is indicated during stage 3 by the replacement of the Neogloboquadrinids by G. bulloides, which occurs at the base of the diatomites in Spain and near the top of the diatomites in Greece. We link this event to the appearance of dryer climates in the Mediterranean at times of relatively low summer insolation in the Northern Hemisphere which would result in higher surface salinities, deep water convection, and deep water ventilation. Stage 4, defined by the dominance of G. glutinata and low concentrations of planktic foraminifera, appears linked to the base of the sapropels both in the western and eastern Mediterranean. The onset of sapropel deposition occurred at a time of relatively high surface water salinities, as suggested by the heavy N 18 O in Orbulina universa, and prior to the 0031-0182 / 02 / $^see front matter ß 2002 Elsevier Science B.V. All rights reserved. PII: S 0 0 3 1 -0 1 8 2 ( 0 2 ) 0 0 6 1 2 -0 (M. Pe ¤rez-Folgado).

Research paper thumbnail of Palaeoenvironmental reconstruction of a Pleistocene lacustrine sequence from faunal assemblages and ostracode shell geochemistry, Baza Basin, SE Spain

Palaeogeography, Palaeoclimatology, Palaeoecology, 1994

We have reconstructed the Early Pleistocene palaeoenvironmental record for a shallow lacustrine s... more We have reconstructed the Early Pleistocene palaeoenvironmental record for a shallow lacustrine sequence from the Baza Basin (Southern Spain), using faunal assemblages and the shell chemistry of two ostracode species (Candona sp. and Cyprideis torosa). In the NE basin sector (Orce area), a Lower Pleistocene lacustrine sequence, up to 10 m thick, contains alternating phases of two fossil assemblages which differ in their salinity requirements. The faunal assemblages record phases of (1) slightly saline, Ca + bicarbonate-rich water, when freshwater organisms predominated, and (2) saline, NaCl-dominant water in which marine-like organisms lived. The ostracode shells from intervals with a saline fauna have higher 6180 values than those from intervals with a freshwater fauna. This feature corresponds to a parallel alternation of positive and negative hydrologic balances. 6180 and 613C values from ostracode calcite display a covariant trend which indicates that the ostracodes lived in a closed lacustrine system. The isotopic data show a better agreement with the inferences from faunal assemblages than with trace element trends. The trace element data, although locally fitting well with the isotope and faunal interpretations, suggest overall that trace element contents in ostracodes are not consistent indicators of salinity and/or temperature variations, but depend on a set of complex factors, which may not be easily deciphered. The alternation of concentration/dilution phases recorded in the studied section can be correlated with climatic cycles described from synchronous ocean basin records from the Late Matuyama chron.

Research paper thumbnail of Factors affecting the distribution of recent lacustrine ostracoda from the Caicedo de Yuso-Arreo Lake (Western Ebro Basin, Spain)

Palaeogeography, Palaeoclimatology, Palaeoecology, 2005

Recent Ostracoda assemblages of the Caicedo de Yuso Lake have been described as representative of... more Recent Ostracoda assemblages of the Caicedo de Yuso Lake have been described as representative of palustrine/ lacustrine environments in Iberian temperate lakes. This study considers the changes in assemblages at a fixed station during two consecutive annual cycles, as well as their distribution in summer and winter profiles of the lake. Total sampleassemblages have been quantified as species diversities, measured by the Shannon-Wiener index H (S). The trends of this index are compared to physical parameters (temperature, conductivity, dissolved oxygen, CO 2 ) of the bottom waters of this lake. The Ostracoda assemblages (8100 adults and juvenile living specimens, belonging to 20 species) are dominated by Cypria ophtalmica, Cypridopsis vidua and Pseudocandona marchica. Biocenotic assemblages are well developed in the western, flat shelf area of the lake (0 to 9 m in depth), where a major substrate of charophytes permits assemblages with moderate diversity levels to be maintained. Waters below 10 m are practically barren of living individuals, and only few specimens of the generalist species Cypria ophtalmica have been found alive at that depth. Differential responses of most abundant species to changes in the environmental parameters of the bottom of the lake have been interpreted in terms of the ecological requirements of those species. Most of these responses are clearly influenced by shifts in the parameters mentioned, and decreases in oxygen and increases in CO 2 produce particularly marked falls in assemblage diversity levels. Conversely, when the oxygen increases and the CO 2 falls, the diversity levels increase. The time delay in responding to these changes is estimated at less than one month. This general behaviour of the ostracod assemblages of Caicedo Lake is not followed by C. ophtalmica, which is considered a particular species that can stand hypoxic waters, with relatively high CO 2 concentrations. This ability of C. ophtalmica allows specimens of this species to occupy deep and environmentally unfavourable niches in the lake, that no other ostracod species of Caicedo Lake does. The knowledge of areal and temporal distribution of Ostracoda species in a temperate lake, such as Caicedo de Yuso, exhibits a good potential for 0031-0182/$ -see front matter D (J. Rodriguez-Lazaro).

Research paper thumbnail of Variation in Sr uptake in the shell of the freshwater gastropod Bithynia tentaculata from Lake Arreo (northern Spain) and culture experiments

Palaeogeography, Palaeoclimatology, Palaeoecology, 2010

The user has requested enhancement of the downloaded file. All in-text references underlined in b... more The user has requested enhancement of the downloaded file. All in-text references underlined in blue are added to the original document and are linked to publications on ResearchGate, letting you access and read them immediately. This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.

Research paper thumbnail of Uptake of Mg, Sr and Na in valves of the ostracod

Experiments with the ostracod "Heterocypris salina" controlled-cultures were carried ou... more Experiments with the ostracod "Heterocypris salina" controlled-cultures were carried out in five kinds of water with conductivities from 1 to 17 mS/cm and different hydrochemistries. The ranges of molar ratios of the waters are Mg/Ca: 0.6 to 13, Sr/Ca: 0.004 to 0.023, and Na/Ca: 0.9 to 130. Individual A-1 moult stage ostracods were introduced and weekly monitored in individual microaquaria within those waters under different constant temperature regimes of 18º, 20º, 25 º and 28°C. The juvenile individuals were grown in these cultures to obtain adults moulted in controlled water and temperature conditions. Well-calcified adult valves grown in the controlled conditions were analysed for Ca, Mg, Na and Sr contents. For the studied waters, in the temperature range of the experiments, the valve Sr/Ca and Na/Ca molar ratios are proportional to the Sr/Ca and Na/Ca molar ratios of the waters where the ostracods moulted. The Mg/Ca of the valves seems to be proportional to the [Mg],...

Research paper thumbnail of Surface water dynamics and phytoplankton communities during deposition of cyclic late Messinian sapropel sequences in the western Mediterranean

Marine Micropaleontology, 2005

Distinctive precession-scale sapropel/marl sequences of late Messinian age are found in several o... more Distinctive precession-scale sapropel/marl sequences of late Messinian age are found in several outcrops bordering the western Mediterranean. To examine the roles of stratification and productivity in driving this cyclic sedimentation, we performed a high resolution analysis of calcareous nannofossil assemblages through four orbital sequences (composed of sapropel/marl/diatomite/marl) from the Sorbas basin in southern Spain. This effort also involved a detailed comparison between calcareous nannofossil abundances and other micropaleontological, sedimentological and geochemical proxies to further understand the behaviour of some taxa. For this period, fluctuations in the depth and gradient of the pycnocline, and the distribution and remobilization of nutrients seem to be the main factors controlling the calcareous nannoplankton assemblages, with temperature of secondary importance.

Research paper thumbnail of Messinian pre-evaporite sapropels and precession-induced oscillations in western Mediterranean climate

Research paper thumbnail of Rise, closure and reactivation of the Bicorb-Quesa evaporite diapir, eastern Prebetics, Spain

Journal of the Geological Society, 1996

ABSTRACT

Research paper thumbnail of Paleoenvironmental evolution of the Pliocene Villarroya Lake, northern Spain, from stable isotopes and trace-element geochemistry of ostracods and molluscs

Journal of Paleolimnology, 2008

Stable isotopes and trace-element content of calcite ostracod valves and aragonite mollusc shells... more Stable isotopes and trace-element content of calcite ostracod valves and aragonite mollusc shells from the Pliocene lacustrine succession of Villarroya allow depicting the geochemical record of environmental changes and to compare our data to the paleoenvironmental reconstruction obtained from other proxies. The lower sequences (A and B) are Electronic supplementary material The online version of this article (

Research paper thumbnail of Formaciones salinas de las cuencas triásicas en la Península Ibérica: caracterización petrológica y geoquímica

Research paper thumbnail of Evolución tectonosedimentaria de la cuenca miocena de Bicorp (Macizo de Carroig, Valencia)

Research paper thumbnail of Paleohydrology of the Upper Miocene Bicorb Lake (eastern Spain) as inferred from stable isotopic data from inorganic carbonates

The hydrological evolution of the Upper Miocene Bicorb lake (eastern Spain) has been established ... more The hydrological evolution of the Upper Miocene Bicorb lake (eastern Spain) has been established based on sedimentology, carbonate mineralogy and stable isotopic data from inorganic carbonates from the upper lacustrine unit. Three main subunits have been recognized. In subunit A, the sedimentological features suggest a hydrologically closed lake although the isotopic data are not conclusive. The isotopic compositions of primary carbonates from subunit B display a distribution typical for a hydrologically closed lake, and allow the differentiation of four developmental stages. The first stage was defined by the deposition of gypsum, LMC, dolomite and aragonite, indicating large variations in the water Mg=Ca ratio. During the second and third stages only LMC was deposited suggesting only minor Mg=Ca fluctuations. The δ 13 C and δ 18 O pattern of the second stage shows a well-defined covariance .r D 0:8/, while in the third stage the isotopic data display a negative covariant relationship .r D 0:8/. Changes in dissolved inorganic carbon composition are considered the main factor to explain the variations from positive to negative covariance. In the fourth stage the lake waters underwent large Mg=Ca fluctuations, as indicated by the deposition of LMC, HMC and aragonite. The isotopic trend is also covariant. Finally, subunit C is characterized by LMC and minor amounts of HMC, suggesting minor changes in Mg=Ca ratio. The isotopic features of this subunit are more congruent with a hydrologically open lake. The lowest δ 13 C and δ 18 O values are very similar in the three subunits, reflecting the most dilute conditions of the lake water, and a uniform isotopic composition of the local meteoric water during these periods. The changes in water balance and solute inputs recorded in the mineralogy and isotopic signatures of carbonates were controlled by the diapiric evolution and changes in the E=P balance.

Research paper thumbnail of Sedimentology and isotopic composition of Upper Palaeocene to Eocene non-marine stromatolites, eastern Ebro Basin, NE Spain

Sedimentology, 1997

... include examples from France (Bertrand-Sarfati et al., 1966; Casanova & Nury, 1989; Durin... more ... include examples from France (Bertrand-Sarfati et al., 1966; Casanova & Nury, 1989; Duringer & Gall, 1994; Donsimoni & Giot, 1977; Freytet & Plaziat, 1965, 1972, 1982; Mouline, 1966; Plaziat, 1966), Germany (Leinfelder & Hartkopf-Froder, 1990; Reis, 1923; Rutte, 1954a,b ...

Research paper thumbnail of Sedimentology and isotope geochemistry of lacustrine carbonates of the Oligocene Campins Basin, north-east Spain

Sedimentology, 1993

The non-marine Campins Basin developed in the Oligocene, during a period of early rifting of the ... more The non-marine Campins Basin developed in the Oligocene, during a period of early rifting of the Catalan Coastal Ranges. Lacustrine deposits, interbedded between two alluvial units, comprise shallow and deep lacustrine facies. The lower, shallow lacustrine facies are made up of microbialite buildups and thin limestone beds. In the studied area, these facies are overlain by deep lacustrine facies which consist of alternations of several, metre-thick carbonate-and mudstone-dominated intervals. In addition to calcite, which is characteristic of the shallow lacustrine facies, aragonite and abundant dolomite are present in the deep lacustrine facies. This mineralogical change in the sequence reflects an overall increase in the Mg/Ca ratio of the lake waters. The deep lacustrine sequences are interpreted as having formed in a hydrologically closed basin that was subject to changes in the Mg/Ca ratio of the water, probably related to variations in the evaporation/precipitation rate.

Research paper thumbnail of Paleoenvironmental evolution of the Pliocene Villarroya Lake, northern Spain. A multidisciplinary approach

Sedimentary Geology, 2002

Research paper thumbnail of Use of charophyte carbonates as proxy indicators of subtle hydrological and chemical changes in marl lakes: example from the Miocene Bicorb Basin, eastern Spain

Sedimentary Geology, 2000

The lower, alluvial unit in the Miocene Bicorb Basin contains several metric-scale limestone inte... more The lower, alluvial unit in the Miocene Bicorb Basin contains several metric-scale limestone intervals which record episodic shallow lacustrine environments in an alluvial setting developed during the early stage of the basin's evolution. Five main carbonate facies have been differentiated in the lacustrine limestones, although calcite charophyte incrustations predominate and constitute the most striking features of these deposits. The thinnest limestone intervals correspond to deposits from charophyte meadows in ponded shallow depressions in floodplains. The thickest limestone intervals are mainly formed by banded limestones and usually correspond to diverse types of regressive sequences that have been interpreted as resulting from the infill of shallow lakes. The sedimentological features and sequences show noticeable differences in the gradient of the littoral zones and the amount of palustrine deposits with models proposed for marl lakes. Charophytic carbonates from the bestpreserved facies show similar microtextures to those from recent charophyte incrustations. The variations in stable isotopes (d 13 C, d 18 O) for these primary carbonates occur in parallel with luminescence variations and correspond to hydrological changes and variations in solute composition and Eh-pH status in the lake waters. The carbonates that display moderate to strong diagenetic modifications show a diverse degree of compaction, aggrading neomorphism, strong cementation and nodulization. The isotopic values for these are arranged in diverse clusters. There is a correlation between the degree of luminescence and the d 13 C. This suggests that hydrological and hydrochemical variations both in the lacustrine and diagenetic environments are being recorded in parallel. We emphasize the need for further comparative studies between recent and ancient charophytic carbonates. As these carbonates have been used in palaeoenvironmental reconstructions, special attention must be paid to the diagenetic changes in ancient charophytic marls. ᭧

Research paper thumbnail of Lacustrine sedimentation in the diapir-controlled Miocene Bicorb Basin, eastern Spain

Palaeogeography, Palaeoclimatology, Palaeoecology, 1998

The Miocene Bicorb Basin is a small elongated basin developed by normal faulting of a thick Juras... more The Miocene Bicorb Basin is a small elongated basin developed by normal faulting of a thick Jurassic-Cretaceous carbonate succession and subsequent diapirism of Upper Triassic mudstones and evaporites. The basin fill comprises a sequence over 650 m thick formed by two units. The lower, alluvial unit consists of a complex alternation of conglomerates, sandstones, mudstones, and minor lacustrine limestones. The upper unit comprises marginal alluvial and lacustrine deposits in which seven lacustrine facies associations have been distinguished. The inner lacustrine deposits comprise mudstones and carbonates with minor evaporitic deposits. At the northeast and southwest basin edges, alluvial inputs led to the development of delta and fan-delta environments where sandstone and conglomerate deposits dominate. The latter stages of the lake evolution are represented by an expansive thick limestone sequence which close to the NW fault-bounded margin pass laterally to breccias. The hierarchical arrangement of the upper unit shows five different orders of sequences. The first-order sequence defines a major vertical trend of lake expansion whereas three second-order sequences are linked to major flooding-expansion episodes. All these sequences are related to the tectonic evolution of the diapir. Metre-scale, third-and fourth-order sequences and fifth-order sequences, which consist of finely laminated rhythmite deposits probably record climatically forced processes. The diapir-graben system evolution and the climatic variations have exerted major controls on the sequential arrangement and evolution of the lacustrine system. Both factors have also strongly influenced the changes in the gastropod assemblages.

Research paper thumbnail of Precession-related sapropelites of the Messinian Sorbas Basin (South Spain): paleoenvironmental significance

Palaeogeography, Palaeoclimatology, Palaeoecology, 2000

Research paper thumbnail of Orbitally-controlled oscillations in planktic communities and cyclic changes in western Mediterranean hydrography during the Messinian

Palaeogeography, Palaeoclimatology, Palaeoecology, 2003

We use quantitative analyses of the planktic foraminiferal assemblages and stable isotope analyse... more We use quantitative analyses of the planktic foraminiferal assemblages and stable isotope analyses of the Sorbas section in the western Mediterranean to reconstruct the cyclical changes in surface and deep water hydrographic conditions during the Late Miocene prior to the Messinian salinity crisis. Oscillations in winter and summer temperatures linked to cyclical fluctuations in the hydrographic conditions and nutrient availability

Research paper thumbnail of A sediment–nutrient–oxygen feedback responsible for productivity variations in Late Miocene sapropel sequences of the western Mediterranean

Palaeogeography, Palaeoclimatology, Palaeoecology, 2003

Research paper thumbnail of Western versus eastern Mediterranean paleoceanographic response to astronomical forcing: a high-resolution microplankton study of precession-controlled sedimentary cycles during the Messinian

Palaeogeography, Palaeoclimatology, Palaeoecology, 2003

Planktic foraminifera and stable isotopes were analyzed in samples from four precession-controlle... more Planktic foraminifera and stable isotopes were analyzed in samples from four precession-controlled sedimentary cycles from southeastern Spain and the island of Gavdos (Greece) to reconstruct the paleobiologic and paleoceanographic response of the western and eastern Mediterranean to astronomically driven climate variability during the Messinian. Although the lithological succession in the western Mediterranean cycles (sapropelĥ omogeneous marl^diatomite^homogeneous marl) is different from that in the eastern Mediterranean (sapropeld iatomite^homogeneous marl), the pelagic biological succession is similar. Four stages were recognized in both environments, characterized by the dominance of warm-oligotrophic foraminifera (stage 1), Neogloboquadrinids and Globorotaliids (stage 2), Globigerina bulloides (stage 3) and Globigerinita glutinata (stage 4). The first stage occurs during deposition of the upper part of the sapropels in Spain, and the sapropels and part of the diatomites on Gavdos. This stage is inferred to relate to high summer insolation and strong surface water stratification with winter temperatures not high enough to allow eutrophic foraminifera growth. Stage 2 occurs during the deposition of the lower homogeneous marls in Spain and the middle^upper part of the diatomites in Greece, most likely indicating stratification, with colder winter temperatures and a nutricline above the euphotic layer. The end of surface water stratification is indicated during stage 3 by the replacement of the Neogloboquadrinids by G. bulloides, which occurs at the base of the diatomites in Spain and near the top of the diatomites in Greece. We link this event to the appearance of dryer climates in the Mediterranean at times of relatively low summer insolation in the Northern Hemisphere which would result in higher surface salinities, deep water convection, and deep water ventilation. Stage 4, defined by the dominance of G. glutinata and low concentrations of planktic foraminifera, appears linked to the base of the sapropels both in the western and eastern Mediterranean. The onset of sapropel deposition occurred at a time of relatively high surface water salinities, as suggested by the heavy N 18 O in Orbulina universa, and prior to the 0031-0182 / 02 / $^see front matter ß 2002 Elsevier Science B.V. All rights reserved. PII: S 0 0 3 1 -0 1 8 2 ( 0 2 ) 0 0 6 1 2 -0 (M. Pe ¤rez-Folgado).

Research paper thumbnail of Palaeoenvironmental reconstruction of a Pleistocene lacustrine sequence from faunal assemblages and ostracode shell geochemistry, Baza Basin, SE Spain

Palaeogeography, Palaeoclimatology, Palaeoecology, 1994

We have reconstructed the Early Pleistocene palaeoenvironmental record for a shallow lacustrine s... more We have reconstructed the Early Pleistocene palaeoenvironmental record for a shallow lacustrine sequence from the Baza Basin (Southern Spain), using faunal assemblages and the shell chemistry of two ostracode species (Candona sp. and Cyprideis torosa). In the NE basin sector (Orce area), a Lower Pleistocene lacustrine sequence, up to 10 m thick, contains alternating phases of two fossil assemblages which differ in their salinity requirements. The faunal assemblages record phases of (1) slightly saline, Ca + bicarbonate-rich water, when freshwater organisms predominated, and (2) saline, NaCl-dominant water in which marine-like organisms lived. The ostracode shells from intervals with a saline fauna have higher 6180 values than those from intervals with a freshwater fauna. This feature corresponds to a parallel alternation of positive and negative hydrologic balances. 6180 and 613C values from ostracode calcite display a covariant trend which indicates that the ostracodes lived in a closed lacustrine system. The isotopic data show a better agreement with the inferences from faunal assemblages than with trace element trends. The trace element data, although locally fitting well with the isotope and faunal interpretations, suggest overall that trace element contents in ostracodes are not consistent indicators of salinity and/or temperature variations, but depend on a set of complex factors, which may not be easily deciphered. The alternation of concentration/dilution phases recorded in the studied section can be correlated with climatic cycles described from synchronous ocean basin records from the Late Matuyama chron.

Research paper thumbnail of Factors affecting the distribution of recent lacustrine ostracoda from the Caicedo de Yuso-Arreo Lake (Western Ebro Basin, Spain)

Palaeogeography, Palaeoclimatology, Palaeoecology, 2005

Recent Ostracoda assemblages of the Caicedo de Yuso Lake have been described as representative of... more Recent Ostracoda assemblages of the Caicedo de Yuso Lake have been described as representative of palustrine/ lacustrine environments in Iberian temperate lakes. This study considers the changes in assemblages at a fixed station during two consecutive annual cycles, as well as their distribution in summer and winter profiles of the lake. Total sampleassemblages have been quantified as species diversities, measured by the Shannon-Wiener index H (S). The trends of this index are compared to physical parameters (temperature, conductivity, dissolved oxygen, CO 2 ) of the bottom waters of this lake. The Ostracoda assemblages (8100 adults and juvenile living specimens, belonging to 20 species) are dominated by Cypria ophtalmica, Cypridopsis vidua and Pseudocandona marchica. Biocenotic assemblages are well developed in the western, flat shelf area of the lake (0 to 9 m in depth), where a major substrate of charophytes permits assemblages with moderate diversity levels to be maintained. Waters below 10 m are practically barren of living individuals, and only few specimens of the generalist species Cypria ophtalmica have been found alive at that depth. Differential responses of most abundant species to changes in the environmental parameters of the bottom of the lake have been interpreted in terms of the ecological requirements of those species. Most of these responses are clearly influenced by shifts in the parameters mentioned, and decreases in oxygen and increases in CO 2 produce particularly marked falls in assemblage diversity levels. Conversely, when the oxygen increases and the CO 2 falls, the diversity levels increase. The time delay in responding to these changes is estimated at less than one month. This general behaviour of the ostracod assemblages of Caicedo Lake is not followed by C. ophtalmica, which is considered a particular species that can stand hypoxic waters, with relatively high CO 2 concentrations. This ability of C. ophtalmica allows specimens of this species to occupy deep and environmentally unfavourable niches in the lake, that no other ostracod species of Caicedo Lake does. The knowledge of areal and temporal distribution of Ostracoda species in a temperate lake, such as Caicedo de Yuso, exhibits a good potential for 0031-0182/$ -see front matter D (J. Rodriguez-Lazaro).

Research paper thumbnail of Variation in Sr uptake in the shell of the freshwater gastropod Bithynia tentaculata from Lake Arreo (northern Spain) and culture experiments

Palaeogeography, Palaeoclimatology, Palaeoecology, 2010

The user has requested enhancement of the downloaded file. All in-text references underlined in b... more The user has requested enhancement of the downloaded file. All in-text references underlined in blue are added to the original document and are linked to publications on ResearchGate, letting you access and read them immediately. This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.

Research paper thumbnail of Uptake of Mg, Sr and Na in valves of the ostracod

Experiments with the ostracod "Heterocypris salina" controlled-cultures were carried ou... more Experiments with the ostracod "Heterocypris salina" controlled-cultures were carried out in five kinds of water with conductivities from 1 to 17 mS/cm and different hydrochemistries. The ranges of molar ratios of the waters are Mg/Ca: 0.6 to 13, Sr/Ca: 0.004 to 0.023, and Na/Ca: 0.9 to 130. Individual A-1 moult stage ostracods were introduced and weekly monitored in individual microaquaria within those waters under different constant temperature regimes of 18º, 20º, 25 º and 28°C. The juvenile individuals were grown in these cultures to obtain adults moulted in controlled water and temperature conditions. Well-calcified adult valves grown in the controlled conditions were analysed for Ca, Mg, Na and Sr contents. For the studied waters, in the temperature range of the experiments, the valve Sr/Ca and Na/Ca molar ratios are proportional to the Sr/Ca and Na/Ca molar ratios of the waters where the ostracods moulted. The Mg/Ca of the valves seems to be proportional to the [Mg],...

Research paper thumbnail of Surface water dynamics and phytoplankton communities during deposition of cyclic late Messinian sapropel sequences in the western Mediterranean

Marine Micropaleontology, 2005

Distinctive precession-scale sapropel/marl sequences of late Messinian age are found in several o... more Distinctive precession-scale sapropel/marl sequences of late Messinian age are found in several outcrops bordering the western Mediterranean. To examine the roles of stratification and productivity in driving this cyclic sedimentation, we performed a high resolution analysis of calcareous nannofossil assemblages through four orbital sequences (composed of sapropel/marl/diatomite/marl) from the Sorbas basin in southern Spain. This effort also involved a detailed comparison between calcareous nannofossil abundances and other micropaleontological, sedimentological and geochemical proxies to further understand the behaviour of some taxa. For this period, fluctuations in the depth and gradient of the pycnocline, and the distribution and remobilization of nutrients seem to be the main factors controlling the calcareous nannoplankton assemblages, with temperature of secondary importance.

Research paper thumbnail of Messinian pre-evaporite sapropels and precession-induced oscillations in western Mediterranean climate

Research paper thumbnail of Rise, closure and reactivation of the Bicorb-Quesa evaporite diapir, eastern Prebetics, Spain

Journal of the Geological Society, 1996

ABSTRACT

Research paper thumbnail of Paleoenvironmental evolution of the Pliocene Villarroya Lake, northern Spain, from stable isotopes and trace-element geochemistry of ostracods and molluscs

Journal of Paleolimnology, 2008

Stable isotopes and trace-element content of calcite ostracod valves and aragonite mollusc shells... more Stable isotopes and trace-element content of calcite ostracod valves and aragonite mollusc shells from the Pliocene lacustrine succession of Villarroya allow depicting the geochemical record of environmental changes and to compare our data to the paleoenvironmental reconstruction obtained from other proxies. The lower sequences (A and B) are Electronic supplementary material The online version of this article (