Ecological environment response of benthic foraminifera to heavy metals and human engineering: A case study from Jiaozhou Bay, China

The estuary and coastal zone are the key areas for socio-economic development,and they are also the important channels for pollutants transported to the sea.The construction of the Jiaozhou Bay Bridge changed the hydrodynamic condition of the bay,which made the self-purification capacity of the bay weakened and the pollution in the estuary and adjacent coastal zone become more serious.In this study,55 surface sediment samples were collected from the three seriously polluted estuaries and the adjacent coastal zone of Jiaozhou Bay to comprehensively study how the benthic foraminifera response to heavy metal pollution and human engineering,and to assess the ecological risks of the bay.A total of 80 species,belonging to 42 genera,were identified in this study.The results showed that Cu,Pb,Cr,Hg,Zn,and As had low to median ecological risks in the study area which would definitely affect the ecological system.The construction of the Jiaozhou Bay Bridge has resulted in pollutants accumulated at the river mouth of Loushan River,which has adverse effects on the survival and growth of benthic foraminifera.The lowest population density and diversity as well as the highest FAI(Foraminiferal Abnormality Index)and FMI(Foraminiferal Monitoring Index)occurred at Loushan River Estuary which indicated that the ecological environment of the northeastern part of Jiaozhou Bay(Loushan River Estuary)had been seriously damaged.Licun River and Haipo River estuaries and the adjacent coastal zone were slightly polluted and had low ecological risk.As a consequence,it suggested that the supervision of industrial and domestic waste discharge and the protection of the ecological environment in northeast Jiaozhou Bay should be paid more attention.

Stable carbon and oxygen isotopes of four planktonic foraminiferal species from core-top sediments of the Indonesian throughflow region and their significance

Horizontal and vertical distributions of δ^18 and δ^13 were investigated in shells of four planktonic foraminiferal species, Globigerinoides ruber, Globigerinoides sacculifer, Pulleniatina obliquiloculata and Neogloboquedrina dutertrei, from a total of 62 core-top sediment samples from the Indonesian throughflow region. Results were compared to modern hydrologic conditions in order to explore potential of proxies in reconstructing fluvial discharge and upper ocean water column characteristics in this region. Our results show that, in the Makassar Strait, both of depleted δ^18 and δ^13 of these four species were linked to freshwater input. In the Bali Sea,however, depleted δ^18 and δ^13 for these species may be due to different reasons. Depleted δ^18 was a result of freshwater input and as well influenced by along-shore currents while depleted δ^13 was more likely due to the Java-Sumatra upwelling. Comparison of shell δ^18 records and hydrographic data of World Ocean Atlas 2005 suggests that G. ruber and G. sacculifer calcify within the mixed-layer, respectively at 0–50 m and 20–75 m water depth, and P. obliquiloculata and N. dutertrei within the upper thermocline, both at 75–125 m water depth. N.dutertrei calcifies at slightly deeper water depth than P. obliquiloculata does. In general, δ^13 values of both G.ruber and G. sacculifer are larger than those of P. obliquiloculata and N. dutertrei at all sites, possibly related to depth habitats of these species and vertical distribution of nutrients in the Indonesian throughflow region.

Natural thermoluminescence of fossil foraminiferals as a potential proxy for deep-sea temperature changes

Foraminiferal shells from two piston cores separately located at the Ninetyeast Ridge and the Bengal Fan of the Indian Ocean were selected and purified for measurements of natural thermoluminescence （NTL） intensity by a high precision thermoluminescence meter （RGD-3）. Variations of the NTL intensity along the two core sequences both spanning the last two glacial--interglacial cycles displayed a strong, identical signal of the global ice volume cycles, which matched well with their corresponding oxygen isotope data. As higher NTL intensity occurred within interglacial periods and changes in an NTL signal were most likely influenced by the temperature of ambient seawater in which the planktonic foraminiferal shells long existed, the NTL signal could be considered as a potential proxy for orbital scale temperature changes of bottom seawater in the tropical Indian Ocean.

Cretaceous-Paleocene Foraminiferal Communities from the Western Tarim Basin and Their Environmental Significance

Foraminifera is one of the most important fossil faunas of the marine Cretaceous and Paleocene in the Western Tarim Basin, which can be divided into 9 communities. This paper deals mainly with the changes of environments in which the foraminiferal communities existed,especially with the changes of temperature and salinity revealed by analyses of test composition and trace elements in the tests , and by statistic studies of species density, richness , diversity ,equitability and dominance .

NotesBenthic foraminiferal distribution in surface sediments along continental slope of the southern Okinawa Trough: dependance on water masses and food supply

Benthic foraminiferal analysis of 29 samples in surface sediments from the southern Okinawa Trough is carried out. The results indicate that benthic foraminiferal abundance decreases rapidly with increasing water depth. Percentage frequencies of agglutinated foraminifera further confirm the modern shallow carbonate lysocline in the southern Okinawa Trough. From continental shelf edge to the bottom of Okinawa Trough, benthic foraminiferal fauna in the surface sediments can be divided into 5 assemblages: (1) Continental shelf break assemblage, dominated by Cibicides pseudoungerianus, corresponds to subsurface water mass of the Kuroshio Current; (2) upper continental slope assemblage, dominated by Cassidulina carinata , Globocassidulina subglobosa, corresponds to intermediate water mass of the Kuroshio Current; (3) intermediate continental slope assemblage, dominated by Uvigerina hispi-da, corresponds to the Okinawa Trough deep water mass above the carbonate lysocline; (4) lower continental slope- trough bottom assemblage, dominated by Pullenia bulloides, Epistominella exigua and Cibicidoides hyalinus, corresponds to deep water mass of the Okinawa Trough; and (5) trough bottom agglutinated assemblage, dominated by Rhabdammina spp. , Bathysiphon flavidus, corresponds to strongly dissolved environment of the trough bottom. The benthic foraminiferal fauna in the southern Okinawa Trough are controlled jointly by water masses and food supply. Water temperature, oxygen concentration and carbonate dissolution of the water masses are important controlling factors especially for the continental shelf break and trough bottom assemblages. The food supply also plays an important role in these benthic foraminiferal assemblages along the western slope of the Okinawa Trough. Both the abundance and the 5 assemblages of benthic foraminifera correspond well to the organic matter supply along the continental slope and a lateral transport of TSM (total suspended matter) and POC (particulate organic carbon) from the shelf break to the deep water is also an important food supply for benthic fauna in this region.

Mg/Ca Variation in Planktonic Foraminiferal Tests:Assessing Influence of Salinity and Diagenetic Carbonate Dissolution for Reconstruction of Palaeo-seawater Temperature

Over the past decade,the Mg/Ca ratio in foraminiferal tests has emerged as a valuable paleotemperature proxy.In this study we describe the application of the Mg/Ca paleothermometer with the aim of illustrate its use in the Mediterranean Basin.We value the influence of the salinity and diagenetic carbonate processes besides temperature as an important environmental factor controlling the foraminiferal Mg/Ca.For this purpose 3 species of

Miocene paleoenvironmental evolution based on benthic foraminiferal assemblages in the Lufeng Sag, northern South China Sea

The Miocene epoch marks the most crucial period during the Cenozoic cooling trend, characterized by the Middle Miocene Climatic Optimum(MMCO) and a series of short–lived cooling events(Miocene isotope events).To understand the paleoenvironmental evolution along the shallow water shelf in the South China Sea during the Miocene, the benthic foraminiferal assemblage and total organic carbon content(TOC) were analyzed at Hole LF14 located in the Lufeng Sag, northern South China Sea. Three benthic foraminiferal assemblages(e.g., the Uvigerina spp. assemblage, the Cibicides spp. assemblage, and the Cibicidoides spp. assemblage), corresponding to different watermass conditions, were recognized based on Q–mode factor analysis. Early studies suggested that Hole LF14 was deposited under semienclosed bay, middle to outer shelf or even upper bathyal environment during ～18.7–4.53 Ma. The dominant Uvigerina spp. assemblage was characterized by low diversity and shallow infaunal to infaunal species, indicating a warm, low–oxygenation and eutrophic conditions since the Early Miocene to MMCO(～18.7–14.24 Ma). An abrupt sea level drop and significant faunal changes were recorded during 14.24–13.41 Ma, suggesting development of the East Antarctic Ice Sheets, which resulted in a drop of sea level and change in benthic foraminiferal assemblages along the shallow water shelf. Beyond the Uvigerina spp.assemblage, the Cibicides spp. assemblage became important during the middle–late Middle Miocene(14.24–11.54 Ma). This assemblage was dominated by epifaunal species with relative high diversity, suggesting high–energy, high–oxygenation and oligotrophic conditions with episodic supply of organic food. The dominant Cibicidoides spp. assemblage with high diversity, indicates a mesotrophic conditions with relative high–oxygen content during the Late Miocene to Pliocene(11.54–4.53 Ma). The appearance and continuous occurrence of Ammonia spp. and Pseudorotalia spp. since 10.02 Ma, may reflect the influence of the Kuroshio Current.

Time-Frequency Variations of Plio-Pleistocene Foraminiferal Isotopes: A Case Study from Southern South China Sea

The continuous wavelet transform (CWT) analysis reveals the instantaneous variability of the foraminiferal δ 18O and δ 13C of Site 1143 for the past 5 Ma at the eccentricity, obliquity and precession bands. The cross CWT analysis further demonstrates nonstationary phases of the benthic -δ 18O relative to ETP at the three primary Milankovitch bands in the last 5 Ma. The instantaneous phases between benthic -δ 18O and δ 13C at the precession band display a prominent 128 ka period, probably the cyclicity of the nonstationary climate close to the eccentricity. To explain these nonstationary phases, it is desirable to introduce a nonlinear response model to the global climate system, in which the output has a prominent cycle around 100 ka to match the 128 ka cycle of the instantaneous phase of the δ 13C and -δ 18O on the precession band.

Paleoceanography and Paleobiogeography Patterns of the Turonian-Campanian Foraminifers from the Abderaz Formation, North Eastern Iran

In this research, the Turonian-early Campanian sedimentary succession of the Abderaz Formation with 510 mthick (comprising: light grey shale and marls) was studied in the type section in eastern Kopeh-Dagh basin. The statistical analysis of the morphotype groups of the identified planktonic foraminifers shows that most of them are shallow water forms (SWF) and deep water forms (DWF). The high planktonic to benthic ratio indicates particular oligotrophic conditions and sedimentation in relatively deeper zones of a marine environment. The salinity of sea water during Coniacian was in the minimum level, whereas it reached maximum in Coniacian-Santonian boundary. Comparing Planktonic assemblages from the study formation with those from the Cretaceous biogeographical provinces reflects a close relationship between the identified species and the planktonic forms of the Tethyan provinces.

Kimmeridgian Foraminiferal Faunas of Northern Eurasia: Significance for Interregional Correlations and Palaeobiogeography

Foraminifer is a very useful microorganism to perform biostratigraphical zonation of the Upper Jurassic. Foraminiferal biozones are calibrated by the ammonite standard zones and can be used for intra- and interregional correlations. Furthermore, the fossil record of foraminiferal faunas is well known among basins of the Northern Eurasia and is also used for accurate palaeoenvironmental, palaeobiogeographical, or biofacial reconstructions. It allows identifying a complex set of biotic and abiotic events which may be used to propose a more general palaeoecoloecological and palaeoceanographical reconstruction of the Subboreal, Boreal, and Arctic seas. Then, the late Kimmeridgian Northern Eurasian seas formed a network of well-connected palaeobasins during the sea-level rise and resulted in rather similar palaeoenvironmental conditions.

Palaeoenvironmental Changes of the Ancient Nihewan Lake Area-Sr Isotope Evidence from Xiaodukou Foraminifera

By using the improved trace(50μg) Sr isotope analytical method the ^87Sr/^86Sr ratios of Xiaodukou foraminifera fossils were measured,giving a range of 0.71105-0.71274,apparently higher than the value of contemporaneous seawater(0.709087-0.709147)and also slightly higher than the average value of modern Yellow River(0.7111),demonstrating that the contemporaneous environment where Xiaodukou foraminifera inhabited was an inland lake.Detailed analyses of △ Sr values showed that there occurred an event responsible for environmental changes in the ancient Nihewan Lake area during the time(about 1.0Ma ago)when Xiaodukou foraminifera appeared.Because of strong evaporation the salinity of the lake would increase and a regional salt-water of brackish-water lacustrine environment would be produced,thus providing a suitable and inhabitable environment for foraminiferae.It is concluded that Xiaodukou foraminiferal fossil assemblaes belong to non-marine foraminiferal species.

On the occurrence of Neoplanorbulinella Matsumaru, 1976(Foraminifera) from the late Oligocene of Central Iran(Qom Formation):Palaeobiogeographic implications

The shallow marine carbonates of the upper Oligocene Qom Formation yielded several occurrences of the foraminiferan genus Neoplanorbulinella Matsumaru. Neoplanorbulinella saipanensis Matsumaru has so far been recorded from the late Eocene-early Miocene of Japan and late Oligocene of NE Italy whereas N. malatyaensis Gedik is only reported from the Oligocene from its type locality in the Malatya Basin, eastern Turkey. The new records reported here from the Qom Formation indicate that both species occur in the Dobaradar section, ca. 10 km south of the city of Qom in North-Central Iran. The palaeogeographic distribution of these two species therefore has to be extended as far as the palaeolongitude of current Central Iran.The accompanying larger benthic foraminifers, including Miogypsinoides complanatus(Schlumberger),M. formosensis Yabe and Hanzawa, Spiroclypeus margaritatus(Schlumberger), Operculina complanata(Defrance), and Risananeiza pustulosa Boukhary et al., indicate the upper Chattian SBZ 23 Zone. The coexistence of the N. saipanensis and N. malatyaensis points to suitable palaeobiogeographic conditions of Central Iran to host Western and Eastern Tethyan taxa.

A broad deglacial δ^(13)C minimum event in planktonic foraminiferal records in the Okinawa Trough

The equatorial Pacific upwelling zone has been suspected of playing an important role in the global atmospheric CO2 changes associated with glacial-interglacial cycles. In order to assess the influencing scope of the surface water deglacial δ13C minimum in the tropical low-latitude Pacific, the core DGKS9603, collected from the middle Okinawa Trough, was examined for δ13C records of planktonic fo-raminifera N. dutertrei and G. ruber. The planktonic fo-raminiferal δ13C records show a clear decreasing event from 20 to 6 cal. kaBP., which is characterized by long duration of about 14 ka and amplitude shift of 0.4×10-3. Its minimum value occurred at 15.7 cal kaBP. The event shows fairly synchrony with the surface water deglacial δ13C minimum identified in the tropical Pacific and its marginal seas. Because there is no evidence in planktonic foraminiferal fauna and δ18O records for upwelling and river runoff enhancement, the broad deglacial δ13C minimum event in planktonic foraminiferal records

Evolutionary pattern of fusulinacean foraminifer in Maokouan, middle Permian

A composite standard section (CSS) has been established for the Maokouan (≈Guadalupian) in Guizhou Province, southwestern China, which includes stratigraphical ranges of 179 fusulinacean species from five sections of the Maokou Formation in this area. Based on statistical results of the first and last appearances of fusulinacean species in the CSS, three evolutionary radiations and four pulses of extinction, characterized by high rates of species origination and extinction significantly different from the rates of background evolution, are recognized in the Maokouan fusulinacean fauna. The evolutionary pattern of fusulinacean foraminifer suggests that the Maokouan mass extinction probably started at the middle Maokouan and dramatically intensified in the late Maokouan.

Discovery of agglutinated foraminifers from the Longzhaogou Group in eastern Heilongjiang Province

The low diversity agglutinated foraminifers are recovered from the Qihulin Formation of the Longzhaogou Group in eastern Heilongjiang, China. The foraminiferal fauna consists of 9 species of 5 genera. The common members are Cribrostomoides nonioninoides (Reuss), Haplophragmoides concavus (Chapman), H. gigas minor Nauss. Although the diagnostic zonal taxa are absent in the agglutinated fauna, according to the global stratigraphic distribution of the above-mentioned species, and the associated Pseudohaploceras ammonite fauna, the foraminiferal fauna may be of a Barremian-Aptian (Early Cretaceous) age.

Light is an Important Limiting Factor for the Vertical Distribution of the Largest Extant Benthic Foraminifer Cycloclypeus carpenteri

Cycloclypeus carpenteri is the largest extant benthic foraminifer,dwelling in the deep euphotic zone(a water depth between 60 and 130 m)of the warm oligotrophic Indo-West Pacific.This foraminifer harbors diatom endosymbionts and the foraminifer-microalgal association acts like a holobiont.To verify that light is an important limiting factor controlling the vertical(depth)distribution of living Cycloclypeus holobionts,their physiological responses to light intensity were examined by short-term metabolic measurements and long-term incubations.Net oxygen production(OP)rates measured under different light levels using an oxygen microelectrode indicate that Cycloclypeus holobionts are daily net primary producers adapted to low light levels,with slight photoinhibition(reduced net OP rates relative to a light-saturated rate)over 100μmol photons m^(−2)s^(−1).Long-term growth increments of asexually reproduced juveniles incubated for two months at different light levels ranging from 0 to 100μmol photons m^(−2)s^(−1) show that Cycloclypeus holobionts are adapted to a low light level(∼5μmol photons m^(−2)s^(−1)),but can be acclimatized to a certain low light ranges(<50μmol photons m^(−2)s^(−1)).These experimental results confirm that light is an important environmental gradient affecting the vertical distribution of Cycloclypeus holobionts.

Quaternary foraminiferal fossil in the Tianshuihai area of the Qinghai-Xizang Plateau

IN July,1995,the authors carried out drilling and sampling at the location 100 m to the south-east of the Tianshuihai Lake(35°21′N,79°35′E,4 840 m a.s.l.) in the northwest of theQinghai-Xizang Plateau.The analytical results show that the deposits of lacustrine facies in acorehole and an exposure contain foraminiferal fossils.The late Quaternary foraminiferal fossilwas first found in the Quaternary deposits of lacustrine facies at the hinterland of the Qinghai-

Quantitative Analysis of Planktonic Foraminifera in Surface Sediments From the South China Sea

Q-mode factor analysis was applied to 99 surface samples from the South China Sea to define four planktonic foraminiferal assemblages: tropical-subtropical assemblage, high-salinity assemblage, transitional assemblage and dissolution resistant assemblage. The tropical-subtropical assemblage is a dominant assemblage. The variation of the planktonic foraminifera of this assemblage reflects the changes of tropical surface water from the west Pacific to South China Sea. These four assemblages reveal that different planktonic foraminiferal assemblages are controlled by different factors in the South China Sea, such as tropical-subtropical assemblage controlled by sea surface temperature (SST), high-sallnity assemblage mainly by salinity besides SST, transitional assemblage by SST and dissolution resistant assemblage by water depth.

Geochemical evidence for non-marine depositional environment of foraminiferal fossils from the Nihewan Basin,China

From the first finding in 1970s, the findings of foraminiferal fossil assemblages in inland basins have been reported from time to time, especially in recent years. The debates on the depositional environment of foraminiferal fossils have become the hot spot of researches again in China. Based on the researches of trace element geochemistry and electron scanning microscope of shells of Quaternary foraminiferal fossils from the Xiaodukou section in the inland Nihewan basin, the original 87Sr/86Sr and other geochemical information of shells were believed to be preserved well and could be used to rebuild the geochemistry of contemporary waters where foraminifera deposited, although there existed some effects of burial diagenesis on the geochemistry of shells to a certain extent. The 87Sr/86Sr ratios of well-preserved Xiaodukou foraminiferal shells were measured, giving a range of 0.711190±25-0.712018±14, apparently higher than the value of contemporary seawater (0.709087-0.709147) and similar to that of the Sanggan River, proving that it represented the value of the ancient lacustrine water. The hyperbolic mixing models of 87Sr/86Sr-palaeosalinity and 87Sr/86Sr-Sr/Ca indicated that the contemporary waters where Xiaodukou foraminifera inhabited was an inland lake and there was no seawater input to the depositional environment.

Palaeobiogeographical constraints on the distribution of foraminifers and rugose corals in the Carboniferous Tindouf Basin,South Morocco

The northern flank of the Tindouf Syncline in southern Morocco exhibits a continuous, well exposed Carboniferous succession with limestones of Late Asbian to Early Bashkirian age containing rich and diverse foraminiferal and rugose coral assemblages. Analysis of these assemblages provides new data on the relatively poorly known Saharan basins. The palaeobiogeographical relationship of the Tindouf Basin with other Palaeotethyan basins is complex. Although there is a predominance of cosmopolitan taxa for the Palaeotethys, it is recognized that there was an influence of basins from NW Europe, such as the UK and Ireland. Some taxa are recorded in both NW Europe and Tindouf without any characteristic contributions from intermediate basins in northern Morocco. The neighbouring Béchar Basin in Algeria presents distinct assemblages. The bulk of the data analyzed suggest that this sector of the western Palaeotethys can be subdivided into four palaeobiogeographical subprovinces: the Atlantic Subprovince (UK, Ireland, N France and Belgium), the Mediterranean Subprovince (Pyrenees, Montagne Noire, Betic Cordillera, Rif (N Morocco) and Balearic Islands), and the Saharan Subprovince (Béchar, Reggan, Ahnet-Mouydir and Tindouf). In between, mobile belts of mixed faunal assemblage characteristics are observed (e.g., SW Spain and Central Meseta) forming the West peri-Gondwanan Subprovince.Analysis of the Tindouf Basin faunas shows that, as in other Saharan basins, there is a high diversity and abundance of foraminiferal taxa, with a higher proportion of survivors and longer stratigraphic ranges; these features also are mirrored by rugose corals. This emphasizes the longevity of the carbonate platform in a tropical setting, where periodic transgressions introduced new assemblages, and oceanic currents are interpreted as one of the main controlling factors for the distribution of the taxa in these subprovinces. Moreover, not only were water temperatures on the platform higher, but also tectonic stability greater. It is considered that the effects of the first phases of the Gond-wanan glaciation were minimal on the Tindouf faunas.