Based on a quantitative analysis of foraminifera in 39 surface samples of the Bering and Chukchi Seas,the nearly absence of planktonic foraminifera in the surface sediments can be related to the low surface primary productivity and strong carbonate dissolution in the study area.It has been revealed that the surface primary productivity,and carbonate dissolution and properties of water masses related to the water depth mainly control the distribution of benthic foraminifera.The shelf of the Chukchi Sea is dominated by the Elphidium spp.assemblage and Nonionella robusta assemblage with low foraminiferal abundance and diversity,which is controlled by the coastal water mass of the Arctic Ocean.The slope of the Bering Sea is dominated by the Uvigerina peregrina-Globobulimina affinis assemblage with abundant N.robusta,and relatively high foraminiferal abundance and diversity,which is controlled by the intermediate and deep water masses of the Pacific Ocean.However,the Bering Sea has relatively shallow carbonate lysocline and compensation depth (CCD),at about 2 000 and 3 800 m,respectively.In addition,there exists Stetsonia arctica in the surface sediments of the upper slope in the Bering Sea,which is a typical deep-sea benthic foraminiferal species of the slope in the Arctic Ocean.This indicates that the deep water of the two seas beside the Bering Strait had ever exchanged.

Foraminiferal oozes were sampled from the tropical West Pacific seamount and seabed of deep sea, by a remotely operated vehicle (ROV) in December 2014 and March 2016. Using standard morphological method, four Miliolinella species, including Miliolinella obesa, M. circularis, M. suborbicularis and M. subrotunda were described. Among the four species, M. obesa is a new species. It is a large member (about 500 μm in length) of the genus. This species is characterized by having a very stout and transverse broadly circular outline, and its body width is greater than the body length. In addition, its chamber demarcations are obscure from the exterior appearance. Three chambers are unclearly visible on one side and two chambers are visible on the opposite. Finally, we provided very detailed taxonomic microphotographs and the ecological distribution information for each species.

A brief morphometric study of the recent planktonic foraminifera in the eastern Indian Ocean was provided with the taxonomic key to species, synonyms, SEM microphotographs of shells and chamber arrays. By recent classification, currently 20 species representing 13 genera and 6 families (Canderinidae, Heterohelicoidae, Hedbergellidae, Higerigerinoidae, Globigerinoidae, and Globorotaloidae) identified from the planktonic material of the eastern Indian Ocean up to a depth of 200 m. Their distribution in water (0–200 m) also reports on the new range of expansion in the eastern Indian Ocean, with Dentigloborotalia anfracta, Hastigerina pelagica, Streptochilus globigerus, Globigerinella calida, Globigerinella adamsi, Orcadia reidelii, Tenuitella parkerae, Tenuitella compressa, reported for the first time in this study area. In general, only around 50 planktonic species are valid worldwide, more specifically the species, e.g., H. pelagica, G. calida, G. adamsi, S. globigerus, O. riedeli, T. parkerae, T. compressa, which occur in the eastern Indian Ocean to fill the the paucity of the recent regional taxonomic literature and the problematic identification from the eastern Indian Ocean. This work aims to bridge this gap and help scientists, managers, educators and students to identify plankton foraminifers by using species notes and images.

Two cores and ten surface sediment samples were taken in the western area of Mid-Pacific during the investigation from December 1978 to July 1979.According to the analysis of planktonic foraminifera and CaCO₃ in the surface samples, the investigated area is divided into three different sediment regions.The initial depth of lysocline of this area is estimated at about 3500 m and the CaCO₃ compensation depth (CCD) is 5000 m.The water depth of the sediment core at L2016 is 2705 m and it is located above the lysocline.The sediments belong to white planktonic foraminiferal ooze.The evolution of paleoclimate is studied according to the variation of the following three parameters:the abundance value of the species indicating warm of planktonic foriminifera, the solution index and the determination of the paleotemperature carve of δ¹⁸O.The age of 4.2 m-long core is estimated at about 300, 000 years BP according to the extinct time of the pink shell G.rubra, and the comparison between cores.

Through densified surface sampling of foraminifera and accurate elevation measurement along three transect lines in open-coast tidal salt-marsh of Jianchuan,particular salt-marsh foraminifera assemblages were found.The salt-marsh foraminifera assemblages are distributed in well-defined vertical zonations with respect to elevation and closely parallel marsh floral zonations.At the top of the vertical zonation all foraminifera disappear abruptly which are accurately located at the highest high water datum.This distribution pattern can be used to relocate former sea levels accurately (to an accuracy of within ±5 cm).A modern regional criterion of foraminifera for relocating the former sea levels in high resolution in our country is provided,and deficiencies of studying the vertical zonation only in sheltered coast salt-marsh abroad are filled up.

Site U1446 (19°50’N, 85°44’E, at water depth 1 430 m) was drilled during Expedition 353 (Indian monsoon rainfall) of the International Ocean Discovery Program (IODP). It is located in the Mahanadi offshore basin, on the northern Bay of Bengal. Sedimentation rates and contents of biocarbonates are high at this relatively shallow site. Using a micropaleontological approach, we examined planktonic and benthic foraminifera in the upper around 40 m of this site, spanning the last around 190 ka. A striking feature of the foraminiferal record is the occurrence of strong but varying dissolution although the site is located well above the modern lysocline. Such strong dissolution has never been reported in this area. We estimated the flux of foraminifera and quantified the ratio of benthic foraminifera over total foraminifera (benthic/total foraminifera) along with the foraminifer fragmentation index in order to characterize past changes in this above-lysocline dissolution. This study reveals a clear glacial-interglacial contrast, with a stronger dissolution during marine isotope stages (MISs) 1 and 5 than during MISs 2–4 and 6. Such a difference in preservation is likely to have a strong impact on geochemical proxies measured on foraminifera. Our new observations call for an in-depth study of the causes of such above-lysocline dissolution in the region, and an evaluation of its impact on the foraminifera-based proxies used for paleoenvironmental reconstruction.

Trace elemental associations and Sr-Nd isotopic compositions are of important to recognition of biogenic material from mixed marine sediments.The foraminifera shell from the Okinawa Trough strongly enrichesSr, P, Mn andBa, enriches Li, U, Th, Sc, Co, Cu, Pb, Zn, Cr, Rb, Y, Sb and light rare earth elements, slightly enriches V, Ga, Zr, Nb, Cd and middle rare earth elements, is short of Mo, In, Sn, Cs, Hf, Ta, W, Ti, Bi and heavy rare earth elements.The mechanism of elemental enrichment in forminifera is the concentrations of trace elements in sea water and selective absorption of trace elements during foraminifera living, as well as the geochemical affinity between major elements and trace elements.The REE (rare earth elements) partition pattern of foraminifera shell of the Okinawa Trough shows enrichment of middle rare earth elements with slightly negative Ce anomaly, which are different from those of foraminifera of the Pacific Ocean.The Sr, Nd isotopic ratios of the Okinawa Trough foraminifera are 0.709 769 and 0.512 162, respectively, which are different not only from those of oceanic water, but also from those of river water of China's Mainland, the former is slightly higher than those of oceanic water, but much lower than those of river water; the latter is slightly lower than those of oceanic water, but higher than those of river water, demonstrating that the Okinawa Trough sea water has been influenced by river water of China's Mainland.

Controlled by climate changes, there were three large-scale transgressions and regressions around the Bohai Sea during the late Quaternary, which were accepted by most geologists. However, a big controversy still exists about the time when the transgressions occurred separately. In order to find out the process of the paleoenvironmental changes around the Bohai Sea in the late Quaternary, the foraminifera assemblages from a new borehole Lz908 in the southern coast of the Laizhou Bay were studied, and then the transgressive strata were indentified. Combined with accelerator mass spectrometry radiocarbon ¹⁴C (AMS¹⁴C) and optically stimulated luminescence (OSL) ages, the occurrence time of these transgressions were re-determined. The result showed that three major large-scale transgressions occurred separately at the beginning of marine isotopic stage 7 (MIS7), the last interglacial period (MIS5) and the Holocene. In addition, a small-scale transgression occurred in the mid-MIS6, and the corresponding transgressive stratum was deposited. The transgressive deposition of MIS3 was also discovered in this study. However, the characteristics of the foraminifera indicated the environment during this period was colder than that in the MIS5. By comparison with the global sea-level changes, the paleoenvironmental changes around the Bohai Sea in the late Quaternary can be consistent with the global climate changes.

Through the analysis of foraminiferal fossils in the cores and the combination with the data of paleomag-netism and ¹C ages, seven transgressive strata are recognized in the plains of coastal areas of Zhejiang Province.Among them the upper five ones are compared with the results of the previous study, and the lower two ones are discovered for the first time.The sixth stratum is formed in the shallow-sea environment with a warm climate and water depth of 20~30 m.and the seventh one is formed in the nearshore environment with a warm climate and water depth of less than 20 m.The distribution, age and paleoenvironment of every transgressive stratum is discussed in this paper.

The distribution of ostracods and benthonic foraminifers in the China sea area is briefly reviewed from the paleobio-geographic viewpoint in this paper.Three regions can be distinguished in the area on the basis of modern distribution data:Region Ⅰ (the Huanghai Sea and the Bohai Sea) with cool and temperate forms,Region Ⅱ (the East China Sea and the northern part of the South China Sea) with subtropical warm-water forms and Region Ⅲ (central and southern parts of the South China Sea) with larger foraminifers and other tropical warm-water forms.The occurrence of Nummulites-Discocyclira fauna in the Eocene deposits of the East China Sea indicates a northward extension of tropical zoogeographical region at the time,whereas the distribution pattern of the Miocene Nephrolepidina-Miogypsiua-Austrotrillina fauna in the South China Sea resembles that of the present larger-foraminiferal fauna.In the South China Sea and Taiwan,a warm-water fauna with Asterorotalia and Pseudorotalia first appeared in late Miocene and then flourished in the Pliocene.