Here, we examined changes in carbonate preservation in a deep-sea record (Hole U1431D, 4240 m water depth) retrieved from the South China Sea (SCS) during the International Ocean Discovery Program (IODP) Expedition 349. To evaluate these changes, we applied a micropaleontological and geochemical multiproxy approach including, planktonic foraminifera (PF) total abundance, fragmentation (FI%) and dissolution

The processes affecting diatom dissolution and upper water column silica recycling are understood in modern environments. However, few studies have been undertaken to understand which processes have the greatest impact on diatom preservation in sedimentary archives. Furthermore, variability in diatom dissolution in the upper water column of past oceans is rarely quantified. Here we present a record

We recorded diatom species succession over one full year (May 2017–May 2018) using automated sediment traps installed in two contrasting Greenlandic fjords: the seasonally ice-covered Young Sound in high-arctic Northeast Greenland and the nearly sea-ice free Godthåbsfjord in subarctic Southwest Greenland. The traps were positioned at differing water depths (37 m in Young Sound vs. 300 m in Godthåbsfjord)

The East Asian monsoon system influences the local oceanographic and climatic conditions of South China Sea (SCS), making the habitat depths of planktonic foraminifera (PF) specific for this region.The previous paleo-ocean reconstructions of SCS have been based on calcification habitat depths derived from other oceans, which may have affected the accuracy of interpretations. In this study, the calcification

The key to the utility of foraminifers as paleo-environmental indicators for coral reefs is the knowledge of modern assemblages in relation to environmental conditions. This study examined 44 surface-sediment samples from three small islands in Yongle Atoll, with the goal to investigate the relationship between foraminiferal distribution and environmental characterization. In samples, 192 foraminiferal

We present fossil benthic foraminiferal assemblage data from marine sediment core SS02/06-GC2 located in the abyssal plain of the Murray Canyon Group (offshore South Australia). The sedimentological characteristics indicate the presence of turbidite deposits showing classical Bouma-like sequences, dated between ~40 and 12 cal ka BP. These results confirm the previous interpretation of the observed

Strata of Valanginian age (Early Cretaceous, 139.8–132.9 Ma) record a 1.5‰ positive carbon isotope excursion (CIE), the Weissert Event. It coincides with volcanic activity of the Paraná-Etendeka large igneous province. Unlike the Mesozoic Oceanic Anoxic Events (OAEs), no organic-rich deposits documenting widespread perturbation of the marine carbon-cycle are associated with the Weissert Event. To study

The evolution of the calcareous nannofossil Eiffellithus turriseiffelii – E. eximius lineage in the Turonian from the western tropical Atlantic and Indian Ocean indicates identical eiffellithid forms with morphological change in the rotation of the crossbar, relative to the longitudinal axis, from an “x” (E. turriseiffelii) to a “+” (E. eximius). Within these indistinguishable eiffellithid assemblages

Calcein is widely used to mark the new calcium carbonate structures in foraminifera, but it remains unclear whether calcein has effects on the biological features (i.e., abundance, size). Here the biological effects of calcein on benthic foraminifera were investigated using a two-factor crossed experiment in which foraminiferal communities (10,393 live specimens in total) were cultured in seawater

The trace elemental composition of planktic foraminifera shells serves as a proxy for understanding the physical environment in which foraminifera lived, but may also reflect chemical alterations that occur after death. Understanding how foraminiferal geochemistry varies across time, species, and after death is therefore essential for deconvolving ecological from diagenetic information and decoding

The Last Abundant Appearance Datum of the endemic Southern Ocean diatom Hemisdiscus karstenii Jousé is dated at around 190,000 years Before Present, which provides a robust and convenient biostratigraphic marker to Late Pleistocene paleoceanographic studies. However, no prior studies have sought to understand what processes may have driven H. karstenii to extinction. We here present the first morphometric

This study presents new stable isotope and dissolution records for a composite “Carnegie Platform” (CP) sediment record composed of KNR195–5 cores CDH-36 and MC-34A (3° 35.85′ S, 83° 57.79′ W, 3225 m) from the Eastern Equatorial Pacific. Renewed interest in this paleoceanographic site prompted a re-coring in 2009 using the CDH giant piston coring system. Giant piston core CDH-36, with a core length

Among the varieties of microbial carbonate rocks, leiolites are rare in ancient rock records and have only few examples in the modern environment, which makes them difficult to study. This study documents the sedimentary environment, characteristics and composition of microbial carbonates, dominated by calcified microbes, which developed in the Cambrian Miaolingian Xuzhuang Formation on the North China

A long-term perspective is essential for understanding environmental change. To be able to access the past, environmental archives such as marine and lake sediments that store information in the form of diverse proxy records are used. Whilst many analytical techniques exist to extract the information stored in these proxy records, the critical assessment and refinement of current methods in addition

In this study, we analyzed 45 surface sediment samples collected in the marginal seas of the Western North Pacific, including the South China Sea, the East China Sea, and the Philippine Sea, to investigate the radiolarian assemblages and their relationship with upper layer environmental conditions. Based on the results of Q-mode cluster analysis, the radiolarian assemblages can be divided into four

A new fossil paracypridine ostracod, Tasmanocypris lochardi sp.nov. is described from late Miocene shallow marine strata of southeastern Australia. It has morphological features similar to a number of modern southern Australian and southwest African Tasmanocypris species, here termed the dartnalli-group. This species group was likely present in early Cenozoic temperate, shallow seas around Antarctica

Palynological analyses of 60 surface sediment samples from West Greenland margin revealed high concentrations of dinoflagellate cysts (dinocysts), particularly in the Disko Bugt area, where they reach >104 cysts g−1. Dinocyst assemblages are characterized by a relatively high species diversity and are dominated by Operculodinium centrocarpum, cysts of Pentapharsodinium dalei, Islandinium minutum, Islandinium

Dinoflagellate cyst (=dinocyst) assemblages are widely used for the reconstruction of multiple oceanographic variables through the application of transfer functions. There is evidence that the number and kind of variables driving compositional changes in dinocyst assemblages vary regionally and that the selection of driving factors and the evaluation of transfer function performances are method-specific

Organic-walled resting cysts of planktonic dinoflagellates occur commonly in modern marine sediment where they represent, with rare exceptions, the only geologically preservable part of the life cycle. Although many species do not produce fossilizable resting cysts, upper Quaternary sediments contain a diverse cyst record that is used frequently for paleoenvironmental reconstruction and stratigraphic

The geographical distribution of dinoflagellate cysts was investigated in palynologically treated surface sediments from the South China Sea (SCS) to understand the driving environmental factors associated with specific taxa. The western SCS generally has higher total cyst concentrations (>300 cysts g−1) than the eastern region (<200 cysts g−1). The highest concentrations (>1000 cysts g−1) occur off

Dinoflagellate resting cysts with rare exception produce the only discrete link between the biology of extant dinoflagellate species and their fossil record. The geological preservability of such cysts allows them to be used for quantitative paleoecological reconstructions, especially in the Quaternary, and for biostratigraphy and the calibration of molecular clocks with the geological record. This

We present a new version of the standardized Northern Hemisphere “modern” dinoflagellate cyst (“dinocyst”) database, which includes abundances of 71 taxa at 1968 sites across the Northern Hemisphere, cross-referenced with 17 environmental parameters extracted mostly from the 2013 World Ocean Atlas. Several taxa with tropical to warm temperate affinities were added to the previous database version.

The use of micro-computed tomography (μCT) provides a unique opportunity to look inside the shells of larger benthic foraminifera to investigate their structure by measuring linear and volumetric parameters. For this study, gamonts/schizonts and agamonts of the species Heterostegina depressa d'Orbigny were examined by μCT; each single chamber's volume was digitally measured. This approach enables cell

Magnesium, incorporated in foraminiferal calcite (Mg/CaCC), is used intensively to reconstruct past seawater temperatures but, in addition to temperature, the Mg/CaCC of foraminiferal tests also depends on the ratio of Mg and Ca in seawater (Mg/CaSW). The physiological mechanisms responsible for these proxy relationships are still unknown. This culture study investigates the impact of different seawater

Within a 5.5-m-thick succession of upper Burdigalian (CNP-zone NN4) shallow neritic sediments from the North Alpine Foreland Basin in Lower Austria a high-resolution section of finely laminated sediment with a thickness of 940.5 mm was logged. The section was continuously sampled, resulting in 100 samples, covering a thickness of ~ 10 mm each. An integrated approach was applied to these samples in

Symbiont-bearing larger benthic foraminifera inhabit the photic zone to provide their endosymbiotic algae with light. Because of the hydrodynamic conditions of shallow water environments, tests of larger foraminifera can be entrained and transported by water motion. To resist water motion, these foraminifera have to build a test able to avoid transport or have to develop special mechanisms to attach

Atlanticodinium n. gen. accommodates small- to medium-sized proximate dinoflagellate cysts with a spherical or subspherical central body having a nonfibrous wall with a smooth to finely ornamented surface bearing numerous, short, hollow, unbranched, nontabular, nonfibrous processes. The archeopyle is precingular, its margins having well defined angles. Atlanticodinium striaticonulum n. gen., n. sp

Dinoflagellates are a major component of the modern plankton. Of the 2192 species of marine free-living dinoflagellates presently described, an increasing number are being shown to produce resting cysts (probably hypnozygotes) within their life cycle. With rare exception, only the resting cysts fossilize, so they are of central importance in tracing the history of dinoflagellates through geological

Stelladinium bifurcatum n. sp. is a large and distinctive brown heterotrophic dinoflagellate cyst recorded from Upper Pleistocene through modern sediments of the eastern Pacific, modern sediments of the western Bay of Bengal and sediment traps from the South China Sea, and Upper Pleistocene through Middle Holocene deposits of the east equatorial Atlantic. It is distinguished by prominent apical and

This paper examines the distribution of 91 modern dinoflagellate cyst taxa from 3636 locations across the world's oceans. Patterns of distributions among the taxa included bi-polarity, cosmopolitan, northern versus southern hemispheres, and geographically restricted. Of the 91 taxa, three dominate these 3636 assemblages at the global scale, Brigantedinium species, Operculodinium centrocarpum sensu