Microfossil Biostratigraphy Research Articles

Calcareous microfossil biostratigraphy of Upper Miocene to Pliocene deposits of the Sinú-San Jacinto Belt, Caribbean region of Colombia

A compilation of previous biostratigraphic studies conducted in Upper Miocene to Pliocene deposits from the Caribbean region of Colombia reveals a predominant reliance on mollusks and benthic foraminifera for age determinations, with planktonic microfossils being less explored. To contribute to this biostratigraphic background, we have performed biostratigraphic analyses of calcareous nannoplankton, an oceanic planktonic micropaleontological group, on 71 mudrock samples from two stratigraphic sections located in the Sinú-San Jacinto Belt (SSJB). The Canalete stratigraphic section, outcropping in the southwestern portion of the belt, yielded the biostratigraphic markers Discoaster bergenii, Discoaster berggrenii, Discoaster surculus, and Reticulofenestra pseudoumbilicus. This assemblage, typical of the Zone NN11, indicates that the 50-m-thick section was accumulated during the Late Miocene, sometime between the late Tortonian and late Messinian. The ANH-Conuco-1 well, a cored stratigraphic section drilled in the northeastern area of the belt, also contained the above-mentioned biostratigraphic markers as well as Amaurolithus primus-delicatus, Ceratolithus acutus, Discoaster quinqueramus, Helicosphaera sellii, and Reticulofenestra rotaria. These taxa suggest that the stratigraphic interval between 754.1 m and 58.4 m in this cored section is enclosed within the zones NN11 and NN12, ranging in age from Late Miocene to Early Pliocene (late Tortonian to earliest Zanclean). Reworked nannofossils Cyclicargolithus floridanus, Discoaster deflandrei, Sphenolithus disbelemnos, and Sphenolithus heteromorphus were observed in both localities, implying the redeposition of Lower to Middle Miocene and, possibly, Paleogene marine sediments. This is supported by previous documentation of reworked planktonic foraminifera in Upper Miocene to Pliocene deposits from the Caribbean region of Colombia. The identified calcareous nannoplankton assemblages not only provide additional constraints on the existing biostratigraphic data of planktonic foraminifera in this region, but also aid in the correlation of both analyzed stratigraphic sections with other Upper Miocene deposits in northwestern South America.

Minimal stratigraphic evidence for coseismic coastal subsidence during 2000 yr of megathrust earthquakes at the central Cascadia subduction zone

AbstractLithology and microfossil biostratigraphy beneath the marshes of a central Oregon estuary limit geophysical models of Cascadia megathrust rupture during successive earthquakes by ruling out >0.5 m of coseismic coastal subsidence for the past 2000 yr. Although the stratigraphy in cores and outcrops includes as many as 12 peat-mud contacts, like those commonly inferred to record subsidence during megathrust earthquakes, mapping, qualitative diatom analysis, foraminiferal transfer function analysis, and 14C dating of the contacts failed to confirm that any contacts formed through subsidence during great earthquakes. Based on the youngest peat-mud contact’s distinctness, >400 m distribution, ∼0.6 m depth, and overlying probable tsunami deposit, we attribute it to the great 1700 CE Cascadia earthquake and(or) its accompanying tsunami. Minimal changes in diatom assemblages from below the contact to above its probable tsunami deposit suggest that the lower of several foraminiferal transfer function reconstructions of coseismic subsidence across the contact (0.1–0.5 m) is most accurate. The more limited stratigraphic extent and minimal changes in lithology, foraminifera, and(or) diatom assemblages across the other 11 peat-mud contacts are insufficient to distinguish them from contacts formed through small, gradual, or localized changes in tide levels during river floods, storm surges, and gradual sea-level rise. Although no data preclude any contacts from being synchronous with a megathrust earthquake, the evidence is equally consistent with all contacts recording relative sea-level changes below the ∼0.5 m detection threshold for distinguishing coseismic from nonseismic changes.

Marine osmium isotope record during the Carnian “pluvial episode” (Late Triassic) in the pelagic Panthalassa Ocean

The Carnian Pluvial Episode (CPE) was a global environmental change and biotic crisis that occurred during the Carnian (Late Triassic). The climate during the CPE was characterized by a short-lived period of extreme rainfall, and an extinction of marine taxa is known to have occurred during the latest Julian (i.e. early Carnian). Although these events are considered to have been caused by the Wrangellia Flood Basalt (FB) volcanism, existing studies have found little direct evidence to support this. We investigated the temporal relationship between the eruption of Wrangellia FB and CPE using high-resolution microfossil biostratigraphy and paleo-seawater Os isotope data of an Upper Triassic bedded chert succession from an accretionary complex in Japan, which accumulated in a pelagic deep-sea environment in an equatorial region of the Panthalassa Ocean. Our biostratigraphic analysis, based on conodonts and radiolarians, and osmium isotope data show: (i) a continuous decline of initial Os isotope ratios (187Os/188Osi) in the early Julian; (ii) low 187Os/188Osi ratios during the late Julian; and (iii) an abrupt increase in 187Os/188Osi ratios at the end of the Julian. The decrease in 187Os/188Osi ratios throughout the Julian suggests an increased input of unradiogenic Os from the eruption of the Wrangellia FB into the ocean. Moreover, redox-sensitive elements, such as V and U, increased abruptly at the end of the Julian, which is the first evidence of reducing conditions during the CPE within the pelagic deep-sea Panthalassa Ocean. Marine anoxic event in the late Julian has been recognized from widespread deposition of black shales and organic-rich marls in intermediate to shallow water Tethyan sections. Thus, oxygen-depleted conditions occurred at the Tethyan shallow continental margin, as well as in the pelagic deep-sea Panthalassa Ocean, at the end of Wrangellia FB volcanism.

Lower Jurassic (Hettangian–Pliensbachian) microfossil biostratigraphy of the Ballinlea-1 well, Rathlin Basin, Northern Ireland, United Kingdom

The thickest section of Early Jurassic strata known from onshore Ireland (total Jurassic thickness 566 m) is reported from the Ballinlea-1 well (Rathlin Basin) situated on the north coast of Northern Ireland. A biostratigraphical and palaeoenvironmental assessment is presented for this section largely based on calcareous benthic microfossils (foraminifera and ostracods). The Early Jurassic Waterloo Mudstone Formation (Lias Group) of Northern Ireland has previously received little micropalaeontological attention, therefore this work provides an opportunity to enhance palaeogeographic and palaeoenvironmental understanding for the Early Jurassic of the province, and this paper illustrates the key microfossil taxa of this age from Ireland for the first time. The records, based on ditch-cuttings samples, demonstrate a stratigraphical range from Hettangian to Early Pliensbachian, consistent with other wells and boreholes in this basin. The assemblage compositions are comparable to those elsewhere in the European boreal Atlantic realm. Hettangian to earliest Sinemurian microfossil assemblages are generally of low diversity and are numerically dominated by metacopid ostracods with occasional influxes of foraminifera. Gradually, foraminiferal abundance (often dominated by species of the Lagenida) come to exceed those of the ostracods in the Early Sinemurian reaching their greatest diversity in the Late Sinemurian. The sediments are considered to represent an inner to mid-shelf environment throughout while the record thickness for this region indicates ongoing syn-sedimentary fault movement along the basin margins within this period.

K-Ar fault gouge dating of Neogene thrusting: The case of the siliciclastic deposits of the Trasimeno Tectonic Wedge (Northern Apennines, Italy)

The Northern Apennines (NA) are a characteristic example of foreland fold-and-thrust belt progressively migrating towards its foreland. Their tectonic evolution has been quite tightly constrained in time by microfossil biostratigraphy applied to syn-orogenic deposits within foreland basins. This makes the NA well suited to test the reliability of K-Ar illite dating of Neogene deformation affecting siliciclastic sequences. We sampled two top-to-the-ENE thrusts, whose well defined cores are defined by scaly gouge formed at the expense of the pelitic component of the host rock. X-ray diffraction (XRD) and K-Ar isotopic analysis of multiple grain-size fractions of the gouge, allowed us to discriminate between syn-kinematic and inherited illite crystals in the fault rocks. Illite age analysis (IAA) constrains fault slip along the thrusts to 15.2 ± 7.6 Ma and 15.4 ± 16.6 Ma. The results, in spite of their analytical uncertainty, are fully consistent with the local evolution of the NA as constrained by the independent biostratigraphic studies and confirm the general suitability of this geochronological approach to Neogene deformation.

Lower Eocene sedimentary succession and microfossil biostratigraphy in the central northern Caucasus basin

The lower Eocene sediments from the classical Paleogene section exposed along the Kheu River, northern Caucasus, southern Russia are here studied. This ca. 50m thick succession is lithologically contrasting: the lower and upper parts are composed by soft marls separated by a thick Radiolaria-rich unit of non-calcareous and low-calcareous mudstones with intercalations of compact cherty layers. According to nannofossil and dinocyst biostratigraphy, the unique intercalation of Total Organic Carbon (TOC)-rich sediment (sapropelitic bed) in the lower part of the lower Eocene correspond to the Paleocene-Eocene Thermal Maximum (PETM) and a series of sapropelitic interlayers in the upper marly part of the lower Eocene succession correlates with the Early Eocene Climatic Optimum (EECO). The study of nannofossil and dinocyst assemblages enabled detailed zonal subdivision and first-order calibration of nannofossil and dinocyst bio-events during this time-span. The studied interval of the section embraces the complete succession of nannofossil zones NP9-NP13 of Martini, 1971, CP8-CP11 of Okada and Bukry, 1980 and CNP11-CNE5 of Agnini et al., 2014. By means of dinocyst stratigraphy, the succession of Apectodinium hyperacanthum, Axiodinium augustum, Deflandrea oebisfeldensis, Dracodinium astra, Stenodinium meckelfeldense, Dracodinium varielongitudum, Ochetodinium romanum/Samlandia chlamydophora and Areosphaeridium diktyoplokum zones are identified in the Ypresian part of the Kheu section.

BP Gulf of Mexico Neogene Astronomically-tuned Time Scale (BP GNATTS)

AbstractThis paper introduces an integrated Neogene microfossil biostratigraphic chart developed within post-merger BP for the Gulf of Mexico Basin and is the first published industrial framework “fully-tuned” to orbital periodicities. Astronomical-tuning was accomplished through a 15-year research program on the Ocean Drilling Program’s (ODP) Leg 154 sediments (offshore NE Brazil) with sampling resolution for calcareous nannofossils and planktonic foraminifera ∼20 k.y. and 40 k.y. (thousand year), respectively. This framework extends from the Late Oligocene (25.05 Ma) to Recent at an average Chart Horizon resolution for the Neogene of 144 k.y., approximately double that of published Gulf of Mexico biostratigraphic charts and a fivefold increase over the highest resolution global calcareous microfossil biozonation. Such resolution approximates that of fourth to fifth order parasequences and is a critical component in the verification of seismic correlations between mini-basins in the deep-water Gulf of Mexico. Its utility in global time-scale construction and correlation has been proven, in part, by application of the scheme in full to internal research for the Oligocene–Miocene boundary interval on the global boundary stratotype section and point (GSSP) in northern Italy and offshore wells in the eastern Mediterranean Sea. This step change in Neogene resolution, now at the level of cyclostratigraphy (the orbital periodicity of eccentricity) and the magnetostratigraphic chron, demonstrates the potential for calcareous microfossil biostratigraphy to more consistently reinforce correlations of these time scale parameters. The integration of microfossil disciplines, consistent taxonomies, and rigorous analytical methodologies are all critical to obtaining and reproducing this new level of biostratigraphic resolution.

Lithostratigraphy and microfossil biostratigraphy of the Pennsylvanian-lower Permian Horquilla Formation at New Well Peak, Big Hatchet Mountains, New Mexico, USA

Lithostratigraphy and microfossil biostratigraphy of the Pennsylvanian-lower Permian Horquilla Formation at New Well Peak, Big Hatchet Mountains, New Mexico, USA

Vase-shaped microfossil biostratigraphy with new data from Tasmania, Svalbard, Greenland, Sweden and the Yukon

The recent revision of the Cryogenian lower boundary from 850 Ma to 720 Ma has nearly doubled the duration of the Tonian Period to 280 Myrs, an interval longer than the Mesozoic and Cenozoic eras combined. Although subdivision of the Tonian will likely emphasize chemostratigraphy, the relatively rich fossil record of this time period may also be useful. In particular, vase-shaped microfossils (VSMs) occur globally and often abundantly in a variety of lithofacies, exhibit a variety of preservational modes, and are stratigraphically constrained by the two major carbon isotopic events of the Tonian Period, the Bitter Springs and Islay anomalies. VSMs have been used as informal, grade-level indicators of late Tonian age (e.g. ca. 800–700 Ma) for several decades but here, based on new data from an assemblage in northwestern Tasmania and restudy of samples from Svalbard, Greenland, Sweden and the Yukon, we report a species-level faunal assemblage indicative of the interval ca. 789 to 729 Ma. Species-level VSM biostratigraphy presents an opportunity for potential biostratigraphic subdivision of the lengthy Tonian Period and is particularly useful in successions where chemostratigraphy and radiometric age constraints are absent.Eight taxa are described from shales and early diagenetic cherts of the Black River Dolomite, Togari Group, Tasmania, including seven previously named species (Bombycion micron, Bonniea dacruchares, Bonniea pytinaia, Cycliocyrillium simplex, Cycliocyrillium torquata, Melanocyrillium hexodiadema and Palaeoarcella athanata), and one newly described genus and species Pakupaku kabin n. gen et n. sp. Study of additional units resulted in new recognition of B. pytinaia, C. simplex and C. torquata in the Draken Formation, Spitsbergen, Svalbard, B. dacruchares and P. athanata in the Ryssö Formation, Nordaustlandet, Svalbard, B. dacruchares, B. pytinaia, C. torquata and P. athanata in Bed 18 of the Eleonore Bay Group, Greenland, and B. dacruchares, B. pytinaia and Bombycion micron in the Visingsö Group, Sweden.

Low-Latitude Miocene Calcareous and Siliceous Microfossil Biostratigraphy from NW South America: Ladrilleros-Juanchaco Section, Colombian Pacific

The Neogene sedimentary basins of the Colombian Pacific coast were formed in forearc basins associated with the uplift of the Andes. In this area, some marine sequences remain unexplored and are marked by a lack of biostratigraphic information. Additionally, available high-resolution biostratigraphic and biochronologic data from this region are limited almost exclusively to open sea research conducted by the Integrated Ocean Drilling Programs (IODP). The Ladrilleros-Juanchaco section is a continuous and well-exposed marine terrigenous sedimentary sequence with abundant Miocene microfossils. Biostratigraphic and biochronologic studies with calcareous nannofossils, planktonic foraminifera and diatoms carried out there revealed the presence of seventeen astronomically calibrated and standard calcareous microfossil biohorizons as well as two tropical diatom biozones. Such information enabled the establishment of a chronologic framework between the Base of Praeorbulina glomerosa and Catinaster coalitus Base, corresponding to 16.27 and 10.79 Ma, respectively (Burdigalian–Tortonian). The proposed biozonation favoured the observation of a high correlation between low-latitude planktonic foraminifera and calcareous nannofossil bioevents whereas diatom biozones and calcareous nannofossil biohorizons are marked by variations since the lowest occurrence of diatoms around 12.2 Ma. Furthermore, by means of interpolating age between the Sphenolithus heteromorphus Top and Fohsella praefohsi Base bioevents, the fact that the Reticulofenestra pseudoumbilicus (>7 µm) Base common took place around 13.6 Ma is interpreted and correlated with other sites, therefore revealing that it can be considered a good bioevent for the base of the Serravallian in these tropical areas. BIOESTRATIGRAFIA DE MICROFOSILES CALCAREOS Y SILICEOS DEL MIOCENO EN BAJAS LATITUDES DEL NW DE SUR AMERICA: SECCION DE LADRILLEROS-JUANCHACO, PACIFICO COLOMBIANO. El relleno sedimentario del Neogeno de las cuencas de antearco del Pacifico Colombiano esta estrechamente relacionado con la dinamica tectonica de los Andes y los cambios paleoceanograficos que ocurrieron durante el Cenozoico. Las unidades marinas en el area permanecen inexploradas y carecen de estudios bioestratigraficos detallados. Los trabajos de este tipo en la zona estan restringidos a los realizados en las campanas del Integrated Ocean Drilling Programs (IODP) en el Pacifico ecuatorial oriental. La seccion de Ladrilleros-Juanchaco es una secuencia continua y bien expuesta con abundantes microfosiles del Mioceno que pueden llenar este vacio en la informacion. El analisis bioestratigrafico y biocronologico de nanofosiles calcareos, foraminiferos planctonicos y diatomeas ha permitido generar un modelo de edad de media-alta resolucion, identificando 17 bioeventos bioestratigraficos estandares calibrados astronomicamente en estudios previos. Esto permitio establecer un modelo de edad y establecer el tiempo de sedimentacion entre los bioeventos Praeorbulina glomerosa Base y Base de Catinaster coalitus, correspondientes a 16.27 y 10.79 Ma (Burdigaliense–Tortoniense, respectivamente). Por otro lado, la biozonacion propuesta facilito observar una alta correlacion entre los biohorizontes de nanofosiles calcareos y foraminiferos planctonicos, mientras que el nanoplancton y las biozonas de diatomeas tropicales demuestran variaciones desde su aparicion a los ~12.2 Ma. Ademas, por medio de la interpolacion entre los bioeventos Sphenolithus heteromorphus Top y Fohsella praefohsi Base se logro estimar la edad del Base comun de Reticulofenestra pseudoumbilicus (>7 µm) a ~13.6 Ma. Esta edad habia sido propuesta anteriormente, sin embargo no se le habia dado importancia a este bioevento.

Evolution of the northern Tethyan Helvetic Platform during the late Berriasian and early Valanginian

AbstractThe Early Cretaceous period is characterized by widespread carbonate production in tropical and subtropical epicontinental seas, which was modulated by changes in sea‐level, detrital and nutrient fluxes, and the global carbon cycle. As a result, carbonate platforms were sensitive recorders of environmental change, which often anticipated global environmental perturbations. A good example is provided by the northern Tethyan carbonate platform, which is presently preserved in the central European Helvetic Alps. There, the latest early to late Valanginian Weissert episode of global change, which is defined by the first important positive shift in δ13C records of the Cretaceous, is expressed by a prolonged, stepwise drowning phase. In this contribution, a detailed reconstruction of palaeoenvironmental change before and during the Weissert episode is provided based on three representative sections of the Helvetic platform. The sections are placed along a deepening transect and correlated by means of ammonite and microfossil biostratigraphy, sequence stratigraphy and δ13C chemostratigraphy. In a first phase of palaeoenvironmental change during the latest Berriasian, photozoan carbonate production was stopped by a major and hitherto undetected drowning episode, which was followed by a phase of renewed carbonate production by heterozoan biota. This phase was linked to major sea‐level rise, a change to a more humid climate and strong regional subsidence associated with tectonic block tilting. During the Valanginian, the circulation of nutrient‐enriched sea waters prevented a return to oligotrophic conditions and two further drowning episodes occurred, which are both documented by condensed phosphate‐rich beds and dated as middle early Valanginian and late Valanginian to early Hauterivian. The exact causes of the three‐step deterioration in carbonate production are not established but a link to episodic volcanic activity is likely, eventually related to the formation of the Paranà‐Etendeka large igneous province.

Integrated microfossil biostratigraphy, facies distribution, and depositional sequences of the upper Turonian to Campanian succession in northeast Egypt and Jordan

Six upper Turonian to Campanian sections in Egypt (Sinai) and Jordan were studied for their microfossil biostratigraphy (calcareous nannofossils and planktonic foraminifera), facies distribution and sequence stratigraphic frameworks. Carbonate (mostly chalk) and chert lithofacies dominate the basinward northern sections passing laterally and vertically to mixed carbonate/siliciclastic lithofacies towards the shoreline in the southeast. Twenty-six lithofacies types have been identified and grouped into six lithofacies associations: littoral siliciclastic facies belt; peritidal carbonate; intertidal carbonate platform/ramp; high-energy ooidal shoals and shelly biostromes; shallow subtidal; and pelagic facies association. The following calcareous nannofossil biozones were recognized: Luianorhabdus malefomis (CC12) (late Turonian), Micula staurophora (CC14) (early Coniacian), Reinhardtites anthophorus (CC15) (late Coniacian), Lucianorhabdus cayeuxii (CC16) (early Santonian) and Broinsonia parca parca (CC18) (Campanian). Equivalent planktonic foraminifera zones recognized are: Dicarinella concavata (Coniacian), the lower most part of Dicarinella asymetrica (earliest Santonian) and Globotruncanita elevata (early Campanian). The integrated zonation presented here is considered to provide higher resolution than the use of either group alone. The absence of calcareous nannofossil biozones CC13 and CC17 in most of the studied sections, associated with regional vertical lithofacies changes, indicates that recognition of the Turonian/Coniacian and Santonian/Campanian stage boundary intervals in the region have been hampered by depositional hiatuses at major sequence boundaries resulting in incomplete sections. These disconformities are attributed to eustatic sea-level fluctuations and regional tectonics resulting from flexuring of the Syrian Arc fold belt. The Coniacian to Santonian succession can be divided into three third-order depositional sequences, which are bounded by four widely recognized sequence boundaries.

Integrating Paleobotanical, Paleosol, and Stratigraphic Data to Study Critical Transitions: A Case Study From The Late Cretaceous–Paleocene Of India

During the Cretaceous and Paleogene, the Indian subcontinent was isolated as it migrated north from the east coast of Africa to collide with Asia. As it passed over the Reunion hotspot in the late Maastrichtian–early Danian, a series of lava flows extruded, known as the Deccan Traps. Also during this interval, there was a major mass-extinction event at the Cretaceous–Paleogene boundary, punctuated by a meteorite impact at Chicxulub, Mexico. What were the biological implications of these changes in paleogeography and the extensive volcanism in terms of biodiversity, evolution, and biogeography? By combining chronostratigraphic, paleosol, and paleobotanical data, an understanding of how the ecosystems and climates changed and the relative contributions of the Chicxulub impact, Deccan Traps volcanism, and paleogeographic isolation can be gained. Understanding relative ages of paleobotanical localities is crucial to determining floristic changes, and is challenging because different methods (e.g., magnetostratigraphy, radiometric dating, vertebrate and microfossil biostratigraphy) sometimes give conflicting answers, or have not been done for paleobotanical localities. Climatic data can be obtained quantitatively by studying paleosol geochemistry, as well as qualitatively by examining functional traits and nearest living relatives of fossil plants. An additional challenge is revising macrofossil data, which includes some confidently identified taxa and others with uncertain affinities. This is important for understanding ecosystem composition both spatially and temporally, as well as the biogeographic implications of an isolated India.

Tithonian and Lower Berriasian calpionellid against ammonite biostratigraphy of the Dvuyakornaya Formation in eastern Crimea

The Dvuyakornaya Formation in eastern Crimea of late Kimmeridgian to Berriasian age represents a thick flysch-like succession of clays, marls and less common limestones. The ammonite zonation includes incomplete record from the Beckeri Zone in the uppermost Kimmeridgian up to the Jacobi Zone in the Lower Berriasian. Two main sections have been micropalaeontologically studied – the Dvuyakornaya Buhta and the Cape Svyatogo Ili’i. Eighteen calpionellid species of the genera Longicollaria, Chitinoidella, Daciella, Dobeniella, Popiella, Praetintinnopsella, Tintinnopsella, Crassicollaria and Calpionella have been found. The calpionellid zones Chitinoidella (with Dobeni and Boneti subzones), Crassicollaria and Calpionella (with Alpina and Elliptica subzones) are described and directly correlated to the existing ammonite biostratigraphy. The Dobeni Subzone corresponds to a part of the barren interval between the ammonite Hybonotum and Microcanthum zones, the Boneti Subzone – to the Microcanthum Zone, and the Crassicollaria Zone – to the Durangites Zone p.p. and Jacobi Subzone p.p. The boundary between the Crassicollaria and Calpionella zones is within the Jacobi Subzone. In the Berriasian, the Alpina Subzone has been correlated to the Jacobi and Grandis subzones, and the Elliptica Subzone – to upper part of the Grandis Subzone that was characterized in the Dvuyakornaya Formation by diverse ammonite faunas of the “Feodosiya Marlstones”. Chitinoidellids of the Dobeni Subzone for the first time determine late Early Tithonian age in the area. Calpionellid to ammonite correlation of the Dvuyakornaya Formation is discussed in the light of previous direct correlations between macro- and microfossil biostratigraphy of the Tithonian and the Lower Berriasian in the Tethyan Realm.

Microfossil Biostratigraphy and Paleoenvironments of the Upper Pliocene Kuwae Formation, Northeast Japan

Microfossils abundantly occur in the upper part of the Pliocene Kuwae Formation in the Sakai stratigraphic section, Tainai City, northern Niigata Prefecture. We clarified the biostratigraphy and reconstructed the vertical paleoenvironmental changes based on micro fossils such as ostracodes, diatoms and planktonic foraminifers. As a result, the sequence in the Sakai section was divided into three parts based on lithology and correlated with the Neodenticula koizumii-N. kamtschatica diatom zone (NPD 8, 3.5-2.7 Ma). At least the lower and middle parts of the study sequence were assigned to the horizon below the datum of the rapid increase of N. koizumii (D85, 3.1-3.0 Ma). An index fossil planktonic foraminiferal species, Globorotalia inflata (s.l.), was abundantly found only in the middle to upper part of the study interval. This interval belonged to the No. 3 G. inflata bed, which has been used as a biozone in the Sea of Japan side during the Pliocene. Four ostracode bio associations were identified using R-mode cluster analysis. Based on ostracode analysis, the Kuwae Formation in the present study section was shown to have benn deposited in the sublittoral to upper bathyal zone and at least one cycle of water depth change was found. In addition, one new ostracode species, Hemicythere sakaiensis sp. nov., was described in this study.

Palynological and microfossil biostratigraphy and palaeoecology over the Paleocene–Eocene transition, Femern Bælt, northern Germany

A palynological and micropalaeontological biostratigraphic and palaeoecological investigation has been carried out on the Paleocene–Eocene transition of core 10.A.057 from the Femern Bælt (Fig. 1). Initial investigations of boreholes from the Femern Bælt indicated that core 10.A.057 included a thick succession of Upper Paleocene – Lower Eocene clay (Sheldon & Nøhr Hansen 2010; Rambøll Arup JV 2011; Fig 2). Complete Paleocene–Eocene sections have been described from Jylland and the Storebælt (Heilmann-Clausen 1985, Laursen & Andersen 1997; Laursen & King 2000, Nielsen et al. 1986), but no detailed studies have been published on these successions from the Femern Bælt. Boreholes were drilled on Lolland in Denmark, under the Femern Bælt and on Fehmarn island, Germany from 2009 to 2011 as part of geological and geophysical investigations performed in preparation for the construction of a fixed road and rail link connecting Denmark and Germany. The boreholes penetrated Campanian – Upper Eocene strata, overlain by Quaternary deposits. Borehole 10.A.057 is located in the southern part of the Femern Bælt (Figs 1, 2).

A high-resolution carbon-isotope record of the Turonian stage correlated to a siliciclastic basin fill: Implications for mid-Cretaceous sea-level change

Turonian strata of the Bohemian Cretaceous Basin, Central Europe, preserve a basin-scale record of shoreline transgressions and regressions, previously interpreted to have been strongly influenced by short-term eustatic cycles. Here, nearshore siliciclastic strata in two separate sub-basins are correlated to a multi-stratigraphic dataset generated from a new research core (Bch-1) drilled in offshore marine sediments of the central basin. A high-resolution δ13Corg record from Bch-1 is presented along with major- and minor-element proxies, TOC, carbonate content, terrestrial to marine palynomorph ratios, and detailed macro- and microfossil biostratigraphy. The 400m thick Turonian through Lower Coniacian interval permits correlation to the highest-resolution C-isotope curves available: all carbon-isotope events demonstrated by δ13Ccarb studies in the British Chalk, NW Germany and other reference sections in Europe are recognized in the δ13Corg curve from Bch-1.A number of short-term, basin-wide regressions in the Bohemian Cretaceous Basin, most likely reflecting eustatic falls, show a recurrence interval of 100kyr or less. This is an order of magnitude shorter than the timing of sea-level falls inferred from the New Jersey margin and the Apulian platform, interpreted to be driven by glacioeustacy. The estimated magnitude of the Bohemian Basin sea-level falls, typically 10–20m and generally <40m, indicates that the 2.4Myr period suggested by others to generate 3rd-order cycles, is too long to be the principal cycle generating unconformities in rapidly-subsiding basins, where the rate of eustatic fall must exceed the subsidence rate. Unconformities in low-accommodation settings such as passive margins most likely represent amalgamated records of multiple cycles of sea-level fluctuations of 100kyr scale, recognizable only in high-resolution datasets from expanded successions.Comparison of the δ13C excursions to the interpreted sea-level record has not yielded a clear causal link. A long-term ‘background’ δ13C cycle shows a duration close to the 2.4Myr long-eccentricity cycle, and shorter-term (1Myr scale) highs and lows in δ13C appear to broadly correspond to intervals characterised by more pronounced short-term sea-level highs and lows, respectively. However, on the scale of intermediate to short-term δ13C fluctuations, no systematic relationship between δ13C and sea-level change can be demonstrated.

Early Eocene warming events and the timing of terrestrial faunal exchange between India and Asia

The timing of initiation of continent-continent collision between Asia and India is controversial, but this major tectonic event is generally thought to have occurred in the Early Eocene, ca. 50 Ma. New and independent data from strontium isotopes, stable carbon isotopes, microfossil biostratigraphy, and mammal fossils from an Early Eocene marginal marine sequence (Cambay Shale) at the Vastan Lignite Mine of western India indicate that terrestrial faunal exchanges, and therefore continental collision, between Asia and the Indian subcontinent took place before 53.7 Ma. This age coincides with the second Eocene Thermal Maximum (ETM2), a short-lived warming episode that followed the Paleocene-Eocene Thermal Maximum (PETM) ca. 55.5 Ma. Our data also document, for the first time, a clear record of the ETM2 in terrestrial organic material from a low-latitude site, which is represented by a 3‰−4‰ carbon isotope excursion (CIE) in lignite and dispersed organic carbon δ13C values. The magnitude of the CIE at this location closely matches that observed in marine cores from the Arctic Ocean, which supports an interpretation that this hyperthermal event, though of lower magnitude, was similar in character to that of the PETM, being a global phenomenon that affected both terrestrial and marine ecosystems.

MEMORIAL TO GERHARD FRIEDRICH LUTZE (1932-2009)

Other| October 01, 2009 MEMORIAL TO GERHARD FRIEDRICH LUTZE (1932–2009) Alexander V. Altenbach; Alexander V. Altenbach 1Department of Earth and Environmental Sciences, Palaeontology & Geobiology, Richard-Wagner-Str. 10, 80333 Munich, Germany Search for other works by this author on: GSW Google Scholar Ralf Schiebel; Ralf Schiebel 2Laboratoire des Bio-Indicateurs Actuels et Fossiles (BIAF), Université d’Angers, 2 Boulevard Lavoisier, 49045 Angers CEDEX 01, France Search for other works by this author on: GSW Google Scholar Joachim Schönfeld; Joachim Schönfeld 3Leibniz Institute of Marine Sciences, IFM-GEOMAR, Wischhofstr. 1-3, 24148 Kiel, Germany Search for other works by this author on: GSW Google Scholar Gerold Wefer Gerold Wefer 4MARUM, Universitaet Bremen, Leobener Strasse, 28359 Bremen, Germany Search for other works by this author on: GSW Google Scholar Author and Article Information Alexander V. Altenbach 1Department of Earth and Environmental Sciences, Palaeontology & Geobiology, Richard-Wagner-Str. 10, 80333 Munich, Germany Ralf Schiebel 2Laboratoire des Bio-Indicateurs Actuels et Fossiles (BIAF), Université d’Angers, 2 Boulevard Lavoisier, 49045 Angers CEDEX 01, France Joachim Schönfeld 3Leibniz Institute of Marine Sciences, IFM-GEOMAR, Wischhofstr. 1-3, 24148 Kiel, Germany Gerold Wefer 4MARUM, Universitaet Bremen, Leobener Strasse, 28359 Bremen, Germany Publisher: Cushman Foundation for Foraminiferal Research First Online: 03 Mar 2017 Online ISSN: 1943-264X Print ISSN: 0096-1191 © 2009 Journal of Foraminiferal Research Journal of Foraminiferal Research (2009) 39 (4): 361–363. https://doi.org/10.2113/gsjfr.39.4.361 Article history First Online: 03 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Alexander V. Altenbach, Ralf Schiebel, Joachim Schönfeld, Gerold Wefer; MEMORIAL TO GERHARD FRIEDRICH LUTZE (1932–2009). Journal of Foraminiferal Research 2009;; 39 (4): 361–363. doi: https://doi.org/10.2113/gsjfr.39.4.361 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyJournal of Foraminiferal Research Search Advanced Search Gerhard Friedrich Lutze was born in Braunschweig, Germany, on 12 April 1932 to Hildegard and Paul Gustav Friedrich Lutze who was an electronic engineer. Gerd attended the Wilhelm-Gymnasium and reformed Oberrealschule in Braunschweig. He moved up a year because he was an extremely gifted student, and graduated from a class of five students. Gerd studied at the Universities of Tübingen and Braunschweig. At the latter, Professor Paul Dorn proposed that Gerd pursue the doctoral thesis in which he established a foraminiferal and ostracodal biostratigraphy for Lower Saxony (NW Germany) that closely correlated with the existing ammonite zonation. While pursuing his... You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

The onset of the Messinian salinity crisis: Insights from Cyprus sections

The Neogene basins of Southern Cyprus provide a good opportunity to improve the knowledge of the paleoenvironmental changes involved in the triggering of the Messinian evaporite deposition in the Mediterranean, and of their chronology, which is still questionable with regards to the parameters responsible for the triggering of the salinity crisis. It is still difficult to discriminate the individual effects of tectonics, climate, global sea-level changes. In Cyprus, considerable progress has been made on the events leading to the MSC, since the 70's, in high-resolution microfossil biostratigraphy, astrochronology, cyclostratigraphy and magnetostratigraphy. A study of the Tochni section, in the Psematismemos Basin, correlated with previously studied sections in the western Polemi and Pissouri basins, allows these regional paleoenvironmental changes to be correlated with the major events identified in other Mediterranean basins. The depth of the basins, in which evaporites were deposited, and the increase of salinity leading to the formation of evaporites are better constrained and studies confirm that restriction proceeded by steps throughout the Mediterranean. The very short time involved in the triggering of the onset of evaporite deposition in Cyprus basins is marked by tectonic instability, and development of very shallow water fauna and microbial communities indicating the water level lowered significantly just before the beginning of the massive gypsum precipitation. Correlation with other peri-Mediterranean basins, where similar changes have been observed, confirms that the period preceding the deposition of evaporites may correspond to the final closure of connections between the Atlantic Ocean and the Mediterranean Basin, leading to a sea-level drop and important hydrologic changes.