Age determination of Southeast Atlantic sediment cores

Angola Basin and Cape Basin (southeast Atlantic) surface sediments and sediment cores show that maxima in the abundance of taraxerol (relative to other land-derived lipids) covary with maxima in the relative abundance of pollen from the mangrove tree genus Rhizophora and that in the surface sediments offshore maxima in the relative abundance of taraxerol occur at latitudes with abundant coastal mangrove forests. Together with the observation that Rhizophora mangle and Rhizophora racemosa leaves are extraordinarily rich in taraxerol, this strongly indicates that taraxerol can be used as a lipid biomarker for mangrove input to the SE Atlantic. The proxy-environment relations for taraxerol and Rhizophora pollen down-core show that increased taraxerol and Rhizophora pollen abundances occur during transgressions and periods with a humid climate. These environmental changes modify the coastal erosion and sedimentation patterns, enhancing the extent of the mangrove ecosystem and/or the transport of mangrove organic matter offshore. Analyses of mid-Pleistocene sediments show that interruption of the pattern of taraxerol maxima during precession minima occurs almost only during periods of low obliquity. This demonstrates the complex environmental response of the interaction between precession-related humidity cycles and obliquity-related sea-level changes on mangrove input.

Characteristics and distribution of Neogene turbidites at ODP Site 108-657

Numerous and variable silty-sandy siliciclastic turbidites were observed in Neogene pelagic sediments (late Miocene to Holocene) at Site 657: (1) thick-bedded, coarse-grained and thin-bedded, fine-grained turbidites; and (2) turbidites composed of eolian dune sand and shallow-water bioclasts or of fluvial-sand or mixed sandy component assemblages. The stratigraphic distribution of these turbidites indicates five periods during which climatic conditions and material sources change. Turbidite occurrence prior to 6.2 Ma (late Miocene) is sparse; the deposits contain coarse and fine-grained turbidites with quartz grains of eolian or mixed origin suggesting the existence of arid conditions at about 8.5 and 6.5 Ma. A coarse-grained turbidite of fluvial origin, recording a humid climate, occurs at about 6.2 Ma. During the early Pliocene, turbidites are frequent (15/Ma); they contain only fine-grained sequences comprising material of mixed origin, which indicates a more humid climate perhaps. The late Pliocene starts with rare coarse-grained turbidites of wind-transported sand while the uppermost Pliocene deposits show a higher frequency of fine-grained sequences (10/0.7 Ma) composed mainly of fluvial material. During the early Pleistocene, similar high turbidite frequency was observed (20/1.3 Ma) but with a total lack of eolian supply. During the last 0.7 Ma, the frequency decreases and the sequences are characterized by highly variable sediment components that could be related to strong variations of climatic conditions. The sedimentary characteristics of turbidites are mainly controlled by sediment source and climate. The frequency must be influenced by sea-level variations, by cyclic processes of climatic origin, and possibly by variations in the continental slope morphology. Clay mineral assemblages suggest a south Saharan source of terrigenous material during the late Miocene and the Pliocene and a northwest Saharan source during the Pleistocene.

Composition of the sand fraction of sediment cores from the West-African continental margin

Seven cores from the West African continental margin in 12-18° N have been investigated by means of a coarse fraction analysis. Four of the seven cores contain allochthonous material: turbidites and debris flow deposits. The source of the allochthonous material is in about 300-600 m water depth. The age of the slide induced debris flow deposits is at the end of oxygen isotope stage 2. One debris flow deposit is covered by a turbidite (core GIK13211-1). The turbidites in the deep-sea core GIK13207-3 originate from river-influenced sediments from the West-African continental margin, whereas the autochthonous sequences are influenced by volcanic material from the Cape Verde Islands. Particle by particle supply from upper slope areas has been found in all four cores from the continental slope. Current sorting occurs on the submarine diapir (core GIK13289-3), whereas core GIK13291-1 on the NW-flanc, 200 m below core GIK13289-3, has no current sorting, except for stage 1 and parts of stage 5. The current sorting is reflected by parallel variations of median diameters of whole tests and of fragments of planktonic foraminifers, by higher median diameters of foraminifers on top of the diapir, by reduced accumulation rates and increased sand fraction percentages in core GIK13289-3 compared to core GIK13291-1. The Late Quarternary climatic history of the West-African near coastal area (12-18° N) has been redrawn: - in oxygen isotope stage 1 a humid climate is found in 12-18° N (This "humid impression" in 18° N, which is actually an arid area, is due to the poleward directed undercurrent, which transports Senegal river material to the north). - in oxygen isotope stage 2 an arid climate existed in 14-18° N, whereas in 12° N river discharfe persisted. But within stage 2 dune formation occured in 12° N on the (dry) shelf, additionally to fluviatile sediment input. - Older periods are preserved in autochthonous sediments of core GIK13289-3 and GIK13291-1, where oxygen stage 3,5 and 7 (the latter only in core GIK13289-3 present) show a humid climate (as well as in stage 5 of core GIK13255-3), interrupted by short arid intervals in core GIK12389-3, and stage 4 and 6 show an arid climate, interrupted by short humid periods The allochthonous stage 5 sediment in core GIK13211-1 also reflects a humid climate. The dissolution of planktonic foraminifers is strongest in th eLate Holocene and shows a minimum in the early Holocene, where also pteropods are preserved. The degree of carbonate dissolution is related mainly to the fine matter content (< 63 µm) whereas water depth is a less decisvive factor.

Age model and sediment description of DSDP Hole 90-594, Chatham Ridge east of New Zealand

Detailed sedimentological investigations were performed on sediments from DSDP-Site 594 (Chatham Rise, east of New Zealand) in order to reconstruct the evolution of paleoclimate and paleoceanographic conditions in the Southwest Pacific during the last 6 million years. The results can be summarized as follows: (1) High accumulation rates of biogenic opal and carbonate and the dominance of smectites in the clay fraction suggest increased oceanic productivity and an equable dominantly humid climate during the late Miocene. (2) During Pliocene times, decreasing contents of smectites and increasing feldspar/quartz ratios point to an aridification in the source area of the terrigenous sediments, culmunating near 2.5 Ma. At that time, accumulation rates of terrigenous components distinctly increased probably caused by increased sediment supply due to intensified atmospheric and oceanic circulation, lowered sea level, and decreased vegetation cover. (3) A hiatus (1.45 to 0.73 Ma) suggests intensified intermediate-water circulation. (4) Major glacial/interglacial cycles characterize the upper 0.73 Ma. During glacial times, oceanic productivity and terrigenous sediment supply was distinctly increased because of intensified atmospheric and oceanic circulations and lowered sea level, whereas during interglacials productivity and terrigenous sediment supply were reduced. (5) An increased content of amphibols in the sediments of Site 594 indicates increased volcanic activities during the last 4.25 Ma.

Pollen record and dating of sediment core GIK16776-1 off Liberia

Based on pollen analysis of a sediment core from the Atlantic Ocean off Liberia the West African vegetation history for the last 400 ka is reconstructed. During the cold oxygen isotope stages 12, 10, 8, 6, 4, 3 and 2 an arid climate is indicated, resulting in a southward shifting of the southern border of the savanna. Late Pleistocene glacial stages were more arid than during the Middle Pleistocene. A persistence of the rain forest in the area, even during the glacial stages, is recorded. This suggests a glacial refuge of rain forest situated in the Guinean mountains. Afromontane forests with Podocarpus occurred in the Guinean mountains from the stages 12 to 2 and disappeared after. The tree expanded from higher to lower elevations twice in the warm oxygen isotope stage 11 (pollen subzones 11d, 11b) and at least twice during the warm stage 5 (pollen subzones 5d, 5a), indicating a relative cool but humid climate for these periods.

Grain size analysis and sedimentation rates of ODP Hole 175-1085A off the Namibian coast

Sediments from the ODP Site 1085A were studied to investigate the impacts of global cooling in the Middle and Late Miocene on the climate in Southwestern Africa. The size composition of the sediment was analysed emphasising the silt fraction. A comparison with the modern grain size distribution and suitable transport processes made it possible to assign specific transport processes to the grain size composition. Three processes are considered for transport of terrigeneous silt: while there was no evidence found for (1) transport by ocean currents, the analyses showed signals of (2) wind transport indicating dry conditions associated with a cool climate and (3) fluvial transport that points to humid and warm conditions. Three climatic phases were defined. The first phase from 13.8 to 11.8 Myr reveals a stable humid climate in Southwest Africa independent of the Antarctic glaciations. During the second phase from 11.8 to 10.4 Myr the regional climate cooled considerably but was not drier. Additionally, the climate during this phase reacted to the Antarctic glaciations. This cooling-trend continued during phase 3 from 10.4 to 9.0 Myr with a significant increase in dust input, pointing to overall drier conditions. However, fluvial transport still remained as the main source.

Experimental analysis of energy savings and hygrothermal conditions improvement by means of air curtaines in stores with intensive pedestrian traffic

Current worldwide building legislation requirements aim to the design and construction of technical services that reduce energy consumption and improve indoor hygrothermal conditions. The retail sector in Spain, with a lot of outdated technical systems, demands energy conservation measures in order to reduce the increasingly electrical consumption for cooling. Climatic separation with modern air curtains and advanced hygrothermal control systems enables energy savings and can keep suitable indoor air temperature and humidity of stores with intense pedestrian traffic, especially when located in hot humid climates. As stated in the article, the energy savings in commercial buildings with these systems exceeds 30%

Impact on agronomic parameters in Vines and wine quality of foliar treatments with specific fractions of yeast derivatives

In hot Spanish climate, Toledo, Syrah and Sauvignon blanc Vineyard were treated in pre veraison with yeast derivatives RD-LM and RD- LA to stimulate phenolic and aromatic maturity respectively (application of yeast derivatives specifically designed to be used with the patent foliar application technology WO/2014/024039, Lallemand Inc. Canada). For studied effects in berry and wine composition three harvest time had been done. Experimented yeast derivatives had no significant effects on yield components and vegetative growth in both varieties. The Syrah RD-LM variety presented higher total and extractable anthocyanins and also more amount of tannins, although this last ones are not evident in the sensory analysis. The sensory analysis of wine has given very similar results in both varieties but with significant results in favored by phenols and tannins derived RD- LM and RD-LA respectively.

Evolución paleoambiental de la Península Ibérica desde hace 1 Ma a partir de los biomarcadores del registro de la Turbera de Padul (Granada)

La Turbera de Padul, en la Provincia de Granada, ofrece unas posibilidades de estudio muy atractivas desde el punto de vista de la reconstrucción paleoambiental. Se trata de una fosa tectónica subsidente de naturaleza detrítica, a cuyo techo aparecen alternantes niveles de turba. El sondeo, de 107 metros, se realizó en un punto donde los estratos de turba aparecen a mayor profundidad, lo que permite obtener un registro geoquímico orgánico con mucho detalle con una antigüedad de hasta 1Ma. Se tomaron muestras cada 20 cm para el análisis de biomarcadores. Estos biomarcadores se obtuvieron mediante extracción Soxhlet, posterior separación de fracciones de diferente polaridad mediante Cromatografía en Columna, con Gel de Sílice y Alúmina, y posteriormente el análisis e identificación por Cromatografía de Gases - Espectrometría de masas, con confirmación de los compuestos químicos identificados por comparación con Bibliotecas de Espectros de Masas. La datación del sondeo se realizó utilizando distintos métodos como datación por 14C, U/Th, y datación por racemización de aminoácidos. Los resultados dataron el muro del sondeo con una antigüedad de 1 millón de años. El estudio de los biomarcadores ha permitido identificar episodios con distintas características en un escenario complejo, como es la Turbera de Padul, donde el aporte de agua por fusión nival complica la interpretación paleoambiental, y es la responsable de la existencia de la lámina de agua en la turbera en periodos secos con temperaturas elevadas. Se han identificado series de n-alcanos, de n-metilcetonas y series de nalcanoles, que han permitido identificar la aportación de materia orgánica de distintas fuentes al sedimento y por tanto la interpretación paleoambiental. La identificación de diterpenoides fenólicos (cis-Totatol, trans-Totarol y Ferruginol) han permitido identificar episodios de clima templado y húmedo con proliferación de cupresáceas, y precipitaciones abundantes. Por otro lado, se han identificado triterpenoides como el Friedelan-3-ona (Friedelin) y el A-norfriedel-8en-10-ona, cuya relación como precursor (Friedelin) y producto (A-norfriedel-8en-10-ona) ha permitido identificar episodios con fluctuaciones del espesor de la lámina de agua y aporte de material vegetal. ABSTRACT The Bog of Padul, in the province of Granada, offers very attractive possibilities for the study of paleoenvironmental reconstruction. It is a subsiding graben of detrital nature, whose upper part appear alternating peat levels. The core of 107 meters, obtained from a borehole drilled in a place where the layers of peat appear deeper, allowing to obtain organic geochemist information along the last 1 million years. Every 20 cm samples for biomarkers analysis were taken. These biomarkers were obtained by Soxhlet extraction, subsequent separation of fractions of different polarity by column chromatography with silica gel and alumina, and then analyzed and identified by gas chromatography - mass spectrometry, with confirmation of the chemicals identified by comparison to mass spectral libraries. The dating of the core was conducted using different methods such as 14C dating, U/Th, and amino acid racemization dating. The results dated the base of the core to be 1 million years old. The study has identified biomarkers episodes with different characteristics in a complex scenario, such as the Bog of Padul, where the contribution of snowmelt water complicates the paleoenvironmental interpretation, and is responsible for the existence of a sheet of water in dry periods with high temperatures. There have been identified series of n-alkanes, n-methyl ketones and series of n-alkanols that have shown the contribution of different organic matter sources to the sediment and therefore allowed to paleo interpretation. The identification of phenolic diterpenoids (cis-Totatol, trans-Totarol and Ferruginol) have identified episodes of mild and humid climate with proliferation of Cupressaceae, and abundant rainfall. In addition, triterpenoids have been identified, as the friedelan-3-one (friedelin) and the A-norfriedel-8en-10-one, whose relationship as precursor (friedelin) and product (A-norfriedel-8en-10-one) has identified episodes with fluctuations on the thickness of the sheet of water and supply of plant material debris.

Rock magnetic records and geochemical methods of sediment cores off NW Africa

Two gravity cores retrieved off NW Africa at the border of arid and subtropical environments (GeoB 13602-1 and GeoB 13601-4) were analyzed to extract records of Late Quaternary climate change and sediment export. We apply End Member (EM) unmixing to 350 acquisition curves of isothermal remanent magnetization (IRM). Our approach enables to discriminate rock magnetic signatures of aeolian and fluvial material, to determine biomineralization and reductive diagenesis. Based on the occurrence of pedogenically formed magnetic minerals in the fluvial and aeolian EMs, we can infer that goethite formed in favor to hematite in more humid climate zones. The diagenetic EM dominates in the lower parts of the cores and within a thin near-surface layer probably representing the modern Fe**2+/Fe**3+ redox boundary. Up to 60% of the IRM signal is allocated to a biogenic EM underlining the importance of bacterial magnetite even in siliciclastic sediments. Magnetosomes are found well preserved over most of the record, indicating suboxic conditions. Temporal variations of the aeolian and fluvial EMs appear to faithfully reproduce and support trends of dry and humid conditions on the continent. The proportion of aeolian to fluvial material was dramatically higher during Heinrich Stadials, especially during Heinrich Stadial 1. Dust export from the Arabian-Asian corridor appears to vary contemporaneous to increased dust fluxes on the continental margin of NW Africa emphasizing that melt-water discharge in the North Atlantic had an enormous impact on atmospheric dynamics.

Miocene microflora and palaeoclimate reconstructions from three sites in Bulgaria

In this study we reconstruct quantitatively the Middle to Upper Miocene climate evolution in the southern Forecarpathian Basin (Central Paratethys area, Northwest Bulgaria) by applying the coexistence approach to 101 well-dated palynofloras isolated from three cores. The climatic evolution is compared with changes in vegetation and palaeogeography. The Middle Miocene was a period of a subtropical/warm-temperate humid climate with mean annual temperature (MAT) between 16 and 18°C and mean annual precipitation (MAP) between 1100 and 1300 mm. Thereby, during the entire Middle Miocene a trend of slightly decreasing temperatures is observed and only small climate fluctuations occur which are presumably related to palaeogeographic reorganisations. The vegetation shows a corresponding trend with a decrease in abundance of palaeotropic and thermophilous elements. The Upper Miocene is characterised by more diverse climatic conditions, probably depending on palaeogeographic and global climatic transformations. The beginning of this period is marked by a slight cooling and a significant drying of the climate, with MAT 13.3-17°C and MAP 652-759 mm. After that, fluctuations of all palaeoclimate parameters occur displaying cycles of humid/dryer and warmer/cooler conditions, which are again well reflected in the vegetation. Our study provides a first quantitative model of the Middle-Upper Miocene palaeoclimate evolution in Southeastern Europe and is characterised by a relatively high precision and resolution with respect to the climate data and stratigraphy.

(Table 1) Content of sand fraction components in sediments of the interglacial MIS 7 optimum from Core LV28-42-4

Distribution of diatoms, radiolarians, planktonic and benthic foraminifers, and sediment components in fraction >0.125 mm was analyzed in a core obtained from the central Sea of Okhotsk within frameworks of the Russian-German KOMEX Project. The core section characterizes the period 190-350 ka, which corresponds to marine-isotopic stages (MIS) 7 to 10. During glacial MIS 10 and MIS 8, the basin accumulated terrigenous material lacking microfossils or containing them in low abundance, which reflects, along with their composition, heavy sea-ice conditions, suppressed bioproductivity, and bottom environment aggressive toward calcium carbonate. Interglacial MIS 9 was characterized by elevated bioproductivity with accumulation of diatomaceous ooze during the climatic optimum (328 to 320 ka). Water exchange with the Pacific was maximal from 328 to 324 ka ago. Environment became moderate and close to the present-day one at the end of the optimum exhibiting possible existence of a dichothermal layer with substantial amounts of surface Pacific water still flowing into the basin. Similar to interglacial MIS 5e and MIS 1, ''old'' Pacific water determined near-bottom environment in the central Sea of Okhotsk during that period, although influx of terrigenous material was higher, probably reflecting more humid climate of the region. Slight warming marked the terminal MIS 8 (approximately 260 ka ago). Paleoceanographic situation during the interglacial MIS 7 was highly variable: from warm-water to almost glacial. The main climatic optimum of MIS 7 occurred within 220-210 ka, when subsurface stratification increased and the dichothermal layer developed. Bottom environment during the studied time interval, except for the optimum of interglacial MIS 9, resembled those characteristic of glacial periods: actively formed ''young'' Okhotsk water displaced ''old'' Pacific deep water.

(Table A1) Calcium carbonate content of boreholes Kirchrode I and II

The technical details of drilling and coring at the Kirchrode I and II sites are presented. At these sites, a sequence of claystones and marlstones from an Albian shelf basin was recovered. Constraints on the ages of the sediments in the two boreholes are provided by the occurrence of the inoceramid bivalve Actinoceramus sulcatus, the first appearance of which is used to define the Middle/Upper Albian boundary and by observed facies changes that can be correlated to the established lithostratigraphy. The cores from the two boreholes provide a rather complete, 285-m-long sequence of the Upper Albian, with a 155.5-m-long overlap. Analysis of the tectonic structures showed considerable shortening in the Middle and Lower Albian part of the sequence due to normal faulting. Of the Upper Albian, only the lowermost part is affected by faults. The increase in sedimentation rates of terrigenous detritus and of marine biogenic carbonate, which occurs in the basal part of the C. auritus Subzone, is interpreted to reflect a regional change to a more humid climate and regional tectonic movements (uplift of the Rhenish Bohemian massif, subsidence of the Lower Saxony basin intensified locally by halokinetic movements). The further increase in marine productivity in the latest Albian may be related to upwelling of more nutrient-rich deep water along submarine relief in this shelf sea. Identification of Milankovitch cyclicity documented by the fluctuating CaCO3 contents of the sediments is used (i) to constrain the minimum time represented by the Upper Albian deposits, and (ii) to determine the duration of the sea level cycles (Cycle V: >=1.6 Ma, Cycle VI: >=2 Ma), and (iii) to establish the duration of the Late Albian ammonite subzones (e.g. Callihoplites auritus Subzone: 2.1 Ma). Average sedimentation rates determined from the identified 100-ka eccentricity cycles show a stepwise increase in sedimentation rates from 1-2 cm/1000 a in the Lower Albian dark claystones to 7-13 cm/1000 a in the late Late Albian. In addition to the general deepening trend through the Late Albian, two, nearly completely documented 3rd-order sea-level cycles in the Upper Albian of Kirchrode I were recognised, plus another one, cut short by faulting, at the base of the Upper Albian (documented in Kirchrode II). These global sea-level cycles were identified on the basis (a) of the sequence of the abundance maxima of selected benthos and plankton groups, (b) of trends in the fluctuations of the CaCO3 content, and (c) of the abundance of glauconite. The transgression periods in this Upper Albian deep shelf-basin are characterised by intensified circulation. This intensified circulation is found to have affected first the surface-near waters, resulting e.g. in an increase in the abundance of immigrant plankton and nekton species from the Tethys. At a later stage the deep water was affected, supporting then an increased population of suspension-feeding benthos, and causing condensation and erosion in the sediment at the sea floor.

Upper and Lower Body Anaerobic Muscular Power is Adversely Affected by Active Dehydration

A gap exists in the knowledge of acute dehydration and its effect on anaerobic muscular power. Therefore the purpose of this study was to examine the effects of active dehydration by exercise in a hot humid environment on anaerobic muscular power.

Effects of a Cooling Vest on Core and Skin Temperature Following a Heat Stress Trial in Healthy Males

The purpose of this study was to examine the effects of a cooling vest on core body temperature following active dehydration and hyperthermia induced by exercising in a hot, humid environment. Based on our study, we recommend the ClimaTech HeatShieldTM only when athletes present with mild symptoms of heat exhaustion.