42 research outputs found

    TAPHONOMIC TOOLS TO EVALUATE SEDIMENTATION RATES AND STRATIGRAPHIC COMPLETENESS IN ROSSO AMMONITICO FACIES (EPIOCEANIC TETHYAN JURASSIC)

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    A combined multidisciplinary approach has been applied to calculate minimum values of the stratigraphic completeness and, secondarily, sedimentation rates in 9.2 m thick Rosso Ammonitico facies from central Apennines (Italy) and 11 m thick deposits of the same facies in Southern Spain. Middle - Upper Toarcian expanded sedimentation in Valdorbia section (Umbria-Marche Apennines) and extremely condensed Oxfordian-Tithonian sedimentation at Puerto Escaño section (External Subbetic) have been investigated using combined taphonomic, ichnologic and sedimentologic data and analyses. At Valdorbia, infaunal tiering is largely preserved and 27 horizons of infaunal-tiering truncation and casting reveal strong erosional activity forced by tempestite/turbidite events. Therefore, microstratigraphic gaps could be evaluated without biostratigraphic control. In this expanded section, 13 horizons of firm- and hardgrounds have been recorded showing simple or gradational tiering. Conversely, in the condensed Puerto Escaño section, taphonomic analysis reveals 25 horizons of bioclasts truncation (mainly in ammonites), and 56 horizons of firm-hardgrounds intensively bioturbated. In Valdorbia rather than in Puerto Escaño section, the evaluation of flattening in burrows and spherical bioclasts reveal a measurable mechanical compaction and dissolution. In addition, Rosso Ammonitico at Valdorbia section favoured the calculation of decompaction coefficients (nd) for each lithology easier than in Puerto Escaño section. In condensed and essentially hiatal Rosso Ammonitico, mottled deposits due to intense bioturbation dominate and tiering cannot be recognizable. This fact is accentuated by usual overprinting of elementary depositional events, which in turn hampered the accurate calculation of missing deposits. Therefore, in condensed Rosso Ammonitico the latter was only available in terms of minimal missing-record trough the analysis of truncated bioclasts.&nbsp

    Foraminiferal assemblages as palaeoenvironmental bioindicators in Late Jurassic epicontinental platforms: relation with trophic conditions

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    Foraminiferal assemblages from the neritic environment reveal the palaeoecological impact of nutrient types in relation to shore distance and sedimentary setting. Comparatively proximal siliciclastic settings from the Boreal Domain (Brora section, Eastern Scotland) were dominated by inner−shelf primary production in the water column or in sea bottom, while in relatively seawards mixed carbonate−siliciclastic settings from the Western Tethys (Prebetic, Southern Spain), nutrients mainly derived from the inner−shelf source. In both settings, benthic foraminiferal assemblages increased in diversity and proportion of epifauna from eutrophic to oligotrophic conditions. The proximal setting example (Brora Brick Clay Mb.) corresponds to Callovian offshore shelf deposits with a high primary productivity, bottom accumulation of organic matter, and a reduced sedimentation rate for siliciclastics. Eutrophic conditions favoured some infaunal foraminifera. Lately, inner shelf to shoreface transition areas (Fascally Siltstone Mb.), show higher sedimentation rates and turbidity, reducing euphotic−zone range depths and primary production, and then deposits with a lower organic matter content (high−mesotrophic conditions). This determined less agglutinated infaunal foraminifera content and increasing calcitic and aragonitic epifauna, and calcitic opportunists (i.e., Lenticulina). The comparatively distal setting of the Oxfordian example (Prebetic) corresponds to: (i) outer−shelf areas with lower nutrient input (relative oligotrophy) and organic matter accumulation on comparatively firmer substrates (lumpy lithofacies group) showing dominance of calcitic epifaunal foraminifera, and (ii) mid−shelf areas with a higher sedimentation rate and nutrient influx (low−mesotrophic conditions) favouring potentially deep infaunal foraminifers in comparatively unconsolidated and nutrient−rich substrates controlled by instable redox boundary (marl−limestone rhythmite lithofacies).This research was carried out with the financial support of projects CGL2005−06636−C0201 and CGL2005−01316/BTE, and University of Oslo, Norway−Statoil cooperation. M.R. holds a Juan de la Cierva grant from the Ministry of Science and Technology of Spain

    Extracción in situ de ADN genómico para el análisis por PCR de regiones de interés en cuatro especies vegetales y un hongo filamentoso

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    The extraction methods of genomic DNA are usually laborious and hazardous to human health and the environment by the use of organic solvents (chloroform and phenol). In this work a protocol for in situ extraction of genomic DNA by alkaline lysis is validated. It was used in order to amplify regions of DNA in four species of plants and fungi by polymerase chain reaction (PCR). From plant material of Saccharum officinarum L., Carica papaya L. and Digitalis purpurea L. it was possible to extend different regions of the genome through PCR. Furthermore, it was possible to amplify a fragment of avr-4 gene DNA purified from lyophilized mycelium of Mycosphaerella fijiensis. Additionally, it was possible to amplify the region ap24 transgene inserted into the genome of banana cv. `Grande naine' (Musa AAA). Key words: alkaline lysis, Carica papaya L., Digitalis purpurea L., Musa, Saccharum officinarum L.Los métodos de extracción de ADN genómico son generalmente trabajosos y peligrosos para la salud humana y el medio ambiente por el uso de solventes orgánicos (cloroformo y fenol). En este trabajo se valida un protocolo de extracción in situ de ADN genómico por lisis alcalina. Se empleó con el objetivo de amplificar regiones del ADN en cuatro especies de plantas y de un hongo mediante la reacción en cadena de la polimerasa (PCR). Se utilizó material vegetal de Saccharum officinarum L., Carica papaya L., Digitalis purpurea L. de los cuales se logró extender diferentes regiones del genoma a través de PCR. Fue posible amplificar un fragmento del gen avr-4 de ADN purificado a partir de micelio liofilizado de Mycosphaerella fijiensis Morelet. Adicionalmente, se logró amplificar la región del transgen ap24 insertado en el genoma de banano cv. `Grande naine' (Musa AAA). Palabras clave: Carica papaya L., Digitalis purpurea L., lisis alcalina, Musa, Saccharum officinarum L

    Open questions in utility theory

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    Throughout this paper, our main idea is to explore different classical questions arising in Utility Theory, with a particular attention to those that lean on numerical representations of preference orderings. We intend to present a survey of open questions in that discipline, also showing the state-of-art of the corresponding literature.This work is partially supported by the research projects ECO2015-65031-R, MTM2015-63608-P (MINECO/ AEI-FEDER, UE), and TIN2016-77356-P (MINECO/ AEI-FEDER, UE)

    Ammonites from the Oxfordian-Kimmeridgian boundary and the Lower–Upper Kimmeridgian of Kachchh, western India

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    Several new specimens of ammonites from the Oxfordian and Kimmeridgian of Kachchh, western India, are described and illustrated. The Oxfordian ammonites ?Subdiscosphinctes Malinowska, Perisphinctes Waagen, Dichotomoceras Buckman, and ?Larcheria Tintant, all from Bharodia in the Wagad Uplift, enable tentative biochronostratigraphic correlations with the uppermost Middle Oxfordian up to the lower Upper Oxfordian of the unified Submediterranean zonation, whereas the Kimmeridgian ammonites Streblites Hyatt, “Orthosphinctes” Schindewolf, Torquatisphinctes Spath, Pachysphinctes Dietrich, Katroliceras Spath, Aspidoceras Zittel, and Schaireria Checa reconfirm a stratigraphic gap embracing incompletely known parts of the uppermost Oxfordian and the Lower Kimmeridgian as known from the ammonite records of the Kachchh Mainland of the Kachchh Basin

    In situ</font></i><font size="3"> genomic DNA extraction for PCR analysis of regions of interest in four plant species and one filamentous fungi

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    The extraction methods of genomic DNA are usually laborious and hazardous to human health and the environment by the use of organic solvents (chloroform and phenol). In this work a protocol for in situ extraction of genomic DNA by alkaline lysis is validated. It was used in order to amplify regions of DNA in four species of plants and fungi by polymerase chain reaction (PCR). From plant material of Saccharum officinarum L., Carica papaya L. and Digitalis purpurea L. it was possible to extend different regions of the genome through PCR. Furthermore, it was possible to amplify a fragment of avr-4 gene DNA purified from lyophilized mycelium of Mycosphaerella fijiensis. Additionally, it was possible to amplify the region ap24 transgene inserted into the genome of banana cv. `Grande naine' (Musa AAA). Key words: alkaline lysis, Carica papaya L., Digitalis purpurea L., Musa, Saccharum officinarum L
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