Search results for "Sediment"

Rediscovery of the allegedly “destroyed” holotype of Weltrichia fabrei Saporta, 1891 from the Rhaetian?/Hettangian of Lozère (Southern France)

2018

7 pages; International audience; A sandstone slab bearing plant macro-remains was rediscovered during recent investigations led in the buildings of the old Musée Ignon-Fabre (Mende) which were closed in 1995 and emptied in 2003. The study of the slab clearly allows it to be identified as the holotype of Weltrichia fabrei Saporta, 1891 which has been considered destroyed since the end of the 20th Century. Gaston de Saporta described this Bennettitalean fructification based on a cast and considered the type locality as Rhaetian in age. In the present paper, based on the holotype, W. fabrei was revised in order to describe and illustrate the specimen in detail. It consists of a cup with one wh…

Multi-residue determination of 47 organic compounds in water, soil, sediment and fish—Turia River as case study

2017

A sensitive and reliable method based on solid-liquid extraction (SLE) using McIlvaine-Na2EDTA buffer (pH = 4.5)-methanol and solid-phase extraction (SPE) clean up prior to ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC–MS/MS) was applied to determine 47 organic contaminants in fish, soil and sediments. The SPE procedure to clean-up the extracts was also used as extraction method to determine these compounds in water. Recoveries ranged from 38 to 104% for all matrices with RSDs 50% for 36 compounds in front of 9, matrix effect < 20% for 31 compounds against 21, and LOQs <25 ng g−1 for 38 compounds against 22) indicates that the proposed method is mor…

2020

Abstract. We apply three-dimensional (3-D) thermo-mechanical numerical simulations of the shortening of the upper crustal region of a passive margin in order to investigate the control of 3-D laterally variable inherited structures on fold-and-thrust belt evolution and associated nappe formation. We consider tectonic inheritance by employing an initial model configuration with basement horst and graben structures having laterally variable geometry and with sedimentary layers having different mechanical strength. We use a visco-plastic rheology with a temperature-dependent flow law and a Drucker–Prager yield criterion. The models show the folding, detachment (shearing off) and horizontal tra…

Influence of surface processes and initial topography on lateral fold growth and fold linkage mode

2015

Elongation of randomly distributed fold segments and their potential linkage are important for hydrocarbon exploration because it can greatly influence the morphology of the reservoir and both migration and accumulation of hydrocarbons in antiformal traps. Here we study the effects of surface processes and the presence of a topographic slope on the different linkage modes that can occur, and how these parameters affect the required horizontal offset for perturbations to link. The proposed numerical model represents a sedimentary cover detached over a much weaker basal decollement layer. The upper surface is modified by mass redistribution, which is achieved by a combination of fluvial and h…

Tectonic transport directions of the Lycian nappes in southwest Turkey constrained by kinematic indicators

2013

The orientation, asymmetry and cross-cutting relationships of the structures along the contact zone between the Lycian nappes and the Menderes Massif suggest the presence of three deformation phases in the Milas region of southwest Turkey. The first deformation phase (D1) is characterized by a ductile deformation with top-to-the-NE sense of shear. Structural data of the first deformation measured along the uppermost part of the Menderes Massif and the base of the Lycian nappes suggest that the lowermost unit of the Lycian nappes was emplaced initially from southwest to northeast onto the Menderes Massif during the Early Eocene. The second deformation phase (D2) is also ductile in nature and…

Unraveling long-term changes in lake color based on optical properties of lake sediment

2020

A number of boreal surface waters have become browner over the last two decades. Recovery from acid rain is regarded as an important driver for this lake color increase, indicating a general browner lake color in preindustrial times. However, the lack of long-term monitoring data makes it challenging to unravel historical changes in lake color. In this study, we estimated long-term development in lake color (1800 to 2015) based on the optical properties of alkaline extractable dissolved organic matter (DOM) from sediment using UV–Vis and fluorescence spectroscopy. We found that the present lake color (2015) was significantly browner (four times higher in absorption coefficient) than for the…

STUDIO GEOMORFOLOGICO DEL MARGINE IONICO DELLA CALABRIA: EVOLUZIONE MORFO-SEDIMENTARIA RECENTE ED INDIVIDUAZIONE DEGLI ELEMENTI DI PERICOLOSITA' GEOL…

2012

Mikroelementu sadalījums Liepājas ezera sedimentos

2015

Darbā novērtēts vairāku mikroelementu (Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, Hg un Pb) sadalījums Liepājas ezera sedimentos. Telpiskais elementu sadalījums ir samērā heterogēns, kas norāda uz vairākiem iespējamiem mikroelementu izcelsmes avotiem. Sedimenti tika sadalīti frakcijās ar sekojošiem daļiņu izmēriem: 100 μm, 80 μm, 63 μm, 50 μm un <50 μm. Visaugstākās koncentrācijas visiem elementiem tika konstatētas sedimentu frakcijās ar daļiņu izmēriem 63 un 50 μm. Sedimentu kvalitāte un piesārņotības pakāpe tika novērtēta izmantojot ģeoakumulācijas indeksu, bagātinātības faktoru, piesārņojuma slodzes indeksu un koncentrēšanas faktoru, kas parādīja, ka sedimenti visās frakcijās nav piesārņoti ar …

Ecotoxicological status of a watercourse recovering from heavy loading by pulp and paper industry

2013

A lacustrine record of the early stage of the Miocene Climatic Optimum in Central Europe from the Most Basin, Ohře (Eger) Graben, Czech Republic.

2014

AbstractThis study reports on a ~ 150 m thick macrofossil-barren sequence of siliciclastic sediments from a Burdigalian age (Early Miocene) freshwater lake. The lake was located within an incipient rift system of the Most Basin in the Ohře (Eger) Graben, which was part of the European Cenozoic Rift System, and had an original area of ≈ 1000 km2. Sediments from the HK591 core that cover the entire thickness of the lake deposits and some of the adjacent stratigraphic units were analysed by X-ray fluorescence spectroscopy (a proxy for element composition) and magnetic polarity measurement. The element proxies were subjected to frequency analysis, which provided estimated sedimentation rates, a…