Search results for "Processes"
showing 10 items of 3831 documents
Coralline algal growth-increment widths archive North Atlantic climate variability
2011
Over the past decade coralline algae have increasingly been used as archives of paleoclimate information. Encrusting coralline algae, which deposit annual growth increments in a high Mg-calcite skeleton, are amongst the longest-lived shallow marine organisms. In fact, a live-collected plant has recently been shown to have lived for at least 850 years based on radiometric dating. While a number of investigations have successfully used geochemical information of coralline algal skeletons to reconstruct sea surface temperatures, less attention has been paid to employ growth increment widths as a temperature proxy. Here we explore the relationship between growth and environmental parameters in …
Eurhomalea exalbida (Bivalvia): A reliable recorder of climate in southern South America?
2012
Abstract Due to the lack of suitable high-resolution archives, regional and continental-scale climate dynamics of southern South America are not well understood. Shells of the long-lived, shallow-marine bivalve mollusk, Eurhomalea exalbida (Dillwyn), are likely to contain information on the past water temperatures. As yet, however, no rigorous calibration study has been presented so that growth history traits and the reliability of shell oxygen isotope-based temperature estimates remain unknown. Shell growth patterns and oxygen isotope ratios of four young specimens of E. exalbida from the Falkland Islands (Southwest Atlantic) were analyzed and cross-calibrated with environmental parameters…
Unique growth pattern of Metoposaurus diagnosticus krasiejowensis (Amphibia, Temnospondyli) from the Upper Triassic of Krasiejów, Poland
2013
Morphology and bone histology of femora, tibiae, and fibulae of the temnospondyl Metoposaurus diagnosticus krasiejowensis from the Upper Triassic locality of Krasiejow (Poland) are studied for the first time. The growth pattern of Metoposaurus as preserved in a small growth series of femora, shows a regular alternating sequence of fast and slow growth phases, which are interpreted as representing zones and annuli. The slow growth phases (annuli) of the inner and outer cortex as well as those of different specimens are of a regular broad thickness. Such broad annuli are so far unknown for any vertebrate and make the growth pattern for Metoposaurus unique. These slow growth phases always cont…
The unique skeleton of siliceous sponges (Porifera; Hexactinellida and Demospongiae) that evolved first from the Urmetazoa during the Proterozoic: a …
2007
Abstract. Sponges (phylum Porifera) had been considered as an enigmatic phylum, prior to the analysis of their genetic repertoire/tool kit. Already with the isolation of the first adhesion molecule, galectin, it became clear that the sequences of the sponge cell surface receptors and those of the molecules forming the intracellular signal transduction pathways, triggered by them, share high similarity to those identified in other metazoan phyla. These studies demonstrated that all metazoan phyla, including the Porifera, originate from one common ancestor, the Urmetazoa. The sponges evolved during a time prior to the Ediacaran-Cambrian boundary (542 million years ago (myr)). They appeared du…
Magnetostratigraphy and biostratigraphy of the Carnian/Norian boundary interval from the Pizzo Mondello section (Sicani Mountains, Sicily)
2001
The 146.5 m-thick Upper Triassic limestone section at Pizzo Mondello in the Sicani Mountains of western Sicily is characterized by high quality of exposure, accessibility, and stratigraphic continuity. Magnetostratigraphic results delineate 12 normal and reverse polarity magnetozones, labelled successively from the base upwards as PM1n, PM1r, PM6n, PM6r. The Carnian/Norian boundary, based on conodont biostratigraphy, falls somewhere in the PM3n to PM5n interval which corresponds to the E14n to E16n magnetozone interval in the Newark reference sequence of polarity reversals. Comparison of magnetobiostratigraphic data from the Newark basin, Pizzo Mondello and other Late Triassic marine sectio…
Unraveling the origin of the Late Triassic multitaxic bone accumulation at Krasiejów (S Poland) by diagenetic analysis
2012
Abstract A study of aquatic and terrestrial vertebrate remains from a bonebed in the Late Triassic continental succession near Krasiejow (S Poland) shows it was deposited by a single catastrophic event, perhaps a flood. Hardparts of Metoposaurus, Paleorhinus, and Stagonolepis show sedimentary infill and geochemical evidence for early diagenesis at different times and in different microenvironments. The infills in the aquatic animal bones (sediment, pyrite and calcite) show deposition in a freshwater environment, while those in the terrestrial Stagonolepis remains (mainly barite) point to an arid terrestial environment. The trace element content of the remains, together with the absence of a…
Stable isotope (δ18O and δ13C) sclerochronology of Callovian (Middle Jurassic) bivalves (Gryphaea (Bilobissa) dilobotes) and belemnites (Cylindroteut…
2014
Abstract Incremental δ 18 O and δ 13 C signals were obtained from three well-preserved specimens of Cylindroteuthis puzosiana and from three well-preserved specimens of Gryphaea ( Bilobissa ) dilobotes from the Peterborough Member of the Oxford Clay Formation (Cambridgeshire, England). Through-ontogeny (sclerochronological) δ 18 O data from G. ( B. ) dilobotes appear to faithfully record seasonal temperature variations in benthic Callovian waters of the study area, which range from c . 14 °C to c . 17 °C (arithmetic mean temperature c . 15 °C). Water depth is estimated to have been in the region of c . 50 m, based upon comparisons between these data, previously published non-incremental sea…
Tarbellastraea (Scleractinia): A new stable isotope archive for Late Miocene paleoenvironments in the Mediterranean
2008
Abstract Geochemical proxy records of sea surface temperature (SST) or sea surface salinity (SSS) variability on intra- and interannual time-scales in corals from geological periods older than Pleistocene are extremely rare due to pervasive diagenetic alteration of coralline aragonite. Very recently, however, stable isotope data (δ18O, δ13C) from specimens of Porites of Late Miocene age (10 Ma) have been shown to preserve original environmental signatures. In this paper we describe new finds of the zooxanthellate corals Porites and Tarbellastraea in exceptional aragonite preservation from the island of Crete in sediments of Tortonian (∼ 9 Ma) and Early Messinian (∼ 7 Ma) age. Systematic, co…
A new calibration of the effective scattering albedo and soil roughness parameters in the SMOS SM retrieval algorithm
2017
Abstract This study focuses on the calibration of the effective vegetation scattering albedo (ω) and surface soil roughness parameters (H R , and N Rp , p = H,V) in the Soil Moisture (SM) retrieval from L-band passive microwave observations using the L-band Microwave Emission of the Biosphere (L-MEB) model. In the current Soil Moisture and Ocean Salinity (SMOS) Level 2 (L2), v620, and Level 3 (L3), v300, SM retrieval algorithms, low vegetated areas are parameterized by ω = 0 and H R = 0.1, whereas values of ω = 0.06 − 0.08 and H R = 0.3 are used for forests. Several parameterizations of the vegetation and soil roughness parameters (ω, H R and N Rp , p = H,V) were tested in this study, tre…
Consequences of applying new technologies to sources of law (overview)
2020
Technological change has a very significant impact on the functioning of a lawyer. It is not only an advocate, judge, adviser or notary public with a law, but also specialized software in which the law is incorporated. The quality of this software, safety but also the certainty of its correctness is very important for legal certainty and functioning of lawyers. Modern law is not only the text of legal acts or contracts but also IT codes in which the law is incorporated (for example, smart contract). The law is controlled by the courts. The question arises as to who will control the codes in which the law is written. In the EU, only a few countries have recognised this problem when creating …