54 research outputs found
High-frequency cyclicity in the Mediterranean Messinian evaporites: evidence for solar-lunar climate forcing
The deposition of varved sedimentary sequences is usually controlled by
climate conditions. The study of two Late Miocene evaporite successions (one
halite and the other gypsum) consisting of annual varves has been carried out
to reconstruct the paleoclimatic and paleoenvironmental conditions existing
during the acme of the Messinian salinity crisis, ~ 6 Ma, when thick evaporite
deposits accumulated on the floor of the Mediterranean basin. Spectral analyses
of these varved evaporitic successions reveal significant periodicity peaks at
around 3-5, 9, 11-13, 20-27 and 50-100 yr. A comparison with modern
precipitation data in the western Mediterranean shows that during the acme of
the Messinian salinity crisis the climate was not in a permanent evaporitic
stage, but in a dynamic situation where evaporite deposition was controlled by
quasi-periodic climate oscillations with similarity to modern analogs including
Quasi-Biennial Oscillation, El Ni\~no Southern Oscillation, and decadal to
secular lunar- and solar-induced cycles. Particularly we found a significant
quasi-decadal oscillation with a prominent 9-year peak that is commonly found
also in modern temperature records and is present in the contemporary Atlantic
Multidecadal Oscillation (AMO) index and Pacific Decadal Oscillation (PDO)
index. These cyclicities are common to both ancient and modern climate records
because they can be associated with solar and solar-lunar tidal cycles.Comment: 13 pages, 10 figures, 1 Tabl
The deep record of the Messinian salinity crisis: Evidence of a non-desiccated Mediterranean Sea
This research is focused on a complete reexamination of the evaporite facies present in all the cores that cut
through the topmost deposits of the Messinian salinity crisis lying below the floor of the Mediterranean Sea
(DSDP Legs 13 and 42A, ODP Legs 107 and 161). This review suggests that the uppermost evaporite units in
both western and eastern deep Mediterranean basins consist mainly of clastic (gypsrudite, gypsarenite and
gypsiltite) and fully subaqueous deposits (laminar gypsum, selenite and cumulate halite) that are partially
affected by burial anhydritization and tectonic induced recrystallization. No unequivocal evidence of shallow
water or even supratidal (sabkha) deposition is in evidence, suggesting that at the very last phase of the salinity
crisis the Mediterranean Sea did not experience desiccation, but that deposition took place under permanent
subaqueous conditions
The Messinian salinity crisis: open problems and possible implications for Mediterranean petroleum systems
Abstract: A general agreement on what actually happened during the Messinian salinity crisis (MSC) has been reached in the
minds of most geologists but, in the deepest settings of the Mediterranean Basin, the picture is still far from being finalized and
several different scenarios for the crisis have been proposed, with different significant implications for hydrocarbon
exploration. The currently accepted MSC paradigm of the ‘shallow-water deep-basin’ model, which implies high-amplitude
sea-level oscillations (> 1500 m) of the Mediterranean up to its desiccation, is usually considered as fact. As a consequence, it is
on this model that the implications of the MSC events on the Mediterranean petroleum systems are commonly based.
In fact, an alternative, deep-water, non-desiccated scenario of the MSC is possible: it (i) implies the permanence of a large
water body in the Mediterranean throughout the entire Messinian salinity crisis, but with strongly reduced Atlantic connections;
and (ii) envisages a genetic link between Messinian erosion of the Mediterranean margins and deep brine development.
In this work, we focus on the strong implications of an assessment of the petroleum systems of the Mediterranean and
adjoining areas (e.g. the Black Sea Basin) that can be based on such a non-desiccated MSC scenario. In particular, the near-full
basin model delivers a more realistic definition of Messinian source-rock generation and distribution, as well as of the
magnitude of water-unloading processes and their effects on hydrocarbon accumulation
The onset of the Messinian salinity crisis in the deep Eastern Mediterranean basin
Astronomical tuning of the Messinian pre-salt succession in the Levant Basin allows
for the first time the reconstruction of a detailed chronology of the Messinian salinity
crisis (MSC) events in deep setting and their correlation with marginal records
that supports the CIESM (2008) 3-stage model. Our main conclusions are (1) MSC
events were synchronous across marginal and deep basins, (2) MSC onset in deep
basins occurred at 5.97 Ma, (3) only foraminifera-barren, evaporite-free shales
accumulated in deep settings between 5.97 and 5.60 Ma, (4) deep evaporites
(anhydrite and halite) deposition started later, at 5.60 Ma and (5) new and published
87Sr/86Sr data indicate that during all stages, evaporites precipitated from the
same water body in all the Mediterranean sub-basins. The wide synchrony of
events and 87Sr/86Sr homogeneity implies inter-sub-basin connection during the
whole MSC and is not compatible with large sea-level fall and desiccation of the
Mediterranean
The Messinian salinity crisis in Cyprus: a further step towards a new stratigraphic framework for Eastern Mediterranean
A revised stratigraphic framework for the Messinian succession of Cyprus is proposed demonstrating that the three-stage model for the Messinian salinity crisis recently established for the Western Mediterranean also applies to the Eastern Mediterranean, at least for its marginal basins. This analysis is based on a multidisciplinary study of the Messinian evaporites and associated deposits exposed in the Polemi, Pissouri, Maroni/Psematismenos and Mesaoria basins. Here, we document for the first time that the base of the unit usually referred to the 'Lower Evaporites' in Cyprus does not actually correspond to the onset of the Messinian salinity crisis. The basal surface of this unit rather corresponds to a regional-scale unconformity, locally associated with an angular discordance, and is related to the erosion and resedimentation of primary evaporites deposited during the first stage of the Messinian salinity crisis. This evidence suggests that the 'Lower Evaporites' of the southern basins of Cyprus actually belong to the second stage of the Messinian salinity crisis; they can be thus ascribed to the Resedimented Lower Gypsum unit that was deposited between 5.6 and 5.5\ua0Ma and is possibly coeval to the halite deposited in the northern Mesaoria basin. Primary, in situ evaporites of the first stage of the Messinian salinity crisis were not preserved in Cyprus basins. Conversely, shallow-water primary evaporites deposited during the third stage of the Messinian salinity crisis are well preserved; these deposits can be regarded as the equivalent of the Upper Gypsum of Sicily. Our study documents that the Messinian stratigraphy shows many similarities between the Western and Eastern Mediterranean marginal basins, implying a common and likely coeval development of the Messinian salinity crisis. This could be reflected also in intermediate and deep-water basins; we infer that the Lower Evaporites seismic unit in the deep Eastern Mediterranean basins could well be mainly composed of clastic evaporites and that its base could correspond to the Messinian erosional surface
The Messinian salinity crisis in Cyprus: a further step toward a new stratigraphic framework for Eastern Mediterranean
Oral abstracts 3: RA Treatment and outcomesO13. Validation of jadas in all subtypes of juvenile idiopathic arthritis in a clinical setting
Background: Juvenile Arthritis Disease Activity Score (JADAS) is a 4 variable composite disease activity (DA) score for JIA (including active 10, 27 or 71 joint count (AJC), physician global (PGA), parent/child global (PGE) and ESR). The validity of JADAS for all ILAR subtypes in the routine clinical setting is unknown. We investigated the construct validity of JADAS in the clinical setting in all subtypes of JIA through application to a prospective inception cohort of UK children presenting with new onset inflammatory arthritis. Methods: JADAS 10, 27 and 71 were determined for all children in the Childhood Arthritis Prospective Study (CAPS) with complete data available at baseline. Correlation of JADAS 10, 27 and 71 with single DA markers was determined for all subtypes. All correlations were calculated using Spearman's rank statistic. Results: 262/1238 visits had sufficient data for calculation of JADAS (1028 (83%) AJC, 744 (60%) PGA, 843 (68%) PGE and 459 (37%) ESR). Median age at disease onset was 6.0 years (IQR 2.6-10.4) and 64% were female. Correlation between JADAS 10, 27 and 71 approached 1 for all subtypes. Median JADAS 71 was 5.3 (IQR 2.2-10.1) with a significant difference between median JADAS scores between subtypes (p < 0.01). Correlation of JADAS 71 with each single marker of DA was moderate to high in the total cohort (see Table 1). Overall, correlation with AJC, PGA and PGE was moderate to high and correlation with ESR, limited JC, parental pain and CHAQ was low to moderate in the individual subtypes. Correlation coefficients in the extended oligoarticular, rheumatoid factor negative and enthesitis related subtypes were interpreted with caution in view of low numbers. Conclusions: This study adds to the body of evidence supporting the construct validity of JADAS. JADAS correlates with other measures of DA in all ILAR subtypes in the routine clinical setting. Given the high frequency of missing ESR data, it would be useful to assess the validity of JADAS without inclusion of the ESR. Disclosure statement: All authors have declared no conflicts of interest. Table 1Spearman's correlation between JADAS 71 and single markers DA by ILAR subtype ILAR Subtype Systemic onset JIA Persistent oligo JIA Extended oligo JIA Rheumatoid factor neg JIA Rheumatoid factor pos JIA Enthesitis related JIA Psoriatic JIA Undifferentiated JIA Unknown subtype Total cohort Number of children 23 111 12 57 7 9 19 7 17 262 AJC 0.54 0.67 0.53 0.75 0.53 0.34 0.59 0.81 0.37 0.59 PGA 0.63 0.69 0.25 0.73 0.14 0.05 0.50 0.83 0.56 0.64 PGE 0.51 0.68 0.83 0.61 0.41 0.69 0.71 0.9 0.48 0.61 ESR 0.28 0.31 0.35 0.4 0.6 0.85 0.43 0.7 0.5 0.53 Limited 71 JC 0.29 0.51 0.23 0.37 0.14 -0.12 0.4 0.81 0.45 0.41 Parental pain 0.23 0.62 0.03 0.57 0.41 0.69 0.7 0.79 0.42 0.53 Childhood health assessment questionnaire 0.25 0.57 -0.07 0.36 -0.47 0.84 0.37 0.8 0.66 0.4
Abdominal aortic aneurysm is associated with a variant in low-density lipoprotein receptor-related protein 1
Abdominal aortic aneurysm (AAA) is a common cause of morbidity and mortality and has a significant heritability. We carried out a genome-wide association discovery study of 1866 patients with AAA and 5435 controls and replication of promising signals (lead SNP with a p value < 1 × 10-5) in 2871 additional cases and 32,687 controls and performed further follow-up in 1491 AAA and 11,060 controls. In the discovery study, nine loci demonstrated association with AAA (p < 1 × 10-5). In the replication sample, the lead SNP at one of these loci, rs1466535, located within intron 1 of low-density-lipoprotein receptor-related protein 1 (LRP1) demonstrated significant association (p = 0.0042). We confirmed the association of rs1466535 and AAA in our follow-up study (p = 0.035). In a combined analysis (6228 AAA and 49182 controls), rs1466535 had a consistent effect size and direction in all sample sets (combined p = 4.52 × 10-10, odds ratio 1.15 [1.10-1.21]). No associations were seen for either rs1466535 or the 12q13.3 locus in independent association studies of coronary artery disease, blood pressure, diabetes, or hyperlipidaemia, suggesting that this locus is specific to AAA. Gene-expression studies demonstrated a trend toward increased LRP1 expression for the rs1466535 CC genotype in arterial tissues; there was a significant (p = 0.029) 1.19-fold (1.04-1.36) increase in LRP1 expression in CC homozygotes compared to TT homozygotes in aortic adventitia. Functional studies demonstrated that rs1466535 might alter a SREBP-1 binding site and influence enhancer activity at the locus. In conclusion, this study has identified a biologically plausible genetic variant associated specifically with AAA, and we suggest that this variant has a possible functional role in LRP1 expression
- …