Search results for "Wedge"
showing 10 items of 135 documents
Foreland Basin System Evolution along the Sicilian Fold and Thrust Belt
2016
Foreland Basin System tettono-sedimentary evolution along the Sicilian Fold and Thrust Belt
Effects of Rayleigh number length thickness of continent on time of mantle flow reversal
1998
Abstract Numerical experiments are carried out to study the effects of continents on the structure of thermal convection in the mantle. The mantle is modelled by a viscous fluid occupying a horizontally extended rectangular 2-D region of aspect ratio 10:1. Continents are treated as thick rigid heat-conducting plates placed in the mantle, with free-slip and with no-slip conditions. Continents restrict the heat release from the underlying mantle; the mantle material heats up and becomes lighter; as a result, a hot upwelling flow replaces downwelling. We calculate the characteristic time τ of this restructuring for various values of model parameters and obtain analytical approximations for τ a…
Constraints on mantle source and interactions from He-Sr isotope variation in Italian Plio-Quaternary volcanism
2008
[1] Helium isotope ratios of olivine and pyroxene phenocrysts from Plio-Quaternary volcanic rocks from southern Italy (seven Aeolian Islands, Mt. Vulture, Etna, Ustica, and Pantelleria) range from 2.3 to 7.1 Ra. Importantly, the phenocryst 3He/4He correlate well with whole rock Sr isotopic composition (0.70309–0.70711), reflecting the mixing of two sources. A significant contribution of He from crustal contamination is recorded only occasionally (e.g., pyroxenes from Vulcano). When merged with data from the Roman Comagmatic Province, a remarkably strong near-linear He-Sr isotope correlation is apparent. The general northward decrease in 3He/4He corresponds to an increase in 87Sr/86Sr (and a…
Comment on “Topological invariants, instantons, and the chiral anomaly on spaces with torsion”
1999
In Riemann-Cartan spacetimes with torsion only its axial covector piece $A$ couples to massive Dirac fields. Using renormalization group arguments, we show that besides the familiar Riemannian term only the Pontrjagin type four-form $dA\wedge dA$ does arise additionally in the chiral anomaly, but not the Nieh-Yan term $d^\star A$, as has been claimed in a recent paper [PRD 55, 7580 (1997)].
Dimensional interpolation and the Selberg integral
2019
Abstract We show that a version of dimensional interpolation for the Riemann–Roch–Hirzebruch formalism in the case of a grassmannian leads to an expression for the Euler characteristic of line bundles in terms of a Selberg integral. We propose a way to interpolate higher Bessel equations, their wedge powers, and monodromies thereof to non–integer orders, and link the result with the dimensional interpolation of the RRH formalism in the spirit of the gamma conjectures.
Timing of subduction and exhumation in a subduction channel: Evidence from slab melts from La Corea Mélange (eastern Cuba)
2011
article i nfo High pressure igneous rocks (tonalites), generated by partial melting of subducted basaltic rocks accreted to the mantle wedge, are present in the La Corea serpentinite-matrix melange (eastern Cuba) as centimeter- to meter-sized blocks and as concordant to crosscutting veins within high-pressure parent amphibolite blocks. The slab melts have adakitic signatures, in agreement with formation after partial melting of metabasite. Thermobarometric calculations indicate 620-680 °C and 13-15 kbar during crystallization of tonalites and down to 250-300 °C, 6 kbar during retrogression, indicating counter-clockwise P-T paths (hot subduction- cool exhumation). Free water required for mel…
Current status of phosphodiesterase inhibitors in the treatment of congestive heart failure.
1992
The phosphodiesterase inhibitors have been recognised as potent inotropic and vasodilating drugs. In acute congestive heart failure they increase cardiac output, decrease left pulmonary capillary wedge pressure, and reduce total peripheral resistance with an improvement in loading conditions of the failing heart. Their potency in reversal of symptoms of acute congestive heart failure is quite similar to, or even better than, treatment with intravenous catecholamines and sodium nitroprusside. In chronic congestive heart failure, however, these agents increase mortality and have deleterious effects in the outcome of patients with severe left ventricular dysfunction.
Combined endo-laparoscopic treatment of large gastrointestinal stromal tumor of the stomach: Report of a case and literature review
2020
Highlights • We report a case of 75-year-old Caucasian men with unknown voluminous gastric GIST, who came to our attention complaining melena. We decided to perform a laparoscopic-endoscopic combined surgical approach. • Intraoperative endoscopy identified gastric GIST and confirmed the submucosal origin and the integrity of the capsule. A 10 cm laparoscopic gastrotomy was carried out along the gastric found in order to realize a laparo-endoscopic rendez-vous technique. • Laparoscopy has rapidly become a preferable approach for gastric GISTs surgical treatment. The magnified view and the lesser invasiveness of laparoscopic technique allow the surgeon to perform a more meticulous dissection,…
Pattern and rate of post-20 ka verticaltectonic motion around Capo Vaticanopromontory (W Calabria, Italy) based onoffshore geomorphological indicators
2013
The magnitude and rate of Late Pleistocene – Holocene vertical tectonic movements offshore Capo Vaticano (western Calabria) have been quantified on the basis of the depths of infralittoral prograding wedges (IPWs) and associated abrasion platforms formed during the stillstand of the Last Glacial Maximum (LGM). These features were identified on high-resolution reflection seismic profiles acquired along the continental shelf and upper slope around the promontory. The pattern of vertical movements of the Capo Vaticano promontory is characterized by a marked asymmetry associated with a NE-directed tilt. Removal of the non tectonic component of vertical changes using an ice-volume equivalent eus…