Search results for "extension"

Gravity-driven stratal pattern in late orogenic extensional setting: an example from north-eastern Sicily

2008

Extensions and corona decompositions of low-dimensional intrinsic Lipschitz graphs in Heisenberg groups

2020

This note concerns low-dimensional intrinsic Lipschitz graphs, in the sense of Franchi, Serapioni, and Serra Cassano, in the Heisenberg group $\mathbb{H}^n$, $n\in \mathbb{N}$. For $1\leq k\leq n$, we show that every intrinsic $L$-Lipschitz graph over a subset of a $k$-dimensional horizontal subgroup $\mathbb{V}$ of $\mathbb{H}^n$ can be extended to an intrinsic $L'$-Lipschitz graph over the entire subgroup $\mathbb{V}$, where $L'$ depends only on $L$, $k$, and $n$. We further prove that $1$-dimensional intrinsic $1$-Lipschitz graphs in $\mathbb{H}^n$, $n\in \mathbb{N}$, admit corona decompositions by intrinsic Lipschitz graphs with smaller Lipschitz constants. This complements results that…

Removing the saturation assumption in Bank-Weiser error estimator analysis in dimension three

2020

International audience; We provide a new argument proving the reliability of the Bank-Weiser estimator for Lagrange piecewise linear finite elements in both dimension two and three. The extension to dimension three constitutes the main novelty of our study. In addition, we present a numerical comparison of the Bank-Weiser and residual estimators for a three-dimensional test case.

Restricted compositions and permutations: from old to new Gray codes

2011

Any Gray code for a set of combinatorial objects defines a total order relation on this set: x is less than y if and only if y occurs after x in the Gray code list. Let @? denote the order relation induced by the classical Gray code for the product set (the natural extension of the Binary Reflected Gray Code to k-ary tuples). The restriction of @? to the set of compositions and bounded compositions gives known Gray codes for those sets. Here we show that @? restricted to the set of bounded compositions of an interval yields still a Gray code. An n-composition of an interval is an n-tuple of integers whose sum lies between two integers; and the set of bounded n-compositions of an interval si…

Approximate treatment of higher excitations in coupled-cluster theory. II. Extension to general single-determinant reference functions and improved a…

2008

The theory and implementation of approximate coupled-cluster (CC), in particular approximate CC singles, doubles, triples, and quadruples methods, are discussed for general single-determinant reference functions. While the extension of iterative approximate models to the non-Hartree-Fock case is straightforward, the generalization of perturbative approaches is not trivial. In contrast to the corresponding perturbative triples methods, there are additional terms required for non-Hartree-Fock reference functions, and there are several possibilities to derive approximations to these terms. As it turns out impossible to develop an approach that is consistent with the canonical Hartree-Fock-base…

Geomorphological evolution of western Sicily, Italy

2017

Abstract This paper proposes a morphoevolutionary model for western Sicily. Sicily is a chain–foredeep–foreland system still being built, with tectonic activity involving uplift which tends to create new relief. To reconstruct the morphoevolutionary model, geological, and geomorphological studies were done on the basis of field survey and aerial photographic interpretation. The collected data show large areas characterized by specific geological, geomorphological, and topographical settings with rocks, landforms, and landscapes progressively older from south to north Sicily. The achieved results display: (1) gradual emersion of new areas due to uplift, its interaction with the Quaternary gl…

The relationships between soft-sediment deformation structures and synsedimentary extensional tectonics in Upper Triassic deep-water carbonate succes…

2016

Abstract We describe soft-sediment deformation structures into the Upper Triassic cherty limestone outcropping in the Pizzo Lupo section (Central Sicily, Italy), pertaining to the deep-water palaeodomain of the Southern Tethyan margin. In the study section, mainly consisting of thin-bedded mudstone/marl alternations with bedded chert intercalations, some lithofacies have been separated on the basis of the abundance of the calcium carbonate/clay content and the overall textural features. The deformational structures, displaying different deformational styles as folded and faulted beds, disturbed layers, clastic dikes, and slumps occur mainly in the deformed horizons that involve marl-dominat…

Paleoclimate and extensional tectonics of short-lived lacustrine environments. Lower Cretaceous of the Panormide Southern Tethyan carbonate platform …

2017

Abstract Subaerial erosion and continental sedimentation interbedded with shallow-water carbonates are unequivocal stratigraphic records to evaluate paleoenvironmental and paleoclimate evolution of emerged landmass. Stratigraphic analysis of the Cretaceous Monte Gallo section of the Mesozoic Panormide carbonate platform, in the northern side of the Palermo Mountains (NW Sicily) records a peculiar continental-derived clays that interrupted the shallow-water carbonate sedimentation. These clays rest, with lenticular geometries, above the tectonically-enhanced subaerial erosional unconformity of the Barremian-Lower Aptian Requienid limestones and are covered by the Upper Cretaceous Rudistid li…

Basin analysis in the Southern Tethyan margin: Facies sequences, stratal pattern and subsidence history highlight extension-to-inversion processes in…

2018

Abstract In the Mediterranean, the South-Tethys paleomargin experienced polyphased tectonic episodes and paleoenvironmental perturbations during Mesozoic time. The Cretaceous shallow-water carbonate successions of the Panormide platform, outcropping in the northern edge of the Palermo Mountains (NW Sicily), were studied by integrating facies and stratal pattern with backstripping analysis to recognize the tectonics vs. carbonate sedimentation interaction. The features of the Requienid limestone, including geometric configuration, facies sequence, lithological changes and significance of the top-unconformity, highlight that at the end of the Lower Cretaceous the carbonate platform was tecton…

Sea–land geology of Marettimo (Egadi Islands, central Mediterranean sea)

2016

We present a 1:10,000 scale geological map of Marettimo Island and its offshore (Egadi Archipelago, central Mediterranean Sea). The map was achieved by integrating a new geological survey with data from recent, marine, geological and geophysical surveys acquired along the adjacent continental shelf. The island is composed of a Mesozoic, mostly carbonate platform succession, which is overlain by continental to coastal marine Quaternary deposits. Extensional tectonics have affected the carbonate platform since the Late Triassic producing an initial increase of accommodation space that was filled by interbed breccias, marls and calcareous marls. During the Jurassic, a NE-SW-directed normal fau…