Reservoirs are manmade habitats, intermediate between rivers and lakes, presenting distinct hydrological and morphometric characteristics, with differential mean water residence time. They also present proper vertical and horizontal organisations, and their evolution depends on several variables acting on different special and temporal scales. The water quality evolution of the Itaipu Reservoir...

Here we report multiple lamniform shark teeth recovered from fluvial sediments in the (Campanian-Maastrichtian) Cerro Fortaleza Formation, Santa Cruz Province, Argentina. This small tooth assemblage is compared to various lamniform sharks possessing similar dental morphologies, including Archaeolamna, Cretalamna, Dwardius, Dallasiella, and Cretodus. Although the teeth share numerous morphologic...

The chemicalmineralogical composition of the sand fractions of mortars found in Roman villas dating from the 1 st century A.C. located in Northern Italy has been investigated by optical microscopy, scanning electron microscopy plus energy dispersive spectroscopy microanalysis and x-ray diffractometry. The petrographic results on the mortar samples have been compared with mineralogical data avai...

A drainage basin simulation model introduced here incorporates creep and threshold slumping and both detachmentand transport-limited fluvial processes. Fluvial erosion of natural slopes and headwater channels is argued to be dominantly detachment-limited. Such slopes undergo nearly parallel retreat and replacement with alluvial surfaces under fixed base level, in contrast with gradual slope dec...

[1] Ground-penetrating radar (GPR) helps to constrain the origin of relict and largely buried fluvial channels in the Bir Kiseiba region of southern Egypt. Our results indicate that the trunk channel to a tributary system identified in Shuttle Imaging Radar data is incised 10–12 m into bedrock, was southwest draining in its final configuration and laterally migrating toward the northwest, and a...

Antioxidant enzymes are involved in important processes of cell detoxification during oxidative stress and have, therefore, been used as biomarkers in algae. Nevertheless, their limited use in fluvial biofilms may be due to the complexity of such communities. Here, a comparison between different extraction methods was performed to obtain a reliable method for catalase extraction from fluvial bi...

[1] We compare morphologies of drainage basins on Mars and Earth in order to confine the formation process ofMartian valley networks. Basins on both planets are computationally extracted from digital topography. Integral-geometry methods are used to represent each basin by a circularity function that encapsulates its internal structure. The shape of such a function is an indicator of the style ...

The purpose of this paper is to first show how an Euler-Lagrange theorem can be applied to the steady-state fluvial landscape model, thereby allowing the geomorphic solution surfaces to be understood as those that globally optimize the difference between kinetic and potential energy dissipation (Hamilton’s Principle) while conserving mass. It is then shown how this variational formulation of th...

Introduction: Tyrrhena Terra is located in cratered and dissected Noachian terrains in the southern hemisphere [1] south of Isidia Planitia and north of Hellas basin. Tyrrhena Terra contains both highlands and a series of intercrater plains. In this region, many outcrops of phyllosilicates are observed by OMEGA spectrometer on many craters walls or ejecta [2, 3]. Several plains in Tyrrhena Terr...