Tectonically driven deposition and landscape evolution within upland incised valleys: Ambra Valley fill,Pliocene–Pleistocene,Tuscany, Italy

Sedimentation in the upstream reaches of incised valleys is predominantly of alluvial origin and, in most cases, independent from relative sea‐level or lake‐level oscillations. Preserved facies distributions record the depositional response to a combination of allogenic factors, including tectonics, climate and landscape evolution. Tectonics drive fluvial aggradation and degradation through local changes in gradient, both longitudinal and transverse to the valley slope. This article deals with a Pliocene–Pleistocene fluvial valley fill developed in the north‐eastern shoulder of the Siena Basin (Northern Apennines, Italy). Evolution of the valley was not influenced by sea‐level or lake‐level changes and morphological and depositional evolution of valley resulted from extensional tectonics that gave rise to normal and oblique‐slip faults orthogonal and parallel to the valley axis. Data from both field observations and geophysical study are interpreted to develop a comprehensive tectono‐sedimentary model of coeval longitudinal and lateral tilting of the developing alluvial plain. Longitudinal tilting was generated by a transverse, upstream‐dipping normal fault that controlled the aggradation of fining‐upward strata sets. Upstream of the fault zone, valley back‐filling generated an architecture similar to that of classic, sea‐level‐controlled, coastal incised valleys. Downstream of the fault zone, valley down‐filling was related to an overwhelming sediment supply sourced and routed from the active fault zone itself. Lateral tilting was promoted by the activity of a fault oriented parallel to the valley axis, as well as by different offsets along near orthogonal faults. As a result, the valley trunk system experienced complex lateral shifts, which were governed by interacting fault‐generated subsidence and by the topographic confinement of progradational, flank‐sourced alluvial fans.     

Special Issue: Renewable Ocean Energy Development and the Environment

Renewable energy harvested from ocean waves, tides, and winds as part of a portfolio of reliable low-carbon energy sources to address climate change and energy security is under consideration by many nations. Engineering designs and characterization of the harvestable resource are moving forward, particularly in Europe, Asia, and North America. At the same time, stakeholders and regulators have expressed the need to understand potential effects on marine animals, habitats, and ecosystem processes. These potential effects are prompting researchers and resource managers to examine interactions of species and ocean areas with energy conversion devices. This volume demonstrates the breadth of disciplines engaged in the quest to understand potential effects and the proactive efforts to develop these new sources of energy to the world, in a responsible manner.     

Enhancing preparedness for managing debris from earthquakes: lessons from Italy

Natural Hazards - Earthquakes can generate large volumes of debris which may threaten public health, hinder reconstruction and impact the environment. The present paper aims at investigating how...     

On the efficiency and effectiveness of automatic deep drainage systems during an extreme rainfall event: the Mendatica landslide case study (western Liguria,Italy)

Landslides - This study presents the employment of automatic deep drainage systems to stabilize the Mendatica landslide, one of the largest relict landslides of western Liguria (north-western...     

An INSPIRE-compliant open-source GIS for fire-fighting management

Every year, there are almost 50,000 forest fires in Europe (127/day), which have burned an area equal to more than 450,000 ha. An effective management of forest fires is therefore fundamental in order to reduce the number of the fires and, especially, the related burned areas, preserving the environment and saving human lives. However, some problems still exist in the structure of information and in the harmonization of data and fire management procedures among different European countries. Pursuing the same interoperability aims, the European Union has invested in the development of the INSPIRE Directive (Infrastructure for Spatial Information in Europe) to support environmental policies. Furthermore, the EU (European Union) is currently working on developing ad hoc infrastructures for the safe management of forests and fires. Moving from this premises and following an analysis of the state of the art of information systems for forest fire-fighting, in the light of the end-user requirements, the paper presents the INSPIRE—compliant design of a geographical information system, implemented using open-source platforms.     

Crystallisation sequence and magma evolution of the De Beers dyke (Kimberley,South Africa)

We present petrographic and mineral chemical data for a suite of samples derived from the De Beers dyke, a contemporaneous, composite intrusion bordering the De Beers pipe (Kimberley, South Africa). Petrographic features and mineral compositions indicate the following stages in the evolution of this dyke: (1) production of antecrystic material by kimberlite-related metasomatism in the mantle (i.e., high Cr-Ti phlogopite); (2) entrainment of wall-rock material during ascent through the lithospheric mantle, including antecrysts; (3) early magmatic crystallisation of olivine (internal zones and subsequently rims), Cr-rich spinel, rutile, and magnesian ilmenite, probably on ascent to the surface; and (4) crystallisation of groundmass phases (i.e., olivine rinds, Fe-Ti-rich spinels, perovskite, apatite, monticellite, calcite micro-phenocrysts, kinoshitalite-phlogopite, barite, and baddeleyite) and the mesostasis (calcite, dolomite, and serpentine) on emplacement in the upper crust. Groundmass and mesostasis crystallisation likely forms a continuous sequence with deuteric/hydrothermal modification. The petrographic features, mineralogy, and mineral compositions of different units within the De Beers dyke are indistinguishable from one another, indicating a common petrogenesis. The compositions of antecrysts (i.e., high Cr-Ti phlogopite) and magmatic phases (e.g., olivine rims, magnesian ilmenite, and spinel) overlap those from the root zone intrusions of the main Kimberley pipes (i.e., Wesselton, De Beers, Bultfontein). However, the composition of these magmatic phases is distinct from those in ‘evolved’ intrusions of the Kimberley cluster (e.g., Benfontein, Wesselton water tunnel sills). Although the effects of syn-emplacement flow processes are evident (e.g., alignment of phases parallel to contacts), there is no evidence that the De Beers dyke has undergone significant pre-emplacement crystal fractionation (e.g., olivine, spinel, ilmenite). This study demonstrates the requirement for detailed petrographic and mineral chemical studies to assess whether individual intrusions are in fact ‘evolved’; and that dykes are not necessarily produced by differentiated magmas.

     

Geochemical,mineralogical and Re-Os isotopic constraints on the origin of Tethyan oceanic mantle and crustal rocks from the Central Pontides,northern Turkey

Mineralogy and Petrology - Chromite, ultramafic and mafic rocks from Eldivan, Yapraklı, Ayli Dağ, Küre, Elekdağ and Kızılırmak in northern Turkey have been...     

Synchrotron radiation applications to past volcanism archived in speleothems: An overview

Precise dating and correlation of past key volcanic eruptions over a wide geographic area in archives of past climate variability is necessary to support a direct causality between volcanism and climate changes. Research has mostly focused on ice cores and varved sediments, which capture a record of volcanic eruptions in geochemistry and the presence of tephra and criptotephra. Precisely dated cave carbonate deposits, collectively known as speleothems are other valuable palaeoclimate archives, and encode information on past volcanism in their sulphate concentration variability. Due to the physical characteristic of speleothems, detection of sulphate concentration variability requires techniques capable of high spatial resolution, very low limit of detection (ppm to ppb) and low background noise. Synchrotron radiation-based (SR) micro X-ray fluorescence (µXRF) and X-ray absorption near-edge spectrometry prove to be one of the most effective techniques to detect short-lived pulses of sulphate concentration increase, which may be interpreted as being related to atmospheric load due to volcanic eruptions. Here, we provide an overview of existing work as well as a novel interpretation of a SR µXRF-based sulphate series in an annually laminated stalagmite with robust chronology. Sulphate concentration peaks in the years 1815–1816, 1844 and 1947, possibly coinciding with Tambora, Krakatau, and Hekla eruptions. It is concluded that sulphate concentration in speleothems expand the potential to correlate volcanic eruption events at a global scale.