Abstract Volcanoes produce probably the most spectacular geological phenomena on Earth. Any of their eruptions can have a strong consequence on the surrounding environment, often captured in great detail in the sedimentary records of volcanically active regions. In addition, flank landslides and background erosive processes affecting volcanic sequences release volcanic particles that circulate within sedimentary environments up to billions of years after their generation. Therefore, exploring volcanically influenced sedimentary environments is an exciting and challenging scientific exercise requiring insights across multiple geological disciplines, drawing upon an increasing varied range of expertise and analytical approaches from across the geoscientific community. This book aims to provide an updated collection of works that illustrate the state-of-the-art in this topic, and to define the future directions of the geological sciences in utilizing and interpreting sedimentary records of volcanism.

Abstract The genesis of particles and their transport mechanisms are the two fundamental factors driving the accumulation of sediments associated with volcanism or derived from volcanic sources. These factors are therefore the most important criteria on which to base a useful classification of sediments in such environments. However, the relative significance of the nature of particles v. the transporting mechanism forming a deposit varies in existing terminological schemes: those schemes applied where volcanological contextual information is available tend to give precedence to the transportation process; whereas sedimentological schemes examining ancient deposits tend to focus principally on the nature of particles. Here, we provide an outline of the challenges in classifying volcanically derived sediments and put forward a scheme that aims to bridge current terminological differences and accommodate variable levels of uncertainty. This work defines three endmembers ( primary volcaniclastic , secondary volcaniclastic , volcanic epiclastic ) that correspond to (a) deposits whose particles are produced, transported and emplaced directly by volcanic mechanisms; (b) deposits whose particles are produced directly by volcanic events but transported and accumulated by non-volcanic mechanisms, either in continuum with the events or after interim storage; (c) deposits whose particles are produced by weathering/erosion of volcanic terrains and transportation of derived material by non-volcanic mechanisms. When the complex combination of genetic and transportation processes accumulating volcaniclastic sequences is not clear, but a strong relationship between an eruptive event and the studied volcaniclastic deposit can still be demonstrated, a further category ( volcanogenic ) has been introduced.

Abstract Sand and sandstone composition of volcanic origin may be clues to the provenance of the sediments and sedimentary rocks. Volcaniclastic provenance studies contribute significantly to unravelling the generation and provenance of sediment under investigation, which in the Aeolian archipelago comprises preserved units of outcrops dominated by lava flows intercalated with airfall tephras as source rocks. The focus of this paper is the study of the petrographical composition and textures of beach sands, which can then be used as a guide in the interpretation of provenance and origin of beach sand(stone)s rich in volcanic debris transported into deeper water. The composition of Aeolian beach deposits defines a single immature petrofacies with a large amount of unweathered glass and mafic minerals. Panarea island is dominated by dacites and new grain categories have been proposed to differentiate this provenance. Surface processes such as mechanical erosion (mass wasting and surface runoff) produce an overestimation of mafic components compared to the felsic components in the beach sand fraction.

In the central Apennines, interacting siliciclastic and carbonate marine clastic wedges filled the foreland basin system during the late Miocene. Conjunction of collisional thrust tectonics and prethrusting normal faults generated a complex foredeep with intrabasinal structural highs that represented additional source areas to the basin. Detrital modes of the late Miocene central Apennines orogenic system range in composition from intrabasinal carbonate to quartzofeldspatholithic and calclithite arenites. The external zone of the foredeep is characterized by hemipelagic deposits, called the Orbulina Marl. Their arenite beds are composed by intrabasinal carbonate, with dominant bioclasts and minor intraclasts, and glauconite derived from an active shallow-marine carbonate source. These hemipelagic deposits are partly coeval with and partly overlain by siliciclastic turbidites of the Frosinone and the Argilloso-Arenacea Formations, and they represent deposition within local foredeep depocenters. Siliciclastic turbidite sandstones are quartzofeldspatholithic, which documents provenances from metamorphic, plutonic, ophiolitic, and sedimentary rocks. Carbonate intrabasinal structural highs were the main source for carbonate breccias, intrabasinal arenites, and calclithites of the Brecce della Renga Formation, the deposits of which are locally interbedded with the coeval siliciclastic turbidite sandstones. Evolution of late Miocene sandstone detrital modes reflected the changing nature of the central Apennines thrust belt through time and the complex architecture of the foreland basin system; it records the history of accretion, deformation of the foredeep, and progressive areal reduction of carbonate-producing areas along with the sedimentary and structural evolution of local intrabasinal highs.

This work represents an integrated analysis of weathering landforms, including minor landform morphologies and soil profiles developed on granitoid terrains of the Sila Massif uplands (Calabria, southern Italy). The results of our analysis indicate that cryoclastic and thermoclastic processes, along with chemical weathering, are the main factors controlling rock degradation. Microscale features observed in primary minerals and parent rock fabrics, such as structural discontinuities, cleavage planes, fracturing patterns, and variations in chemical composition, play important roles in triggering weathering and, given sufficient time, progressively lead to grussification and soil development. Exfoliation, hydration, and splitting apart of biotite, as well as hydrolysis and etching of plagioclase and K-feldspar, appear to be prominent factors in the breakdown of bedrock. Whereas time controls the degree of development of the main weathering features and climate infiuences type and intensity of the dominant processes, relief strongly influences the development and preservation/removal of the regolith/soil cover. Geomorphological evidence of severe surface erosion is quite good, especially along steep slopes where weathering products are quickly removed, although on the highest, dissected paleosurfaces (the oldest paleolandscape remnants in the Sila Massif), wide boulder fields represent relics of past, deep spheroidal weathering that have been exhumed by intense erosion. Erosive, depositional, or reworking phenomena, often enhanced by human activity, are well recorded by macro- and micromorphological features of soils, which show simple, poorly differentiated, rejuvenated profiles, buried or truncated horizons, abundant coarse-grained primary minerals or rock fragments, and pedorelicts. The soil clay mineralogy, characterized by illite, chlorite, and vermiculite, and the dominance of coarse textures confirm a young pedogenetic stage of evolution, although highly weathered sand grains (quartz included) occur in rarely preserved mature paleosols. This interpretation is also consistent with the compositional immaturity of fiuvial sands, which have undergone low to moderate transport.