Structures and grain size distribution in surge deposits as a tool for modelling the dynamics of dilute pyroclastic density currents at La Fossa di Vulcano (Aeolian Islands, Italy)

Dellino, Pierfrancesco; Volpe, L. La

doi:10.1016/s0377-0273(99)00140-7

Cited by 55 publications

(31 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It was, therefore, not able to be accessed in its entirely, reducing the main descriptions to proximal sections, where some deposits features are displayed. Beds and layers were described, and lithofacies recorded, using a combination of grain size, bed thickness, fabric, structures, relative sorting, grading pattern, lithification, unconformities, and sedimentary features and the relative juvenile to lithic pyroclasts ratio according to [8][9][10][11][12][13][14][15][16][17][18][19], [29,38]. Determination of clasts sizes, shapes, types, and abundances were limited to qualitative appreciations.…”

Section: Fieldworkmentioning

confidence: 99%

“…Maardiatreme volcanoes are surrounded by a low rim of bedded pyroclastic ejecta, of several metres to over 100 m high, with a radial width of 2-5 km (when measured from the centre of the maar) [4,6,7]. Recent studies following a tephrostratigraphic approach have significantly enhanced our knowledge on the evolution of the tephra ring around maar craters, with an emphasis on pyroclastic facies and depositional processes [8][9][10][11][12][13][14][15] [ [16][17][18][19][20][21][22]. Research by Houghton and Hackett [23] and Martin and Németh [24] offer insights on the identification of strombolian and phreatomagmatic eruption styles, whereas [25][26][27] discussed the explosion mechanism, and [1], [25], [28] the quantification and control of water during fragmentation.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Eruptive history of the Barombi Mbo Maar, Cameroon Volcanic Line, Central Africa: Constraints from volcanic facies analysis

et al. 2013

View full text Add to dashboard Cite

his study presents the first and detail field investigations of exposed deposits at proximal sections of the Barombi Mbo Maar (BMM), NE Mt Cameroon, with the aim of documenting its past activity, providing insight on the stratigraphic distribution, depositional process, and evolution of the eruptive sequences during its formation. Field evidence reveals that the BMM deposit is about 126m thick, of which about 20m is buried lowermost under the lake level and covered by vegetation. Based on variation in pyroclastic facies within the deposit, it can be divided into three main stratigraphic units: U 1 , U 2 and U 3 . Interpretation of these features indicates that U 1 consists of alternating lapilli-ash-lapilli beds series, in which fallout derived individual lapilli-rich beds are demarcated by surges deposits made up of thin, fine-grained and consolidated ash-beds that are well-defined, well-sorted and laterally continuous in outcrop scale. U 2 , a pyroclastic fall-derived unit, shows crudely lenticular stratified scoriaceous layers, in which many fluidal and spindle bombs-rich lapilli-beds are separated by very thin, coarse-vesiculatedash-beds, overlain by a mantle xenolith-and accidental lithic-rich explosive breccia, and massive lapilli tuff and lapillistone. U 3 displays a series of surges and pyroclastic fall layers. Emplacement processes were largely controlled by fallout deposition and turbulent diluted pyroclastic density currents under "dry" and "wet" conditions. The eruptive activity evolved in a series of initial phreatic eruptions, which gradually became phreatomagmatic, followed by a phreato-Strombolian and a violent phreatomagmatic fragmentation. A relatively long-time break, demonstrated by a paleosol between U 2 and U 3 , would have permitted the feeding of the root zone or the prominent crater by the water that sustained the next eruptive episode, dominated by subsequent phreatomagmatic eruptions. These preliminary results require complementary studies, such as geochemistry, for a better understanding of the changes in the eruptive styles, and to develop more constraints on the maar's polygenetic origin.

show abstract

Section: Fieldworkmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Eruptive history of the Barombi Mbo Maar, Cameroon Volcanic Line, Central Africa: Constraints from volcanic facies analysis

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Speeds (up to 300 km/h) and temperatures (up to 600-700°C) of these flows are generally highon the earth surface (Wilson and Houghton, 2000). PDC are mainly controlled by gravity (Carey, 1991;Druitt, 1998a;Belousov et al, 2002;Burgisser and Bergantz, 2002) and commonly indicating a turbulent regime (Fisher, 1990;Carey, 1991;Dellino and La Volpe, 2000;Valentine and Fisher, 2000). A pyroclastic flow is diluted when he have a solid volume concentration equal or less than a few percent; a concentrated suspension or of high concentration will thus have a concentration of several percent or several tens of percent (Choux, 2001).…”

Section: Pyroclastic Density Currents Depositsmentioning

confidence: 99%

Hazards from Pyroclastic Density Currents at Mount Bamenda (West-Cameroon, Cameroon Volcanic Line): Mapping and Assessment by AMS Method

Dedzo¹,

Kamgang²,

Njonfang³

et al. 2015

American Journal of Geoscience

View full text Add to dashboard Cite

Hazards related to pyroclastic density current continue to raise victims on many volcanoes in our planet. The Cameroon is not spared to this type of hazard because deposits of pyroclastic flows and surges are found on Mount Bamenda; products of this volcano are relatively young (27-0 Ma). Besides Mount Bamenda, Mounts Bambouto and Oku are the only volcanoes located in the central part of the Cameroon Volcanic Line where these ignimbritic deposits are found. Several factors highlight dangerousness and damage that can cause ignimbritic flows on the flanks of this volcano. This is essentially the high aspect ratio of these ignimbrites, the important population (about 750,000 people) that lives on the slopes and around the volcano. In order to have an idea of a nowadays ignimbritic eruption scenario on Bamenda volcano, the Anisotropy of Magnetic Susceptibility (ASM) method is used in this study to highlight the palaeoflow in ancient deposits of ignimbrites which are mostly discontinuous and isotropic. Results of AMS study are used to produce map of hazards and assess risks that may be related with such eruptions in Bamenda volcano.

show abstract

“…However, the analysis of the facies architecture of DPDCs' deposits has also proved to be a powerful tool for understanding the fluid dynamic properties and the sedimentation processes of these flows (e.g., Brown et al 2007;Sulpizio et al 2007) and developing "reverse engineering" or inverse modeling approaches, i.e., starting from the result (the deposit) to infer the process (the flow) (Chough and Sohn 1990;Dellino et al 2000Dellino et al , 2004. In fact, DPDC deposits are characterized by peculiar properties, in particular concerning their stratigraphy: the typical bedset starts from the base with a layer made of coarse particles (generally lapilli, layer A in Fig.…”

Section: Introductionmentioning

confidence: 99%

PYFLOW_2.0: a computer program for calculating flow properties and impact parameters of past dilute pyroclastic density currents based on field data

Dioguardi

Mele

2018

Bull Volcanol

View full text Add to dashboard Cite

This paper presents PYFLOW_2.0, a hazard tool for the calculation of the impact parameters of dilute pyroclastic density currents (DPDCs). DPDCs represent the dilute turbulent type of gravity flows that occur during explosive volcanic eruptions; their hazard is the result of their mobility and the capability to laterally impact buildings and infrastructures and to transport variable amounts of volcanic ash along the path. Starting from data coming from the analysis of deposits formed by DPDCs, PYFLOW_2.0 calculates the flow properties (e.g., velocity, bulk density, thickness) and impact parameters (dynamic pressure, deposition time) at the location of the sampled outcrop. Given the inherent uncertainties related to sampling, laboratory analyses, and modeling assumptions, the program provides ranges of variations and probability density functions of the impact parameters rather than single specific values; from these functions, the user can interrogate the program to obtain the value of the computed impact parameter at any specified exceedance probability. In this paper, the sedimentological models implemented in PYFLOW_2.0 are presented, program functionalities are briefly introduced, and two application examples are discussed so as to show the capabilities of the software in quantifying the impact of the analyzed DPDCs in terms of dynamic pressure, volcanic ash concentration, and residence time in the atmosphere. The software and user's manual are made available as a downloadable electronic supplement.

show abstract

Structures and grain size distribution in surge deposits as a tool for modelling the dynamics of dilute pyroclastic density currents at La Fossa di Vulcano (Aeolian Islands, Italy)

Cited by 55 publications

References 26 publications

Eruptive history of the Barombi Mbo Maar, Cameroon Volcanic Line, Central Africa: Constraints from volcanic facies analysis

Eruptive history of the Barombi Mbo Maar, Cameroon Volcanic Line, Central Africa: Constraints from volcanic facies analysis

Hazards from Pyroclastic Density Currents at Mount Bamenda (West-Cameroon, Cameroon Volcanic Line): Mapping and Assessment by AMS Method

PYFLOW_2.0: a computer program for calculating flow properties and impact parameters of past dilute pyroclastic density currents based on field data

Contact Info

Product

Resources

About