Document
type: Class

Journal of Volcanology and Geothermal Research
type: Continuant
type: Thing
type: Generically Dependent Continuant
type: Information Content Entity
type: Collection
type: Entity
type: Journal
type: Document
publication venue for: Computer-assisted image analysis on clast shape fabric from the Orvieto-Bagnoregio ignimbrite (Vulsini District, central Italy): Implications on the emplacement mechanisms
type: Periodical

Computer-assisted image analysis on clast shape fabric from the Orvieto-Bagnoregio ignimbrite (Vulsini District, central Italy): Implications on the emplacement mechanisms
page start: 75
most specific type: Document
type: Document
abstract: Computer-assisted Image Analysis can be succesfully used to derive quantitative information about grain-size distribution, particle shape and fabric on both consolidated and unconsolidated solid aggregates. We have developed a new analytical method that provides a series of quantitative textural parameters from whatever particulate deposits by combining commercial image acquisition system with devoted C-software. After exhaustive tests of the method, we applied it to a widespread Quaternary ignimbrite formation in central Italy (the Orvieto-Bagnoregio formation). The results suggest some new aspects of emplacement mechanisms of ignimbrites: (1) elongated particles shows variable degrees of flow-related preferred orientation both on horizontal and vertical planes; (2) vertical variations of flow-related preferred particle orientations follow a zig-zag pattern that we interpret to result from deposition by progressive aggradation during the passage of a particulate flow. The filling up of paleovalleys by means of progressive aggradation proceeds flank to flank due to alternating flow directions, induced by the already deposited material; (3) the occurrence of vertically spaced peaks on the strength of clast orientation suggests the existence of discrete depositional units deposited by aggradation from an unsteady but persisting flow. Strong fabrics are inferred to result from the high amount of shear stress imparted to particles at the depositional boundary layer, which at the same time can be responsible for the development of the basal inversely graded layer. Image analysis can also provide useful indications of paleoflow directions, paleotopographic details and ignimbrite source areas.
volume: 70
type: Thing
type: Generically Dependent Continuant
type: Information Content Entity
origen: scopus
has publication venue: Journal of Volcanology and Geothermal Research
issue: 1-2
type: Continuant
page end: 90
related by: authorship 2326
freetext keyword: clast shape fabric; emplacement mechanism; ignimbrite; image analysis; Italy, Lazio, Vulsini
doi: 10.1016/0377-0273(95)00049-6
most specific type: Article
crisid: 523
e iscopus: 2-s2.0-0029730786
date time value: article date 523
related by: authorship 2327
type: Entity
estado: published
type: Article

Continuant
type: Class

Entity
type: Class

Generically Dependent Continuant
type: Class

individual
rights: termsOfUse
date: 2026-08-28T03:00:16
publisher: vivo
type: Document
label: RDF description of Computer-assisted image analysis on clast shape fabric from the Orvieto-Bagnoregio ignimbrite (Vulsini District, central Italy): Implications on the emplacement mechanisms - http://orbis.uaslp.mx/vivo/individual/scopus522

Article
type: Class

Information Content Entity
type: Class