Clast measurement; a simple manual device and its semiautomatic electronic equivalent

Ibbeken, Hillert; Denzer, P.

doi:10.1306/212f8e36-2b24-11d7-8648000102c1865d

Cited by 9 publications

(9 citation statements)

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“…The pebble-box was developed by Ibbeken and Denzer (1988) who conducted several large studies of gravel particle shapes. The pebble-box is a convenient device for easy measurements of the three particle axes because it does not require repositioning the particles between measurements, as ruler measurements do, and ensures all three measured particle axes are at right angles.…”

Section: Pebble-boxmentioning

confidence: 99%

Sampling surface and subsurface particle-size distributions in wadable gravel-and cobble-bed streams for analyses in sediment transport, hydraulics, and streambed monitoring

Bunte¹,

Abt²

2001

521

553

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Section: Pebble-boxmentioning

confidence: 99%

Sampling surface and subsurface particle-size distributions in wadable gravel-and cobble-bed streams for analyses in sediment transport, hydraulics, and streambed monitoring

Bunte¹,

Abt²

2001

521

553

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“…There is adifference in sphericity between rock types, but no significant changes during transport. Figure 13 shows the corresponding sphericities for the two petrographic groups, which were measured with a simple mechanical device (Ibbeken & Denzer, 1988). As expected, there are no significant changes during transportation.…”

Section: Field Investigationmentioning

confidence: 72%

How round is round? A new approach to the topic ‘roundness’by Fourier grain shape analysis

1992

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Numerous methods for roundness measurement have been developed. None, however, has been generally accepted, because of conceptual and practical deficiencies. Modern image processing and Fourier grain shape analysis have eliminated the practical shortcomings, but the conceptual ones remained. Single, higher harmonics of the Fourier series, for example, fail to serve as reliable equivalents for roundness evaluation. The concept outlined in this paper recognizes three criteria for the evaluation of roundness. (1) All curvatures, convex as well as concave or plane elements, must be considered. (2) The positions of morphological elements are significant because salient parts of a particle are more easily abraded than protected ones. Consequently, the curvatures have to be weighted by their relative position on the particle. (3) Positions and curvatures of morphological elements have to be compared with the particle's ultimate abraded shape, which is assumed to be an ellipsoid. The ellipsoid reflects the aspect of form or sphericity. The distinction between sphericity and roundness is retained because there is no evidence that sphericity changes significantly during transport. The measurement is based on the outline of a particle's maximum projection plane, which is transformed to a Fourier series. Roundness data are derived from the complete amplitude spectrum. The aspect of sphericity is eliminated by subtracting the amplitude spectrum of the best approximating ellipse from the spectrum of the empirical shape. The residual amplitudes are normalized and summed. In a final step the resulting values are rescaled. This guarantees reasonable boundaries and a normal distribution of roundness values. The procedure is automated and its efficiency permits the calculation of large samples. Tests on fluvial and coastal gravel populations demonstrate that the method is sensitive to abrasional wear during all stages of roundness.

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“…In this regard, bidimensional concepts have been described in the geological literature as the ‘maximum projection plane’ (Krumbein ). Most recently, they have been used for bidimensional representations as the ‘smallest projected area’ (McLane ), or for three‐dimensional representations as the ‘pebble box’ (Ibbeken and Denzer ), the ‘enclosing box’ (McLane ) or the ‘smallest box’ (Blott and Pye ), amongst others.…”

Section: Methods Of Spatial Representationmentioning

confidence: 99%

“…In this regard, bidimensional concepts have been described in the geological literature as the 'maximum projection plane' (Krumbein 1941). Most recently, they have been used for bidimensional representations as the 'smallest projected area' (McLane 1995), or for threedimensional representations as the 'pebble box' (Ibbeken and Denzer 1988), the 'enclosing box' (McLane 1995) or the 'smallest box' (Blott and Pye 2008), amongst others. In the archaeological literature, the bidimensional concept has been applied to the products of the prehistoric lithic industry by some prehistorians as the 'rectangle minimal' (Laplace 1974a).…”

Section: The Dimensions As Representation Axesmentioning

confidence: 99%

A New Methodology and Classification System for Describing Three-Dimensional Particle Formats: Application to Clastic Lithic Products of Archaeological and Geological Origin

Tarriño

2014

Archaeometry

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A new classification system is proposed to describe the volumetric formats of clastic lithic products of geological and archaeological origin. In order to build this operative classification, the rectangular block or cuboid is established as the standard geometric format to represent their three‐dimensional format (the X‐axis being length or long diameter, the Y‐axis being the width or intermediate diameter, and the Z‐axis being the thickness or short diameter) on a two‐dimensional diagram. To obtain this graph, each absolute coordinate (X, Y, Z) defining the prisms is projected on to an auxiliary plane with a new set of relative coordinates (x, y, z), expressed as the percentage of their sum. The projection generates a triangular diagram on which the indices of elongation and flatness are represented. A geometric transformation converting the triangular diagram into a quadrangular diagram has been produced in order to better represent the scatter points. Then, a double scale is necessary: (i) an absolute scale to quantify the indices, and (ii) a relative scale to calculate where the graphic locus is projected. This new graph also allows us to work with statistical parameters. Finally, two classic examples of applications selected from the literature are shown.

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Clast measurement; a simple manual device and its semiautomatic electronic equivalent

Cited by 9 publications

References 0 publications

Sampling surface and subsurface particle-size distributions in wadable gravel-and cobble-bed streams for analyses in sediment transport, hydraulics, and streambed monitoring

Sampling surface and subsurface particle-size distributions in wadable gravel-and cobble-bed streams for analyses in sediment transport, hydraulics, and streambed monitoring

How round is round? A new approach to the topic ‘roundness’by Fourier grain shape analysis

A New Methodology and Classification System for Describing Three-Dimensional Particle Formats: Application to Clastic Lithic Products of Archaeological and Geological Origin

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