The spatial distribution of grains and crystals in rocks

Jerram, Dougal A.; Cheadle, M. J.; Hunter, Robert H.; Elliott, M.T.

doi:10.1007/s004100050206

Cited by 139 publications

(130 citation statements)

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“…The comparison of volume of coarse clasts with fine clasts and cement in a deposit can be used as proxy for the degree of sorting. Sorting is inversely proportional to the degree of packing of clasts (Jerram et al, 1996). We introduce the parameter F-1, which is the percentage of clasts <2 mm (or >-1 ) and/or void or cement in a deposit.…”

Section: Clast Volumementioning

confidence: 99%

Grain-size distribution of volcaniclastic rocks 2: Characterizing grain size and hydraulic sorting

Jutzeler

McPhie

Allen

et al. 2015

Journal of Volcanology and Geothermal Research

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Proussevitch, A.A.. 2015 Grain-size distribution of volcaniclastic rocks 2: Characterizing grain size and hydraulic sorting. Journal of Volcanology and Geothermal Research. 10.1016/j.jvolgeores.2015.05.019 (In Press) Contact NOC NORA team at publications@noc.soton.ac.ukThe NERC and NOC trademarks and logos ('the Trademarks') are registered trademarks of NERC in the UK and other countries, and may not be used without the prior written consent of the Trademark owner. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. ÔØ Å ÒÙ× Ö ÔØ A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT Highlights:Functional stereology is efficient to interpret sedimentation mechanisms Simple hydraulic sorting ratios allow inference on styles of deposition Transport and deposition mechanisms can be evaluated from pumiceous rocksModes are more adequate than median to characterize sediment grain size Keywords:Stereology; Image analysis; Hydraulic sorting; Hydraulic equivalence, Grain size distribution; Volcaniclastic rock; Clastic rock; Ohanapecosh; Dogashima; Manukau; Sierra La Primavera. sorting ratios can be applied to any type of clastic rocks, and indifferently on consolidated and unconsolidated samples. A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT

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Section: Clast Volumementioning

confidence: 99%

Grain-size distribution of volcaniclastic rocks 2: Characterizing grain size and hydraulic sorting

Jutzeler

McPhie

Allen

et al. 2015

Journal of Volcanology and Geothermal Research

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“…Theoretical and experimental simulations together with studies of natural samples suggest high initial porosities for cumulate rocks (e.g., 40-70%; Shirley 1986;Philpotts et al 1998;Jerram et al 1996Jerram et al , 2003Donev et al 2004). In a crystal mush that accumulates at the floor of a magma chamber, the lower part is a compacting layer with a theoretical thickness given by d c (compaction length scale in m), while the upper part is not compacted.…”

Section: Compactionmentioning

confidence: 99%

“…Formation of adcumulates, which have trapped liquid fraction below 7% (Irvine 1982), requires these mechanisms to be highly efficient in segregating the melt from the crystal framework, thought to contain 40-70% intercumulus melt (e.g., Shirley 1986;Philpotts et al 1998;Jerram et al 1996Jerram et al , 2003Donev et al 2004).…”

mentioning

confidence: 99%

Efficiency of compaction and compositional convection during mafic crystal mush solidification: the Sept Iles layered intrusion, Canada

Namur

Charlier

2012

Contrib Mineral Petrol

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Adcumulate formation in mafic layered intrusions is attributed either to gravity-driven compaction, which expels the intercumulus melt out of the crystal matrix, or to compositional convection, which maintains the intercumulus liquid at a constant composition through liquid exchange with the main magma body. These processes are length-scale and time-scale dependent, and application of experimentally derived theoretical formulations to magma chambers is not straightforward. New data from the Sept Iles layered intrusion are presented and constrain the relative efficiency of these processes during solidification of the mafic crystal mush. Troctolites with meso-to ortho-cumulate texture are stratigraphically followed by Fe-Ti oxide-bearing gabbros with adcumulate texture. Calculations of intercumulus liquid fractions based on whole-rock P, Zr, V and Cr contents and detailed plagioclase compositional profiles show that both compaction and compositional convection operate, but their efficiency changes with liquid differentiation. Before saturation of Fe-Ti oxides in the intercumulus liquid, convection is not active due to the stable liquid density distribution within the crystal mush. At this stage, compaction and minor intercumulus liquid crystallization reduce the porosity to 30%. The velocity of liquid expulsion is then too slow compared with the rate of crystal accumulation. Compositional convection starts at Fe-Ti oxide-saturation in the pore melt due to its decreasing density. This process occurs together with crystallization of the intercumulus melt until the residual porosity is less than 10%. Compositional convection is evidenced by external plagioclase rims buffered at An 61 owing to continuous exchange between the intercumulus melt and the main liquid body. The change from a channel flow regime that dominates in troctolites to a porous flow regime in gabbros results from the increasing efficiency of compaction with differentiation due to higher density contrast between the cumulus crystal matrix and the equilibrium melts and to the bottom-up decreasing rate of crystal accumulation in the magma chamber.

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“…His work is based on the fact that the area of the surface boundary between two phases can be estimated to be equal to the length of the boundary between the same two phases on a 2D slice (Underwood, 1970). Also, Jerram et al (1996) build a three-dimensional model of a rock, where the different parts of the rock are represented by spheres (of the same size), which serves as a reference to compare the pattern obtained in the thin sections. This approach has the major shortcoming of not creating a space-filling model, and thus adjacency relationships between phases can not be studied.…”

Section: Geological Microstructuresmentioning

confidence: 99%

Modelling three‐dimensional geoscientific fields with the Voronoi diagram and its dual

Ledoux

Gold

2008

International Journal of Geographical Information Science

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Fields as found in the geosciences have properties that are not usually found in other disciplines: the phenomena studied are often three-dimensional, they tend to change continuously over time, and the collection of samples to study the phenomena is problematic, which often results in highly anisotropic distributions of samples. In the GIS community, raster structures (voxels or octrees) are the most popular solutions, but, as we show in this paper, they have shortcomings for modelling and analysing 3D geoscientific fields. As an alternative to using rasters, we propose a new spatial model based on the Voronoi diagram (VD) and its dual the Delaunay tetrahedralization (DT), and argue that they have many advantages over other tessellations. We discuss the main properties of the 3D VD/DT, present some GIS operations that are greatly simplified when the VD/DT is used, and, to analyse two or more fields, we also present a variant of the map algebra framework where all the operations are performed directly on VDs. The usefulness of this Voronoi-based spatial model is demonstrated with a series of potential applications.

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The spatial distribution of grains and crystals in rocks

Cited by 139 publications

References 0 publications

Grain-size distribution of volcaniclastic rocks 2: Characterizing grain size and hydraulic sorting

Grain-size distribution of volcaniclastic rocks 2: Characterizing grain size and hydraulic sorting

Efficiency of compaction and compositional convection during mafic crystal mush solidification: the Sept Iles layered intrusion, Canada

Modelling three‐dimensional geoscientific fields with the Voronoi diagram and its dual

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