This semantic conflict highlights the need for a definition of вЂpeperiteвЂ™ that is widely acceptable (see below and White et al., 2000). Hence, in France the term вЂpeperiteвЂ™ is commonly used in a different sense, to apply to any rock that comprises juvenile glassy volcanic components in a non-juvenile matrix (De GoГ«r, 2000). Jones (1969) interpreted the rocks as the product of simultaneous deposition of lime mud and reworked volcanic clasts, but most of the Limagne вЂpeperitesвЂ™ are now interpreted as pyroclastic fall and base surge deposits, which were erupted through lime mud, incorporating some of this sediment, or else were emplaced subaqueously on lime mud (De GoГ«r et al., 1998, De GoГ«r, 2000). The intrusive origin of the majority of the Limagne peperites has been disputed (Kieffer, 1970, Vincent, 1974, De GoГ«r, 2000). The term вЂpeperiteвЂ™ is now most commonly used to refer to clastic rocks comprising both igneous and sedimentary components, which were generated by intrusive processes, or along the contacts of lava flows or hot volcaniclastic deposits with unconsolidated, typically wet, sediments. Scrope (1858) interpreted the rocks as having originated by a вЂviolent and intimate union of volcanic fragmentary matter with limestone while yet in a soft stateвЂ™, whereas Michel-Levy (1890) more specifically interpreted them as having formed by intrusion of magma into wet lime mud. This area is now considered the type locality for вЂpeperiteвЂ™. The term вЂpeperinoвЂ™ was used by Scrope (1827) to describe clastic rocks from the Limagne dвЂ™Auvergne region of central France that comprise mixtures of lacustrine limestone and basalt and which resembled ground pepper. Mingling of juvenile clast populations, formed under different thermal and mechanical conditions, complicates the interpretation of magma fragmentation and mingling mechanisms. The presence of peperite intraclasts within peperite and single juvenile clasts with both sub-planar and fluidal margins imply that peperite formation can be a multi-stage process that varies both spatially and temporally. Sediment rheology may be affected by dewatering, compaction, cementation, vesiculation, fracturing, fragmentation, fluidisation, liquefaction, shear liquification and melting during magma intrusion and peperite formation. Factors which could influence fragmentation and mingling processes include magma, host sediment and peperite rheologies, magma injection velocity, volatile content of magma, total volumes of magma and sediment involved, total volume of pore-water heated, presence or absence of shock waves, confining pressure and the nature of local and regional stress fields.

Fluidisation of host sediment, hydromagmatic explosions, forceful intrusion of magma and sediment liquefaction and shear liquification are probably the most important mechanisms by which juvenile clasts and host sediment are mingled and dispersed. Magma fragmentation by fluidвЂ“fluid shearing and surface tension effects is probably also important in fluidal peperite. Magma is dominantly fragmented by quenching, hydromagmatic explosions, magmaвЂ“sediment density contrasts, and mechanical stress as a consequence of inflation or movement of magma or lava. Peperite can often be described on the basis of juvenile clast morphology as blocky or fluidal, but other shapes occur and mixtures of different clast shapes are also found. It also occurs in phreatomagmatic vent-filling deposits and along contacts between sediment and intrusions, lavas and hot volcaniclastic deposits in many environments. Peperite is common in arc-related and other volcano-sedimentary sequences, where it can be voluminous and dispersed widely from the parent intrusions. This paper reviews the processes and products of peperite genesis. 20A, pp.The study of peperite is important for understanding magmaвЂ“water interaction and explosive hydrovolcanic hazards. Allison: Paper presented at the ASM Material Solution and Exhibition, Pittsburgh, PA, Oct. Dissertation, University of Illinois at Urbana-Champaign, Urbana, IL, 2001 Luty, eds., Springer-Verlag, New York, NY, 1992 Kohler: in Theory and Technology of Quenching, B. on Metallurgical Modeling for Aluminum Alloys, ASM INTERNATIONAL Pittsburgh, PA, 2003, pp. Chang: Light Metals 2001, TMS, Warrendale, PA, 2001, pp. Melanie: An Introduction to Genetic Algorithms, MIT Press, Cambridge, MA, 1996 Zoutendijk: Methods of Feasible Directions, Elsevier, Amsterdam, Netherlands, 1960

Magmasoft heat transfer