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Scientists from the University of Southampton have discovered apreviously unrecognised volcanic process, similar to one that isused in chocolate manufacturing, which gives important new insightsinto the dynamics of volcanic eruptions. The scientists investigated how a process called 'fluidised spraygranulation' can occur during kimberlite eruptions to producewell-rounded particles containing fragments from the Earth'smantle, most notably diamonds. This physical process is similar tothe gas injection and spraying process used to form smooth coatingson confectionary, and layered and delayed-release coatings in themanufacture of pharmaceuticals and fertilisers. Kimberlite volcanoes are the primary source of diamonds on Earth,and are formed by gas-rich magmas from mantle depths of over 150km. Kimberlite volcanism involves high-intensity explosiveeruptions, forming diverging pipes or 'diatremes', which can beseveral hundred metres wide and several kilometres deep. A conspicuous and previously mysterious feature of these pipes are'pelletal lapilli ' - well-rounded magma coated fragments of rockconsisting of an inner 'seed' particle with a complex rim, thoughtto represent quenched magma. These pelletal lapilli form by spray granulation when kimberlitemagma intrudes into earlier volcaniclastic infill close to thediatreme root zone. Intensive degassing produces a gas jet in whichthe seed particles are simultaneously fluidised and coated by aspray of low-viscosity melt. In kimberlites, the occurrence of pelletal lapilli is linked todiamond grade (carats per tonne), size and quality, and thereforehas economic as well as academic significance. Dr Thomas Gernon, Lecturer in Earth Science at the University ofSouthampton, says: "The origin of pelletal lapilli is important forunderstanding how magmatic pyroclasts are transported to thesurface during explosive eruptions, offering fundamental newinsights into eruption dynamics and constraints on vent conditions,notably gas velocity." "The ability to tightly constrain gas velocities is significant, asit enables estimation of the maximum diamond size transported inthe flow. Gas fluidisation and magma-coating processes are alsolikely to affect the diamond surface properties." Dr Gernon and colleagues studied two of the world's largest diamondmines in South Africa and Lesotho. In the Letseng pipe in Lesotho,pelletal lapilli have been found in association with concentrationsof large diamonds (up to 215 carat), which individually can fetchup to tens of millions of pounds. Knowledge of flow dynamics willinform models of mineral transport, and ultimately could improveresource assessments. Dr Gernon says: "This multidisciplinary research, incorporatingEarth sciences, chemical and mechanical engineering, providesevidence for fluidised granulation in natural systems which will beof considerable interest to engineers and chemical, pharmaceuticaland food scientists who use this process routinely. The scale andcomplexity of this granulation process is unique, as it has notpreviously been recognised in natural systems." The paper 'The origin of pelletal lapilli in explosive kimberliteeruptions' is published in the latest issue of NatureCommunications. I am an expert from agrochemical-pesticide.com, while we provides the quality product, such as Pesticide Technical , Difenoconazole Manufacturer, Agrochemical Insecticide,and more.
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