caa a22 4500 386402639 CHVBK 20180307112205.0 cr unu---uuuuu 161130e198905 xx s 000 0 eng 10.1017/S0016756800022342 doi S0016756800022342 pii (NATIONALLICENCE)cambridge-10.1017/S0016756800022342 Thomson B. Upper Kennerty Mills Cottage, Kennerty Mills Road, Peterculter, Aberdeen AB1 OLR, Scotland, U.K. Petrology and stratigraphy of some texturally well preserved thin komatiites from Kambalda, Western Australia [Elektronische Daten] [B. Thomson] Archaean komatiite volcanics at Kambalda, Western Australia have been metamorphosed to upper greenschist-lower amphibolite grade and have experienced intense though heterogeneously developed polyphase deformation. Despite this, preservation of igneous textural features is often good, particularly in areas which underwent only ‘static style' metamorphism. Thin lavas from the Tripod Hill Member of the Kambalda Komatiite Formation over the western margin of the Hunt nickel shoot display textural elements and facies variations which are virtually identical to those found in fresher thin komatiite sequences in other Archaean greenstone belts. Four principal flow profile (facies) types are defined, comprising nine subtypes. These represent stages in a facies continuum, ranging from ‘mature' profiles which comprise thick spinifex textured tops and close packed cumulate bases through to massive, jointed ‘immature' profiles devoid of mesoscopic spinifex texture. The causes of textural diversity within and between profiles are many and complex. However, facies variations can be attributed mainly to the effects of lava velocity at the time of major heat loss, combined with relative lateral position within any flow. The most mature textural (and geochemical) profiles developed in parts of lavas which had become ponded prior to major heat loss, whereas the least evolved profiles developed along the lateral margins (levees) of moving lavas. The study area komatiites occur as alternating stacks of flows of similar type. This stratigraphy records temporal and spatial shifts in the locus of lava ponding over the western margin of the Hunt nickel shoot. Such shifts may have been caused by irregularities in the underlying volcanic topography and/or by synvolcanic faulting and subsidence. Copyright © Cambridge University Press 1989 Geological Magazine Cambridge University Press 126/3(1989-05), 249-261 0016-7568 126:3<249 1989 126 GEO https://doi.org/10.1017/S0016756800022342 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0016756800022342 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Thomson B. Upper Kennerty Mills Cottage, Kennerty Mills Road, Peterculter, Aberdeen AB1 OLR, Scotland, U.K NATIONALLICENCE 773 0- Geological Magazine Cambridge University Press 126/3(1989-05), 249-261 0016-7568 126:3<249 1989 126 GEO CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge