Results 121 to 130 of about 518 (163)

New insights into volcanic processes from deep mining of the southern diatreme within the Argyle lamproite pipe, Western Australia

Mineralogy and Petrology, 2018
Underground mining and deep drilling of the richly diamondiferous ~1.2 Ga Argyle lamproite in Western Australia has prompted a re-evaluation of the geology of the pipe. Argyle is considered to be a composite pipe that formed by the coalescence of several
Volker Lorenz, A L Jaques
exaly   +2 more sources

Lamproite

, 2011
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lamproite

, 2009
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lamproite pipe

, 2009
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LAMPROITES OF NORTHERN ALGERIA

International Geology Review, 1993
The mineralogy and chemistry of lamproitic rocks from two bodies in northern Algeria, near the city of Constantine, have been studied in detail. On the basis of the ultra-alkaline, highly potassic and highly mag-nesian composition and the presence of magnesian olivine, low-alumina and low-soda diopside and other minerals, these rocks are classified as ...
F. V. Kaminskiy, Ye. F. Roman'ko, S. K. Kolesnikov, M. Salkhi   +3 more
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Mineralogy of Lamproites

1991
The mineralogy of the lamproite clan is perhaps one of the most exotic of all alkaline rocks. The perpotassic and peralkaline traits of the magmas lead to a distinctive mineral assemblage that is virtually unparalleled. The paragenesis and composition of the minerals comprising lamproites are detailed in this chapter.
Roger H. Mitchell, Steven C. Bergman
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Petrogenesis of Lamproites

1991
The development of realistic hypotheses for the petrogenesis of potassic rocks has been hindered, until recently, by the tendency of petrologists to consider all leucite-bearing K-rich rocks as being related. Sufficient geological, geochemical, and mineralogical evidence (see Chapter 2) has now accumulated to show that this assumption is not correct ...
Roger H. Mitchell, Steven C. Bergman
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The Geochemistry of Lamproites

1991
Relative to other mafic alkaline rocks lamproites are distinguished by their high K2O, TiO2, P2O5, and MgO contents, K2O/Na2O ratios and low Al2O3 and CaO contents. The general characteristics of the lamproite clan have been outlined in Section 2.6. In this section the compositional averages and ranges of lamproites are compared with those of other ...
Roger H. Mitchell, Steven C. Bergman
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Petrogenesis of Kaapvaal lamproites (aka orangeites) constrained by the composition of olivine and similarities with kimberlites and other diamondiferous lamproites

Lithos, 2021
Abstract Kaapvaal lamproites, also known as orangeites, are H2O-rich, diamondiferous, highly micaceous, ultrapotassic rocks. Olivines in kimberlites have been shown to be extremely useful in tracking melt evolution, highlighting the importance of the chemical effects of SCLM assimilation on asthenosphere-derived melts. Kaapvaal lamproites are derived
Geoffrey H. Howarth, Thendo Nembambula
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Fluorine-bearing phases in lamproites

Mineralogy and Petrology, 1991
The distribution of F between phlogopite, amphibole, apatite, and glass has been determined for 261amproites from Leucite Hills, Wyoming; West Kimberley, Western Australia; Smoky Butte, Montana; Prairie Creek, Arkansas; and Gaussberg, Antarctica. The F contents of these phases are inconsistent in different lamproite localities, with distinct variations,
A. D. Edgar, H. E. Charbonneau
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