Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 68 for “"Kimberlite."”.
-
Geochemistry and petrogenesis of kimberlite intrusions from the eastern lobe the Du Toitspan kimberlite pipe, South Africa
The Du Toitspan kimberlite pipe located on the outskirts of Kimberley South Africa, is one four Cretaceous aged major kimberlite pipes from the well-known Kimberley cluster, the type locality for archetypal group I kimberlites. Twenty-seven samples representative of various kimberlite intrusions …
-
Oxygen isotope composition of megacrysts from the Monastery kimberlite
Kimberlite megacrysts are large (>1 cm diameter) crystals that are thought to have crystallized from sub lithospheric proto-kimberlite melts near the base of the subcontinental lithospheric mantle (SCLM) during complex melt-SCLM interactions. Thus, these megacrysts represent an excellent …
-
Surface textures on pyrope, picroilmenite and chrome diopside from Kimberlite
… pyrope, picroilmenite and chrome diopside from kimberlite gives valuable information on the history of these minerals both during and after kimberlite emplacement. Descriptions and scanning electron photo-micrographs of surface features observed on these mantle-derived minerals from thirty-four …
-
Mantle conditions and kimberlite geochemical criteria controlling diamond survival in Kimberlites
… in the mantle and transport to the surface by kimberlite magma, they may be exposed to deformation or oxidising conditions outside of their stability field, causing diamond corrosion and resorption processes. The infiltration of silicate-rich melts and hydrothermal fluids are key processes that …
-
Diamonds and related minerals from the Dokolwayo Kimberlite, Kingdom of Swaziland
Several physical characteristics, the carbon isotopic compositions, inclusion mineralogy, and distribution of the Dokolwayo diamonds were investigated. A representative suite of concentrate garnet megacrysts and macrocrysts were analyzed for their compositions. Concentrate macrocryst spinels and …
-
Geochemical aspects of the megacryst suite from the monastery kimberlite pipe
[Missing Pages - Abstract unavailable]
-
Petrogenesis of the Northwest corner intrusive phases, Dutoitspan kimberlite, South Africa
The Outoitspan Group 1 kimberlite pipe forms part of the well-known cluster of pipes located in and around the city of Kimberley, South Africa. Eight macroscopically distinct intrusive phases, i.e. D2 Type 2, D2 Type 3, D2/D5, D5, D18, Type 5, D16 and the D16 dyke are present in the Northwest …
-
A study of mantle inclusions in the Koffiefontein Kimberlite Pipe, South Africa
… and mineral fragments from the Koffiefontein Kimberlite Pipe have been studied in the form of xenoliths, megacrysts, concentrate minerals and inclusions in diamonds. Mantle derived xenoliths are unusually scarce. The predominant xenoliths are pyroxenites. Peridotites are rare and eclogites are …
-
A study of mantle inclusions in the Koffiefontein Kimberlite pipe, South Africa
… and mineral fragments from the Koffiefontein Kimberlite Pipe have been studied in the form of xenoliths, megacrysts, concentrate minerals and inclusions in diamonds. Mantle derived xenoliths are unusuaLly scarce. The predominant xenoliths are pyroxenites. Peridotites are rare and eclogites are …
-
Volcanology and geochemistry of selected kimberlites from the Lulo kimberlite field, Angola
Abstract The area under study is the Lulo Kimberlite Field in the province of Lunda Norte, Angola, which is located 630 km east of the capital, Luanda. This 3000 km2 concession is one of the world's most abundant alluvial diamond fields, producing high value Type IIa diamonds, as well as hosting a …
-
A detailed investigation into diamond-bearing xenoliths from Newlands Kimberlite, South Africa
… peridotite and eclogite from Newlands kimberlite, located on the Kaapvaal craton, South Africa. Eighteen peridotitic garnet macrocrysts (1 to 3 cm in size) containing diamond, and one with graphite, consist predominantly of lilac garnet with diamond (or graphite) ± chromite and altered …
-
A study of unusual diamonds from the George Creek K1 Kimberlite dyke, Colorado
… diamonds from the George Creek Kl (section 28) kimberlite dyke in Colorado reveal complex intergrowth relationships between CO?-free and CO?-bearing diamond growth generations. The distribution of the CO?-bearing diamond in some specimens suggests that this generation is younger than the …
-
Petrogenesis of the Swartruggens and Star Group II kimberlite dyke swarms, South Africa
The Swartruggens (156 Ma) and Star (128 Ma) kimberlites are two Group II, diamondiferous, hypabyssal kimerlite dyke swarms, situated in the Northern Province and the Free State respectively, South Africa. Representative samples from all dykes exposed in the mining operations, the Main and …
-
Guiana Shield diamonds, the sub-cratonic lithosphere, and kimberlite emplacement in the upper crust.
… seal experiments at 100-200 MPa on hypabyssal kimberlite from the Jericho kimberlite (Northwest Territories, Canada) to examine sub-solidus reactions that occur syn- to post- emplacement. We observe that olivine in the presence of calcite is unstable and monticellite is precipitated, within the …
-
The geochemistry of a suite of eclogite xenoliths from the Rietfontein Kimberlite, South Africa
The Rietfontein kimberlite is an off-craton kimberlite pipe, located west of the Kaapvaal Craton at 26.75°, 20.04°E and hosts a range of xenocryst lithologies, including peridotite, eclogite and a suite of megacryst minerals. This study focuses on a suite of eclogite xenoliths, which were subject …
-
A detailed geochemical investigation of diamond-bearing eclogite xenoliths from the Kaalvallei kimberlite, South Africa
The eclogites are essentially bimeneralic assemblages of garnet and clinopyroxene. Thirteen xenoliths contain accessory diamond with graphite on diamond surfaces. One has accessory ilmenite. The rocks are well equilibrated and are classified as Group 1 eclogites, based on their mineral textures and …
-
A study of the kimberlites, diamonds and associated rocks and minerals from the monastery mine, South Africa. Volume 1: Text
The hypabyssal quarry kimberlite is the most abundant phase at Monastery. Four petrographically distinct varieties are recognized. Mineralogically, the Ql and Q4 kimberlites are opaque oxide-rich serpentine-phlogopite kimberlites, the Q2, a phlogopite-monticellite kimberlite and the Q3, a …
-
The kimeerlite occurrences from the vicinity of Rayton, South of premier mine, and from East Lynne, East of Pretoria
… mineralogy, petrography, and petrology of five kimberlite occurrences were investigated. Four of the occurrences i.e., Rietfontein, Kaalfontein, and Montrose No. 1 pipes, and the Puntlyf fissure are south of Premier Mine. The East Lynne occurrence is just east of Pretoria. The mineralogy and …
Page 1 of 4