ON THE DISTRIBUTION AND DISPERSION OE ' PLATINUM IN THE SOILS OF THE TULAMEEN ULTRA . MAFIC COMPLEX , SOUTHERN BRITISH COLUMBIA
INTRODUCTION Exploration for platinum in British Columbia is hampered by a lack of data on its distribution and behavior in the surficial environment. To obtain some of the information required and suggest practical guidelines for exploration, this study, involving systematic sampling and analysis of soils and other media in the vicinity of a platinum deposit in the Tulameen district of southwestern British Columbia, was initiated in 1988 (Fletcher. 19x9). Preliminary results of work in progress are described. Tulameen River, approximately 25 kilometres west of Prince-The field area, on Grasshopper Mountain north of the ton, is divided into the main study area, on the southern slope of the mountain, and a second, smaller area near the summit (Figure 6.2-I). The lower part is accessible by pack trail from the Tulameen River road. Several kilometres of recently constructed drill road on the north and west sides of g e o l o g y , Tulameen ultramafic c o m p l e x. B. C. Figure 6-2-1, Location of the study areas and generalized (1) Nicola Group (2) syenogabhrn. (3) dunite. (4) olivine clinopyroxenite,(5) homblendr~linopqmxenite. (6)rnyloni-tic rocks. (7) Eagle granodiorile (modified after Nixon and Rublee. 1988). Grasshopper Mountain connect with the Lawless 'Creek forestry road and provide access from both the village of Tulameen and the Coquihalla Highway. BEDROCK GEOLOGY dissected dunite core of the Tulameen ultramafic complex, a Grasshopper Mountain is the northern segment o' the Late Triassic zoned Alaskan-type ultramafic-gabbroic intrusion within metasedimentary and metavolcanic rocks c,f the Upper Triassic Nicola Group. Geology of the complex, described by Findlay (1969) and Nixon and Rublea (1988). comprises a dunite core surrounded by crudely concentric shells of olivine clinopyroxenite, hornblende c h o p r o x-enite and gabbroic rocks ((Figure 6-2-1). The focus of the current study is within the dunite :ore. The dunite is typically Fine grained, extensively sepen-tinized, and weathers buff-brown on exposed surfaces "lati-num mineralization is restricted to chromite-rich dunite (Nixon e t a /. is best exposed in the summit region and in the sub\ertical randomly distributed massive to discontinuous pods, segre-gations. schlieren and disseminated grains. Schlierel are randomly distributed thrcmughout the dunite and are thought to represent foliation-concordant remnants of former cumu-late layers (Nixon and Rublee, 1988:1. Several cons of central region of the cor'? (Bohme, 19x7). but till-covered mineralization have beer1 defined within the well-exposed areas are largely untested. platinum-iron alloys and platinum antimonides …
Origin of the Tulameen ultramafic-gabbro complex, southern British Columbia
The Tulameen Complex is a composite ultramafic-gabbroic intrusion that outcrops over 22 sq. mi. (57 km2) in the Southern Cordillera of British Columbia. The complex intruded Upper Triassic metavolcanic and metasedimentary rocks of the Nicola Group, and on the basis of geologic relations and a K–Ar age determination (186 m.y.) is tentatively dated as Late Triassic.The principal ultramafic units — dunite, olivine clinopyroxenite, and hornblende clinopyroxenite — form an elongate, non-stratiform body whose irregular internal structure is best explained by deformation contemporaneous with crystallization of the rocks. The derivation of the ultramafic rocks is attributed to fractional crystallization of an ultrabasic magma. The gabbroic mass, which consists of syenogabbro and syenodiorite, partly borders and partly overlies the ultramafic body and was apparently intruded by it.The ultramafic and gabbroic parts of the complex probably formed from separate intrusions of different magmas, but the two suites have ...
The Clinopyroxenes of the Garbh Eilean Sill, Shiant Isles
Abstract Ten clinopyroxenes have been investigated chemically and optically. Eight of these were separated from the rocks of the Garbh Eilean sill and two from other rocks relevant to this inquiry into the trend during crystallization of pyroxenes in minor basic intrusions of mildly alkaline and undersaturated type.