干旱区生态环境知识资源中心(Arid): Metamorphosed carbonate platforms and controls on the genesis of sapphire, gem spinel, and lapis lazuli: Insight from the Lake Harbour Group, Nunavut, Canada and implications for gem exploration

Arid

DOI	10.1016/j.oregeorev.2019.103259
	Metamorphosed carbonate platforms and controls on the genesis of sapphire, gem spinel, and lapis lazuli: Insight from the Lake Harbour Group, Nunavut, Canada and implications for gem exploration
	Belley, Philippe M.; Groat, Lee A.
通讯作者	Belley, Philippe M.
来源期刊	ORE GEOLOGY REVIEWS
ISSN	0169-1368
EISSN	1872-7360
出版年	2020
卷号	116
英文摘要	Baffin Island's Lake Harbour Group (LHG), a Paleoproterozoic granulite facies metasedimentary sequence rich in carbonates, contains occurrences of the gemstones sapphire (corundum), spinet (including vivid blue, cobaltenriched spinet), and lapis lazuli (hailyne-bearing rock). Most occurrences of these gem minerals are uniquely metasedimentary (carbonates and calc-silicate rock), while a few spinet occurrences formed from metasomatic reactions between Si-Al-rich rock (syenogranite or gneiss) and marble. The metasedimentary corundum, spinet, and hatiyne occurrences have similar protoliths: primarily dolomitic marls with a high Al/Si relative abundance (interpreted as sandy mud to clay siliciclastic fraction in the protolith). Kimmirut-type sapphire deposits formed via a multi-step metamorphic process under three different and specific P-T conditions. Lapis lazuli formation required the presence of evaporites to provide Na and possibly S for the blue mineral hatiyne. In addition to high Al/Si calc-silicate rocks, spinet also occurs in impure dolomitic marbles with very low K/Al. Potential for Kimmirut-type sapphire deposits is expected to be restricted to metacarbonate sequences proximal to the thrust fault separating the LHG from the Narsajuaq Arc, where retrograde upper amphibolite fades mineralization is most pervasive. Spinel and Kimmirut-type sapphire deposits are expected to be found in dolomitic marble sequences rich in calc-silicate layers. The potential occurrence of lapis lazuli is more difficult to predict but deposits could be identified thanks to large geographical footprints and their color. Similar gem occurrences or deposits to those in the LHG may be found in other metacarbonate-bearing terranes with similar metamorphic conditions (and for Kimmirut-type sapphire, a similar metamorphic history). Aerial hyperspectral and photographic surveys are well-suited to gemstone exploration on southern Baffin Island thanks to excellent rock exposure with minimal sediment or plant/lichen cover. Spectral mapping of dolomite-, diopside-, phlogopite-, and scapolite-rich domains in LHG metacarbonate sequences using airborne hyperspectral data is expected to provide exploration targets. Remote sensing exploration could be used in other metacarbonate-bearing, upper amphibolite to granulite facies metamorphic terranes found in polar climates, arid climates, or at high elevation in mountainous regions where such rocks are well exposed with minimal vegetative cover.
英文关键词	Gemstones Metaearbonates Metasediments Exploration Remote sensing
类型	Review
语种	英语
国家	Canada
收录类别	SCI-E
WOS记录号	WOS:000512220700026
WOS关键词	SOUTHERN BAFFIN-ISLAND ; PALEOPROTEROZOIC TECTONIC EVOLUTION ; TRANS-HUDSON OROGEN ; AMPHIBOLITE-FACIES ; PB GEOCHRONOLOGY ; RUBY DEPOSITS ; LUC YEN ; U-PB ; MARBLE ; ORIGIN
WOS类目	Geology ; Mineralogy ; Mining & Mineral Processing
WOS研究方向	Geology ; Mineralogy ; Mining & Mineral Processing
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/315253
作者单位	Univ British Columbia, Dept Earth Ocean & Atmospher Sci, 6339 Stores Rd, Vancouver, BC V6T 1Z4, Canada
推荐引用方式 GB/T 7714	Belley, Philippe M.,Groat, Lee A.. Metamorphosed carbonate platforms and controls on the genesis of sapphire, gem spinel, and lapis lazuli: Insight from the Lake Harbour Group, Nunavut, Canada and implications for gem exploration[J],2020,116.
APA	Belley, Philippe M.,&Groat, Lee A..(2020).Metamorphosed carbonate platforms and controls on the genesis of sapphire, gem spinel, and lapis lazuli: Insight from the Lake Harbour Group, Nunavut, Canada and implications for gem exploration.ORE GEOLOGY REVIEWS,116.
MLA	Belley, Philippe M.,et al."Metamorphosed carbonate platforms and controls on the genesis of sapphire, gem spinel, and lapis lazuli: Insight from the Lake Harbour Group, Nunavut, Canada and implications for gem exploration".ORE GEOLOGY REVIEWS 116(2020).