Mineral resources and prospectivity of the ultramafic rocks of New Caledonia
Mineral resources and prospectivity of the ultramafic rocks of New Caledonia
复制标题
DOI：
10.1144/m51-2016-17
复制
发表时间：
2020-01-01
期刊：
影响因子：
--
通讯作者：
Robineau, B.
中科院分区：
文献类型：
--
作者：
Maurizot, P.;Sevin, B.;Robineau, B.
新喀里多尼亚的主要金属矿产资源位于仰俯橄榄岩推覆体中。 Ni、Co、Cr 和 Pt 族元素 (PGE) 是该超镁铁质地体特有的元素。铬是最上地幔中的豆荚状铬铁矿，是过去唯一经济开采的地下金属。最大的铬铁矿矿床位于二辉橄榄岩蒂巴吉地块。表生镍和钴矿床集中于中新世以来盛行的热带气候。新喀里多尼亚红土镍矿床占全球镍资源量的10%。水合硅酸镁和氧化物类型共存于单一矿床中。提出了一种基于地貌演化的局部遗传模型。 Sc 是与这些表生矿床相关的潜在资源。 PGEs 是一种与铬铁矿相关的潜在资源，在浅源、表源和河流沿岸领域具有潜力。 Pt和Pd是最重要的元素。上地幔和地壳堆积物之间的过渡带构成了区域性 Pt-Pd 富集层位。这些浓度与富含辉石岩性中的小型浸染式铬铁矿透镜体有关。 PGE 集中在风化剖面中。富铬铁矿砂作为砂矿或沙滩沉积物的价值可能因铂族元素的出现而提高。
The main metallic mineral resources of New Caledonia are hosted by the obducted Peridotite Nappe. Ni, Co, Cr and the Pt group elements (PGEs) are specific to this ultramafic terrane. Cr, as podiform chromitite in the uppermost mantle, is the only hypogene metal mined economically in the past. The largest chromitite deposits are located in the lherzolitic Tiebaghi Massif. Supergene Ni and Co deposits are concentrated by the tropical climate that has prevailed since the Miocene. New Caledonian lateritic Ni deposits account for 10% of the global Ni resources. Hydrous Mg silicate and oxide types coexist in a single deposit. A local genetic model based on geomorphological evolution is proposed. Sc is a prospective resource associated with these supergene deposits. The PGEs are a prospective resource associated with chromite, with potential in the hypogene, supergene and fluvio-littoral domains. Pt and Pd are the most significant elements. The transition zone between the upper mantle and crustal cumulates constitutes a regional Pt-Pd-enriched horizon. The concentrations are related to small disseminated chromite lenses in a pyroxene-rich lithology. The PGEs are concentrated in weathering profiles. The value of chromite-rich sands as placers or sand beach deposits might be enhanced by the occurrences of PGEs.