Sulfide minerals in mantle xenoliths from the Kurose reef, Fukuoka Prefecture, Japan
Sulfide minerals in mantle xenoliths from the Kurose reef, Fukuoka Prefecture, Japan
复制标题
DOI：
10.2465/jmps.081022c
复制
发表时间：
2009-06
影响因子：
0.7
通讯作者：
K. Shindo;K. Komuro;Ken‐ichiro Hayashi
中科院分区：
文献类型：
--
作者：
K. Shindo;K. Komuro;Ken‐ichiro Hayashi
描述了日本九州北部黑岩礁碱性玄武岩中地幔橄榄岩包体中硫化物的矿物组合及其化学成分。硫化物在橄榄石或辉石中以1)包裹体和2)间隙硫化物的形式出现。作为包裹体的硫化物矿物组合有五黄铁矿、五黄铁矿+黄铜矿、五黄铁矿+斑铜矿、单硫化物固溶体(MSS)+黄铜矿+五黄铁矿、五黄铁矿+磁黄铁矿、千里矿，间隙硫化物的矿物组合为磁黄铁矿+五黄铁矿+黄铜矿。镍黄铁矿中镍含量为22.91~33.45at%，铁含量为18.77~28.82at%，S含量为46.57~48.31at%。MSS的化学成分多种多样。根据橄榄石和(或)辉石的晶化温度以及Fe-Ni-S和Fe-Cu-S体系之间的相关系，推测橄榄石中发现的MSS+黄铜矿+镍黄铁矿矿物组合初步被捕获为固相含铜MSS，其他矿物组合被捕获为硫化物液体。地幔橄榄岩包体中硫化物矿物组合的多样性和矿物组合的不同化学成分是由于MSS的分异结晶时间及其在硅酸盐矿物中的捕获所致。推测黑硒二辉橄榄岩中初始硫化物液体的化学成分为含铜MSS中的S亏损部分。这表明，上地幔中最初的硫化物液体可能具有类似的成分。
Mineral assemblages of sulfides in the mantle peridotite xenoliths embedded in the alkali basalts of the Kurose reef, northern Kyushu, Japan and the chemical compositions of the mineral assemblages are described. Sulfides occur as 1) inclusions and 2) interstitial sulfides in olivine or pyroxene. The mineral assemblages of sulfides that occur as inclusions are pentlandite, pentlandite + chalcopyrite, pentlandite + bornite, monosulfide solid solution (mss) + chalcopyrite ± pentlandite, pentlandite + pyrrhotite, and millerite; and the mineral assemblage of sulfides as interstitial sulfides is pyrrhotite + pentlandite + chalcopyrite. The contents of Ni, Fe, and S in pentlandite are 22.91-33.45, 18.77-28.82, and 46.57-48.31 at%, respectively. The chemical composition of mss is variable. On the basis of the crystallization temperature of olivine and/or pyroxene and the phase relationship between the Fe-Ni-S and the Fe-Cu-S systems, it can be inferred that the mineral assemblage of mss + chalcopyrite ± pentlandite found in olivine is considered to have been initially trapped as a solid-phase Cu-bearing mss and that the other mineral assemblages were trapped as a sulfide liquid. The diversity of mineral assemblages of sulfides in the mantle peridotite xenoliths and the various chemical compositions of the mineral assemblages are due to timing of differential crystallization of mss and its capture in silicate minerals. It can also be inferred that the chemical composition of the initial sulfide liquid in the Kurose lherzolite is the S-poor portion of the Cu-bearing mss. This suggests that initial sulfide liquids in the upper mantle might have similar compositions.