Ultrahigh-Temperature Pelitic Granulites from Kontum Massif, Central Vietnam: Evidence for East Asian Juxtaposition at ca. 250 Ma
Ultrahigh-Temperature Pelitic Granulites from Kontum Massif, Central Vietnam: Evidence for East Asian Juxtaposition at ca. 250 Ma
复制标题
DOI：
10.1016/s1342-937x(05)70518-9
复制
发表时间：
2001-10
影响因子：
6.1
通讯作者：
Y. Osanai;M. Owada;T. Tsunogae;T. Toyoshima;T. Hokada;T. V. Long;K. Sajeev;N. Nakano
中科院分区：
文献类型：
--
作者：
Y. Osanai;M. Owada;T. Tsunogae;T. Toyoshima;T. Hokada;T. V. Long;K. Sajeev;N. Nakano
肯尼亚新元古代莫桑比克造山带的最大段位于南北走向的裂谷系统以东。过去几十年在该国进行的地质调查揭示了该地区莫桑比克带地质、构造和构造的复杂性。该带重要的高级别构造热事件发生在约845-715 Ma之间，构造热事件达到了6.5-7.0kbar和500-750“C的P/T条件。随后的基底冷却和抬升被黑云母K-Ar测年追踪到，范围在528-438 Ma。近20年来建立的新岩性单位包括莫桑比克带东段中部广泛的花岗岩类、斜长岩、辉长岩-超镁铁质侵入岩和有限的安山质火山岩。以前，这个中部地区的地质被认为主要由单调的泥质和半泥质片岩和片麻岩、混合岩和角闪岩组成。在更靠北的钱勒瀑布和阿切尔哨区，这一段主要是副片岩和片岩、大理石和钙硅酸盐岩石、麻粒岩以及变质的镁铁质和超镁铁质岩石。在该带南部反复发现与北部相似的岩性变质组合。在靠近坦桑尼亚边境的泰塔山地区，广泛分布着具有蛇绿岩特征的斜长岩、大理石、角闪岩和变质的超镁铁质岩石。西
The largest segment of the Neoproterozoic Mozambique orogenic belt in Kenya occurs east of the north-south oriented rift system. Geological investigations carried out in the country during the last few decades have revealed the complexity of the geology, structures and tectonics of the Mozambique Belt in the region. Important high-grade tectonothermal events in the belt took place between ca. 845 and 715 Ma, The tectonothermal events attained P/T conditions of 6.5-7.0 kbars and 500-750" C. The subsequent cooling and uplift of the basement has been traced by K-Ar dates on biotites, which range between 528 and 438 Ma.New lithological units established in the last two decades include widespread granitoid, anorthositic, gabbroic to ultramafic intrusions and limited andesitic volcanics in the central region of this eastern segment of the Mozambique belt. Previously the geology of this central region had been considered to consist predominantly of monotonous pelitic and semi-pelitic schists and gneisses, migmatites, and amphibolites. Further north in the Chanler's Falls and Archer's Post areas, this segment is dominated by paragneisses and schists, marbles and calc-silicate rocks, granulites, as well as metamorphosed mafic and ultramafic rocks. A similar lithological metamorphic assemblage as the one in the north is repeatedly noted in the southern part of this belt. Here in the Taita Hills region, close to the Tanzania border, paragneisses, marbles, amphibolites and metamorphosed ultramafic rocks, with ophiolitic signatures are widespread. West