Tectonic and metamorphic architecture of the HP belt of New Caledonia
Tectonic and metamorphic architecture of the HP belt of New Caledonia
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DOI：
10.1016/j.earscirev.2018.01.006
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发表时间：
2018-03
影响因子：
12.1
通讯作者：
A. V. Brovarone;P. Agard;P. Monié;A. Chauvet;A. Rabaute
中科院分区：
文献类型：
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作者：
A. V. Brovarone;P. Agard;P. Monié;A. Chauvet;A. Rabaute
新喀里多尼亚是澳大利亚-太平洋板块边界新生代板块构造重组形成的高压造山带的一个暴露良好的例子。该变质带交通便利，主要因其变质作用和岩石学特征而受到广泛关注。然而，这一地带的结构仍然缺乏普遍共识。本文的目的是（i）审查的性质和成因的主要构造单元的带，和（ii）重新访问现有的结构模型描述其架构和地球动力学演化。为此，我们整合了现有的现场，岩石学，地球化学和地质年代学数据，以及大规模实地调查的新结果和重点Ar-Ar地质年代学数据。所有这些数据允许提出一个新的模式的构造和变质结构的带，也包括一个新建立的构造地层单位。这种结构类似于在非太平洋环境中形成的阿尔卑斯型变质带，与东太平洋地区的科迪勒拉型变质带明显不同。此外，收集到的数据也使我们能够更好地理解始新世俯冲所涉及的海洋（和过渡）海洋岩石圈，以及与当今海洋-大陆过渡区中已知的超扩展边缘的合理类比。
New Caledonia includes a well-exposed example of high-pressure orogenic belt formed as a result of Cenozoic plate tectonic reorganizations at the Australia-Pacific plate boundary. The metamorphic belt is relatively well accessible and has deserved extensive attention mainly for its metamorphic and petrological features. The architecture of this belt, however, still lacks general consensus. The aim of this paper is (i) to review the nature and origin of the main tectonic units of the belts, and (ii) to revisit the available structural models describing its architecture and geodynamic evolution. For that, we integrate the available field, petrological, geochemical and geochronological data, together with new results from large-scale field survey and focused Ar-Ar geochronological data. All together, these data allow proposing a new model for the tectonic and metamorphic architecture of the belt, also comprising a newly established tectonostratigraphic unit. This architecture resembles that characterizing Alpine-type metamorphic belts formed in non-Pacific settings, and clearly differs from Cordilleran-type belts found in eastern Pacific regions. Moreover, the collected data also allow refining our understanding of the oceanic (and transitional) oceanic lithosphere involved in the Eocene subduction, and plausible analogies with hyper-extended margins known in present-day ocean-continent transition zones.