论文标题
超镁铁质滑石碳酸盐单元 - 北极圆顶和梳妆台组
Ultramafic talc-carbonate unit -- The North Pole Dome and Dresser Formation
论文作者
论文摘要
在这里，我们描述了北极圆顶的超镁铁质滑石碳酸盐单元。北极圆顶（NPD）位于东比尔巴拉地座的中心（van Kranendonk等，2007）。 NPD是沃拉沃纳（Warrawoona）和凯利（Kelly）群体的层状，庞菲火山岩石的结构圆顶，它们从圆顶的核心中轻轻地倾斜了北极的蒙索石（图1）（van Kranendonk，1999，2000）。在圆顶的外部，平均倾角在圆顶内部的30度到60度不等（Van Kranendonk，2000年）。北极的蒙索里特岩被解释为代表了全景地层的同步volcanic laccolith（Thorpe等，1992），并且据估计，基于重力调查，估计将其延伸到表面以下约1.5公里（Blewett等人，2004年）。长英质的火山地层与绿色石质相交（Hickman，1983），这些岩层由指示火山库中心的cher封闭（Barley，1993; Van Kranendonk，2006）。 Barley（1993）有利于弧弧相关的水热活性模型，而最近的研究表明，北极圆顶上的火成岩和热液活性模型（Van Kranendonk等，2002，2002，2007; Smithies et al。，van Kranendonk and 2003; van Kranendonk and Pirajno，2004; Smithies et al。
Here we describe the ultramafic talc-carbonate unit of the North Pole Dome. The North Pole Dome (NPD) is located in the centre of the East Pilbara Terrane (Van Kranendonk et al., 2007). The NPD is a structural dome of bedded, dominantly mafic volcanic rocks of the Warrawoona and Kelly Groups that dip gently away from the North Pole Monzogranite exposed in the core of the dome (Figure 1) (Van Kranendonk, 1999, 2000). Average dips vary from 30 to 60 degrees in the inner part of the dome to about 60 to 80 degrees in the outer part of the dome (Van Kranendonk, 2000). The North Pole Monzogranite is interpreted to represent a syn-volcanic laccolith to the Panorama Formation (Thorpe et al., 1992) and has been estimated to extend approximately 1.5km below the surface, based on gravity surveys (Blewett et al., 2004). Felsic volcanic formations are interbedded with the greenstones (Hickman, 1983), and these are capped by cherts that indicate hiatuses in volcanism (Barley, 1993; Van Kranendonk, 2006). An overall arc-related model for hydrothermal activity is favored by Barley (1993), whereas more recent studies have indicated a mantle-plume model for igneous and hydrothermal activity at the North Pole Dome (Van Kranendonk et al., 2002, 2007; Smithies et al., 2003; Van Kranendonk and Pirajno, 2004).
