A tectonic mélange containing blueschists and eclogites, Middle Ordovician mid-ocean ridge basalt, cherts, and clastic sediments occurs at Port Macquarie in the southern New England Orogen, Australia. The clastics are quartz-poor and are dominated by mafic volcanic and fragmented plagioclase clasts; felsic volcanic clasts are less common. They exhibit erosional bases, graded bedding, load structures, and lithologies ranging from laminated mudstones to pebbly sandstones. Based on these features, they are interpreted as turbidites. During subduction, these turbidites were deformed and metamorphosed under prehnite–pumpellyite and lower greenschist facies conditions. Geochemically, they have a calc-alkaline, intra-oceanic arc signature; show no recycling; and have been derived from a provenance dominated by mafic volcanic rocks of basaltic-andesite composition. Further, chemical index of alteration (44–69) and Index of Compositional Variability (0.8–2.4) data reveal they show little weathering and are immature. The lack of weathering of rocks in a location where tropical climatic conditions existed is attributed to extreme erosion associated with a dynamic setting resulting in rapid transportation of the sediments to the fore arc basin and subsequently to the trench. As a consequence, little time was available for weathering to take place. The detritus in the turbidites is thought to have been derived from Late Ordovician volcanics in the Macquarie Arc and fore arc basin sequences of the Murrawong Formation. The cherts with which they are associated record both a continental and oceanic arc geochemical signature.

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俯冲浊积岩，构造混杂岩，麦格理港区块，澳大利亚新英格兰南部造山带的碎屑来源-从地球化学角度看

在澳大利亚新英格兰造山带南部的麦格理港发生了构造混杂的混合岩，包括蓝晶岩和榴辉岩，中奥陶纪中洋脊玄武岩、,石和碎屑沉积物。碎屑岩缺乏石英，主要由镁铁质火山岩和碎斜长石碎屑为主。长英质火山碎屑较少见。它们表现出侵蚀性基底，梯度层理，荷载结构和岩性，范围从层压泥岩到卵石砂岩。基于这些特征，它们被解释为浊石。在俯冲过程中，这些浊浊体在绿橄榄石-球墨石和较低的绿片岩相条件下发生变形和变质。从地球化学角度看，它们具有钙碱性，大洋内部弧形特征。显示没有回收；源自于玄武质安山岩组成的镁铁质火山岩。此外，化学变化指数（44–69）和成分变异性指数（0.8–2.4）数据显示它们几乎没有风化，并且不成熟。在存在热带气候条件的地方，岩石缺乏风化的原因是与动态环境有关的极端侵蚀，导致沉积物快速输送到前弧盆地，然后又输送到海沟。结果，几乎没有时间进行风化。浊浊岩中的碎屑被认为是由麦格理弧中的奥陶纪晚期火山岩和Murrawong组的前弧盆地序列产生的。