GEOLOGICAL AND PALEOMAGNETIC SIGNIFICANCE OF THE KULGERA DYKE SWARM, MUSGRAVE BLOCK, NT, AUSTRALIA
GEOLOGICAL AND PALEOMAGNETIC SIGNIFICANCE OF THE KULGERA DYKE SWARM, MUSGRAVE BLOCK, NT, AUSTRALIA
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DOI：
10.1111/j.1365-246x.1991.tb01154.x
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发表时间：
1991-10-01
影响因子：
2.8
通讯作者：
SCHMIDT, PW
中科院分区：
文献类型：
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作者：
CAMACHO, A;SIMONS, B;SCHMIDT, PW
Kulgera岩墙群由侵入澳大利亚中部马斯格雷夫地块东部晚元古代过渡麻粒岩片麻岩和花岗岩的橄榄拉斑玄武岩组成。 初步的Rb/Sr结果表明，粗粒岩的侵位时间为1054 +/- 14 Ma。 此外，Rb/Sr年龄为1060 +/- 10 Ma的黑云母伟晶岩表明热重置的围岩矿物在岩脉侵位。 对岩墙的古地磁研究得出了一个主热释电磁化方向，对应于17 ° S，266 ° E（A95 = 12度）的古磁极。 除了这一主要磁化，叠印组件存在于许多样品，提供了一个古磁极在30度S，138度E（A95 = 24度），这是类似于以前的结果，从其他中澳大利亚岩石受爱丽丝泉造山运动。 结果将石炭纪爱丽丝泉造山运动的影响范围向南扩展到马斯格雷夫地块。 此外，研究结果没有提供任何证据，早期，晚元古代，彼得曼造山运动影响马斯格雷夫块在Kulgera地区。 然而，彼得曼造山热叠印被爱丽丝泉造山运动抹去的可能性不能被排除。
The Kulgera Dyke Swarm consists of olivine tholeiites which have intruded late Proterozoic transitional-granulite gneisses and granites of the eastern Musgrave Block, in central Australia. Preliminary Rb/Sr results suggest that the dolerites were emplaced at 1054 +/- 14 Ma. In addition, a Rb/Sr age of 1060 +/- 10 Ma on a biotite from a pegmatite indicates thermal resetting of the country rock minerals during dyke emplacement. Palaeomagnetic investigations of the dykes yield a primary thermoremanent magnetization direction corresponding to a palaeomagnetic pole at 17-degrees-S, 266-degrees-E (A95 = 12-degrees). In addition to this primary magnetization, an overprint component was present in many of the samples, providing a palaeomagnetic pole at 30-degrees-S, 138-degrees-E (A95 = 24-degrees), which is similar to previous results from other central Australian rocks affected by the Alice Springs Orogeny. The results extend the area of influence of the Carboniferous Alice Springs Orogeny southward into the Musgrave Block. Further, the results provide no evidence for an earlier, Late Proterozoic, Petermann Orogeny affecting the Musgrave Block in the Kulgera region. However, the possibility that a Petermann Orogeny thermal overprint has been erased by the Alice Springs Orogeny cannot be dismissed.