{"title":"约 2675-2630 Ma Kalgoorlie造山运动期间阿格纽-维鲁纳绿岩带和卡尔古利特伦主峰的变形:新元古代弧后地区 45 Ma 的水平缩短","authors":"Quentin Masurel, Nicolas Thébaud","doi":"10.1016/j.precamres.2024.107586","DOIUrl":null,"url":null,"abstract":"<div><div>This study re-evaluates the tectonic processes that contributed to the final assembly of the Yilgarn Craton (Western Australia) in the late Neoarchean. We combine regional-scale (10–100 km) geological data collected from surface exposures over the Agnew-Wiluna Greenstone Belt (AWGB) in the Kalgoorlie Terrane of the Eastern Goldfields Superterrane (EGST) together with published and open-file geochronological and structural data from the Geological Survey of Western Australia. The combined datasets are then compared with the structural record in the Kalgoorlie Terrane, allowing for new insights into the tectonic evolution of the EGST and broader Yilgarn Craton. We show that c. 2675–2630 Ma orogenic deformation in the AWGB was associated with a protracted sequence of events, marked by the activation of distinct shear zones through time and repeated shifts in the location of sedimentary depocentres. We propose that the observed strain pattern resulted from the complex interplay of deformation, magmatism, and sediment deposition under progressive, ENE-WSW-directed horizontal shortening spanning ∼45 Ma. We suggest that the identified deformation scheme represents the local expression of tectono-thermal events affecting the Kalgoorlie-Kurnalpi Rift and broader EGST. Building on prior knowledge on the geological evolution of the Yilgarn Craton, our study supports a model proposed more than a decade ago whereby orogenesis was driven by a west-dipping, outboard subduction zone located further east of the exposed margins of the Yilgarn Craton. Lastly, we emphasize that such scale-integrated, unified perspective provides a balanced reconciliation between the debated allochthonous and <em>para</em>-autochthonous models for the EGST.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"414 ","pages":"Article 107586"},"PeriodicalIF":3.2000,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Deformation in the Agnew-Wiluna Greenstone Belt and host Kalgoorlie Terrane during the c. 2675–2630 Ma Kalgoorlie Orogeny: ∼45 Ma of horizontal shortening in a Neoarchean back-arc region\",\"authors\":\"Quentin Masurel, Nicolas Thébaud\",\"doi\":\"10.1016/j.precamres.2024.107586\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>This study re-evaluates the tectonic processes that contributed to the final assembly of the Yilgarn Craton (Western Australia) in the late Neoarchean. We combine regional-scale (10–100 km) geological data collected from surface exposures over the Agnew-Wiluna Greenstone Belt (AWGB) in the Kalgoorlie Terrane of the Eastern Goldfields Superterrane (EGST) together with published and open-file geochronological and structural data from the Geological Survey of Western Australia. The combined datasets are then compared with the structural record in the Kalgoorlie Terrane, allowing for new insights into the tectonic evolution of the EGST and broader Yilgarn Craton. We show that c. 2675–2630 Ma orogenic deformation in the AWGB was associated with a protracted sequence of events, marked by the activation of distinct shear zones through time and repeated shifts in the location of sedimentary depocentres. We propose that the observed strain pattern resulted from the complex interplay of deformation, magmatism, and sediment deposition under progressive, ENE-WSW-directed horizontal shortening spanning ∼45 Ma. We suggest that the identified deformation scheme represents the local expression of tectono-thermal events affecting the Kalgoorlie-Kurnalpi Rift and broader EGST. Building on prior knowledge on the geological evolution of the Yilgarn Craton, our study supports a model proposed more than a decade ago whereby orogenesis was driven by a west-dipping, outboard subduction zone located further east of the exposed margins of the Yilgarn Craton. 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引用次数: 0
摘要
本研究重新评估了在新元古代晚期促成伊尔加恩克拉通(西澳大利亚)最终组装的构造过程。我们将从东部金田超岩系(EGST)卡尔古尔利地层的阿格纽-威卢纳绿岩带(AWGB)地表出露采集的区域尺度(10-100 公里)地质数据,与西澳大利亚地质调查局已公布和公开的地质年代和构造数据相结合。然后将这些综合数据集与卡尔古利地层的构造记录进行比较,从而对东部金田超大地层(EGST)和更广泛的伊尔加恩克拉通(Yilgarn Craton)的构造演化有了新的认识。我们的研究表明,AWGB 约 2675-2630 Ma 的造山运动变形与一连串旷日持久的事件有关,其特点是不同剪切带随着时间的推移而被激活,沉积沉积中心的位置也一再发生变化。我们认为,所观察到的应变模式是变形、岩浆活动和沉积物沉积在ENE-WSW方向的渐进式水平缩短作用下复杂相互作用的结果,其时间跨度为45 Ma。我们认为,已确定的变形方案代表了影响卡尔古尔利-库纳尔皮断裂和更广泛的东部地质构造的构造-热事件的局部表达。在对伊尔加恩克拉通地质演化已有了解的基础上,我们的研究支持十多年前提出的模型,即造山运动是由位于伊尔加恩克拉通暴露边缘以东的西倾外侧俯冲带驱动的。最后,我们强调,这种尺度整合的统一视角平衡地调和了关于东部地质构造的同生和副自生模式的争论。
Deformation in the Agnew-Wiluna Greenstone Belt and host Kalgoorlie Terrane during the c. 2675–2630 Ma Kalgoorlie Orogeny: ∼45 Ma of horizontal shortening in a Neoarchean back-arc region
This study re-evaluates the tectonic processes that contributed to the final assembly of the Yilgarn Craton (Western Australia) in the late Neoarchean. We combine regional-scale (10–100 km) geological data collected from surface exposures over the Agnew-Wiluna Greenstone Belt (AWGB) in the Kalgoorlie Terrane of the Eastern Goldfields Superterrane (EGST) together with published and open-file geochronological and structural data from the Geological Survey of Western Australia. The combined datasets are then compared with the structural record in the Kalgoorlie Terrane, allowing for new insights into the tectonic evolution of the EGST and broader Yilgarn Craton. We show that c. 2675–2630 Ma orogenic deformation in the AWGB was associated with a protracted sequence of events, marked by the activation of distinct shear zones through time and repeated shifts in the location of sedimentary depocentres. We propose that the observed strain pattern resulted from the complex interplay of deformation, magmatism, and sediment deposition under progressive, ENE-WSW-directed horizontal shortening spanning ∼45 Ma. We suggest that the identified deformation scheme represents the local expression of tectono-thermal events affecting the Kalgoorlie-Kurnalpi Rift and broader EGST. Building on prior knowledge on the geological evolution of the Yilgarn Craton, our study supports a model proposed more than a decade ago whereby orogenesis was driven by a west-dipping, outboard subduction zone located further east of the exposed margins of the Yilgarn Craton. Lastly, we emphasize that such scale-integrated, unified perspective provides a balanced reconciliation between the debated allochthonous and para-autochthonous models for the EGST.
期刊介绍:
Precambrian Research publishes studies on all aspects of the early stages of the composition, structure and evolution of the Earth and its planetary neighbours. With a focus on process-oriented and comparative studies, it covers, but is not restricted to, subjects such as:
(1) Chemical, biological, biochemical and cosmochemical evolution; the origin of life; the evolution of the oceans and atmosphere; the early fossil record; palaeobiology;
(2) Geochronology and isotope and elemental geochemistry;
(3) Precambrian mineral deposits;
(4) Geophysical aspects of the early Earth and Precambrian terrains;
(5) Nature, formation and evolution of the Precambrian lithosphere and mantle including magmatic, depositional, metamorphic and tectonic processes.
In addition, the editors particularly welcome integrated process-oriented studies that involve a combination of the above fields and comparative studies that demonstrate the effect of Precambrian evolution on Phanerozoic earth system processes.
Regional and localised studies of Precambrian phenomena are considered appropriate only when the detail and quality allow illustration of a wider process, or when significant gaps in basic knowledge of a particular area can be filled.