Jon Engström, Kathryn Cutts, Stijn Glorie, Esa Heilimo, Ester M. Jolis, Radoslaw M. Michallik
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引用次数: 0
Abstract
Abstract. The Southern Finland granites and associated migmatitic rocks have a complex metamorphic history, being affected by multiple events during the ca. 1.88–1.79 Ga Svecofennian orogeny. In this study, the prolonged tectonic evolution of migmatites and associated rocks in SW Finland has been studied using the new in situ Lu-Hf method. Results reveal detailed temporal constraints for the tectonic evolution that can be linked to major events in adjacent tectonic blocks in both Finland and Sweden during the Svecofennian orogeny. The metamorphic peak at the Olkiluoto site occurred at 1834 ± 7 Ma based on in situ Lu-Hf dating of garnet. The P-T path for the rocks indicates a prograde evolution, with peak P-T conditions of 3–5 kbar and approximately 700 °C. The metamorphic constraints and age presented in this paper enhance our understanding of the geological and tectonic evolution in SW Finland, coupling the Olkiluoto site to the Häme metamorphic and tectonic belt in Finland and highlighting tectonic and metamorphic similarities with the Ljusdal Block of Sweden.
摘要芬兰南部花岗岩及相关的岩浆岩具有复杂的变质历史,在约 1.88-1.79 Ga 的斯维科芬尼造山运动期间受到多次影响。1.88-1.79 Ga Svecofennian造山运动期间的多次事件的影响。在这项研究中,采用新的原位Lu-Hf方法研究了芬兰西南部伟晶岩及相关岩石的长期构造演化。研究结果揭示了构造演化的详细时间约束条件,这些约束条件可与斯维科芬尼造山运动期间芬兰和瑞典相邻构造区块发生的重大事件联系起来。根据石榴石的原位Lu-Hf年代测定,Olkiluoto地点的变质高峰出现在1834 ± 7 Ma。岩石的P-T轨迹表明其为顺行演化,峰值P-T条件为3-5千巴和约700 °C。本文提出的变质约束条件和年龄加深了我们对芬兰西南部地质和构造演化的理解,将奥尔基卢奥托遗址与芬兰的海梅变质构造带联系起来,并突出了与瑞典柳斯达尔区块在构造和变质方面的相似性。
期刊介绍:
Solid Earth (SE) is a not-for-profit journal that publishes multidisciplinary research on the composition, structure, dynamics of the Earth from the surface to the deep interior at all spatial and temporal scales. The journal invites contributions encompassing observational, experimental, and theoretical investigations in the form of short communications, research articles, method articles, review articles, and discussion and commentaries on all aspects of the solid Earth (for details see manuscript types). Being interdisciplinary in scope, SE covers the following disciplines:
geochemistry, mineralogy, petrology, volcanology;
geodesy and gravity;
geodynamics: numerical and analogue modeling of geoprocesses;
geoelectrics and electromagnetics;
geomagnetism;
geomorphology, morphotectonics, and paleoseismology;
rock physics;
seismics and seismology;
critical zone science (Earth''s permeable near-surface layer);
stratigraphy, sedimentology, and palaeontology;
rock deformation, structural geology, and tectonics.