Seismo- and neotectonics in Finnmark, Kola Peninsula and the southern Barents Sea. Part 1: Geological and neotectonic framework
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- 作者：Roberts ; D. ; Olesen ; O. ; Karpuz ; M.R.
- 关键词：lineaments ; neotectonics ; shear zones ; Baltic Shield ; Finnmark ; Kola Peninsula
- 刊名：Tectonophysics
- 出版年：1997
- 出版时间：February 28, 1997
- 年：1997
- 卷：270
- 期：1-2
- 页码：1-13
- 全文大小：1.08 M
文摘
As a background for assessing the seismo- and neotectonics of the Finnmark–Kola Peninsula region, emphasis has been directed towards the lineament framework, involving a careful examination of digital Landsat-TM imagery integrated with a variety of data-sets ranging from geophysics and digital elevation models to microtectonics. Based on a detailed field-structural control of many of the multiphase lineaments in this 70,000 km2 area of the northeastern part of the Fennoscandian Shield, as well as microscopic investigation of the fault mylonites and breccias, five principal lineament sets were distinguished. Of the NW–SE polyphasal megafractures, the Murmansk Shear Zone carries geological and isotopic evidence of an Archaean tectonothermal history, and demarcates an important terrane boundary. Lineaments, irrespective of their trends, were classified according to their significance in the regional-geological framework. Some lineaments are clearly associated with gravity and aeromagnetic anomalies and probably extend to deep crustal levels. Quite a few of the prominent faults within lineament zones were reactivated in post-glacial times. In one area in Finnmark, core drilling through a SE-dipping post-glacial reverse-fault has confirmed its listric shape at depth. Earthquake focal mechanisms for this same fault are presented in the second part of this dual contribution.