Abstract This study presents an example of the extensional basin, namely Tromso, which developed along the Southwestern Barents Sea (SWBS) transform margin. Three previous models have been proposed to explain the tectonic evolution and architecture of the basin, but there is no consensus on development of individual structures. In this study, we use 2D industry seismic reflection data, potential field and well data, as well as previously published information to understand the Early Cretaceous structural evolution of the Tromso Basin in the context of the geodynamic processes in the SWBS. Mapping of the main seismic sequences and faults, time thickness map were integrated with modeled gravity anomalies along a composite 2D regional seismic section to facilitate the interpretation of crustal structures, which then were structurally restored. We propose a revised Early Cretaceous structural model for the Tromso Basin, which involves oblique extension and formation of an intra-basinal transpressional transfer zone. This explains formation of the compressional faulting during overall extension in the SW Barents Sea. Basement heterogeneity most likely played an important role in localizing strain. The 2D sequential restoration of the composite regional seismic section yields an estimate of ca. 35 km of crustal extension in the SW Barents Sea margin, from the earliest Cretaceous until the present. Crustal thickness along the gravity modeled 2D regional section displayed a thinner crust below the Tromso Basin as compared to the Sorvestnaget and Hammerfest basins favoring the interpretation of the Tromso Basin as oblique rifting. This study illustrates the importance of detailed and regionally integrated analysis of rifted basins for reconstructing their evolution, as analysis of oblique rifted basins using two-dimensional plane strain can lead to erroneous assessment of faulting style and deformation.

中文翻译：

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挪威西南巴伦支海特罗姆瑟盆地早白垩世演化

摘要 本研究展示了一个伸展盆地的例子，即特罗姆瑟，它沿着西南巴伦支海 (SWBS) 变换边缘发育。先前已经提出了三种模型来解释盆地的构造演化和结构，但对单个构造的发展尚未达成共识。在这项研究中，我们使用二维工业地震反射数据、势场和井数据以及先前发布的信息来了解特罗姆瑟盆地在 SWBS 地球动力学过程背景下的早白垩世构造演化。绘制主要地震序列和断层、时间厚度图与沿复合二维区域地震剖面的模拟重力异常相结合，以促进地壳结构的解释，然后进行结构恢复。我们为特罗姆瑟盆地提出了一个修正的早白垩世构造模型，该模型涉及斜向伸展和盆地内压压转换带的形成。这解释了在西南巴伦支海整体伸展过程中压缩断层的形成。基底异质性很可能在定位菌株中发挥了重要作用。复合区域地震剖面的 2D 顺序恢复产生了大约 从最早的白垩纪到现在，西南巴伦支海边缘有 35 公里的地壳延伸。与 Sorvestnaget 和 Hammerfest 盆地相比，沿重力建模的 2D 区域剖面的地壳厚度显示特罗姆瑟盆地下方更薄的地壳，有利于将特罗姆瑟盆地解释为斜裂谷。