scholarly journals Near-surface Palaeocene fluid flow, mineralisation and faulting at Flamborough Head, UK: new field observations and U-Pb calcite dating constraints

2020 ◽  
Author(s):  
Nick M. W. Roberts ◽  
Jack K. Lee ◽  
Robert E. Holdsworth ◽  
Christopher Jeans ◽  
Andrew R. Farrant ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Fault Zone ◽  
Strike Slip ◽  
Field Observations ◽  
Deformation History ◽  
Near Surface ◽  
History Of ◽  
Tensile Fractures ◽  
Compressional Deformation ◽  
Slip Motion

Abstract. We present new field observations from Selwicks Bay, NE England, an exposure of the Flamborough Head Fault Zone (FHFZ). We combine these with U-Pb geochronology of syn- to post-tectonic calcite mineralisation to provide absolute constraints on the timing of deformation. The extensional Frontal Fault zone was active at ca. 63 Ma, with protracted fluid activity occurring as young as ca. 55 Ma. Other dated tensile fractures overlap this timeframe, and also cross-cut earlier formed fold structures, providing a lower bracket for the timing of folding and compressional deformation. The Frontal Fault zone acted as a conduit for voluminous fluid flow, linking deeper sedimentary units to the shallow sub-surface, and exhibiting a protracted history of several million years. Most structures at Selwicks Bay may have formed in a deformation history that is simpler than previously interpreted, with a protracted phase of extensional and strike-slip motion along the FHFZ. The timing of this deformation overlaps that of the nearby Cleveland Dyke intrusion and of regional uplift in NW Britain, opening the possibility that extensional deformation and hydrothermal mineralisation at Selwicks Bay are linked to these regional and far-field processes.

scholarly journals Near-surface Palaeocene fluid flow, mineralisation and faulting at Flamborough Head, UK: new field observations and U–Pb calcite dating constraints

Solid Earth ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 1931-1945
Author(s):  
Nick M. W. Roberts ◽  
Jack K. Lee ◽  
Robert E. Holdsworth ◽  
Christopher Jeans ◽  
Andrew R. Farrant ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Fault Zone ◽  
Time Frame ◽  
Field Observations ◽  
Deformation History ◽  
Near Surface ◽  
Shallow Subsurface ◽  
History Of ◽  
Tensile Fractures ◽  
And Storage

Abstract. We present new field observations from Selwicks Bay, NE England, an exposure of the Flamborough Head Fault Zone (FHFZ). We combine these with U–Pb geochronology of syn- to post-tectonic calcite mineralisation to provide absolute constraints on the timing of deformation. The extensional frontal fault zone, located within the FHFZ, was active at ca. 63 Ma, with protracted fluid activity occurring as late as ca. 55 Ma. Other dated tensile fractures overlap this time frame and also cross-cut earlier formed fold structures, providing a lower bracket for the timing of folding and compressional deformation. The frontal fault zone acted as a conduit for voluminous fluid flow, linking deeper sedimentary units to the shallow subsurface, potentially hosting open voids at depth for a significant period of time, and exhibiting a protracted history of fracturing and fluid flow over several million years. Such fault-hosted fluid pathways are important considerations in understanding chalk reservoirs and utilisation of the subsurface for exploration, extraction and storage of raw and waste materials. Most structures at Selwicks Bay may have formed in a deformation history that is simpler than previously interpreted, with a protracted phase of extensional and strike-slip motion along the FHFZ. The timing of this deformation overlaps that of the nearby Cleveland Dyke intrusion and of regional uplift in NW Britain, opening the possibility that extensional deformation and hydrothermal mineralisation at Selwicks Bay are linked to these regional and far-field processes during the Palaeocene.

40Ar/39Ar dating of strike-slip motion on the Tan–Lu fault zone, East China

2005 ◽  
Vol 27 (8) ◽  
pp. 1379-1398 ◽  
Author(s):  
Guang Zhu ◽  
Yongsheng Wang ◽  
Guosheng Liu ◽  
Manlan Niu ◽  
Chenglong Xie ◽  
...  
Keyword(s):  
Fault Zone ◽  
Strike Slip ◽  
East China ◽  
Slip Motion

scholarly journals Deformation history of the eclogite- and jadeitite-bearing mélange from North Motagua Fault Zone, Guatemala: insights in the processes of a fossil subduction channel

2009 ◽  
Vol 44 (2) ◽  
pp. 167-190 ◽  
Author(s):  
Michele Marroni ◽  
Luca Pandolfi ◽  
Gianfranco Principi ◽  
Alessandro Malasoma ◽  
Francesca Meneghini
Keyword(s):  
Fault Zone ◽  
Deformation History ◽  
Subduction Channel ◽  
History Of

Neotectonics of the SW Marmara region, NW Anatolia, Turkey

2006 ◽  
Vol 143 (2) ◽  
pp. 229-241 ◽  
Author(s):  
ÖMER FEYZI GÜRER ◽  
ERCAN SANGU ◽  
MUZAFFER ÖZBURAN
Keyword(s):  
Fault Zone ◽  
Structural Characteristics ◽  
Strike Slip ◽  
North Anatolian Fault ◽  
Marmara Region ◽  
Field Observations ◽  
Extensional Tectonics ◽  
North Anatolian Fault Zone ◽  
The North ◽  
Differential Movement

This study reports on the geometric and structural characteristics of the North Anatolian Fault Zone in the southwest Marmara region. The geometric and kinematic features of the faults in the region are described, based on field observations. In addition, the Neogene and Quaternary basin fill which occupies large areas in the region has been determined, and the tectonic regimes controlling these basins are explained. The neotectonic regime is also explained considering different deformation phases affecting the region. The N–S extension and E–W strike-slip have affected the region possibly since the latest Pliocene–Quaternary. Field observations show that these extensional tectonics around the south Marmara region are related to right strike-slip on the E–W North Anatolian fault zone and the N–S Aegean extensional system. The faults in this zone trend approximately E–W in the eastern part of the region and NE–SW towards the west of the region, indicating that they accommodate rotation in addition to differential movement between adjacent blocks.

scholarly journals Strike-Slip Motion Within the Yalu River Fault Zone, NE Asia: The Development of a Shear Continental Margin

Tectonics ◽  
2018 ◽  
Vol 37 (6) ◽  
pp. 1771-1796 ◽  
Author(s):  
Shuai Zhang ◽  
Guang Zhu ◽  
Cheng Liu ◽  
Yunjian Li ◽  
Nan Su ◽  
...  
Keyword(s):  
Fault Zone ◽  
Continental Margin ◽  
Strike Slip ◽  
Yalu River ◽  
Slip Motion

scholarly journals Structural analysis of S-wave seismics around an urban sinkhole: evidence of enhanced dissolution in a strike-slip fault zone

2017 ◽  
Vol 17 (12) ◽  
pp. 2335-2350 ◽  
Author(s):  
Sonja H. Wadas ◽  
David C. Tanner ◽  
Ulrich Polom ◽  
Charlotte M. Krawczyk
Keyword(s):  
Fault Zone ◽  
Fracture Network ◽  
Strike Slip ◽  
Strike Slip Fault ◽  
Normal Faults ◽  
S Wave ◽  
Seismic Profiles ◽  
Near Surface ◽  
Reflection Seismic ◽  
Enhanced Dissolution

Abstract. In November 2010, a large sinkhole opened up in the urban area of Schmalkalden, Germany. To determine the key factors which benefited the development of this collapse structure and therefore the dissolution, we carried out several shear-wave reflection-seismic profiles around the sinkhole. In the seismic sections we see evidence of the Mesozoic tectonic movement in the form of a NW–SE striking, dextral strike-slip fault, known as the Heßleser Fault, which faulted and fractured the subsurface below the town. The strike-slip faulting created a zone of small blocks ( < 100 m in size), around which steep-dipping normal faults, reverse faults and a dense fracture network serve as fluid pathways for the artesian-confined groundwater. The faults also acted as barriers for horizontal groundwater flow perpendicular to the fault planes. Instead groundwater flows along the faults which serve as conduits and forms cavities in the Permian deposits below ca. 60 m depth. Mass movements and the resulting cavities lead to the formation of sinkholes and dissolution-induced depressions. Since the processes are still ongoing, the occurrence of a new sinkhole cannot be ruled out. This case study demonstrates how S-wave seismics can characterize a sinkhole and, together with geological information, can be used to study the processes that result in sinkhole formation, such as a near-surface fault zone located in soluble rocks. The more complex the fault geometry and interaction between faults, the more prone an area is to sinkhole occurrence.

Deformation and Microstructure in Machining

2011 ◽  
Vol 223 ◽  
pp. 325-331 ◽  
Author(s):  
Yang Guo ◽  
Christopher Saldana ◽  
James B. Mann ◽  
Rachid M'Saoubi ◽  
Srinivasan Chandrasekar
Keyword(s):  
Plastic Deformation ◽  
Image Analysis ◽  
Severe Plastic Deformation ◽  
Strain Distribution ◽  
Machining Process ◽  
Fine Scale ◽  
Deformation History ◽  
Machined Surface ◽  
Near Surface ◽  
History Of

Deformation history and state of chip and machined surface in low-speed cutting have been characterized using image analysis, complemented by microstructure and hardness. Fine scale details of the deformation field of relevance to machining modelling are highlighted. The severe plastic deformation inherent to chip formation results in microstructure changes which can be controlled through appropriate process parameters selected with the aid of machining simulations. Scaling of subsurface strain distribution is observed. Similarity in deformation history of chip and near-surface suggests opportunities for engineering surfaces with controlled deformation levels and microstructures, directly, by machining. The deformation characterization offers substantial scope for improvement and validation of machining models, and enhancement of machining process capability.

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