The Borborema Strike-Slip Shear Zone System (NE Brazil): Large-Scale Intracontinental Strain Localization in a Heterogeneous Plate
AbstractLarge-scale strike-slip faults are fundamental tectonic elements of the continental lithosphere. They constitute plate boundaries (continental transforms), separate terranes with contrasting geological histories within accretionary orogens, or accommodate heterogeneous deform...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
GeoScienceWorld
2021-12-01
|
| Series: | Lithosphere |
| Online Access: | https://pubs.geoscienceworld.org/lithosphere/article/2021/Special%206/6407232/609660/The-Borborema-Strike-Slip-Shear-Zone-System-NE |
| _version_ | 1811237191773323264 |
|---|---|
| author | Sergio P. Neves Andréa Tommasi Alain Vauchez Thais Andressa Carrino |
| author_facet | Sergio P. Neves Andréa Tommasi Alain Vauchez Thais Andressa Carrino |
| author_sort | Sergio P. Neves |
| collection | DOAJ |
| description |
AbstractLarge-scale strike-slip faults are fundamental tectonic elements of the continental lithosphere. They constitute plate boundaries (continental transforms), separate terranes with contrasting geological histories within accretionary orogens, or accommodate heterogeneous deformation in intracontinental settings. In ancient orogens, where deeper levels of the crust are exposed, these faults are expressed as shear zones materialized by up to tens of km-wide mylonitic belts. The Borborema shear zone system in northeastern Brazil is one of the largest and best-exposed intracontinental strike-slip shear zone systems in the world, cropping out over 250,000 km2. Here, we review its main geophysical, structural, petrologic, and geochronologic characteristics and discuss the factors controlling its development. This complex continental scale shear zone system is composed of a set of NE- to NNE-trending dextral shear zones from which there are two major E-trending dextral shear zones with horse-tail terminations into the transpressional belt branch, as well as several smaller E-trending dextral and NE-trending dextral and sinistral shear zones. The major shear zones are marked by extensive linear or curvilinear magnetic gradients, implying their continuation at depth. The major shear zones are materialized by migmatite to amphibolite-facies mylonites, but the entire system shows evidence of late deformation at lower temperatures. The system developed during the late stages of the Neoproterozoic Brasiliano (Pan-African) orogeny (mainly from 590 to 560 Ma), postdating by more than 20 Ma the main stage of contractional deformation. Localization of strike-slip shearing in this intraplate setting was controlled by rheological contrasts between blocks with distinct Paleoproterozoic histories, the presence of preorogenic Neoproterozoic rifts, the craton geometry, and zones of enhanced magmatic activity, highlighting the importance of rheological heterogeneity in controlling shear zone nucleation and evolution. |
| first_indexed | 2024-04-12T12:21:52Z |
| format | Article |
| id | doaj.art-279231aea34045089e1874a819800d07 |
| institution | Directory Open Access Journal |
| issn | 1941-8264 1947-4253 |
| language | English |
| last_indexed | 2024-04-12T12:21:52Z |
| publishDate | 2021-12-01 |
| publisher | GeoScienceWorld |
| record_format | Article |
| series | Lithosphere |
| spelling | doaj.art-279231aea34045089e1874a819800d072022-12-22T03:33:17ZengGeoScienceWorldLithosphere1941-82641947-42532021-12-012021Special 610.2113/2021/6407232The Borborema Strike-Slip Shear Zone System (NE Brazil): Large-Scale Intracontinental Strain Localization in a Heterogeneous PlateSergio P. Neves0http://orcid.org/0000-0001-6690-3278Andréa Tommasi1http://orcid.org/0000-0002-6457-1852Alain Vauchez2http://orcid.org/0000-0003-4127-8976Thais Andressa Carrino3http://orcid.org/0000-0001-8528-5225Departamento de Geologia Universidade Federal de Pernambuco 50740-530 Recife PE Brazil ufpe.brGéosciences Montpellier CNRS & Université de Montpellier Montpellier FranceGéosciences Montpellier CNRS & Université de Montpellier Montpellier FranceDepartamento de Geologia Universidade Federal de Pernambuco 50740-530 Recife PE Brazil ufpe.br AbstractLarge-scale strike-slip faults are fundamental tectonic elements of the continental lithosphere. They constitute plate boundaries (continental transforms), separate terranes with contrasting geological histories within accretionary orogens, or accommodate heterogeneous deformation in intracontinental settings. In ancient orogens, where deeper levels of the crust are exposed, these faults are expressed as shear zones materialized by up to tens of km-wide mylonitic belts. The Borborema shear zone system in northeastern Brazil is one of the largest and best-exposed intracontinental strike-slip shear zone systems in the world, cropping out over 250,000 km2. Here, we review its main geophysical, structural, petrologic, and geochronologic characteristics and discuss the factors controlling its development. This complex continental scale shear zone system is composed of a set of NE- to NNE-trending dextral shear zones from which there are two major E-trending dextral shear zones with horse-tail terminations into the transpressional belt branch, as well as several smaller E-trending dextral and NE-trending dextral and sinistral shear zones. The major shear zones are marked by extensive linear or curvilinear magnetic gradients, implying their continuation at depth. The major shear zones are materialized by migmatite to amphibolite-facies mylonites, but the entire system shows evidence of late deformation at lower temperatures. The system developed during the late stages of the Neoproterozoic Brasiliano (Pan-African) orogeny (mainly from 590 to 560 Ma), postdating by more than 20 Ma the main stage of contractional deformation. Localization of strike-slip shearing in this intraplate setting was controlled by rheological contrasts between blocks with distinct Paleoproterozoic histories, the presence of preorogenic Neoproterozoic rifts, the craton geometry, and zones of enhanced magmatic activity, highlighting the importance of rheological heterogeneity in controlling shear zone nucleation and evolution.https://pubs.geoscienceworld.org/lithosphere/article/2021/Special%206/6407232/609660/The-Borborema-Strike-Slip-Shear-Zone-System-NE |
| spellingShingle | Sergio P. Neves Andréa Tommasi Alain Vauchez Thais Andressa Carrino The Borborema Strike-Slip Shear Zone System (NE Brazil): Large-Scale Intracontinental Strain Localization in a Heterogeneous Plate Lithosphere |
| title | The Borborema Strike-Slip Shear Zone System (NE Brazil): Large-Scale Intracontinental Strain Localization in a Heterogeneous Plate |
| title_full | The Borborema Strike-Slip Shear Zone System (NE Brazil): Large-Scale Intracontinental Strain Localization in a Heterogeneous Plate |
| title_fullStr | The Borborema Strike-Slip Shear Zone System (NE Brazil): Large-Scale Intracontinental Strain Localization in a Heterogeneous Plate |
| title_full_unstemmed | The Borborema Strike-Slip Shear Zone System (NE Brazil): Large-Scale Intracontinental Strain Localization in a Heterogeneous Plate |
| title_short | The Borborema Strike-Slip Shear Zone System (NE Brazil): Large-Scale Intracontinental Strain Localization in a Heterogeneous Plate |
| title_sort | borborema strike slip shear zone system ne brazil large scale intracontinental strain localization in a heterogeneous plate |
| url | https://pubs.geoscienceworld.org/lithosphere/article/2021/Special%206/6407232/609660/The-Borborema-Strike-Slip-Shear-Zone-System-NE |
| work_keys_str_mv | AT sergiopneves theborboremastrikeslipshearzonesystemnebrazillargescaleintracontinentalstrainlocalizationinaheterogeneousplate AT andreatommasi theborboremastrikeslipshearzonesystemnebrazillargescaleintracontinentalstrainlocalizationinaheterogeneousplate AT alainvauchez theborboremastrikeslipshearzonesystemnebrazillargescaleintracontinentalstrainlocalizationinaheterogeneousplate AT thaisandressacarrino theborboremastrikeslipshearzonesystemnebrazillargescaleintracontinentalstrainlocalizationinaheterogeneousplate AT sergiopneves borboremastrikeslipshearzonesystemnebrazillargescaleintracontinentalstrainlocalizationinaheterogeneousplate AT andreatommasi borboremastrikeslipshearzonesystemnebrazillargescaleintracontinentalstrainlocalizationinaheterogeneousplate AT alainvauchez borboremastrikeslipshearzonesystemnebrazillargescaleintracontinentalstrainlocalizationinaheterogeneousplate AT thaisandressacarrino borboremastrikeslipshearzonesystemnebrazillargescaleintracontinentalstrainlocalizationinaheterogeneousplate |