Tectonic evolution of the Malay and Penyu Basins, offshore Peninsular Malaysia
<p>The Malay and Penya Basins, offshore Peninsular Malaysia, were formed during the early Oligocene as a result of regional dextral shear deformation caused by the indentation of India into Eurasia in the early Tertiary. Pre-existing basement inhomogeneities exerted a strong control on basin d...
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| Format: | Thesis |
| Language: | English |
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1995
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| _version_ | 1826304094984208384 |
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| author | Madon, M |
| author2 | Dewey, J |
| author_facet | Dewey, J Madon, M |
| author_sort | Madon, M |
| collection | OXFORD |
| description | <p>The Malay and Penya Basins, offshore Peninsular Malaysia, were formed during the early Oligocene as a result of regional dextral shear deformation caused by the indentation of India into Eurasia in the early Tertiary. Pre-existing basement inhomogeneities exerted a strong control on basin development. The Penyu Basin developed, initially, as isolated grabens and half-grabens at basement fault intersections, in response to roughly N-S extension. The major structures which include low-angle listric normal faults, pull-apart rhomb grabens and flower structures, suggest that "thin-skinned" crustal extension and strike-slip tectonics have played an important role in basin evolution.</p><p>Basement faults in the Malay Basin are oblique (E-W trending) to the basin trend (NW-trending). The Basin developed by transtension of NW-trending sinistral shear zone, in which fault-bounded blocks rotate in response to the shear deformation, producing a series of E-trending half-graben depocentres. The Basins were subjected to transpressive inversion during the middle-late Miocene, as a result of rotation of the regional stress field, caused by progressive indentation of India into Eurasia.</p><p>Subsidence analysis suggests that lithospheric stretching was the dominant process of basin formation. The high heat flows (85-100 mW m⁻²) are consistent with stretching factors, β, of 1.2 to 4.3. In the Malay Basin, uplift of the basin flanks preceeded subsidence during the rifting phase as a result of non-uniform stretching and lateral heat flow from the centre of the Basin. Both basins are undercompensated isostatically and characterised by low negative free-air gravity anomaly in the order of -20 mGal. Undercompensation suggests that the basins were formed, partly, by "thin-skinned" crustal extension which did not involve stretching of the subcrustal lithosphere.</p> |
| first_indexed | 2024-03-07T06:12:35Z |
| format | Thesis |
| id | oxford-uuid:f00a727d-8769-4ac8-88ab-35d8c662ea61 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T06:12:35Z |
| publishDate | 1995 |
| record_format | dspace |
| spelling | oxford-uuid:f00a727d-8769-4ac8-88ab-35d8c662ea612022-03-27T11:44:39ZTectonic evolution of the Malay and Penyu Basins, offshore Peninsular MalaysiaThesishttp://purl.org/coar/resource_type/c_db06uuid:f00a727d-8769-4ac8-88ab-35d8c662ea61Earth sciencesEarthquakes and tectonicsAsiaEnglishOxford University Research Archive - Valet1995Madon, MDewey, J<p>The Malay and Penya Basins, offshore Peninsular Malaysia, were formed during the early Oligocene as a result of regional dextral shear deformation caused by the indentation of India into Eurasia in the early Tertiary. Pre-existing basement inhomogeneities exerted a strong control on basin development. The Penyu Basin developed, initially, as isolated grabens and half-grabens at basement fault intersections, in response to roughly N-S extension. The major structures which include low-angle listric normal faults, pull-apart rhomb grabens and flower structures, suggest that "thin-skinned" crustal extension and strike-slip tectonics have played an important role in basin evolution.</p><p>Basement faults in the Malay Basin are oblique (E-W trending) to the basin trend (NW-trending). The Basin developed by transtension of NW-trending sinistral shear zone, in which fault-bounded blocks rotate in response to the shear deformation, producing a series of E-trending half-graben depocentres. The Basins were subjected to transpressive inversion during the middle-late Miocene, as a result of rotation of the regional stress field, caused by progressive indentation of India into Eurasia.</p><p>Subsidence analysis suggests that lithospheric stretching was the dominant process of basin formation. The high heat flows (85-100 mW m⁻²) are consistent with stretching factors, β, of 1.2 to 4.3. In the Malay Basin, uplift of the basin flanks preceeded subsidence during the rifting phase as a result of non-uniform stretching and lateral heat flow from the centre of the Basin. Both basins are undercompensated isostatically and characterised by low negative free-air gravity anomaly in the order of -20 mGal. Undercompensation suggests that the basins were formed, partly, by "thin-skinned" crustal extension which did not involve stretching of the subcrustal lithosphere.</p> |
| spellingShingle | Earth sciences Earthquakes and tectonics Asia Madon, M Tectonic evolution of the Malay and Penyu Basins, offshore Peninsular Malaysia |
| title | Tectonic evolution of the Malay and Penyu Basins, offshore Peninsular Malaysia |
| title_full | Tectonic evolution of the Malay and Penyu Basins, offshore Peninsular Malaysia |
| title_fullStr | Tectonic evolution of the Malay and Penyu Basins, offshore Peninsular Malaysia |
| title_full_unstemmed | Tectonic evolution of the Malay and Penyu Basins, offshore Peninsular Malaysia |
| title_short | Tectonic evolution of the Malay and Penyu Basins, offshore Peninsular Malaysia |
| title_sort | tectonic evolution of the malay and penyu basins offshore peninsular malaysia |
| topic | Earth sciences Earthquakes and tectonics Asia |
| work_keys_str_mv | AT madonm tectonicevolutionofthemalayandpenyubasinsoffshorepeninsularmalaysia |