scholarly journals A seismic stratigraphic model for understanding the sedimentary and tectonic evolution of Solander Trough, offshore Fiordland, New Zealand

2021 ◽  
Author(s):  
◽  
Jiten Patel
Keyword(s):  
New Zealand ◽  
Seismic Reflection ◽  
Age Determination ◽  
Petroleum Industry ◽  
Plate Boundary ◽  
Sediment Supply ◽  
Initial Growth ◽  
Seismic Reflection Data ◽  
The North ◽  
Stratigraphic Model

<p>Solander Trough is located offshore and south of Fiordland, New Zealand, adjacent to the geologically young Pacific-Australian plate boundary. Petroleum industry exploration was restricted to the near-shore. This thesis presents the first stratigraphic analysis of Solander Trough south of ~46.5°S, using 2D seismic reflection data acquired and processed onboard the R/V Marcus G. Langseth in 2018 (voyage MGL1803). The only pre-existing high-quality line, which was acquired onboard the R/V Maurice Ewing during voyage EW9601a in 1996, was reprocessed.  The study area is divided into northern and southern sub-basins by Tauru High. Four megasequences and eight sequences are identified in the northern sub-basin (SLN). In the southern sub-basin (SLS), three megasequences and seven sequences are mapped. Biostratigraphy from the Parara-1 exploration well enabled age determination in the northern sub-basin. High resolution (~10 m) swath bathymetry data collected along seismic reflection lines provide insight into modern sedimentary processes.  Solander Trough formed in the Eocene, but most sediment is young (<~15 Ma). Puysegur Ridge formed in the Miocene during subduction initiation and now shelters Solander Trough from the Antarctic Circumpolar Current, which affects depositional architecture. The oldest megasequences, SLN1 and SLS1, relate to normal-faulted basement with irregular relief. An increase in sediment supply from the north created megasquence SLN2, but it is thin and not recognised in the southern sub-basin. Megasequence SLN3 signals reverse reactivation on the Parara Anticline and Tauru High; its equivalent (SLS2) marks the first sediments rapidly deposited in southern Solander Trough, and is also linked in the south to initial growth of Puysegur Ridge. SLN4 is a product of Pliocene-Quaternary reverse reactivation of Solander Anticline, and its correlative, SLS3 in the southern sub-basin, is related to folding and widening of the eastern margin of Puysegur Ridge.</p>

scholarly journals A seismic stratigraphic model for understanding the sedimentary and tectonic evolution of Solander Trough, offshore Fiordland, New Zealand

2021 ◽  
Author(s):  
◽  
Jiten Patel
Keyword(s):  
New Zealand ◽  
Seismic Reflection ◽  
Age Determination ◽  
Petroleum Industry ◽  
Plate Boundary ◽  
Sediment Supply ◽  
Initial Growth ◽  
Seismic Reflection Data ◽  
The North ◽  
Stratigraphic Model

<p>Solander Trough is located offshore and south of Fiordland, New Zealand, adjacent to the geologically young Pacific-Australian plate boundary. Petroleum industry exploration was restricted to the near-shore. This thesis presents the first stratigraphic analysis of Solander Trough south of ~46.5°S, using 2D seismic reflection data acquired and processed onboard the R/V Marcus G. Langseth in 2018 (voyage MGL1803). The only pre-existing high-quality line, which was acquired onboard the R/V Maurice Ewing during voyage EW9601a in 1996, was reprocessed.  The study area is divided into northern and southern sub-basins by Tauru High. Four megasequences and eight sequences are identified in the northern sub-basin (SLN). In the southern sub-basin (SLS), three megasequences and seven sequences are mapped. Biostratigraphy from the Parara-1 exploration well enabled age determination in the northern sub-basin. High resolution (~10 m) swath bathymetry data collected along seismic reflection lines provide insight into modern sedimentary processes.  Solander Trough formed in the Eocene, but most sediment is young (<~15 Ma). Puysegur Ridge formed in the Miocene during subduction initiation and now shelters Solander Trough from the Antarctic Circumpolar Current, which affects depositional architecture. The oldest megasequences, SLN1 and SLS1, relate to normal-faulted basement with irregular relief. An increase in sediment supply from the north created megasquence SLN2, but it is thin and not recognised in the southern sub-basin. Megasequence SLN3 signals reverse reactivation on the Parara Anticline and Tauru High; its equivalent (SLS2) marks the first sediments rapidly deposited in southern Solander Trough, and is also linked in the south to initial growth of Puysegur Ridge. SLN4 is a product of Pliocene-Quaternary reverse reactivation of Solander Anticline, and its correlative, SLS3 in the southern sub-basin, is related to folding and widening of the eastern margin of Puysegur Ridge.</p>

scholarly journals Active fault segments along the North Anatolian Fault system in the Sea of Marmara: implication for seismic hazard

2021 ◽  
Author(s):  
Luca Gasperini ◽  
Massimiliano Stucchi ◽  
Vincenzo Cedro ◽  
Mustapha Meghraoui ◽  
Gulsen Ucarkus ◽  
...  
Keyword(s):  
High Resolution ◽  
Seismic Hazard ◽  
Seismic Reflection ◽  
Strike Slip ◽  
North Anatolian Fault ◽  
Sediment Supply ◽  
Fault System ◽  
Sea Of Marmara ◽  
Seismic Reflection Data ◽  
The North

AbstractA new analysis of high-resolution multibeam and seismic reflection data, collected during several oceanographic expeditions starting from 1999, allowed us to compile an updated morphotectonic map of the North Anatolian Fault below the Sea of Marmara. We reconstructed kinematics and geometries of individual fault segments, active at the time scale of 10 ka, an interval which includes several earthquake cycles, taking as stratigraphic marker the base of the latest marine transgression. Given the high deformation rates relative to sediment supply, most active tectonic structures have a morphological expression at the seafloor, even in presence of composite fault geometries and/or overprinting due to mass-wasting or turbidite deposits. In the frame of the right-lateral strike-slip domain characterizing the North Anatolian fault system, three types of deformation are observed: almost pure strike-slip faults, oriented mainly E–W; NE/SW-aligned axes of transpressive structures; NW/SE-oriented trans-tensional depressions. Fault segmentation occurs at different scales, but main segments develop along three major right-lateral oversteps, which delimit main fault branches, from east to west: (i) the transtensive Cinarcik segment; (ii) the Central (East and West) segments; and (iii) the westernmost Tekirdag segment. A quantitative morphometric analysis of the shallow deformation patterns observed by seafloor morphology maps and high-resolution seismic reflection profiles along the entire basin allowed to determine nature and cumulative lengths of individual fault segments. These data were used as inputs for empirical relationships, to estimate maximum expected Moment Magnitudes, obtaining values in the range of 6.8–7.4 for the Central, and 6.9–7.1 for the Cinarcik and Tekirdag segments, respectively. We discuss these findings considering analyses of historical catalogues and available paleoseismological studies for the Sea of Marmara region to formulate reliable seismic hazard scenarios.

scholarly journals Constraints on the proposed Marie Byrd Land-Bellingshausen Plate Boundary from seismic reflection data

1999 ◽  
Vol 104 (B11) ◽  
pp. 25321-25330 ◽  
Author(s):  
J. Heinemann ◽  
J. Stock ◽  
R. Clayton ◽  
K. Hafner ◽  
S. Cande ◽  
...  
Keyword(s):  
Seismic Reflection ◽  
Plate Boundary ◽  
Seismic Reflection Data ◽  
Reflection Data

Geodetic strain and the deformational history of the North Island of New Zealand during the late Cainozoic

1987 ◽  
Vol 321 (1557) ◽  
pp. 163-181 ◽  
Keyword(s):  
New Zealand ◽  
Subduction Zone ◽  
East Coast ◽  
Late Quaternary ◽  
Plate Boundary ◽  
Boundary Zone ◽  
Metamorphic Belt ◽  
Volcanic Region ◽  
The North ◽  
Plate Boundary Zone

The subduction zone under the east coast of the North Island of New Zealand comprises, from east to west, a frontal wedge, a fore-arc basin, uplifted basement forming the arc and the Central Volcanic Region. Reconstructions of the plate boundary zone for the Cainozoic from seafloor spreading data require the fore-arc basin to have rotated through 60° in the last 20 Ma which is confirmed by palaeomagnetic declination studies. Estimates of shear strain from geodetic data show that the fore-arc basin is rotating today and that it is under extension in the direction normal to the trend of the plate boundary zone. The extension is apparently achieved by normal faulting. Estimates of the amount of sediments accreted to the subduction zone exceed the volume of the frontal wedge: underplating by the excess sediments is suggested to be the cause of late Quaternary uplift of the fore-arc basin. Low-temperature—high-pressure metamorphism may therefore be occurring at depth on the east coast and high-temperature—low-pressure metamorphism is probable in the Central Volcanic Region. The North Island of New Zealand is therefore a likely setting for a paired metamorphic belt in the making.

Marine Terraces Reveal Complex Near-Shore Upper-Plate Faulting in the Northern Hikurangi Margin, New Zealand

2020 ◽  
Vol 110 (2) ◽  
pp. 825-849 ◽  
Author(s):  
Nicola J. Litchfield ◽  
Kate J. Clark ◽  
Ursula A. Cochran ◽  
Alan S. Palmer ◽  
Joshu Mountjoy ◽  
...  
Keyword(s):  
New Zealand ◽  
Plate Boundary ◽  
River Mouth ◽  
Seismic Reflection Data ◽  
Subduction Earthquakes ◽  
Reflection Data ◽  
Marine Terraces ◽  
Need To Evaluate ◽  
Near Shore ◽  
Recent Earthquakes

ABSTRACT Recent earthquakes involving multiple fault ruptures highlight the need to evaluate complex coastal deformation mechanisms, which are important for understanding plate boundary kinematics and seismic and tsunami hazards. We compare ages and uplift of the youngest Holocene marine terraces at Puatai Beach and Pakarae River mouth (∼10  km apart) in the northern Hikurangi subduction margin to examine whether uplift is the result of subduction earthquakes or upper-plate fault earthquakes. From stepped platform-cliff morphology, we infer uplift during 2–3 earthquakes and calculate an average uplift-per-event of 2.9±0.5  m at Puatai Beach and 2.0±0.5  m at Pakarae River mouth. Radiocarbon ages from the youngest beach deposit shells on each terrace and a tephra coverbed on one terrace constrain the timing of earthquakes to 1770–1710, 1100–910, and 420–250 cal. B.P. at Puatai Beach, and 1490–1290 and 660–530 cal. B.P. at Pakarae River mouth. The ages differ at each site indicating uplift is neither the result of subduction earthquakes nor single upper-plate fault earthquakes. A reinterpretation of new and existing bathymetry and seismic reflection data, combined with dislocation modeling, indicates that near-shore fault segmentation is more complex than previously thought and ruptures likely involve multiple upper-plate faults. Future updates of the New Zealand National Seismic Hazard Model should revise the northern Hikurangi subduction seismic sources so that rupture does not uplift Puatai Beach and Pakarae River mouth and include new near-shore upper-plate faults as multifault sources.

The discovery of a new sedimentary basin: offshore Raukumara, East Coast, North Island, New Zealand

2008 ◽  
Vol 48 (1) ◽  
pp. 53 ◽  
Author(s):  
Chris Uruski ◽  
Callum Kennedy ◽  
Rupert Sutherland ◽  
Vaughan Stagpoole ◽  
Stuart Henrys
Keyword(s):  
New Zealand ◽  
Oil And Gas ◽  
East Coast ◽  
Plate Boundary ◽  
Source Rocks ◽  
Fault System ◽  
Northern Coast ◽  
The South ◽  
Petroleum Potential ◽  
The North

The East Coast of North Island, New Zealand, is the site of subduction of the Pacific below the Australian plate, and, consequently, much of the basin is highly deformed. An exception is the Raukumara Sub-basin, which forms the northern end of the East Coast Basin and is relatively undeformed. It occupies a marine plain that extends to the north-northeast from the northern coast of the Raukumara Peninsula, reaching water depths of about 3,000 m, although much of the sub-basin lies within the 2,000 m isobath. The sub-basin is about 100 km across and has a roughly triangular plan, bounded by an east-west fault system in the south. It extends about 300 km to the northeast and is bounded to the east by the East Cape subduction ridge and to the west by the volcanic Kermadec Ridge. The northern seismic lines reveal a thickness of around 8 km increasing to 12–13 km in the south. Its stratigraphy consists of a fairly uniformly bedded basal section and an upper, more variable unit separated by a wedge of chaotically bedded material. In the absence of direct evidence from wells and samples, analogies are drawn with onshore geology, where older marine Cretaceous and Paleogene units are separated from a Neogene succession by an allochthonous series of thrust slices emplaced around the time of initiation of the modern plate boundary. The Raukumara Sub-basin is not easily classified. Its location is apparently that of a fore-arc basin along an ocean-to-ocean collision zone, although its sedimentary fill must have been derived chiefly from erosion of the New Zealand land mass. Its relative lack of deformation introduces questions about basin formation and petroleum potential. Although no commercial discoveries have been made in the East Coast Basin, known source rocks are of marine origin and are commonly oil prone, so there is good potential for oil as well as gas in the basin. New seismic data confirm the extent of the sub-basin and its considerable sedimentary thickness. The presence of potential trapping structures and direct hydrocarbon indicators suggest that the Raukumara Sub-basin may contain large volumes of oil and gas.

scholarly journals Morphotectonics and strain partitioning at the Iberia–Africa plate boundary from multibeam and seismic reflection data

2009 ◽  
Vol 267 (3-4) ◽  
pp. 156-174 ◽  
Author(s):  
P. Terrinha ◽  
L. Matias ◽  
J. Vicente ◽  
J. Duarte ◽  
J. Luís ◽  
...  
Keyword(s):  
Seismic Reflection ◽  
Plate Boundary ◽  
Strain Partitioning ◽  
Seismic Reflection Data ◽  
Reflection Data
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