scholarly journals Stratigraphic and tectonic framework of Late Cretaceous and Paleogene strata of southern Aotea Basin, northwest New Zealand

2021 ◽  
Author(s):  
◽  
Callum Skinner

<p>Seismic reflection data reveal thick sediment sequences of Late Cretaceous to Paleogene age in the region northwest of Taranaki Basin. A new stratigraphic framework for latest Cretaceous and Paleogene strata is created based on stacking patterns and stratal termination relationships of seismic reflectors. Sequence-bounding reflectors are tied to petroleum exploration wells, including recently-drilled Romney-1, to assign age and paleoenvironment interpretation. I identify the following sequences: (1) a late Haumurian to Teurian (68 – 56 Ma) aggradational shelf sequence, with at least two regressional events linked to eustatic sea-level falls; (2) a diachronous deepening of the basin that progressed from north to south during the late Waipawan to Heretaungan (53 – 46 Ma); (3) small-scale volcanism at the southern boundary with Taranaki Basin is contemporaneous with this deepening; (4) a prograding delta on Challenger Plateau during the Porangan to Runangan (46 – 35 Ma) that is evidence for tectonic uplift of the basin margins; and (5) an onlapping sequence from latest Runangan to present (35 – 0 Ma) that indicates Challenger Plateau subsided 1,300 m. A revised set of paleogeography maps and generalised stratigraphic chart summarise these observations. The Eocene phase (52-46 Ma) of tectonic subsidence and diffuse volcanism is one of the earliest signs of tectonic activity associated with development of the Cenozoic plate boundary through New Zealand. Petroleum system analysis reveals that southern Aotea Basin is prospective for petroleum exploration, with 3 plays identified in the Late Haumurian to Teurian (79 – 56 Ma) strata, in spite of Romney-1 proving unsuccessful.</p>

2021 ◽  
Author(s):  
◽  
Callum Skinner

<p>Seismic reflection data reveal thick sediment sequences of Late Cretaceous to Paleogene age in the region northwest of Taranaki Basin. A new stratigraphic framework for latest Cretaceous and Paleogene strata is created based on stacking patterns and stratal termination relationships of seismic reflectors. Sequence-bounding reflectors are tied to petroleum exploration wells, including recently-drilled Romney-1, to assign age and paleoenvironment interpretation. I identify the following sequences: (1) a late Haumurian to Teurian (68 – 56 Ma) aggradational shelf sequence, with at least two regressional events linked to eustatic sea-level falls; (2) a diachronous deepening of the basin that progressed from north to south during the late Waipawan to Heretaungan (53 – 46 Ma); (3) small-scale volcanism at the southern boundary with Taranaki Basin is contemporaneous with this deepening; (4) a prograding delta on Challenger Plateau during the Porangan to Runangan (46 – 35 Ma) that is evidence for tectonic uplift of the basin margins; and (5) an onlapping sequence from latest Runangan to present (35 – 0 Ma) that indicates Challenger Plateau subsided 1,300 m. A revised set of paleogeography maps and generalised stratigraphic chart summarise these observations. The Eocene phase (52-46 Ma) of tectonic subsidence and diffuse volcanism is one of the earliest signs of tectonic activity associated with development of the Cenozoic plate boundary through New Zealand. Petroleum system analysis reveals that southern Aotea Basin is prospective for petroleum exploration, with 3 plays identified in the Late Haumurian to Teurian (79 – 56 Ma) strata, in spite of Romney-1 proving unsuccessful.</p>


2020 ◽  
Vol 110 (2) ◽  
pp. 825-849 ◽  
Author(s):  
Nicola J. Litchfield ◽  
Kate J. Clark ◽  
Ursula A. Cochran ◽  
Alan S. Palmer ◽  
Joshu Mountjoy ◽  
...  

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.


2021 ◽  
pp. petgeo2021-003
Author(s):  
Laura-Jane C. Fyfe ◽  
Nick Schofield ◽  
Simon Holford ◽  
Adrian Hartley ◽  
Adrian Heafford ◽  
...  

The Sea of Hebrides Basin and Minch Basin are late Palaeozoic-Mesozoic rift basins located to the northwest of the Scottish mainland. The basins were the target of small-scale petroleum exploration from the late 1960s to the early 1990s, with a total of three wells drilled within the two basins between 1989 and 1991. Although no commercially viable petroleum discoveries were made, numerous petroleum shows were identified within both basins, including a gas show within the Upper Glen 1 well in Lower Jurassic limestones. Organic rich shales have been identified throughout the Jurassic succession within the Sea of Hebrides Basin, with one Middle Jurassic (Bajocian-Bathonian) shale exhibiting a Total Organic Carbon content of up to 15 wt%. The focus of this study is to review the historic petroleum exploration within these basins, and to evaluate whether the conclusions drawn in the early 1990s of a lack of prospectivity remains the case. This was undertaken by analysis of seismic reflection data, gravity and aeromagnetic data and sedimentological data, from both onshore and offshore wells, boreholes and previously published studies. The key findings from our study suggest that there is a low probability of commercially sized petroleum accumulations within either the Sea of Hebrides Basin or the Minch Basin. Ineffective source rocks, likely due to low maturities (due to lack of burial) and the fact that the encountered Jurassic and Permian-Triassic reservoirs are of poor quality (low porosity and permeability) has led to our interpretation of future exploration being high risk, with any potential accumulations being small in size. While petroleum accumulations are unlikely within the basin, applying the knowledge obtained from the study could provide additional datasets and insight into petroleum exploration on other northeast Atlantic margin basins, such as the Rockall Trough and the Faroe-Shetland Basin.


1989 ◽  
Vol 20 (2) ◽  
pp. 287
Author(s):  
C.D. Cape ◽  
R.M. O'Connor ◽  
J.M. Ravens ◽  
D.J. Woodward

Late Cenozoic deformation along the Australian/Pacific plate boundary is seen in onshore New Zealand as zones characterised by extension- or transcurrent- or contraction-related structures. High-resolution multichannel seismic reflection data were acquired in several of these tectonic zones and successfully reveal the shallow structures within them. Thirty kilometres of dynamite reflection data in the Rangitaiki Plains, eastern Bay of Plenty, define a series of NE-trending normal faults within this extensional back-arc volcanic region. The data cross surface ruptures activated during the 1987 Edgecumbe earthquake. In the southern North Island, a 20 km Mini-Sosie? seismic profile details the Quaternary sedimentation history and reveals the structure of the active strike-slip and thrust fault systems that form the western and eastern edges of the Wairarapa basin, respectively. This basin is considered to sit astride the boundary between a zone of distributed strike-slip faults and an active accretionary prism. In the Nelson area, northwestern South Island, previously unrecognised low-angle thrust faults of Neogene or Quaternary age are seen from Mini-Sosie data to occur at very shallow depths. Crustal shortening here was previously thought to arise from movement on high-angle reverse faults, and the identification of these low-angle faults has prompted a reassessment of that model. A grid of 18 km of Mini-Sosie seismic data from the central eastern South Island delineates Neogene or Quaternary thrust faults in Cenozoic sediments. The thrusts are interpreted as reactivated Early Eocene normal faults, and the thrust fault geometry is dominated by these older structures.


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

2021 ◽  
Author(s):  
Piotr Krzywiec ◽  
Łukasz Słonka ◽  
Quang Nguyen ◽  
Michał Malinowski ◽  
Mateusz Kufrasa ◽  
...  

&lt;p&gt;In 2016, approximately 850 km of high-resolution multichannel seismic reflection data of the BALTEC survey have been acquired offshore Poland within the transition zone between the East European Craton and the Paleozoic Platform. Data processing, focused on removal of multiples, strongly overprinting geological information at shallower intervals, included SRME, TAU-P domain deconvolution, high resolution parabolic Radon demultiple and SWDM (Shallow Water De-Multiple). Entire dataset was Kirchhoff pre-stack time migrated. Additionally, legacy shallow high-resolution multichannel seismic reflection data acquired in this zone in 1997 was also used. All this data provided new information on various aspects of the Phanerozoic evolution of this area, including Late Cretaceous to Cenozoic tectonics and sedimentation. This phase of geological evolution could be until now hardly resolved by analysis of industry seismic data as, due to limited shallow seismic imaging and very strong overprint of multiples, essentially no information could have been retrieved from this data for first 200-300 m. Western part of the BALTEC dataset is located above the offshore segment of the Mid-Polish Swell (MPS) &amp;#8211; large anticlinorium formed due to inversion of the axial part of the Polish Basin. BALTEC seismic data proved that Late Cretaceous inversion of the Koszalin &amp;#8211; Chojnice fault zone located along the NE border of the MPS was thick-skinned in nature and was associated with substantial syn-inversion sedimentation. Subtle thickness variations and progressive unconformities imaged by BALTEC seismic data within the Upper Cretaceous succession in vicinity of the Kamie&amp;#324;-Adler and the Trzebiat&amp;#243;w fault zones located within the MPS documented complex interplay of Late Cretaceous basin inversion, erosion and re-deposition. Precambrian basement of the Eastern, cratonic part of the study area is overlain by Cambro-Silurian sedimentary cover. It is dissected by a system of steep, mostly reverse faults rooted in most cases in the deep basement. This fault system has been regarded so far as having been formed mostly in Paleozoic times, due to the Caledonian orogeny. As a consequence, Upper Cretaceous succession, locally present in this area, has been vaguely defined as a post-tectonic cover, locally onlapping uplifted Paleozoic blocks. New seismic data, because of its reliable imaging of the shallowest substratum, confirmed that at least some of these deeply-rooted faults were active as a reverse faults in latest Cretaceous &amp;#8211; earliest Paleogene. Consequently, it can be unequivocally proved that large offshore blocks of Silurian and older rocks presently located directly beneath the Cenozoic veneer must have been at least partly covered by the Upper Cretaceous succession; then, they were uplifted during the widespread inversion that affected most of Europe. Ensuing regional erosion might have at least partly provided sediments that formed Upper Cretaceous progradational wedges recently imaged within the onshore Baltic Basin by high-end PolandSPAN regional seismic data. New seismic data imaged also Paleogene and younger post-inversion cover. All these results prove that Late Cretaceous tectonics substantially affected large areas located much farther towards the East than previously assumed.&lt;/p&gt;&lt;p&gt;This study was funded by the Polish National Science Centre (NCN) grant no UMO-2017/27/B/ST10/02316.&lt;/p&gt;


2021 ◽  

The most utilized technique for exploring the Earth's subsurface for petroleum is reflection seismology. However, a sole focus on reflection seismology often misses opportunities to integrate other geophysical techniques such as gravity, magnetic, resistivity, and other seismicity techniques, which have tended to be used in isolation and by specialist teams. There is now growing appreciation that these technologies used in combination with reflection seismology can produce more accurate images of the subsurface. This book describes how these different field techniques can be used individually and in combination with each other and with seismic reflection data. World leading experts present chapters covering different techniques and describe when, where, and how to apply them to improve petroleum exploration and production. It also explores the use of such techniques in monitoring CO2 storage reservoirs. Including case studies throughout, it will be an invaluable resource for petroleum industry professionals, advanced students, and researchers.


2019 ◽  
Vol 500 (1) ◽  
pp. 115-128 ◽  
Author(s):  
Jacob Geersen ◽  
Andrea Festa ◽  
Francesca Remitti

AbstractThe subduction of large and heterogeneous mass-transport deposits (MTDs) is discussed to modify the structure and physical state of the plate boundary and therewith exert an influence on seismicity in convergent margins. Understanding which subduction-zone architectures and structural boundary conditions favour the subduction of MTDs, primarily deposited in oceanic trenches, is therefore highly significant. We use bathymetric and seismic reflection data from modern convergent margins to show that a large landslide volume and long runout, in concert with thin trench sediments, increase the chances for an MTD to become subducted. In regions where the plate boundary develops within the upper plate or at its base (non-accretionary margins), and in little-sedimented trenches (sediment thickness <2 km), an MTD has the highest potential to become subducted, particularly when characterized by a long runout. On the contrary, in the case of a heavily sedimented trench (sediment thickness >4 km) and short runout, an MTD will only be subducted if the thickness of subducting sediments is higher than the thickness of sediments under the MTD. The results allow identification of convergent margins where MTDs are preferentially subducted and thus potentially alter plate-boundary seismicity.


2010 ◽  
Vol 47 (5) ◽  
pp. 621-632 ◽  
Author(s):  
R. D. Hyndman

The crust and upper mantle thermal regime of the Canadian Cordillera and its tectonic consequences were an important part of the Cordillera Lithoprobe program and related studies. This article provides a review, first of the thermal constraints, and then of consequences in high surface elevation and current tectonics. Cordillera and adjacent craton temperatures are well constrained by geothermal heat flow, mantle tomography velocities, upper mantle xenoliths, and the effective elastic thickness, Te. Cordillera temperatures are very high and laterally uniform, explained by small scale convection beneath a thin lithosphere, 800–900 °C at the Moho, contrasted to 400–500 °C for the craton. The high temperatures provide an explanation for why the Cordillera has high elevation in spite of a generally thin crust, ∼33 km, in contrast to low elevation and thicker crust, 40–45 km, for the craton. The Cordillera is supported ∼1600 m by lithosphere thermal expansion. In the Cordillera only the upper crust has significant strength; Te ∼ 15 km, in contrast to over 60 km for the craton. The Cordillera is tectonically active because the lithosphere is sufficiently weak to be deformed by plate boundary and gravitational forces; the craton is too strong. The Canadian Cordillera results have led to new understandings of processes in backarcs globally. High backarc temperatures and weak lithospheres explain the tectonic activity over long geological times of mobile belts that make up about 20% of continents. They also have led to a new understanding of collision orogenic heat in terms of incorporation of already hot backarcs.


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