scholarly journals Stratigraphy of Architectural Elements of a Buried Monogenetic Volcanic System

2019 ◽  
Vol 11 (1) ◽  
pp. 581-616 ◽  
Author(s):  
Alan Bischoff ◽  
Andrew Nicol ◽  
Jim Cole ◽  
Darren Gravley

Abstract Large volumes of magma emplaced and deposited within sedimentary basins can have an impact on the architecture and geological evolution of these basins. Over the last decade, continuous improvement in techniques such as seismic volcano-stratigraphy and 3D visualisation of igneous bodies has helped increase knowledge about the architecture of volcanic systems buried in sedimentary basins. Here, we present the complete architecture of the Maahunui Volcanic System (MVS), a middle Miocene monogenetic volcanic field now buried in the offshore Canterbury Basin, South Island of New Zealand. We show the location, geometry, size, and stratigraphic relationships between 25 main intrusive, extrusive and sedimentary architectural elements, in a comprehensive volcano-stratigraphic framework that explains the evolution of the MVS from emplacement to complete burial in the host sedimentary basin. Understanding the relationships between these diverse architectural elements allows us to reconstruct the complete architecture of the MVS, including its shallow (<3 km) plumbing system, the morphology of the volcanoes, and their impact in the host sedimentary basin during their burial. The plumbing system of the MVS comprises saucer-shaped sills, dikes and sill swarms, minor stocks and laccoliths, and pre-eruptive strata deformed by intrusions. The eruptive and associated sedimentary architectural elements define the morphology of volcanoes in the MVS, which comprise deep-water equivalents of crater and cone-type volcanoes. After volcanism ceased, the process of degradation and burial of volcanic edifices formed sedimentary architectural elements such as inter-cone plains, epiclastic plumes, and canyons. Insights from the architecture of the MVS can be used to explore for natural resources such as hydrocarbons, geothermal energy and minerals in buried and active volcanic systems elsewhere.

2019 ◽  
Author(s):  
Alan Bischoff ◽  
Andrew Nicol ◽  
Jim Cole ◽  
DDarren Gravley

Large volumes of magma emplaced and deposited within sedimentary basins can have an impact on the architecture and geological evolution of these basins. Over the last decade, continuous improvement in techniques such as seismic volcano-stratigraphy and 3D visualisation of igneous bodies has helped increase knowledge about the architecture of volcanic systems buried in sedimentary basins. Here, we present the complete architecture of the Maahunui Volcanic System (MVS), a middle Miocene monogenetic volcanic field now buried in the offshore Canterbury Basin, South Island of New Zealand. We show the location, geometry, size, and stratigraphic relationships between 25 main intrusive, extrusive and sedimentary architectural elements, in a comprehensive volcano-stratigraphic framework that explains the evolution of the MVS from emplacement to complete burial in the host sedimentary basin. The plumbing system of the MVS comprises saucer-shaped sills, dikes and sill swarms, minor stocks and laccoliths, and pre-eruptive strata deformed by intrusions. The eruptive and associated sedimentary architectural elements define the morphology of volcanoes in the MVS, which comprise deep-water equivalents of crater and cone-type volcanoes. After volcanism ceased, the process of degradation and burial of volcanic edifices formed sedimentary architectural elements such as inter-cone plains, epiclastic plumes, and canyons. Understanding the relationships between these diverse architectural elements allows us to reconstruct the complete architecture of the MVS, including its shallow (&lt;3 km) plumbing system, the morphology of the volcanoes, and their impact in the host sedimentary basin during their burial. Insights from the architecture of the MVS can be used to explore for geoenergy resources such as oil, gas and geothermal energy in buried and active monogenetic volcanic systems elsewhere.


2017 ◽  
Vol 5 (3) ◽  
pp. SK141-SK159 ◽  
Author(s):  
Alan Patrick Bischoff ◽  
Andrew Nicol ◽  
Mac Beggs

The interaction between magmatism and sedimentation creates a range of petroleum plays at different stratigraphic levels due to the emplacement and burial of volcanoes. This study characterizes the spatio-temporal distribution of the fundamental building blocks (i.e., architectural elements) of a buried volcano and enclosing sedimentary strata to provide insights for hydrocarbon exploration in volcanic systems. We use a large data set of wells and seismic reflection surveys from the offshore Taranaki Basin, New Zealand, compared with outcropping volcanic systems worldwide to demonstrate the local impacts of magmatism on the evolution of the host sedimentary basin and petroleum system. We discover the architecture of Kora volcano, a Miocene andesitic polygenetic stratovolcano that is currently buried by more than 1000 m of sedimentary strata and hosts a subcommercial discovery within volcanogenic deposits. The 22 individual architectural elements have been characterized within three main stratigraphic sequences of the Kora volcanic system. These sequences are referred to as premagmatic (predate magmatism), synmagmatic (defined by the occurrence of intrusive, eruptive, and sedimentary architectural elements), and postmagmatic (degradation and burial of the volcanic structures after magmatism ceased). Potential petroleum plays were identified based on the distribution of the architectural elements and on the geologic circumstances resulting from the interaction between magmatism and sedimentation. At the endogenous level, emplacement of magma forms structural traps, such as drag folds and strata jacked up above intrusions. At the exogenous level, syneruptive, intereruptive, and postmagmatic processes mainly form stratigraphic and paleogeomorphic traps, such as interbedded volcano-sedimentary deposits, and upturned pinchout of volcanogenic and nonvolcanogenic coarse-grained deposits onto the volcanic edifice. Potential reservoirs are located at systematic vertical and lateral distances from eruptive centers. We have determined that identifying the architectural elements of buried volcanoes is necessary for building predictive models and for derisking hydrocarbon exploration in sedimentary basins affected by magmatism.


2021 ◽  
Vol 83 (6) ◽  
Author(s):  
Gianmaria Tortelli ◽  
Anna Gioncada ◽  
Carolina Pagli ◽  
Mauro Rosi ◽  
Laura De Dosso ◽  
...  

AbstractDuring continental rifting, strain and magmatism are believed to localize to narrow magmatic segments, while the rift margin is progressively abandoned. We integrate volcanological, geochemical, petrological and seismic data from the Ma’Alalta volcanic field (MVF) near the western margin of Afar, to show that the MVF is an active magmatic segment. Magmatism in MVF initiated with lava flows and large-volume, caldera-forming ignimbrites from a central edifice. However, the most recent magmatic activity shifted towards mafic lava fields, cinder cones and obsidian-rich silicic domes erupted from vents aligned NNW-SSE, defining a ~ 35-km-long magmatic segment. Along the same area, a NNW-SSE alignment of earthquakes was recorded by two local seismic networks (2005–2009 and 2011–2013). The geochemistry of the mafic rocks is similar to those of nearby axial volcanoes. Inferred magma storage depth from mineral geobarometry shows that a shallow, silicic chamber existed at ~ 5-km depth below the stratovolcano, while a stacked plumbing system with at least three magma storage levels between 9 and 24 km depth fed the recent basalts. We interpret the wide set of observations from the MVF as evidence that the area is an active magmatic segment, showing that localised axial extension can be heavily offset towards the rift margin.


Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 706
Author(s):  
Jacek Majorowicz ◽  
Stephen E. Grasby

We summarize the feasibility of using geothermal energy from the Western Canada Sedimentary Basin (WCSB) to support communities with populations >3000 people, including those in northeastern British Columbia, southwestern part of Northwest Territories (NWT), southern Saskatchewan, and southeastern Manitoba, along with previously studied communities in Alberta. The geothermal energy potential of the WCSB is largely determined by the basin’s geometry; the sediments start at 0 m thickness adjacent to the Canadian shield in the east and thicken to >6 km to the west, and over 3 km in the Williston sub-basin to the south. Direct heat use is most promising in the western and southern parts of the WCSB where sediment thickness exceeds 2–3 km. Geothermal potential is also dependent on the local geothermal gradient. Aquifers suitable for heating systems occur in western-northwestern Alberta, northeastern British Columbia, and southwestern Saskatchewan. Electrical power production is limited to the deepest parts of the WCSB, where aquifers >120 °C and fluid production rates >80 kg/s occur (southwestern Northwest Territories, northwestern Alberta, northeastern British Columbia, and southeastern Saskatchewan. For the western regions with the thickest sediments, the foreland basin east of the Rocky Mountains, estimates indicate that geothermal power up to 2 MWel. (electrical), and up to 10 times higher for heating in MWth. (thermal), are possible.


2021 ◽  
Author(s):  
Benjamin Adams ◽  
Jonathan Ogland-Hand ◽  
Jeffrey M. Bielicki ◽  
Philipp Schädle ◽  
Martin Saar

<p><b>Abstract</b></p><p>Sedimentary basins are ubiquitous, naturally porous and permeable, and the geothermal heat in these basins can be extracted with geologic water or CO<sub>2</sub> and used to generate electricity. Despite this, the broad potential that these formations may have for electricity generation is unknown. Here we investigate this potential, which required the creation of the <u>gen</u>eralizable <u>GEO</u>thermal techno-economic simulator (genGEO). genGEO is built with only publicly available data and uses five standalone, but integrated, models that directly simulate all components of geothermal power plants to estimate electricity generation and cost. As a result of this structure, genGEO, or a portion of it, can be applied or extended to study any geothermal power technology. In contrast, the current techno-economic tools for geothermal power plants rely on characterizations of unpublished ASPEN results and are thus not generalizable enough to be applied to sedimentary basin geothermal power plants which use subsurface CO<sub>2</sub>.</p> <p>In this study, we present genGEO as open-source software, validate it with industry data, and compare its estimates to other geothermal techno-economic tools. We then apply genGEO to sedimentary basin geothermal resources and find that using CO<sub>2</sub> as a subsurface heat extraction fluid compared to water decreases the cost of geothermal electricity across most geologic conditions that are representative of sedimentary basins. Using genGEO results and p50 geologic data, we produce supply curves for sedimentary basin geothermal power plants in the U.S., which suggests that there is present-day potential to profitably increase the capacity of geothermal power by ~10% using water as the subsurface heat extraction fluid. More capacity is available at lower cost when CO<sub>2</sub> is used as the subsurface fluid, but realizing this capacity requires geologically storing between ~2 and ~7 MtCO<sub>2</sub>/MW<sub>e</sub>. But developing sedimentary basin resources in the short-term using subsurface water may not eliminate options for CO₂-based power plants in the long-term because the least-cost order of sedimentary basins is not the same for both CO<sub>2</sub> and water. With sufficient geologic CO<sub>2</sub> storage, developing sedimentary basins using CO<sub>2</sub>- and water-based power plants may be able to proceed in parallel.</p>


1969 ◽  
Vol 20 ◽  
pp. 91-94
Author(s):  
Michael B.W. Fyhn ◽  
Henrik I. Petersen ◽  
Anders Mathiesen ◽  
Lars H. Nielsen ◽  
Stig A.S. Pedersen ◽  
...  

A number of sedimentary basins of various ages are located onand offshore Vietnam (Fig. 1). Some of them have significant petroleum resources and have thus attracted interest from industry and academia (Rangin et al. 1995; Matthews et al. 1997; Lee & Watkins 1998; Lee et al. 2001). Moreover, Vietnam is located in a position central to the understanding of the geological development of South-East Asia (Hall & Morley 2004). The structural style and the stratigraphy of the Vietnamese basins thus provide a valuable record about the development of South-East Asia throughout the Phanerozoic and the subsequent Eocene as well as younger deformation associated with the collision and indentation of India into Eurasia and the opening of the South China Sea (Fyhn et al. 2009a, 2010a).


1994 ◽  
Vol 37 (6) ◽  
Author(s):  
D. Fah ◽  
G. F. Panza

Three applications of a numerical technique are illustrated to model realistically the seismic ground motion for complex two-dimensional structures. First we consider a sedimentary basin in the Friuli region, and we model strong motion records from an aftershock of the 1976 earthquake. Then we simulate the ground motion caused in Rome by the 1915, Fucino (Italy) earthquake, and we compare our modelling with the damage distribution observed in the town. Finally we deal with the interpretation of ground motion recorded in Mexico City, as a consequence of earthquakes in the Mexican subduction zone. The synthetic signals explain the major characteristics (relative amplitudes, spectral amplification, frequency content) of the considered seismograms, and the space distribution of the available macroseismic data. For the sedimentary basin in the Friuli area, parametric studies demonstrate the relevant sensitivity of the computed ground motion to small changes in the subsurface topography of the sedimentary basin, and in the velocity and quality factor of the sediments. The relative Arias Intensity, determined from our numerical simulation in Rome, is in very good agreoment with the distribution of damage observed during the Fucino earthquake. For epicentral distances in the range 50 km-100 km, the source location and not only the local soil conditions control the local effects. For Mexico City, the observed ground motion can be explained as resonance effects and as excitation of local surface waves, and the theoretical and the observed maximum spectral amplifications are very similar. In general, our numerical simulations estimate the maximum and average spectral amplification for specific sites, i.e. they are a very powerful tool for accurate micro-zonation


2021 ◽  
Vol 23 (1) ◽  
pp. 195-211
Author(s):  
I.M. Okiyi ◽  
S.I. Ibeneme ◽  
E.Y. Obiora ◽  
S.O. Onyekuru ◽  
A.I. Selemo ◽  
...  

Residual aeromagnetic data of parts of Southeastern Nigerian sedimentary basin were reduced to the equator and subjected to magnetic vector inversion and spectral analysis. Average depths of source ensembles from spectral analysis were used to compute depth to magnetic tops (Z), base of the magnetic layer (Curie Point t Depth (CPD)), and estimate geothermal gradient and heat flow required for the evaluation of the geothermal resources of the study area. Results from spectral analysis showed depths to the top of the magnetic source ranging between 0.45 km and 1.90 km; centroid depths of 4 km - 7.87 km and CPD of between 6.15 km and 14.19 km. The CPD were used to estimate geothermal gradients which ranged from 20.3°C/km to 50.0°C/km 2 2 and corresponding heat flow values of 34.9 mW/m to 105 mW/m , utilizing an average thermal conductivity -1 -1 of 2.15 Wm k . Ezzagu (Ogboji), Amanator-Isu, Azuinyaba, Nkalagu, Amagunze, Nta-Nselle, Nnam, Akorfornor environs are situated within regions of high geothermal gradients (>38°C/Km) with models delineated beneath these regions using 3D Magnetic Vector Inversion, having dominant NW-SE and NE-SW trends at shallow and greater depths of <1km to >7 km bsl. Based on VES and 2D imaging models the geothermal system in Alok can be classified as Hot Dry Rock (HDR) type, which may likely have emanated from fracture systems. There is prospect for the development of geothermal energy in the study area. Keywords: Airborne Magnetics, Magnetic Vector Inversion, Geothermal Gradient, Heat Flow, Curie Point Depth, Geothermal Energy.


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