James A. Hammerstein, Raffaele Di Cuia, Michael A. Cottam, gonzalo Zamora, Robert W. H. Butler, 2020. "Fold and thrust belts: structural style, evolution and also exploration – an introduction", Fold and Thrust Belts: structural Style, Evolution and also Exploration, J. A. Hammerstein, R. Di Cuia, M. A. Cottam, G. Zamora, R. W. H. Butler
Download quote file:
This is an Open accessibility article spread under the terms of the an imaginative Commons Attribution 4.0 license (http://creativecommons.org/licenses/by/4.0/).
You are watching: A fold-thrust belt is associated with
The outer parts the collision hill belts are commonly represented by fold and also thrust belts. Plenty of of the an essential concepts in the structure geology the fold and thrust belts have origins in old orogens such together the Appalachians and also Caledonian chains of Europe, in addition to the Alps. Incentive in thrust belt research then come from the desire to manipulate geological sources that reside in the subsurface, especially arising from hydrocarbon expedition in the foothills the the Canadian Cordillera in the 1960s and 1970s. Notwithstanding decades of exploitation, continent fold and thrust belts are still estimated to host reserves of 700 billion barrels the oil equivalent. However exploration will focus increasingly ~ above small, hard-to-resolve structures. Basic geological understanding remains as vital today together it did because that the pioneering explorers in the Canadian foothills. It is a template that operation throughout this special Publication.
For many, the key advances in understanding thrust solution arise indigenous hydrocarbon exploration in the foothills that the Canadian Cordillera, together exemplified through landmark records by petroleum geologists (e.g. Bally et al. 1966; Dahlstrom 1969, 1970). Thus, although countless of the vital concepts in the structure geology of fold and also thrust belts have previously origins in various other orogens, the impetus has come indigenous the desire to make use of geological resources that reside in the subsurface. The meaning of continent fold and also thrust belts as hosts because that hydrocarbons is reviewed by Cooper (2007). Roeder (2010) approximates that globally these systems hold known make reservation of 700 exchange rate barrels that oil equivalent. However, both authors identify that very big fields room unlikely come be discovered so that exploration will focus increasingly on small, hard-to-resolve structures.
Exploration in continent thrust belts is complex. Terrain is generally inaccessible, make seismic acquisition exceptionally problematic, compounded by extr uncertainties emanating from complicated near-surface geology, weathering profiles and topography the create considerable challenges for seismic processing. Therefore, the high quality of subsurface imaging can be lot poorer than, for example, the submarine rift basins. Numerous approaches come reducing the resultant unpredictabilities in forecasting subsurface framework use theory and also models of structure behaviours to recognize structural style and its evolution.
The an easy styles that thin-skinned tectonics deduced because that the foothills that the Canadian Cordillera room just part of a spectrum that deformation styles by which the continental crust can deform during contractional tectonics (as listed for example by Ramsay 1980; Coward 1983; butler & Mazzoli 2006). Pre-existing structures regulating the layouts of crustal-scale deformation, and the variable role of detachment surfaces within, and at the basic of, sedimentary successions, have the right to generate facility structures that evolve in various ways. Orogenic contraction have the right to involve complicated sequences of thrust-sheet emplacement and also the formations that arrays the subsidiary faults that affect on the evaluate of petroleum prospectivity in different ways. Far-ranging challenges remain in down-scaling explanation of fold and thrust frameworks to estimate deformation top top the reservoir scale (e.g. Servant et al. 2018).
The files in this unique Publication represent the recent endeavour to collect together the existing state of scholastic understanding of these systems along with their definition for petroleum exploration. Over the years there have been countless attempts to collate research study addressing contractional tectonics in general and also specifically the framework of fold and thrust belts. However, these have only rarely lugged together study from the diverse neighborhoods – not just those who construct interpretational methods and also tools for constructing cross-sections and associated visualizations to estimate subsurface structure but likewise those who apply and test these concepts in herbal settings – basically through drilling. Yet there space exceptions: the compilation of documents that brought together researchers and also explorers include ‘Thrust tectonics and also hydrocarbon systems’ (McClay 2004), ‘Oil and also gas in compressional belts’ (Needham et al. 2004), ‘Thrust belts and foreland basins’ (Lacombe et al. 2007), and also ‘Hydrocarbons in convulsion belts’ (Goffey et al. 2010).
In the previous decade there have actually been far-reaching developments in structure methodologies that enhance well-established approaches in geometric cross-section construction and restoration. Simultaneously, advanced acquisition technologies are helping to minimize uncertainties in the characterization and also evaluation of subsurface structures and also reservoirs. Brand-new technologies and also approaches space helping to advance understanding the fold and also thrust belts, not just opening new exploration methods in these solution but likewise in making hydrocarbon production an ext efficient. The insights and workflows emerged by the oil and also gas sector in characterizing and forecasting the subsurface in structurally facility settings room assisting other industrial applications, including waste storage. These insights might also assist to forecast and also mitigate earthquake perils in tectonically active settings.
It is apparent from the files in this one-of-a-kind Publication that fold and also thrust belts are far from an easy structures presented in idealized models, v a variety of controls that need to be thought about in bespeak to totally understand them. Specifics pre-orogenic architecture, basement interactions, sedimentation and mechanical properties of stratigraphy, every play roles in the evolution of a convergent system. Organic fold–thrust structures have the right to show considerable variations in their geometry along their lengths, an interpretation that insights obtained in one area may not use to one more even in the same fold–thrust belt.
The 19 papers accumulated here are separated into four sections. The first section presents 6 papers analyzing modelling techniques and also general techniques used to know the mechanisms and also controls on the evolution of fold and thrust belts, and to evaluate potential petroleum systems. There follow documents on a range of instance studies which are grouped below into 3 regions: Europe, Asia–Pacific and also the center East. Jointly they show how multi-disciplinary philosophies are crucial for reducing hesitation in the deductions of structural evolution. The papers use a variety of observations, indigenous outcrop and the subsurface, allied with remote imaging both from satellites and seismically. Thermal and stratigraphic data are provided to evaluate geological histories. Insights are acquired from modelling, both utilizing analogue materials and numerical methods. However to appreciate the diversity of potential structures, insights come native understanding different natural examples, and also from revisiting locations again using legacy data educated by brand-new ideas. The various places of situation studies and other instances used in this distinct Publication are presented on figure 1. Ideas, models and also interpretations of fold–thrust belts room evolving; assessing whether their applications leads to much better exploration outcomes continues to be for the future.
Global digital elevation model (DEM) showing places of researches presented in this volume. Associated paper and type of study shown by number and marker colour respectively. Ar studies encompass those including sample repertoire for laboratory analysis. (1) butler et al.; (2) Butler; (3) kendall et al.; (4) Grant; (5) Muirhead et al.; (6) Pharaoh et al.; (7) García-Sen et al.; (8) Malz et al.; (9) pace et al.; (10) Casabianca et al.; (11) Tamas et al.; (12) McArthur et al.; (13) Ollarves et al.; (14) Duran et al.; (15) Baillie et al.; (16) Legeay et al.; (17) Tozer et al.; (18) Ginés et al. elevation data courtesy the NASA.
Global digital elevation design (DEM) showing areas of studies presented in this volume. Associated record and kind of study indicated by number and also marker color respectively. Field studies encompass those entailing sample collection for activities analysis. (1) butler et al.; (2) Butler; (3) kendall et al.; (4) Grant; (5) Muirhead et al.; (6) Pharaoh et al.; (7) García-Sen et al.; (8) Malz et al.; (9) pace et al.; (10) Casabianca et al.; (11) Tamas et al.; (12) McArthur et al.; (13) Ollarves et al.; (14) Duran et al.; (15) Baillie et al.; (16) Legeay et al.; (17) Tozer et al.; (18) Ginés et al. elevation data courtesy the NASA.
The an initial papers research general worries in understanding fold–thrust belts. One way to inspection structural evolution is v the usage of deformation experiments on analogue materials, an approach pioneered through Henry Cadell in the direction of the finish of the nineteenth century. Butler et al. (2020) evaluation Cadell"s results and also motivations the sprung indigenous fieldwork in the NW Highlands the Scotland. This examine of historical scientific investigation, utilizing Cadell"s original ar notes and commentary, notifies a conversation of uncertainties and also biases that can result from making use of analogue experiments to help interpretation that the subsurface in the herbal world.
As Cadell showed, deformation layouts are very sensitive come the mechanical properties of the material. Hughes (2020) explores this notion through computational methods, using discrete facet modelling to see just how strain is distributed in folding and faulting. This models show that ‘weak’ rocks kind folds with distributed strain so that layer thicknesses end up being heterogeneous v deformation. In contrast rock sequences with moderate strength fold with flexural slip and therefore form concentric structures with far better preservation of great thickness. With more powerful strain-weakening properties the propensity the rocks come deform with the development of faults increases.
In enhancement to the mechanically properties of the stratigraphy, sedimentation and also the syn-kinematic strata have the right to have a strong influence over the structural format of emergent fold and also thrust belts. With examples from the Apennines and Himalayas, Butler (2019) illustrates exactly how the price of syn-kinematic sedimentation relative to thrust displacement price controls even if it is thrusts are imbricate-dominated or allochthon-prone. Here it is demonstrated that high sedimentation rates, relative to displacement, appear to generate imbricate equipment with ramp-dominated geometries, in contrast to areas of tiny sedimentation whereby thrust allochthons space emplaced. Furthermore, lateral and also temporal sports in sedimentation price can cause the structural layout to evolve, and as together it is likely that emergent thrust solution will demonstrate complex deformation activities.
Source-rock distribution, pre-orogenic architecture and its communication with the orogenic processes, and also mechanical stratigraphy are basic in the advancement of a petroleum system. With these components in mind, Kendall et al. (2019) examine just how a petroleum tectonic analysis can be offered as one effective method of evaluating the orogenic procedures of fold and thrust belts comprise organic-rich intervals. Instances from the Zagros, Pyrenees, Sevier and Beni Sub-Andean show the duty of flexural and dynamics processes, wedge taper kinematics, mechanically stratigraphy, source-rock distribution and inherited design can either develop or destroy a petroleum system.
When considering lot of hydrocarbon prospects, easily usable devices for examining the petroleum device are critical for expedition and advance of drilling programmes. Grant (2020) proposes one empirical 1D expansion model that presents a method of assessing the geo-history and trap integrity of a farming toe thrust structure. Offering due referral to the an ext simplistic nature that this method and crucial assumptions used, Grant suggests that this model can carry out a rapid assessment of the geo-history. These representative results have the right to then be tested against well data and also have potential for the evaluation of adjoining structures.
Understanding the thermal history of a system is basic to hydrocarbon exploration and also can test various predictions of thrust belt advancement (e.g. Deville & Sassi 2005; Aldega et al. 2017). Muirhead et al. (2019) talk about the use of Raman spectroscopy in determining the thermal maturation of carbonaceous sediments. Formerly utilized for metamorphic samples exceeding 270°C, the authors display that Raman spectroscopy can be an efficient thermal marker because that temperatures under to 75°C. Raman data from the Bornes an ar of the French Sub-Alpine chain are contrasted with released vitrinite reflectance and thermal modelling data, and critically is shown to it is in consistent. The authors argue the Raman spectroscopy may therefore be thought about a quick and effective device for lithological analysis of samples through a geology temperature of less than 300°C. Together this temperature window is aligned with the oil and gas generation window, the an approach represents a an effective tool for trial and error models that structural advancement in fold and also thrust belts, and calibrating models that hydrocarbon generation in sedimentary basins.
Crustal toughness plays a vital role in the evolution of fold and thrust belts. Pharaoh et al. (2019) examine seismic data native the Môn-Deemster-Ribblesdale fold–thrust belt, the Variscan turning back of the Bowland Basin, in order to construct a comprehensive model because that the structure evolution. Significantly, a region of weak crust located between rigid massifs to the north and south is identified as the crucial control because that the evolution of the Bowland Basin and also Môn-Deemster-Ribblesdale fold and thrust belt. Subsequent inversion was focused on reactivated enlarge structures.
García-Senz et al. (2019) examine the role of contrasting crustal strength in the Cantabrian–Pyrenean Orogen. The authors here existing five crustal-scale balanced and restored cross-sections based on field data, released seismic data and new gravity and also magnetic models. Below it is postulated that the visibility of an exhumed mantle body, said by gravity and also magnetic data, acts together a strictly buttress because that weaker continental product to be thrust outwards and also upwards throughout Alpine collision. This process resulted in the development of 2 triangular crustal zones at the borders of the exhumed mantle body.
As well together crustal toughness it is crucial to consider the control pre-existing structures have the right to have top top the advancement of a fold and also thrust belt. Malz et al. (2019) provide a detailed evaluation of the so late Miocene Mandach Thrust, easternmost Jura mountains (Northern Switzerland). The construction, restoration and also forward modelling of eight cross-sections, constrained by depth-migrated 2D seismic data and also geological maps show predominantly thin-skinned thrust tectonics. Along-strike sports in thrusting format is regulated by pre-existing structures, particularly the adjust in relief the the mechanical basement beneath the thrust. Additional along-strike alters are linked with regional activation of secondary detachment and lateral sedimentary facies changes. The authors additionally postulate the variation in recorded shortening of separation, personal, instance sections may relate to at this time unidentified transport structures.
Pace et al. (2020) reappraise vintage data from the southern Apennines thrust belt, southerly Italy, with contemporary techniques to identify the remaining hydrocarbon potential that an existing oil field. Revisiting heritage data with more up-to-date knowledge of the geological framework, structure style and geophysical characteristics, as well as far better understanding of tight-fractured carbonate reservoirs allowed for reappraisal of the abandoned Benevento Field. To know of new prospective structures demonstrate similarities through other discoveries along the exact same structural trend. Structure reconstruction indicate that this newly established structures are pertained to Pliocene optimistic inversion of pre-existing Permian–Triassic half grabens, and therefore the structural development of the Apulian thrust belt is continual with a basement-involved inversion tectonics model.
Casabianca et al. (2020) study the role of pre-existing extensional structures and how they have managed the development of the Maiella anticline: a fold and thrust belt-related structure in the southerly Apennines, Italy. When mentioning the potential evolutionary models for the an ar the authors examine the ramifications for the size and also distribution of reservoir elements for hydrocarbon exploration. With data because that this study mostly coming from field observations and also well bore data, the authors additionally raise the inquiry of how their conclusions might have differed if this to be purely based upon a seismic dataset. The writer conclude that observation of syn-sedimentary typical faults within the structure might not have been observed, with an unfavorable consequences for basic understanding and also hydrocarbon exploration. This highlights the require for an integrated approach, including ar observations where possible, to capture the full story the these complex systems.
The visibility of salt can have detrimental effects on subsurface imaging. In together instances scaled analogue modelling have the right to inform interpretation. Tămaş et al. (2019) current the results of 2 scaled analogue models in an effort to understand the Mid-Miocene tectonic evolution, structural geometries and also effects the penetrative strain for the Diapir wrinkles Zone, eastern Carpathian Bend, Romania. Negative seismic quality due to the existence of salt has actually led to contrasting structure models for this complicated system. A mix of digital image correlation techniques and digital elevation-model evaluation were supplied to aid interpretation of class parallel compaction, thickening, fault propagation and reactivation history. The structural style of the models is defined by sub-salt duplex frameworks overlain by wide supra-salt detachment folds v steep limbs, which are considered equivalent to structures observed in the Diapir wrinkles Zone. Whilst the authors acknowledge that the means penetrative stress, overload affects analogue models and nature is different, they display how penetrative strain might be temporally and also spatial spread in such systems.
The third section of the volume presents four files discussing fold and thrust belts in Asia–Pacific.
With an integrated study using gravity, bathymetry and also 2D seismic data McArthur et al. (2019) research the structural and also stratigraphic sport in the southern regions of the Hikurangi subduction wedge, phibìc Island, new Zealand. The authors demonstrate that whilst longitudinal variation of accommodation and sediment circulation styles exists, a vast inboard-to-outboard subdivision is observed. The examine highlights the variable style of sedimentation across the margin and the duty of underlying frameworks for the advance of distinctive varieties of accommodation, sediment flux and stratigraphic evolution. The is concluded the lateral and longitudinal sports in structure and also sedimentation is vital to exploiting such regions for frontier hydrocarbon exploration.
Poor geophysical imaging and preservation of syn-kinematic stratigraphy of study locations leads to different approaches being adopted. Ollarves et al. (2019) existing a morphotectonic analysis of the surface expressions that folded structures in bespeak to evaluate the folding style and also sequence the the west Papua brand-new Guinea Highlands. Folds to be initially identified by shape, aspect ratio and symmetry. Fold front sinuosity and also karst advancement observations allow for relative periods to it is in assessed and drainage network analyses were offered to refine these ages. These analyses highlighted common characteristics associated with particular structural styles, such that the folds might be group according come their most likely evolution.
Two papers in this section analyze the broadband BandaSeis 2D seismic survey. Interpretations from Martinez Duran et al. (2019) describe structural and tectonic features, not formerly reported, the the Timor Orogen, whilst Baillie et al. (2020) consider an ext regional observations. The complicated collision the the Eurasia, Australia and also Pacific plates brought about a distinctive horseshoe morphology, that has been connected with so late Jurassic rifting and also breakup of eastern Gondwana (e.g. Longley et al. 2002; hall 2012). The authors describe how the fold and thrust belts readjust in size, shape and degree of basement reactivation roughly the Banda Arc.
With frequently excellent outcrop exposure, combination with huge volumes of known hydrocarbon reserves, regions such as the Zagros Mountains have actually presented geologists with prime opportunities to recognize the advancement of fold and also thrust belts and their relationship with hydrocarbon generation, migration and also trapping. The last section the this volume brings three files discussing fold and also thrust belts in the Middle-East region.
With a mix of field studies and also interpretation of seismic data, Legeay et al. (2019) build a collection of regional cross-sections come constrain the structure and evolution that the Sivas Basin, central–eastern Anatolia, Turkey. Critically, the authors think about the affect syn-orogenic salt has had actually on the structural style and lateral variability the a fold and also thrust belt.
Tozer et al. (2019) think about vertical movements associated with fold and also thrust belts presenting a case study indigenous the Kurdistan region of northern Iraq. The authors demonstrate how a mix of 1D subsidence evaluation of fine data, construction of cross-sections combine a usual structural datum and also vitrinite-reflectance data have the right to be provided to assess the subsidence, uplift and erosion of the region. When considering the uplift history, the prominence of considering the regional context is indicated; as soon as a structural datum native a regional cross-section is employed second 0.9 km of basement-involved uplift is calculated. Significantly, that is argued that this added basement-involved uplift possibly the explanation for unsuccessful hydrocarbon exploration in parts of the region.
When areas of interest room inaccessible the is crucial to utilize different methodologies. Ginés et al. (2019) examine exactly how remote sensing methods can be provided to good effect in areas such as the Zagros Mountains, Iran. Offered the climatic conditions, excellent exposure and ever boosting resolution that satellite imagery, geological attributes exposed in ~ the surface have the right to be evaluate in an excellent detail. By combine optical data, digital elevation models and InSAR data it is feasible to take it structural measurements and also map lithologies and also make predictions because that the subsurface geology. The authors show the interaction between sedimentary cover and also basement structures and how sports in structural format can be observed in the region. Further analysis of longitudinal river profiles was provided to show the existence of basement faults.
It is noticeable from the records in this special Publication the fold and also thrust belts are far from basic structures. Special, pre-orogenic architecture, basement interactions, sedimentation and also mechanical properties of stratigraphy, all play a an important part top top the development of a convergent system. Failure to incorporate these natural variations and complexities when structure structural understanding can lead to significant problems when forecasting the subsurface to construct prospects because that hydrocarbons and also other resources.
Lateral and longitudinal sport in attributes of fold–thrust belts are commonly reported and also need to be extensively assessed, particularly when considering the far-reaching hydrocarbon potential of such regions. With technological advancement there is not just the possibility of collecting new, higher quality data, but additionally to re-examine legacy data. Using scaled physical, numerical and also empirical models can inform our translate of real data yet it is an essential that we perform not depend on any one design or realization together a definitive solution. They type part the a spectrum of feasible solutions. Recognizing diversity is key. Also in this digital period of ‘big data’, good field monitorings and vital interpretation remain essential.
The editors would favor to sincerely thank all those involved with the production of this one-of-a-kind Publication. We are extremely grateful come the many authors that have taken the moment to prepare and present their research study for consists in this volume. Us would also like to give thanks to Jürgen Adam, Patrice Baby, Sabina Bigi, Kyle Bland, Caroline Burberry, Nestor Cardozo, man Cosgrove, Peter DeCelles, Tim Dooley, Oscar Fernandez, Lawrence Gill, Paul Griffiths, Rosalind King, Hemin Koyi, Piotr Krzywiec, Olivier Lacombe, Richard Law, Gianreto Manatschal, Jon Mosar, Paolo Pace, James Rigg, Alberto Riva, Nicola Scarselli, Oliver Schenk, Ian Sharp, Juan I. Soto, Richard Swarbrick, Stefano Tavani, Peter Turner, Robert Wilson, Nigel Woodcock, Jonny Wu and also other anonymous reviewers that have offered generously their time and effort to help shape the papers; the is considerably appreciated. Sincere many thanks are given for the aid and patience provided by Bethan Phillips, Tamzin Anderson and also Samuel Lickiss at the Geological culture of London.
This research received no specific grant from any funding company in the public, commercial, or not-for-profit sectors.
JAH: conceptualization (equal), writing – initial draft (equal); RDC: conceptualization (equal), composing – original draft (equal); MAC: conceptualization (equal), writing – original draft (equal); GZ: conceptualization (equal), writing – initial draft (equal); RWHB: conceptualization (equal), writing – original draft (equal).
See more: Legia Warsaw Vs Real Madrid Vs Legia Warsaw Highlights, Real Madrid Vs Legia Warsaw 5
Data share is no applicable to this short article as no datasets were generated or analysed throughout the present study.