Arctic fold-and-thrust belts

The origin and evolution of sedimentary basin could be a clue for oil-gas deposits forecasting. For simulation of the basin evolution and pressure and heat flow density distribution the thermomechanical modelling was used. Data on vitrinite reflectance were used as a geot-hermometer for paleothermal reconstruction of the sedimentary basin. Thermomechanical modelling together with field investigations and wells data gives the possibility to research the geothermal field changing during the sedimentary basin evolution. All geological, geophysical and petrological data were used for sedimentary basins evolution modelling. Different sedimentological models were used for analysing of sedimentary cover formation and evolution. For simulation of sedimentary basins formation and evolution the hierarchical mechanical-mathematical multi-layer models of high-vis cous fluid were used.

Summary Deformation in the Campeche area of the southern Gulf of Mexico Basin was caused by tectonic events along the plate boundary between the Cocos and North American plates. The deformation history of prospects and timing of hydrocarbon migration can be understood in the context of these events in the deep water of Campeche. Multiple phases of deformation have led to the formation of fold and thrust belt structures with different styles and varying degrees of complexity. Throughout the Tertiary, subduction of the Cocos plate underneath the North American plate, translation of the Chortis block, and indentation of the Chiapas terrane have generated distinct orogenic pulses. Two main uplift phases are associated with thin- and thick-skinned contractional deformation. These events have caused nearly perpendicular structural fabric orientations in the deepwater area of the Campeche Basin. The northern and western area of the Basin is dominated by NE-SW structures while the eastern area is dominated by NW-SE trending structures. In addition, the presence of salt in the basin has helped to control fault and fold geometries. Onshore uplift caused by subduction of the Cocos plate together with the thermal subsidence of the Gulf of Mexico, has resulted in an overall NW tilting of the Campeche margin. This has led to the development of a large gravity slide with up-dip extension and down-dip contraction, and to shelf instability on the proximal part of the margin (in shallow water). Large-scale extensional faulting which occurs up-dip is linked to a well-developed, down-dip deep water fold and thrust belt (Catemaco FB) that is oriented NE-SW. However, the onshore Chiapanecan orogeny also caused regional contraction and not all of the outboard contraction is accommodated by the extensional basins. Gravity sliding occurs above a single extensive regional ductile detachment layer in most of the Campeche area (Louann salt), but in some areas gravity sliding has occurred along multiple, complex detachment layers. Contractional structures in Blocks 1 and 3 show several styles that are detaching along different stratigraphic units (ductile shales or salt). These weak detachment units have different spatial distributions and partly controlled the structural style. A change in accumulated strain along the length of the Catemaco FB is thought to be due to a change in the length (i.e. areal extent) of the Louann salt detachment layer. A high degree of accumulated strain is observed in the area of shorter length of the basal detachment level and is characterized by complex structure styles and subsequent hydrocarbon migration uncertainties. The structural complexity and deformation history in deep water Campeche and in Blocks 1 and 3 influenced trap formation as well as hydrocarbon generation timing and migration and therefore play a crucial role in the general hydrocarbon prospectivity of the basin.

Research Article| September 01, 1974 Continental Breakup and the Development of Post-Paleozoic Sedimentary Basins around Southern Africa R. V. DINGLE; R. V. DINGLE 1Department of Geology, Marischal College, Aberdeen, Scotland Search for other works by this author on: GSW Google Scholar R. A. SCRUTTON R. A. SCRUTTON 2Grant Institute of Geology, The University, Edinburgh, Scotland Search for other works by this author on: GSW Google Scholar GSA Bulletin (1974) 85 (9): 1467–1474. https://doi.org/10.1130/0016-7606(1974)85<1467:CBATDO>2.0.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation R. V. DINGLE, R. A. SCRUTTON; Continental Breakup and the Development of Post-Paleozoic Sedimentary Basins around Southern Africa. GSA Bulletin 1974;; 85 (9): 1467–1474. doi: https://doi.org/10.1130/0016-7606(1974)85<1467:CBATDO>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Since Paleozoic time, the development of sedimentary basins on the continental margin of southern Africa has been controlled by the structures formed during the breakup of Gondwanaland. In Mozambique, the earliest rift (∼180 m.y. B.P.), between East and West Gondwana, produced a north-south–trending series of large horsts and grabens which were buried beneath detritus from the Limpopo and Zambezi river systems. Oceanward sediment dispersion was controlled by the Mozambique Ridge. This stage of continental breakup coincided with the establishment of marine conditions in the older, epicontinental basins which lay over the present-day Agulhas Bank and off the Transkei and Natal coasts (Outeniqua, St. Johns, and Durban basins).When West Gondwana broke up (125 to 130 m.y. B.P.), a large sediment wedge (Orange Basin) was initiated on the west coast of southern Africa by discharge from the Orange River and associated rivers onto a downfaulted, tensional-formed margin. At the same time, a large transform fault (Agulhas fracture zone) truncated the Outeniqua to Durban Basins as the Falkland Plateau separated from south and east Africa. These movements resulted in the formation of new ocean basins and the enlargement of older adjacent ones.Subsequent major sea-level movements are attributable to epeirogenic/eustatic events which are possibly related to variations in world-wide ocean-ridge spreading rates. Most variations in sediment accumulation rates are related to the distribution of marginal traps rather than differences in detrital discharge rates from the major river systems. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

The vast Eurasian Arctic epicontinental shelf and adjoining mainland has a very complex structure and tectonic history as a result of a series of continent–continent collisions, accretion of terranes and crustal extension phases during Neoproterozoic and Phanerozoic times. Significant parts of major Eurasian fold belts extend far north into the Arctic below thick infill of post-orogenic sedimentary basins, where their architecture remains highly disputed. Large Eurasian Arctic sedimentary basins formed as a result of orogenic collapse, back-arc extension, or intracontinental extension associated with the breakup of the Laurussia, Laurasia, Pangea and Eurasia supercontinents. There are over 40 sedimentary basins of variable age and genesis which are thought to bear significant undiscovered hydrocarbon resources in the region. This article reviews the current state-of-knowledge of Eurasian Arctic tectonics and highlights questions that remain to be addressed. The overall focus is on the Russian sector of the Arctic being less known to a broad geoscience community.

Tectonic evolution of early Mesozoic sedimentary basins in the North China block

The integrated understanding of processes and mechanisms driving the coupled evolution of orogens and sedimentary basins and the underlying lithosphere-mantle system, requires a multi-scale temporal and spatial approach that crosses the traditional boundaries of disciplines and methodologies. While analysing the sedimentary infill we need to account for the characteristics and variations of the exhumation, evolving topography and external forcing in the source area, and the complexity of a transport system that is often characterized by a massive unidirectional sediment influx during moments of activity at tipping points or gateways. Such an influx can often span across multiple depocenters and sedimentary basins and is conditioned by an evolving structural geometry that can migrate in time, directly related to the evolving lithospheric structure in orogens that are influenced by their inherited rheology. Depocenters can be fed from multiple directions, while having an endemic or endorheic character during key evolutionary moments. The thermal structure and its variability in continental and oceanic domains conditions the rheology and subsequent structural evolution of the orogens, subduction zones and sedimentary basins, with significant consequences for understanding societally relevant issues. Quantifying basin deposition requires analysing the sediment transport network that can often span multiple interacting orogenic and sedimentary systems, where understanding the allogenic or autogenic nature of sedimentary processes can be significantly enhanced by knowing the inherited and evolving structural and tectonic parameters. Such sedimentary quantification is important for understanding the orogenic structure and the evolution of subduction systems, that include mechanisms such as cycles of burial-exhumation, formation of highly arcuate orogens and timings of nappe stacking events. Deriving processes in orogen - sedimentary basins systems also requires testing process-oriented hypotheses by focused studies in well-known natural laboratories, such as the examples from the Pannonian-Carpathians - Alps - Dinarides system and its analogues used by the numerous contributions in the special Global and Planetary Change issue entitled Understanding the multi-scale and coupled evolution of orogens, sedimentary basins and their underlying lithosphere , whose significance is explained in our review. • Integrated understanding of processes and mechanisms driving the coupled evolution of orogens and sedimentary basins. • Quantifying deposition requires analysing sediment transport across multiple interacting orogenic and sedimentary basins. • Quantifying sedimentary basins is important for understanding the orogenic structure and the evolution of subduction systems. • Testing process-oriented hypotheses in well-known natural laboratories, such the Pannonian - Carpathians - Alps - Dinarides.

Metallogeny and tectonic development of the Tasman Fold Belt System in Queensland

Fold-and-thrust belts are hot topics in the research of orogens. However, the single geological or geophysical discipline often provides multisolutions on the geometry of a fold-and-thrust belt. We introduce here a multidisciplinary method combining geological and geophysical methods, take the Hutubi River section as a case to study the geometry of the fold-and-thrust belt in the northern piedmont of Tianshan. Firstly, we have carefully taken geological survey and got structural data on the surface. Secondly, petroleum seismic profile was re-interpreted based on the surface data and drilled wells. However, the seismic profile is absent in the contact zone between the mountain and the Junggar basin. We therefore carried out gravity measurements and forward modeling along this profile with the densities of the basement and sediments. The result shows that the northern flank fault of Tianshan doesn't exist along the Hutubi River profile, and the basin sediments could be continually followed from the basin to the mountain interior. This indicates that the tectonic structures in the contact zones between the mountain and the basin are variable, as the western section in the Jingou River section shows that the Tianshan basement thrusts northward on the basin sediments. Based on the balance-section technology, the restored section shows 4. 8 km of shortening. Comparing with previous results, this indicates the heterogeneous deformation along the northern piedmont of Tianshan. It also implies that this multidisciplinary method could be widely used in the fold-and-thrust belt.

The Northern Apennines (NA) is a NE-verging thrust and fold belt (Fig. 1) produced by the Cenozoic collision between the Corso-Sardinian block and the Adria Plate (Boccaletti and Guazzone, 1972; 1974; Principi and Treves, 1984; Malinverno and Ryan, 1986, among others). The NA thrust-nappe pile consists of sequences deposited on the Adria Plate continental margin (Tuscan and Umbria-Marche Units) which were overthrust by the Ligurian Units during continental collision. The Ligurian Units, which consist of ophiolites and their sedimentary covers, represent the remnants of the Ligurian-Piedmont paleo-ocean (Abbate et al., 1970). The NA evolution, after the Oligocene continental collisional phase, has been referred to two different models. In the first one, the development of an external thrust belt shifting eastwards, coupled with an internal extensional area is envisaged. In this process both the crust and the lithosphere would be involved (Merla, 1951; Boccaletti and Guazzone, 1974; Elter et al., 1975; Carmignani et al., 1980; Boccaletti et al., 1990; Patacca et al., 1990). In front of the migrating chain a foredeep basin developed during Late Oligocene-Miocene, whose deposits were progressively annexed to the chain (Ricci Lucchi, 1986; Boccaletti et al., 1990). In the second model, the accretionary prism, thickened by crustal collision, would collapse to recover its equilibrium conditions (Carmignani and Kligfield, 1990). As a consequence of the gravitational collapse, the development of core complex structures and of extensional tectonics has taken place since Burdigalian-Langhian (Carmignani et al., 1994). In this model, the Northern Apennines thrust belt is explained as due to gravitational tectonics active since the Early Miocene (Decandia et al., 1993; Carmignani et al., 1995). Starting in late Tortonian, the internal area (hinterland) of NA was characterized by the development of continental and marine basins, mostly striking from NW-SE to N-S, and subparallel to the main thrust fronts of the chain. Their formation has been commonly referred to the extensional processes related to the opening of the Tyrrhenian Basin, either in a back-arc regime (Boccaletti and Guazzone, 1972; 1974; Malinverno and Ryan, 1986; Royden et al., 1987; Boccaletti et al., 1990; Patacca et al., 1990), or as due to late orogenic gravity collapse (Carmignani and Kligfield, 1990; Cameli et al., 1993; Carmignani et al., 1994; Keller et al., 1994). The eastward younging trend of the hinterland basins has been related to the eastward shifting of the extensional front, which followed the migration of the thrust front (Merla 1951; Elter et al., 1975). However, in the last two decades structural studies have shown that the deposits of the hinterland basins have been affected by widespread compressional deformations and by major angular unconformities (Boccaletti et al., 1995, and references therein) that allow to subdivide the entire succession into five Unconformity Bounded Stratigraphic Units (UBSUs, Salvador, 1987).) since the unconformities that limited each UBSU have been correlated on a regional scale, (Boccaletti et al., 1994; 1995). The deformations affecting the basin fill, their architecture, the presence of regional unconformities strongly suggest that they have mostly developed under a compressional tectonic regime, tied to reactivation of thrust faults affecting the pre-Neogene substrate (Boccaletti et al., 1995; 1997; Bonini and Moratti, 1995; Landi et al., 1995). The objective of this excursion, whose road log is reported in Fig. 2, is to illustrate the relationships between tectonics and sedimentation in the hinterland basins along a transect across Southern Tuscany including the Baccinello-Cinigiano, Velona and Siena-Radicofani Basins. In this area, basin development has been mainly related to the activity of two crustal thrusts: the Mid-Tuscany Metamorphic Ridge and the Cetona Mountain thrusts (Fig. 3).

Much of the North American Cordillera is a tectonic collage of allochthonous crustal fragments accreted to the western margin of the craton from middle Paleozoic time onward. This End_Page 2467------------------------------ feature is obscured by the three, major, through-going, late Mesozoic-early Tertiary elements of the Cordillera, namely (1) the eastern fold and thrust belt, formed largely from the displaced Proterozoic to Jurassic sedimentary prism (or miogeocline) that once fringed the craton, (2) the western accretionary prisms or subduction complexes, and (3) extensive granitic rocks. These impose a superficial simplicity on this 8,000-km-long fold belt. Its intrinsic complexity is reflected by the segmented nature of the Cordillera. The Alaskan-western Yukon, Canadian-northwestern United States, California-Coloradan, and Mexican segments each have distinctive geologic characteristics different from those of adjoining segments. In part, these differences are due to features formed late in Cordilleran history, such as pervasive, dextral strike-slip faults in Alaska and Canada, and rotations and extensions in the conterminous United States. Other, far more fundamental, differences emerge from stratigraphic analysis of rocks west of the fold and thrust belt. The western rocks can be divided into more than 40 terranes, each with distinctive laterally persistent stratigraphy which is different from those of neighboring terranes, and each is commonly separated from neighboring terranes by major faults. Each terrane consists of one or more tectonostratigraphic assemblages, interpreted mainly as deposits of volcanic arcs and ocean basins but including some rocks of probable continental origin. In addition, many terranes have paleontologic and paleomagnetic records different from those of coeval, colatitudinal deposits on the craton, so that the western Cordillera is interpreted as a collage of small crustal fragments accreted in different ways and times to the western margin of North America. The Alaska-western Yukon segment is largely composed of small terranes, many of southerly derivation, each of which apparently remained a discrete entity until accretion late in Mesozoic time. The Canadian-northwestern United States segment is dominated by two large composite terranes made up of smaller fragments, again mainly derived from the south, that coalesced prior to accretion. The inner terrane accreted to the miogeocline in the Jurassic and the outer to the inner in the Cretaceous. Boundaries of the two composite terranes with one another and the miogeocline coincide with the two metamorphic, granitic, and deformational welts that dominate the Canadian Cordillera. Because the times of development of these welts also are the times of accretion, the welts are interpreted as bei g due largely to collisions of crustal fragments, rather than subduction of oceanic crust with accompanying upper plate magmatism. The California-Coloradan segment reflects successive accretions of small discrete fragments from middle Paleozoic time onward, together with possible removal of terranes, some of which subsequently possibly lodged farther north in the Cordillera. Recent studies in Mexico suggest that it, too, is made up of allochthonous fragments. From the foregoing, it should be obvious that only the most rigorous and detailed geologic studies will enable us to understand the evolution of such a long-lived mountain belt as the Cordillera. This is only to be expected from the rapidly changing, complex patterns of movement known from recent plate movements. End_of_Article - Last_Page 2468------------

Metallogeny and tectonic development of the Tasman Fold Belt System in New South Wales

Tectonic Models for the Evolution of Sedimentary Basins

Evolution of sedimentary basins took place in the Barmer, Jaisalmer and Bikaner regions during K-T (Cretaceous-Tertiary) time in western Rajasthan, India. These intra-cratonic rift basins developed under an extensional tectonic regime from early Jurassic to Tertiary time. Rift evolution resulted in alkaline magmatism at the rift margins. This magmatism is dated at 68.5 Ma and has been considered to be an early phase of Deccan volcanism. Deccan volcanism, sedimentary basin development and the alkaline magmatism of western Rajasthan have thus been considered to be the products of Reunion plume activity. However, sedimentary basin evolution began in western Rajasthan prior to Deccan volcanism and K-T alkaline magmatism. Gondwanaland fragmentation during the Mesozoic caused the development of the rift basins of Gujarat and western Rajasthan. This resulted in the opening of the Jurassic rift system and mildly alkaline magmatism at ca. 120 Ma in western India. This event is pre-K-T and plume activity has not hypothesized for it. Continental fragmentation under an extensional tectonic regime during K-T time resulted in the magmatism and basin tectonism in western Rajasthan. Crustal development during the K-T period in western Rajasthan results from an extensional tectonic regime and is not the manifestation of Reunion plume activity. Key wordsK-T magmatism, mantle plume, western Rajasthan, extensional tectonics, K-T basins

Curvature of fold‐and‐thrust belts (FTBs) is a rather common feature in foreland basins. The problem of how curves in FTBs originate is essential for understanding the propagation of deformation and tectonic history of orogens. In this study, we carried out systematic paleomagnetic studies in the westernmost part of the Qiulitage FTB, southern Tian Shan foreland, where thrusting, strike‐slip fault, and tectonic boundary coexist. Our new results suggest that the study area has been subjected to ~20° clockwise rotations after ~5 Ma. Oroclinal test of the paleomagnetic data across the FTB suggests that oroclinal bending caused by the formation of the curved Qiulitage FTB is the dominate reason for these tectonic rotations. The Kalayuergun dextral strike‐slip transfer fault delimiting the western boundary of the Qiulitage FTB is a thin‐skinned structure accommodating the discrepancy in horizontal displacement on both sides of it. These results also suggest that the formation of the curved Qiulitage FTB should not be older than ~5 Ma, indicating that the southern Tian Shan foreland has experienced significant tectonic shortening since the latest Miocene to early Pliocene. Our new results, together with previous studies on deformation history, estimates of crustal shortening, GPS observations and earthquake records, suggest that the southern Tian Shan foreland has been subjected to significant deformation during the past ~5 million years, and the crustal shortening is still ongoing.

Die Vererzung am Westrand der Böhmischen Masse-Metallogenese in einer ensialischen Orogenzone. (The mineralization on the western margin of the Bohemian Massif — metallogenesis in an ensialic orogenic zone) : H. Dill. Geologisches Jahrbuch, Reihe D, Heft 73, 461 pages, 90 figures, 25 tables, 39 plates. Sold by Schweizerbartsche Verlagsbuchhandlung, Johannesstrasse 3A, D-7000 Stuttgart 1, West Germany. In German; English, French,