Proceedings of Geofluids V, Fifth International Conference on Fluid Evolution, Migration and Interaction in Sedimentary Basins and Orogenic Belts, Windsor, Ontario, Canada, May 16th–21st, 2006

2006 ◽  
Vol 89 (1-3) ◽  
pp. xiii-xiv
Author(s):  
I.M. Samson ◽  
M.T. Cioppa ◽  
D.T.A. Symons
2021 ◽  
Author(s):  
Juliana Silva ◽  
Jurandyr Ross ◽  
Grace Alves ◽  
Fábio de Oliveira ◽  
Marcos Antonio Nascimento ◽  
...  

<p>Research related to the assessment of Geodiversity is highly relevant both at the international and national levels, especially in the last 20 years. These researches aim at valuing abiotic aspects as inseparable components of natural heritage and, thus, as well as Biodiversity, must be understood and valued through the ordering of their use and Geoconservation. Geodiversity studies are developed on the basis of several approaches, from the broadest ones, which contemplate the measurement of abiotic elements in a full way, to those that assess Geoheritage through the values ​​of Geodiversity. The present research follows the broader approach of the evaluation and analysis of the entire Geodiversity, applying the measurement of abiotic elements without their valuation, with the purpose of the spatialization of areas with greater and lesser density of the selected elements related in this research to lithology, relief and soil. For this purpose, bases produced by systematic surveys of national research institutions such as the Brazilian Institute of Geography and Statistics (IBGE) and the Geological Survey of Brazil (CPRM) were used. As a result, the mapping of the subindexes was obtained pointing from the division into 5 classes, the areas that present greater and lesser diversity of each element, as well as the synthesis map for the indexes of Geodiversity elements in Brazil, considering the three elements selected for this mapping. A spatial analysis was also carried out between the Geodiversity Index Map and the Brazilian Conservation Units, as well as the areas where Geopark Projects are being developed. The majority of the Brazilian territory presents low Geodiversity index (32%), followed by medium (28%), very low (17%), high (15%) and very high (8%). The higher indexes are found in ancient Orogenic Belts, associated with Crystalline Basement that shows broad variation of rocks, in some cases linked with soil and relief elements. Areas of medium diversity are concentrated in Cratons and Sedimentary Basins borders, and low diversity areas are found in the central regions of large Sedimentary Basins, as well as in the Pantanal Floodplain. The Conservation Units present the following percentage of Geodiversity index: very high: 12%; high:10%; medium 16%; low: 23%; very low 22%. The analysis was done taking into account the categories of Conservation Units as well, and the higher indexes were found in Natural Monuments and Wildlife Refuges (38 and 43% respectively). 8 geopark projects have predominance of very high and high Geodiversity indexes; 7 presents medium index and only one amongst the 16 presents predominance of low index. No geopark project has very low index predominant in territory. The analysis of the spatialization of the indexes was carried out from a descriptive and genetic perspective, aiming at clarifying the causes of the distribution of the abiotic elements in the Brazilian territory, being able to provide subindexes for studies in the scope of environmental services, nature and territory conservation planning.</p>


2021 ◽  
Vol 2 (1) ◽  
pp. 25-31
Author(s):  
Mikhail M. Buslov ◽  
Anna V. Kulikova

The stages of the formation of mountain systems (orogens) and sedimentary basins of Asia are highlighted and an analogy is given. The stages are manifested in the Jurassic, Cretaceous, and Cenozoic as a result of collisions to the southern active margin of the Asian continent, respectively, of the Quingtang, North China, and Indian continental blocks, which led to the formation of large intracontinental orogenic belts that are the source of sedimentary basin demolition.


1985 ◽  
Vol 76 (4) ◽  
pp. 451-462 ◽  
Author(s):  
P. F. Friend

ABSTRACTSedimentary basins are structures that formed either by subsidence of an area relative to its surroundings, or by uplift of the surroundings. The basin is defined by its sedimentary fill, and the vertical kinematics of the fill are reflected by stratal wedging, unconformities and, or, faulting. The following basin mechanisms are distinguished: locally (a) stretch, (b) thrust and piggy-back, (c) local uplift, and regionally (d) stretch-and-cool, (e) load-and-flex and (f) cratonic uplift.Basin patterns are reviewed for the three main Phanerozoic episodes for which molasse-like features of sedimentation or tectonics are claimed. Sediment accumulation rates are used as an index of the vigour of basinal activity.Within the area of the Caledonian orogen, Devonian basinal activity was locally very rigorous, some of it being late orogenic and some post-orogenic, and mostly apparently of ‘stretch-type’. The orogenic area stood high, relative to sea level, throughout Devonian times, but outside the orogenic area, the basins were less vigorous and marine.Within the area of the Hercynian orogen, and outside it, Permian basins were generally not so active, apparently reflecting a different style of orogenesis. However, the whole area was standing high, relative to sea level. The Triassic basins, though post-orogenic, were rather more vigorous, although a marine transgression records the general lowering of the continental surface. Major evaporites accumulated in these settings.In Cenozoic times, the narrow orogenic belts formed the most active basins, and these were of load-and-flex type, reflecting the importance of thrust-sheet movement, itself perhaps a result of the presence of Triassic evaporites. Other non-orogenic basins reflect both ‘stretch’ and ‘stretch-and-cool’ mechanisms. Only the Spanish basins appear to have been standing high, relative to sea level, perhaps in response to cratonic uplift.


2021 ◽  
Vol 225 (2) ◽  
pp. 998-1019
Author(s):  
Xiao Xiao ◽  
Shihua Cheng ◽  
Jianping Wu ◽  
Weilai Wang ◽  
Li Sun ◽  
...  

SUMMARY We construct a high-resolution shallow 3-D seismic model in the top 10 km of the upper crust in the continental China, with constraints of P polarization, Rayleigh wave ellipticity and receiver function obtained from records of 3848 seismic stations. Our 3-D seismic model has a spatial resolution of 0.6–1.2° in the north–south seismic belt and the trans-north China orogen, and 1–2° in the rest of the continental China (except the Tarim basin and the southwest Tibet). The seismic model exhibits low velocity anomalies of deposits in major sedimentary basins and high velocity anomalies of crustal bedrocks in young orogenic belts and old tectonic blocks. The inferred sediment thickness maps display thick deposits in major sedimentary basins, some compacted sediments in the intermontane basins in young orogenic belts and little sediments in old tectonic blocks. We also discuss compaction effects of the sediments and implications of tectonic history and geological evolution of the major basins in the continental China based on the inferred seismic models. This study provides an effective mean of seismic imaging through joint inversion of various seismic constraints and establishes a framework of seismic data sharing for future studies in the seismological community in a first step of developing a China Seismological Reference Model.


Author(s):  
Xiang Ge ◽  
Chuanbo Shen ◽  
Renjie Zhou ◽  
Peng He ◽  
Jianxin Zhao ◽  
...  

Fluid migration in sedimentary basins enable mass and energy transport and play critical roles in geochemical and geodynamical evolution of sedimentary basins. Moreover, reconstructing sedimentary basin fluid evolution from the geological record aids in constraining the evolution of associated petroleum and mineralization systems. As a relict of fluid flow activity, calcite is often a record of fluid flow and therefore can be used to characterize the fluids responsible for its precipitation. Here we study the Nanpanjiang Basin in South China where petroleum reservoirs and Carlin-type gold deposits spatially coincide. Through in situ U-Pb dating and geochemical analysis (87Sr/86Sr, δ18OVienna standard mean ocean water, δ13CVienna Peedee belemnite, rare earth elements) of calcite, this work constrains the key times related to petroleum migration/accumulation and Carlin-type gold mineralization, defines the basin fluid evolution, and proposes a genetic model for petroleum accumulation and gold mineralization within the Nanpanjiang Basin. The U-Pb age (ca. 241.4 Ma) for the gray/black calcite related to bitumen indicates the petroleum migration/accumulation occurred during the Triassic. The U-Pb date (ca. 106−121 Ma) of the white calcite associated with the gold-bearing pyrite, realgar, and fluorite record the lower timing limit of the Carlin-type gold systems. The geochemical data suggest both calcite types are cogenetic but suffered complex evolution with the gray/black calcite precipitating under low temperatures related to the continuous basin burial and the white calcite affected by post formation alteration related to both hydrothermal and meteoric fluids. Combined with the regional tectonic history, the Early Triassic petroleum migration/accumulation and the Early Cretaceous secondary Carlin-type gold mineralization events are considered to be related to the collision between the Indo-China and South China blocks, and the subduction between the Paleo-Pacific and Eurasian plates, respectively.


Geology ◽  
2005 ◽  
Vol 33 (8) ◽  
pp. 673-676 ◽  
Author(s):  
Sandra McLaren ◽  
Mike Sandiford ◽  
Roger Powell

Abstract Proterozoic terranes in Australia record complex tectonic histories in the interval 1900– 1400 Ma that have previously been interpreted by means of simple intracratonic or plate-tectonic models. However, these models do not fully account for (1) repeated tectonic reactivation (both orogenesis and rifting), (2) mainly high-temperature–low-pressure metamorphism, (3) rifting and sag creating thick sedimentary basins, (4) the nature and timing of voluminous felsic magmatism, (5) relatively large aspect ratio orogenic belts, and (6) a general paucity of diagnostic plate-boundary features. A key to understanding these histories is the observation that Australian Proterozoic terranes are characterized by an extraordinary, but heterogeneous, enrichment of the heat-producing elements. This enrichment must contribute to long-term lithospheric weakening, and thus we advocate a hybrid lithospheric evolution model with two tectonic switches: plate-boundary–derived stresses and heat-producing-element–related lithospheric weakening. The Australian Proterozoic crustal growth record is therefore a function of the magnitude of these stresses, the way in which the heat-producing elements are distributed, and how both of these change with time.


Author(s):  
Lars Stemmerik

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Stemmerik, L. (2000). Palynology and deposition in the Wandel Sea Basin, eastern North Greenland. Geology of Greenland Survey Bulletin, 187, 1-6. https://doi.org/10.34194/ggub.v187.5191 _______________ This collection of papers adds to the understanding of the stratigraphic, depositional and structural history of the Wandel Sea Basin in eastern North Greenland (Fig. 1). Most importantly, the ages of the initial (Carboniferous) and final (Palaeogene) depositional events are now much better constrained than previously, allowing correlation with the successions in East Greenland, Svalbard and the Barents Sea. The Wandel Sea Basin was an area of accumulation through the Early Carboniferous to the Palaeogene period, located at the margins of the stable Greenland craton where the Caledonian and Ellesmerian orogenic belts intersect (Fig. 1). Two main epochs of basin evolution have been recognised during previous studies of the basin fill: a Late Palaeozoic – Early Triassic epoch characterised by a fairly simple system of grabens and half-grabens, and a Mesozoic epoch dominated by strike-slip movements (Håkansson & Stemmerik 1989). The Mesozoic epoch only influenced that part of the basin north of the Trolle Land fault zone and its eastward extension (Fig. 1). Thus the northern and southern parts of the basin have very different structural and depositional histories, and accordingly different thermal histories and hydrocarbon potential as exemplified by the tectono-stratigraphic study of northern Amdrup Land by Stemmerik et al. (2000, this volume). This study shows that the Sommerterrasserne fault is the south-eastern extension of the Trolle Land fault zone, dividing Amdrup Land into two areas with different stratigraphic and structural histories. Sediments of the Upper Permian Midnatfjeld Formation are restricted to north-east of the Sommerterrasserne fault where they are conformably overlain by Upper Jurassic sediments. In this area the Carboniferous – Upper Jurassic succession is folded in broad domal folds with NE–SW-oriented axes, whereas the Upper Palaeozoic sediments are gently dipping south-west of the fault. Folding most likely took place during the latest Cretaceous correlating with compressional events that also affected the sedimentary basins at Kilen and Prinsesse Ingeborg Halvø further to the north in the Trolle Land fault zone.


2000 ◽  
Vol 12 (3-4) ◽  
pp. 219-226 ◽  
Author(s):  
P. Bellingham ◽  
N. White

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