Quantification of fluvial-peat interactions in the Pikeville formation Central Appalachian Basin, USA.

2021 ◽  
Author(s):  
Peter Wooldridge ◽  
Robert Duller ◽  
Rhodri Jerrett ◽  
Kyle Straub
Keyword(s):  
Accumulation Rate ◽  
Appalachian Basin ◽  
River Channels ◽  
Channel Depth ◽  
Peat Accumulation ◽  
Floodplain River ◽  
Basin Scale ◽  
Well Data ◽  
Fluvial Architecture ◽  
Sand Bodies

<p>Basin-scale fluvial architecture is, to a large extent, determined by the ability of river systems to migrate and avulse across their own floodplain. River avulsion takes place when a river aggrades by one channel depth to achieve super-elevation above the surrounding floodplain. However, peat enhancement of floodplain aggradation is likely to affect this fluvial behaviour and has received little attention. The interaction between river channels and peat-dominated floodplains is likely to have the effect of inhibiting or prolonging the conditions required for river avulsion, and so will impact on basin scale architecture during prolonged peat accumulation on floodplains. To elucidate and quantify the nature of this channel-floodplain interaction we investigate the coal-bearing clastic interval of the Carboniferous Pikeville Formation, Central Appalachian Basin, USA. Using a combination of well data and outcrop data, two coal horizons and intervening sand bodies, were mapped across an area of 5700 km<sup>2</sup> to ascertain overall basin-scale architecture. Comparison of the accumulation rate of the coal units (corrected for decompaction) with the synchronously deposited sand bodies suggests that extensive and rapid peat accumulation can increase avulsion timescales by 3 orders of magnitude and dramatically alter basin-scale fluvial architecture.</p>

High-Resolution Age-Depth Model of a Peat Bog in Poland as an Important Basis for Paleoenvironmental Studies

Radiocarbon ◽  
2014 ◽  
Vol 56 (1) ◽  
pp. 109-125 ◽  
Author(s):  
B Fiałkiewicz-Kozieł ◽  
P Kołaczek ◽  
N Piotrowska ◽  
A Michczyński ◽  
E Łokas ◽  
...  
Keyword(s):  
High Resolution ◽  
Industrial Revolution ◽  
Climatic Factors ◽  
Accumulation Rate ◽  
Bulk Composition ◽  
Water Level Fluctuations ◽  
Peat Bog ◽  
Agricultural Activity ◽  
Peat Accumulation ◽  
Peat Formation

This article focuses on constructing a high-resolution age-depth model for the Puścizna Mała peat bog located in Orawa-Nowy Targ Basin (S Poland). The chronology was established on the basis of both210Pb and14C measurements, and further confirmed by pollen diagrams and the peat bulk composition (density, ash content, and measurements of C, N, S). The137Cs profile revealed significant downward migration of this radionuclide and was not suitable for geochronological interpretation. The peat profile in southern Poland records almost 2000 yr of paleoecological and geochemical changes. Major historical events linked to anthropogenic and climatic changes are recorded in the investigated proxies, which confirm the reliability of the age-depth model. Specifically, the Roman period, Migration period, Medieval times, as well as the Industrial Revolution are reflected in the palynology and bulk composition of the peat. However, dating results obtained for the core segment between 22–45 cm are problematic when confronted with other analyses. The highest peat accumulation rate of 2 mm yr-1(AD 1300–1400 according to the age-depth model) is not compatible with the section of the highest peat decomposition revealed by lithological description. Moreover, the onset of a drastic decline of forests reflected in the palynological data and dated to AD 1280–1340 (40 cm) is difficult to explain in the light of historical data. Therefore, the lithology, bulk density, and pollen were used to validate the obtained age-depth model. External forcing factors on the peat formation process may be indicated, including agricultural activity, water-level fluctuations, and natural climatic factors, which paradoxically caused doubling of the obtained peat accumulation rate.

The Application of Facies Modeling Combination of Well Data and Seismic Data in G25-12 Block

2015 ◽  
Vol 733 ◽  
pp. 92-95
Author(s):  
Jia Hui Wang ◽  
Hong Sheng Lv
Keyword(s):  
Sedimentary Facies ◽  
Distribution Law ◽  
Skeleton Model ◽  
Facies Model ◽  
Body Distribution ◽  
Sand Body ◽  
Geological Conditions ◽  
Single Well ◽  
Well Data ◽  
Sand Bodies

The main purpose of lithofacies modeling is to get the actual reservoir lithofacies skeleton model which is maximum approximation of the underground reservoir. The facies model can effectively solve the problem of predicting sand bodies between wells. At the same time, we still use the stochastic modeling method to build the facies model of unconstrained single well simulation and sedimentary facies controlled constrained simulation. We elected the model which is most consistent to the actual geological conditions, providing theoretical guidance for characterizing the interwell sand body distribution law and improving the accuracy of predicting sand bodies between wells, laiding the foundation for further exploration and development of oil reservoir.

scholarly journals Stratigraphic Architecture of the Karoo River Channels at the End-Capitanian

2021 ◽  
Vol 8 ◽  
Author(s):  
Emese M. Bordy ◽  
Francisco Paiva
Keyword(s):  
Environmental Drivers ◽  
River Channels ◽  
Fold Belt ◽  
Karoo Basin ◽  
Architectural Elements ◽  
Stratigraphic Architecture ◽  
Cape Fold Belt ◽  
Biotic Change ◽  
Extinction Events ◽  
Fluvial Architecture

The main Karoo Basin of southern Africa contains the continental record of the end-Triassic, end-Permian, and end-Capitanian mass extinction events. Of these, the environmental drivers of the end-Capitanian are least known. Integrating quantitative stratigraphic architecture analysis from abundant outcrop profiles, paleocurrent measurements, and petrography, this study investigates the stratigraphic interval that records the end-Capitanian extinction event in the southwestern and southern main Karoo Basin and demonstrates that this biotic change coincided with a subtle variation in the stratigraphic architectural style ∼260 Ma ago. Our multi-proxy sedimentological work not only defines the depositional setting of the succession as a megafan system that drained the foothills of the Cape Fold Belt, but also attempts to differentiate the tectonic and climatic controls on the fluvial architecture of this paleontologically important Permian succession. Our results reveal limited changes in sediment sources, paleocurrents, sandstone body geometries, and possibly a constant hot, semi-arid paleoclimate during the deposition of the studied interval; however, the stratigraphic trends show upward increase in 1) laterally accreted, sandy architectural elements and 2) architectural elements that build a portion of the floodplain deposits. We consider this to reflect a long-term retrogradational stacking pattern of facies composition that can be linked to changes on the medial parts of southward draining megafans, where channel sinuosity increased, and depositional energy decreased at the end-Capitanian. The shift in the fluvial architecture was likely triggered by basin-wide allogenic controls rather than local autogenic processes because this trend is observed in the coeval stratigraphic intervals from geographically disparate areas in the southwestern and southern main Karoo Basin. Consequently, we propose that this regional backstepping most likely resulted from tectonic events in the adjacent Cape Fold Belt.

scholarly journals Characterization of peat deposit using ground penetrating radar: Survey experiments and data interpretation

2021 ◽  
Vol 928 (1) ◽  
pp. 012011
Author(s):  
A A Sinyutkina
Keyword(s):  
Accumulation Rate ◽  
Spatial Differentiation ◽  
Data Interpretation ◽  
Peat Deposit ◽  
Swamp Forest ◽  
Peat Accumulation ◽  
Raised Bogs ◽  
Peat Deposits ◽  
Zone Of Influence ◽  
Ground Penetrating

Abstract The paper deals with the possibilities of different wave frequency antennae applications for estimation of the depth of peat deposits and detection of peat layers with different physical characteristics. We employed a GPR system “OKO-2” (“Logical systems”, Russia) with 250 MHz, 700 MHz, and 1700 MHz shielded antennae. The surveys were conducted in 2017–2019 within the pristine and drained raised bogs and swamp forest in the south taiga subzone of Western Siberia to assess the spatial differentiation of the peat deposit and the modern peat accumulation rate within drained bogs. The peculiarities of field surveying, GPR data processing and interpretation are shown. Based on GPR data analysis the influence zone of Bakchar bog and modern peat accumulation within drained bogs were assessed. We noted that the Bakchar bog has a vast zone of influence reaching 700 m from the bog border where peat accumulation is observed. The modern peat accumulation is observed within Bakchar the bog. Drained sites of Ust-Bakchar bog are characterised by the absent peat accumulation or degradation of the peat deposits.

USING RADIOGENIC NOBLE GASES TO EVALUATE BASIN SCALE CRUSTAL FLUID MIGRATION OF THE APPALACHIAN BASIN

2018 ◽  
Author(s):  
Brent A. Lary ◽  
◽  
Benjamin S. Grove ◽  
Benjamin S. Grove ◽  
Thomas H. Darrah ◽  
...  
Keyword(s):  
Noble Gases ◽  
Appalachian Basin ◽  
Fluid Migration ◽  
Crustal Fluid ◽  
Basin Scale

A systematic, science-driven approach for predicting subsurface properties

2020 ◽  
Vol 8 (1) ◽  
pp. T167-T181
Author(s):  
Kelly Kathleen Rose ◽  
Jennifer R. Bauer ◽  
MacKenzie Mark-Moser
Keyword(s):  
Language Processing ◽  
A Priori ◽  
Basin Scale ◽  
Porosity And Permeability ◽  
Priori Information ◽  
Efficient Exploration ◽  
Well Data ◽  
Ideal Framework ◽  
Discontinuous Data

As human exploration of the subsurface increases, there is a need for better data- and knowledge-driven methods to improve prediction of subsurface properties. Present subsurface predictions often rely upon disparate and limited a priori information. Even regions with concentrated subsurface exploration still face uncertainties that can obstruct safe and efficient exploration of the subsurface. Uncertainty may be reduced, even for areas with little or no subsurface measurements, using methodical, science-driven geologic knowledge and data. We have developed a hybrid spatiotemporal statistical-geologic approach, subsurface trend analysis (STA), that provides improved understanding of subsurface systems. The STA method assumes that the present-day subsurface is not random, but is a product of its history, which is a sum of its systematic processes. With even limited data and geologic knowledge, the STA method can be used to methodically improve prediction of subsurface properties. To demonstrate and validate the improved prediction potential of the STA method, it was applied in an analysis of the northern Gulf of Mexico. This evaluation was prepared using only existing, publicly available well data and geologic literature. Using the STA method, this information was used to predict subsurface trends for in situ pressure, in situ temperature, porosity, and permeability. The results of this STA-based analysis were validated against new reservoir data. STA-driven results were also contrasted with previous studies. Both indicated that STA predictions were an improvement over other methods. Overall, STA results can provide critical information to evaluate and reduce risks, identify and improve areas of scarce or discontinuous data, and provide inputs for multiscale modeling efforts, from reservoir scale to basin scale. Thereby, the STA method offers an ideal framework for guiding future science-based machine learning and natural language processing to optimize subsurface analyses and predictions.

Paleohydraulic investigation of the Ebro Basin: Implications for Mars

2021 ◽  
Author(s):  
Heath Geil-Haggerty
Keyword(s):  
Water Discharge ◽  
Sedimentary Basins ◽  
Mass Conservation ◽  
Sediment Supply ◽  
Sediment Flux ◽  
River Channels ◽  
Ebro Basin ◽  
Fluvial Systems ◽  
Sediment Size ◽  
Basin Scale

<p>The stratigraphy preserved in Earth’s sedimentary basins offers a record of how landscapes have evolved with time.  This stratigraphy provides insights into the dynamic processes that shaped the surface of the earth.  Fluvial stratigraphy contains many elements that can be used to recreate past conditions in ancient river channels.  Paleohydraulic reconstruction uses measurements of fluvial stratigraphy to model the conditions in the system that created them.  This allows us to answer questions related to water discharge, sediment flux, and duration of fluvial activity.  These are key questions when investigated in the context of Mars.  Paleohydraulic models can be used as compelling analogs for similar systems on Earth as well as Mars and other rocky planets.           </p><p>This study examines what the record of Oligocene-Miocene fluvial stratigraphy in northeastern Spain’s Ebro Basin can tell us about water discharge and sediment flux across distributive fluvial systems at a basin scale.  The Cenozoic stratigraphy of northeastern Spain’s triangular shaped Ebro Basin embodies a classic example of the formation of a closed sedimentary basin.  The Ebro Basin contains a number of remarkably well exposed fluvial sedimentary deposits.  These deposits outcrop as distinctive laterally contiguous channel sand bodies.  Clastic sediment supply in the Ebro Basin is largely governed by tectonic uplift and basin subsidence related to the Pyrenean orogen with peripheral contributions from the Catalan Coast and Iberian Ranges.  We test the idea that the record of conditions in the fluvial systems should reflect the record of lacustrine chemical sediments through sediment mass conservation.  In order to test this hypothesis measurements of bedform height, barform height, sediment size, and paleochannel dimensions were collected in the field.  Our paleohydraulic model uses previously derived theoretical and empirical relationships to recreate the conditions in these ancient fluvial systems.  These results are scaled up by accounting for drainage density and intermittency in order to address the principal question at a basin scale.  Paleodischarges from the fluvial sediments are comparable to those from river chemistry calculations for the lacustrine facies. </p>

FLUVIAL ARCHITECTURE AND THE TECTONIC CONTROL ON DEPOSITION OF ONSHORE EUMERALLA FORMATION, OTWAY RANGES, VICTORIA: IMPLICATIONS FOR EXPLORATION IN THE EARLY CRETACEOUS OTWAY BASIN

2003 ◽  
Vol 43 (1) ◽  
pp. 99 ◽  
Author(s):  
C.A. Noll ◽  
M. Hall
Keyword(s):  
Hanging Wall ◽  
Normal Faults ◽  
River Channels ◽  
Fluvial System ◽  
Reservoir Properties ◽  
Local Study ◽  
Architectural Analysis ◽  
Drainage Patterns ◽  
Potential Source Rock ◽  
Fluvial Architecture

Spectacular outcrops of the terrestrial Aptian-Albian Eumeralla Formation are exposed in the Skenes Creek– Wongarra region, located on the eastern margin of the Otway Ranges, Victoria. The succession comprises mudstone-dominated floodplain and lacustrine successions and fluvially-derived sandstones. Lithofacies observed in the study area comprise intraformational and exotically derived conglomerate, massive and planar laminated sandstone, trough and tabular cross-bedded sandstone, ripple laminated sandstone, interbedded sandstone and mudstone, massive to laminated mudstone and thin coal seams. Architectural analysis of the fluvial system reveals these lithofacies are arranged into architectural elements that include channel elements, sandy bedforms, downstream and lateral accretion elements, laminated sand sheets and overbank fines elements.The fluvial system is characterised by low-sinuousity, braided river channels with high width to depth ratios. Palaeocurrent data indicates that the generally westward palaeoflow is interpreted to have been diverted into local axial-through drainage patterns by active northeast trending normal faults. One of these, the Skenes Creek Fault, is also likely to have structurally isolated floodplain and lacustrine successions from the main channel belt, leading to the deposition of an anomalously thick coal measure sequence in the hanging wall of the fault. The local study therefore provides insight into regional lithofacies and potential source rock distributions, and the associated tectonostratigraphic evolution of the Eumeralla Formation in the eastern Otway Basin. While the nature of the Eumeralla Formation sandstone does not lend itself to good reservoir properties, the geometry and internal structure of the sands provide an excellent model for other fluvial sandstone reservoir reconstructions.

New data on vertical structure and variability of Lake Issyk-Kul

2020 ◽  
Author(s):  
Peter Zavialov
Keyword(s):  
River Runoff ◽  
Field Measurements ◽  
Nutrient Budget ◽  
Bottom Layer ◽  
Mountain Lake ◽  
River Channels ◽  
Distribution Maps ◽  
Littoral Region ◽  
Direct Measurements ◽  
Basin Scale

<p>Lake Issyk-Kul is the World's second deepest mountain lake (depth 668 m), containing over 1700 km<sup>3</sup> of brackish (about 6 g kg<sup>-1</sup>) water. It has been demonstrated by analyses of chemical tracers that the lake mixes very intensively, with the bottom water residence time of only about 10 years [Hofer et al., 2002], although the mechanisms resonsible for such a rapid renewal remain unknown. Some previous studies also suggested that the deep layers of the Issyk-Kul were subject to significant warming at decadal scales in response to climate forcing, however, direct measurements of the lake's thermohaline structure are very sparse.</p><p>Field measurements carried out in 5 consecutive expeditions (2015-2019) made it possible to establish previously unknown features of thermohaline fields and circulation of Lake Issyk-Kul. The most detailed ever salinity distribution maps were constructed. An area of ​​slightly increased salinity was found in the central part of the lake, the specific “dipole” shape of which indicates the existence of not only a general cyclonic circulation, but also two separate gyres of a smaller, sub-basin scale (which is partly confirmed by direct measurements of the current velocity). It has been established that, generally speaking, salinity fields in Issyk-Kul are extremely conservative - their interannual and seasonal changes, as well as spatial variability throughout the lake (with the exception of estuarine regions), are usually measured only in hundredths of g kg<sup>-1</sup>. An important result of the project is the discovery of a subsurface maximum of salinity persisting from year to year at depths from 70 to 130 m. As shown on the basis of balance estimates and then confirmed by analysis of direct measurements of current velocities, the autumn-winter differential cooling leads to the fact that in canyons (i.e., the ancient river channels) in the eastern littoral region, a significant amount (up to 1 km<sup>3</sup>) of cold coastal waters freshened by river runoff enters the bottom layers of the central part of the lake. These waters are then mixed with the more saline waters lying above, which, in a situation where the upper layer of the lake is also desalinated by river runoff, leads to the appearance of a salinity maximum at intermediate depths. Our measurements do not confirm the manifestations of global warming in the form of an inter-decadal temperature increase in the deeper layers of Lake Issyk-Kul, which was previously reported: the current (in 2018) temperature at a depth of 500 m exactly coincided with that noted in the 2003 measurements, namely about 4.44<sup>o</sup>C. However, one can point to a very weak (about 0.03 g kg<sup>-1</sup>) increase in the salinity of the bottom layer over the past 40 years. Based on the analysis of water samples taken from the lake and from the 12 main tributary rivers, improved estimates of the nutrient budget were also obtained.</p>

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