Large Trough Research Articles

Estimation and identification of cost reduction potential avenues for large aperture parabolic trough solar collector

Estimation and identification of cost reduction potential avenues for large aperture parabolic trough solar collector

Multi-method analysis of a historic wooden trough from Kentucky, USA: a case study in corroborating artifact oral histories with heritage science

Oral history indicates that a large wooden trough held in storage at the University of Kentucky’s William S. Webb Museum of Anthropology was a component of the saltpeter mining operation in Mammoth Cave in the late 18th and early 19th centuries, worked largely by enslaved persons. We used multiple heritage science methods, including radiocarbon wiggle-match dating, tree-ring dating, scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM–EDS), and optical scanning, combined with historical research, to examine the trough. Our analysis supports the oral history of the trough as an artifact of the mining system in Mammoth Cave. This case study illustrates how heritage science methods can provide corroboration for the origins and biographies of poorly documented historical artifacts.

New Insights from Legacy Seismic Data regarding Basalt Elevations and Variability on the Hanford Site

Abstract Migration of groundwater contaminants in the Gable Gap area of the Hanford Site in southeastern Washington State is strongly influenced by the distribution and permeability of basalts that lie beneath an unconfined aquifer. Locally, folding and faulting of the Columbia River Basalt associated with the Yakima fold and thrust belt followed by erosion due to the Lake Missoula floods resulted in a complex basalt surface that represents either an impermeable lower boundary to the unconfined aquifer system or localized regions of increased permeability that potentially promote communication between the unconfined aquifer system and deeper, confined aquifer systems. Paleo-channels carved into the basalt by floodwaters are thought to provide preferential flow paths for groundwater contaminants. In 2011, a seismic landstreamer campaign was carried out to image the basalt surface and produced pre-stack depth migrated p-wave reflection images. The reflection images identified two large troughs that may represent paleo-channels and several areas of possible faulting. Here, the streamer data are re-analyzed using refraction travel-time and Rayleigh wave dispersion analyses to obtain images of compressional and shear wave velocities within the suprabasalt sediment sections and the upper basalt surface. The combined interpretation of reflection and seismic velocity images shows complexity in the basalt velocity and elevation, which varies by 50 m or more within the study area. These results, along with other ongoing geophysical investigations, will be used to inform the site geologic model and potentially guide placement of future boreholes needed to quantify vertical flow between the confined and unconfined aquifers.

THE STRUCTURE AND GLACIAL RELIEF OF THE GORODOK UPLAND (NORTH-EASTERN BELARUS)<a href="#FN1"><sup>1</sup></a>

The article presents the results of the first comprehensive study of the structure and morphology of the glacial relief of the Gorodok Upland in the north-eastern Belarus. New data were obtained using lithological-stratigraphic, petrographic and morphometric methods. It has been established that the formation of the upland is predetermined by the uplift in the top of the Upper Devonian rocks. This uplift of the pre-Quaternary surface is overbuilt by Middle Pleistocene glacial deposits with glacial tectonics and erratic masses. The presence of an uplift led to the formation of the upland in the ice divide zone between the Chud and Ladoga Ice Streams during the last glaciation. As a result, during the maximum advance of the last ice sheet, a moraine plateau with kames began to form in the center of the upland. During the Lepel Stage (18–20 cal. ka BP, Edrovo in Russia, Gruda in Lithuania, and Poznan in Poland) the ice lobes of the Chud and Ladoga Ice Streams moved from the periphery to the moraine plateau. In total, there were six distinct oscillations of the glacial edge. As a result, chains of hummocky and ridge end-moraine landforms were formed. Later, during the Braslav Stage (16–18 cal. ka BP, Vepsa in Russia, Baltija in Lithuania and Pomeranian in Poland), hummocky end-moraine landforms were formed on the north-western and north-eastern slopes of the upland. At the same time, large runoff troughs crossing the upland from the north to the south were formed as a result of ice melting. The results of the study are important for the rational conduct of geological surveys and prospecting for mineral building materials within the ice-divide zones of the last glaciation.

Constraints on the composition and thermal structure of Ariel's icy crust as inferred from its largest observed impact crater

The large graben-like troughs and smooth plains visible on the surface of Ariel are indicative of a period of high heat flow in the Uranian moon's past. High heat flows on icy moons like Ariel can also enable viscous flow that removes impact crater topography, a process called viscous relaxation. Here we use numerical modeling to investigate the conditions necessary to viscously relax Ariel's largest impact crater, Yangoor, which is 80 km in diameter and unusually shallow. If we assume that Ariel's crust consists of non-porous water ice, heat fluxes ≥60 mW m−2 are required to reduce an initially deep Yangoor-like crater to its current observed depth. Lower fluxes are required if a high-porosity (30%), low-conductivity surface layer several kilometers thick is assumed to exist, but in any case, fluxes in excess of 30 mW m−2 are necessary to substantially reduce Yangoor's topography. The inclusion of ammonia dihydrate has a negligible effect on our results despite decreasing the viscosity of Ariel's deep ice. Our results are consistent with previous inferences of high heat fluxes on Ariel, but exceed both expected radiogenic heat fluxes and known equilibrium tidal heat fluxes by an order of magnitude. If Yangoor's shallow depth is the result of tidal heating, then short-lived non-equilibrium tidal dissipation or some other source of energy is required. Notably, although our results do not require the presence of an ocean within Ariel, the thermal conditions necessary to viscously relax Yangoor also imply a relatively thin ice shell (∼10-km thick) if conductive heat transport is assumed.

Drainage integration of small endorheic basins at the Pleistocene-Holocene transition: An example from southern Italy

The drainage integration of three Late Pleistocene intramontane basins located in the southern Italian Apennines was reconstructed by integrating information derived from geomorphic, structural, and stratigraphic analyses. The Santaloja (SLJ), Lago (LG), and Pantani (PN) basins are located in the axial zone of the Apennines fold-and-thrust belt where they mainly comprise Mesozoic to Cenozoic deep-sea water siliceous and calcareous rocks. The Quaternary development of these intramontane basins draining the Basento River catchment provides an example of drainage evolution within collisional mountain belts and its tectonic and climatic controlling mechanisms. Tectonically, sets of NW-SE- and NE-SW-trending faults formed a large trough with ensuing river valley development configured to synclinal folds. The ongoing interplay of these active and passive tectonic controls lead to compartmentalisation into three endorheic basins. Uncalibrated radiocarbon dating of peat layers from boreholes reveals that lacustrine facies conditions prevailed during the Late Pleistocene, spanning 34,785 to 41,325 ka during Marine Isotope Stage 3. Morphometric analysis suggests that these endorheic lacustrine basins subsequently became integrated via overspill from 13.25 kyr calBC onwards linked to Late Pleistocene climatic changes creating the Basento River. Within the axial zone of the southern Apennines, tectonically driven headwards erosion is commonly attributed to lengthening of major rivers like the Basento River. However, this study demonstrates a more complex interplay between tectonics and climate change for intramontane basin development and its drainage evolution.

Distribution of Devensian glacial erratics and related evidence elucidate complex ice flow changes across a former ice divide: Northern England

The Lune Gorge and the uplands of the southern Shap Fells represent a key area in developing an understanding of the dynamics of the Late Devensian glaciation (Dimlington Stadial) of northern England. Here ice masses emanating from southern Scotland, the Lake District and the Howgill Fells interacted in the area of the upper Lune valley. Glacial landforms are recorded and tills noted. The dispersal pattern of Shap granite (Sg) erratics is mapped as these clasts are an important tracer of regional ice movements and local ice dynamics. This new information is synthesised with existing literature to provide an understanding of ice dynamics in an area of complex ice flow history. In particular, the ice flow interactions over an area of the western Pennines and the southern Shap Fells have been defined.Early Dimlington ice flow in the vicinity of the upper Lune valley was easterly. Later a northerly shift in the position of a regionally significant west–east aligned ice divide led to topographic steering of southerly basal ice flows, resulting in the development of a western ice stream (Mint Sg plume) and an eastern ice stream (Lune Sg plume); both flowing south around the massif of the southern Shap Fells. At that time, southerly flow of basal ice over the highest ridges of the Grayrigg massif in the southern Shap Fells was relatively weak. Whereas the western stream extended into the Lancashire lowlands, the eastern ice stream was impeded in the Lune Gorge by ice emanating from Borrowdale which forced northern ice to the eastern side of the Lune Gorge where it was blocked by western flowing Howgill ice; the latter extending as far as just east of Kendal.During the late Dimlington, the ice masses over the Mint valley and the southern Shap Fells largely thinned and retreated to the north and west, with a surge in northerly ice movement within the upper Lune valley that did not override the western Pennines. Local ice dynamics are well-illustrated in the western margin of the Pennines (Crosby Ravensworth Fell Gaythorne Plain), where the disposition of erratics reflects local late west-to-east weak down-wasting ice flow and the presence of subglacial meltwater drainage channels. However, ice ultimately decayed in situ on Crosby Ravensworth Fell Gaythorne Plain. Similarly, after complex variable easterly and southerly ice flow during the early Dimlington, there was weak northerly ice flow in the later phase over Birkbeck Fells Common before ice thinned and retreated from Grayrigg Forest. An extensive ice stream, fed by ice emanating from an ice dispersal centre in the eastern Lake District, occupied the large trough of Borrowdale that transverses the southern Shap Fells, but its extension and recession dynamics remain enigmatic.“Glacial Theory …, in its application to the transport of blocks across Stainmoor, involves such obvious mechanical absurdities that the author considers it totally unworthy of the attention of the Society.” William Hopkins, 1842

Thermal and thermodynamic optimization of the performance of a large aperture width parabolic trough solar collector using gaseous and supercritical CO2 as heat transfer fluids

• A coupled optical-thermal-fluid model of a parabolic trough collector is developed. • sCO 2 exhibits better thermal and thermodynamic performance compared to gaseous CO 2. • sCO 2 has comparable thermal performance relative to Therminol-VP1 above 80 bar. • Flow rates above 300 m 3 /h give receiver temperature gradients lower than 50°C. • New correlations for optimal thermal and thermodynamic performance are presented. The degradation of thermal-oil-based working fluids in parabolic trough solar collectors (PTSCs) systems at temperatures above 400 °C has accelerated the search for cost-effective and efficient heat transfer fluids (HTFs) for high-temperature applications. Carbon dioxide is abundant and has the potential to be used as a working fluid in PTSCs. In this work, the performance of a larger aperture width PTSC with CO 2 as the working fluid (either in gaseous or supercritical phase) is investigated. In this study, a PTSC system with an aperture width of 9 m (geometric concentration ratio of 113) was considered. The operating pressure is in the range of 40−100 bar, the HTF inlet temperatures are between 650 and 1000 K, and the flow rate varies from 32.6 to 653 m 3 /h. A thoroughly verified and validated computational model using a combination of Monte-Carlo ray tracing and computational fluid dynamics was used for the numerical study. In addition, the Realizable k- ε model was used for turbulence modeling. The results show that CO 2 at 80 bar has comparable thermal performance relative to current thermal oil-based HTFs. Results further show that supercritical CO 2 (sCO 2 ) has the best thermal performance compared to gaseous CO 2 . In addition, the entropy generation minimization method was used to determine the Reynolds number that minimizes the irreversibilities at a given operating pressure. At low pressures, much higher flow rates are required to achieve high heat transfer rates and reduce temperature gradients in the absorber tube. Furthermore, correlations have been developed for the optimal Reynolds numbers at which the entropy generation rate is minimum and the collector efficiency is maximum.

First record of Aquilegia grubovii (Ranunculaceae) for Russia and key to all currently known species in the country

We report the first record of Aquilegia grubovii (Ranunculaceae) for Russia, a rare species previously known from five localities in Mongolia. The species belongs to A. sect. Aquilegia subsect. Aquilegia and is characterized by curved or hooked spurs slightly longer than the limb of petals, 2–2.8 mm long, straight only at the top diverging fruits with stylodia 2 times shorter than follicles, smooth or tuberculate seed surface and stems covered with simple and glandular hairs. The new records of Aquilegia grubovii are located in the Azas Nature Reserve, which is situated in the central part of the Todzha basin, Tuva Republic (a large intermountain trough within the Altai-Sayan mountain region) of south-central Asia about 500 km west of Lake Baikal. We provide an assessment of the conservation status, geographical distribution and habitat of Aquilegia grubovii, along with an identification key to all species from Russia.

INTEGRATED MODEL OF SOLAR PV INTERCONNECTION USING PSSE SOFTWARE

Due to increase demand of renewable energy, the interest on the solar power plant has recently grown dramatically. However, when a huge generation of power was generating from the solar power plant to the grid interconnection, the system tends to create a stability problem since the generation is depend on varying of solar irradiance. A huge sudden drop of the irradiance will tend to interrupt the stability of the system. When there is large solar power is used it might be interrupting the stability of the PV plant. When there is system increase in penetration to the system the system may be loss its stability which can interrupt the system operation that cause by large penetration trough the PV system. This paper presents the development PV model from scratch until dynamic stability assessment in the PSSE software in order to study the stability of the generation of PV plant to the grid interconnection by developing 30 bus system in the software.

Glacimarine sediments from outer Drygalski Trough, sub-Antarctic South Georgia – evidence for extensive glaciation during the Last Glacial Maximum

South Georgia, one of the largest sub-Antarctic islands, is located within the Southern Ocean and is influenced by the moisture-supplying Southern Westerlies and the Antarctic Circumpolar Current, which are highly susceptible to Southern Hemisphere climate variability. Its unique location causes South Georgia's remaining ice masses to react sensitively to climate change, resulting in highly dynamic ice cap waxing and waning, as well as in geomorphological and sedimentological changes on the island and its continental shelf. Sediments around the island have been archiving this ice cap behaviour since at least the Last Glacial Maximum (LGM) and are therefore an important target to investigate past ice cap evolution and climate. Despite several interdisciplinary studies on land and in coastal areas, much of the glacial history is still poorly constrained due to a lack of offshore data. This study presents the, thus far, most distal marine sediment succession from outer Drygalski Trough on the mid-continental shelf of South Georgia. Composite multi-proxy-analyses, together with radiocarbon dating, sub-bottom profiler and high-resolution bathymetric data provide first insights into the evolution of a large glacial trough south of South Georgia since the LGM. Several moraines close to the shelf edge indicate shelf-wide glaciation during the local LGM, which, based on extrapolation of the oldest reliable radiocarbon date, occurred before 30 ka BP at the earliest. Basal stratified diamicton at the core site was interpreted as waterlain till deposited in a subglacial cavity with restricted seawater access and suggests grounding zone-proximal sedimentation in the early phases of deglaciation. The ice margin remained stable until ∼17.5 cal ka BP, when ice quickly retreated from the mid-continental shelf and sedimentation at the core site was dominated by hemipelagic suspension settling with some iceberg melting. Further retreat was interrupted by a local ice readvance and associated increased hinterland erosion during the Antarctic Cold Reversal (14.5–12.8 ka), as indicated by peak sedimentation rates (>190 cm ka−1) between 13.4 and 12.4 cal ka BP. In contrast, the continuous deposition of ice-distal to open-marine mud at rates of only ∼30 cm ka−1 throughout the Holocene indicate that any other LGM-subsequent glacier readvances reached significantly lesser extents and were probably confined to the fjord. Our data provide new evidence in support of a shelf-wide glaciation during the LGM and suggest rapid, but stepwise ice retreat during deglaciation.

The effect of seasonal biomass availability and energy demand on the operation of an on-farm biomethane plant

Globally, 10% of milk production occurs in countries whereby dairy livestock have pasture access for the majority of the year, leading to the seasonal collection and availability of dairy slurry. This can pose challenges if dairy slurry is used as a feedstock in on-farm biogas plants. On-farm biogas plants may also have limited gas grid access and have to facilitate seasonal gas demands of consumers in their locality. The effects of seasonal gas demand coupled with seasonal slurry availability have yet to be addressed in literature. This work aims to analyse the effects of such seasonal factors, and whether optimised digestate recirculation may alleviate some of these challenges. Countries which employ pasture-based dairy farming require such evidence to successfully develop on-farm biogas plants, reduce fugitive emissions resultant from current manure management practices, and furthermore, produce alternatives to fossil fuels. Ireland is used as a case study in this work and the effects of seasonal or constant slurry availability and seasonal or constant gas demand is investigated. The sustainability of such systems is also evaluated in terms of emissions reductions as per EU regulations. For a farm with slurry production from 100 dairy cows and 10 ha of grass dedicated for anaerobic digestion, the seasonal availability of slurry leads to a 21% reduction in total biomethane production; over 12 times the required digestate recirculation; smaller digester sizes; and increased variation in the organic loading rate throughout the year. Facilitating a seasonal gas demand leads to larger digester sizes due to periods of increased mass flow rates, and large peaks and troughs in biogas flow rates. Seasonal slurry availability increases greenhouse gas emissions by ca. 11 g of CO2 per megajoule of biomethane produced. Pasture-based AD systems may successfully manage the seasonal availability of slurry by optimising digestate recirculation to lower the solids content of the plant.

Optical and structural optimization of a large aperture solar parabolic trough collector

Concentrating solar power is well established renewable energy technology. It involves the same heat engine cycle as the conventional power plants, and the heat produced can be stored effectively. However, expensive mirrors and structural support systems required to maintain high precision in the shape of reflectors for better optical and thermal efficiencies are the challenges involved in making it competitive with other solar power technologies. In the present work, a methodology is proposed based on the finite element method and Monte-Carlo ray tracing to design and optimize a parabolic trough collector. The effect of geometric and optical parameters such as rim angle, the width of the collector, tracking errors, and slope errors are analyzed. The effect of tracking errors in the East-West direction and slope errors are substantial compared to the other non-random errors. Loss of 25% and 7.1% in optical efficiency occurs for tracking errors of 20 mrad and slope error of 3.2 mrad, respectively. Based on the structural and optical study, an optimization method and optimum configurations are proposed. Using the proposed methodology, heat flux maps at the receiver can also be obtained for the structural health monitoring of the receiver tube.

Investigation on wind-structure interaction of large aperture parabolic trough solar collector

Structural analysis and wind load effects on parabolic trough solar collector (PTSC) plays a critical role in the efficient and reliable operation of solar thermal power plants. In this study, the likely effect of the different wind load conditions on the stability of the large aperture PTSC has been undertaken. The investigation is an extension of the coupled optical and thermal analysis of the large aperture of PTSC, considering the manufacturing standard following Euro Trough and the availability of the receiver size (70 mm–110 mm). Based on the optical and thermal analysis, it has been identified that 9 m is the largest achievable aperture size, with a 110 mm absorber having an intercept factor of 0.94. The analysis is performed for the various operating condition such as pitch angle (0°–180°), yaw angle (−90°–90°) and wind speeds (5 m/s to 25 m/s). Firstly, the wind load coefficients have been estimated to determine the pressure, forces and pitching moment on the PTSC. The maximum drag force is encountered for the pitch angle of 0°, i.e. 6888 N for the wind speed of 25 m/s. Based on the pressure and gravity force acting on the concentrator, the effort has also been made to estimate the deformation in the concentrator and same is compared with Euro Trough collector. The maximum variation in the deformation is observed as around 35% for the pitch angle of 30°.

Model Predictive Control of the Mojave solar trough plants

The size of the current commercial solar trough plants poses new challenges in the applications of advanced control strategies. Ensuring safe operation while maintaining the temperature around an adequate set-point can lead to substantial gains in power production. Furthermore, the controller has to take into account the steam generator constraints to avoid trips leading to production losses.Model Predictive Control algorithms have proved to perform well when controlling solar trough plants. In particular, many MPC strategies were developed and tested at the old experimental solar trough plant of ACUREX at the Plataforma Solar de Almería with excellent results.In this paper, a Model Predictive Control algorithm is presented to control the average temperature of the large scale solar trough plants Mojave Alpha and Mojave Beta. This controller takes into account steam generator constraints in order to ensure safe operation. Several tests under different conditions have been carried out at the actual plants. Results show that the controller performs well on clear and cloudy days in spite of the great size of these plants.

Performance Benchmarking of Large Aperture Parabolic Trough Solar Collector for Various Optical Errors and Geometrical Concentration Ratio

Herein, the effect of the various errors associated with concentrator, receiver, and tracking unit has been investigated on the optical performance of the large aperture parabolic trough solar collector (PTSC). The various combinations of the PTSC aperture sizes with the commercially available receiver sizes are considered for the analysis. The best combinations are identified based on the receiver's availability and intercept factor of the collector configuration. The effects of both the random (slope and tracking error) and non‐random (receiver alignment) errors have been investigated. It is observed that the PTSC performance should not be predicted based on the geometrical concentration ratio alone, as the focal length, absorber diameter, and aperture size also affect the PTSC performance. The intercept factor of large aperture PTSC is marginally affected by the receiver alignment error as compared to 5.77 m aperture. The rightward and leftward receiver displacement has no effect on the intercept factor for all the PTSC configurations. The slope error drastically affects the flux distribution as a change in the slope error from 0 to 8 mrad, the peak local concentration ratio decreases from 62 to 47. There is a decrease in the intercept factor by 22%, including a tracking error up to 8 mrad.

Vilyui-Markha interfluve of Yakutia: a region prospective for Cu-Ni-PGM mineralization

Materials are discussed on geologically similar structure of Norilsk ore district (NOD) and Vilyui-Markha interstream area (VMIA), which implies the latter prospects for Cu-Ni-PGM mineralization. Data is provided on Cu-Ni-Co-Zn mineral occurrences within Ygyattinsky diamondiferous region centered on VMIA. Geological similarities of NOD and VMIA are summarized below. Both regions are located in Mesozoic tectonomagmatic activation domain at the edge of large troughs: NOD is localized in the Siberian platform foredeep, and VMIA lies at Vilyui syneclise margin. NOD deposits are hosted by centroclines of large brachysynclines at slopes of Pyasinskoye dome. Within VMIA, prospects are located at Syuldyukarskoye dome slopes in margibal parts of large troughs. NOD and VMIA comprise Paleozoic marl-carbonate strata overlain by carbonaceous Carboniferous-Permian overburden, which could be assimilated by basaltic magma in Mesozoic contributing to its ore differentiation. Norilsk-Kharaelakh ore-bearing intrusion in VMIA appears to be similar to Kholomolokh sulfide-rich intrusion with its inferred extensive ore-bearing sills. They have similar composition and structure including presence of pegmatites. Ore-controlling Norilsk-Kharaelakh fault is believed to be simi- lar to Khatyryk-Kholomolokh fault, which was traced for 24 km by drilling and is one of sutures within deep-seated kimberlite-controlling Vilyui-Markha zone. This fault’s impact zone host concentrated geochemical anomalies and Cu-Ni-Co-Zn-Pt-Au-Ag Khomustakh occurrence. Based on this, Norilsk-type Cu-Ni prospects ranked as a potential ore cluster and three ore fields were identified

KOMPOSISI DAN LUAS RELUNG MAKANAN IKAN PALUNG (Hampala macrolepidota C.V.1823) DI WADUK PB. SOEDIRMAN BANJARNEGARA, JAWA TENGAH

This study aims to determine the composition and value of the natural feed niche of trough fish caught from the waters of the PB Reservoir. Sudirman. The research method used is a survey method with a sampling technique using purposive random sampling. The research location was divided into three stations, namely I (Karang Kemiri), II (Wanadadi), and III (Karang Jambe). Sampling was carried out three times (19 February, 07 March, and 2 August 2020). Data were analyzed descriptively comparatively. The results showed that the composition of the trough fish diet was dominated by Chlorophyta and plant debris. Based on the selectivity index and the most significant part of trough fish, including omnivorous fish. Large trough fish have a high food niche area. Small, medium and large trough fish have stiff competition for food in the waters

Tectonic Deformation and Volatile Loss in the Formation of Noctis Labyrinthus, Mars

AbstractNoctis Labyrinthus is a little‐studied and structurally complex area situated between the Tharsis Rise and Valles Marineris on Mars. Noctis Labyrinthus is dissected by normal faults that form horst and graben, pit craters situated inside the graben, and large troughs that cross‐cut both graben and pit craters. Mass wasting, periglacial, and some erosive fluvial features are observed at the bases of the troughs, suggesting that the troughs hosted liquid and perhaps even ice at some point in the past. We mapped and analyzed these structural and morphological features in Noctis Labyrinthus to establish the region's formational history. Fault throw profiles, combined with morphometric data from pit craters, were used to assess how the pit craters relate to the much larger troughs in the region and whether those troughs were formed by extensional tectonic deformation alone. This comparative analysis suggests that some pit craters grew deeper than the amount of throw accommodated by their bounding faults. We hypothesize that layers with subsurface volatiles (such as ground ice) were intersected and exposed by the larger Noctis Labyrinthus pit craters, enabling sublimation that further promoted mass wasting and the growth and coalescence of pits and graben into the large troughs. Under this scenario, subsurface volatiles played an important role in forming this structurally complex region, and may still be present there.

Pyrolytic data verification in potential assessment and catagenetic transformation of the Proterozoic low-carbon formations of Eastern Siberia

The ancient Precambrian formations of Eastern Siberia include oil and gas source rock (SR) interlayers, but in most cases, they can’t be classified as high-carbon ones, because the actual organic carbon content in these strata is low and rarely exceeds 10%. This point effect the approach to the available geochemical data interpretation and the method of quality samples selection. The aim of the work was to determine methods for pyrolytic data verification and the oil and gas Lower Vendian SR quality assess, that based on the results of geochemical researches. It was identified, that before SR catagenetic transformation analyzation by the Tmax parameter and determining the OM type, samples with a low generation potential or with the migrated bitumen presence should be excluded from the consideration. The presence of secondary epigenetic bitumen also indicates the active HC fluids migration within the basin. After data verification, the SR properties were assessed. So lower Vendian SRs have OM with a satisfactory and high generation potential, second type and low maturity in most cases. The oil and gas window zones are located within large depressions and troughs. In addition, the local heating was noted in zones with a large number of faults, where the heating was conducted due to the intrusions introduction and the hydrothermal fluids action.