Interpretation Of Geological Data Research Articles

The Relationships between the Internal Nappe Zone and the Regional Mylonitic Complex in the NE Variscan Sardinia (Italy): Insight from a New Possible Regional Interpretation?

This study presents an updated interpretation of geological data collected between 1984 and 2022. The area under consideration holds significant regional importance as it is located between the Internal Nappe Zone (INZ) and the Regional Mylonitic Complex (RMC). Re-evaluation of the geological data has highlighted a more intricate structural framework than what is currently documented in the existing literature. This paper aims to illustrate, through structural analysis, that the Posada Valley Shear Zone (PVSZ) does not serve as the transitional boundary between the Inner Nappe Zone and the Regional Mylonitic Complex or High-Grade Metamorphic Complex (HGMC) as traditionally thought. Instead, the authors’ findings indicate that the transition boundary is confined to a shear band with a variable thickness ranging from 10 to 70 m at its widest points. The development of the Posada Valley Shear Zone is characterized by a series of transitions from mylonite I S-C to mylonite II S-C, extending over approximately 5 km. The formation of the Posada Valley Shear Zone is chronologically confined between the development of the East Variscan Shear Zone (EVSZ) and the emplacement of the Late Variscan granites. The differing orientations of Sm and S3 observed in the mylonitic events of the Posada Valley Shear Zone and the Regional Mylonitic Complex, respectively, are likely attributable to an anticlockwise rotation of the shortening directions during the upper Carboniferous period. Furthermore, this study proposes that the Condensed Isogrades Zone (CIZ), despite its unclear formation mechanism, should be recognized as the true transition zone between the Inner Nappe Zone and the Regional Mylonitic Complex or High-Grade Metamorphic Complex. This new interpretation challenges the previously accepted notion of increasing Variscan metamorphic zonation toward the northeast. This conclusion is supported by the identification of the same NE–SW orientation of the D2 tectonic event in both the Old Gneiss Complex (OGC in the Regional Mylonitic Complex) and the lithologies of the Inner Nappe Zone and the Condensed Isogrades Zone. The comprehensive analysis and new insights provided in this paper contribute to a refined understanding of the geological relationships and processes within this region, offering significant implications for future geological studies and interpretations.

Empowering geological data analysis with specialized software GIS modules

This research is devoted to the development of a geographic information system (GIS) for the analysis of geological data. It presents two specialized software modules designed to solve complex geological problems related to potential progress to disturbed masses and magnetotelluric sounding. These modules are integrated into the QGIS environment, offering efficient data processing and analysis capabilities, contributing to a deeper understanding of geological structures. The study presents a mathematical model for the problem of magnetotelluric sounding (MTS) and the continuation of potentials towards the perturbed masses, demonstrating numerical results using the developed algorithm. To confirm the accuracy of the model, a comparative analysis was carried out with empirical data for various chemical elements, which showed high accuracy, especially at shallow depths, with an error rate of less than 2%. In addition, the study highlights the importance of powerful GIS for the analysis and interpretation of geological data, including geochemical, geophysical and remote sensing information. The advanced functionality of QGIS simplifies data processing and visualization, which makes it an invaluable tool for geologists and researchers.

Petrogenesis of the Córrego das Campinas Gabbro-Anorthosite Suite: Characterization of a Neoproterozoic massif-type anorthosite in the Goiás Magmatic Arc and its significance in the evolution of the Brasília belt, Brazil

Córrego das Campinas Anorthosite is a rare example of a massif-type anorthosite developed in the late Proterozoic (∼650 Ma) during the amalgamation of West Gondwana. This undisturbed, oval, and homogeneous massif body primarily consists of labradorite (An49-63) with a porphyritic and cumulatic inequigranular texture. Other rocks are associated with anorthosite, such as a gabbroic body, consisting of olivine gabbro, leucotroctolite and gabbro with granular, ophitic and cumulatic textures. The olivine gabbro presents a more primitive character, showing minerals enriched in Mg and Ca, such as olivine Fo76-78 intercumulates and anorthitic plagioclase (An90-97), albeit with an Al-rich diopside as well. The anorthosite body is also bordered by tonalite and quartz monzodiorite. These leucocratic and granular rocks contain An26-46 plagioclase in tonalite and An12-18 plagioclase in quartz monzodiorite. Given the signature of these rocks, they can be considered residual liquids from anorthosite crystallization, more enriched in Na and Fe. Metamorphosed ferrodiorites, amphibolites and ilmenite-rich levels occur in the form of dikes and veinlets associated with anorthosite and also seem to represent differentiated liquids from anorthosite crystallization. A quartz syenite body also occurs, consisting of perthitic orthoclase cumulates with an albite mantle, whose genesis is also associated with a process of accumulation in a magma chamber. A albite granite plug occurs intrusively. This albite granite presents enriched in enriched in Na, Si, Rb, Th, Ta, Nb, Ce, Zr, Hf, Y and Yb showing typical signature of an anorogenic granite. Zircon U–Pb dating of olivine gabbro, tonalite, quartz monzodiorite, ferrodiorite and albite granite indicate that these rocks are contemporaneous, with crystallization ages ranging from 648 to 661 Ma, showing older zircon grains indicating Neoproterozoic crustal material contamination (∼870–900 Ma) and even older in the genesis of these rocks. Sm–Nd model ages around 0.75 Ga and positive ϵNd(t) suggest that these rocks are juvenile and derive from depleted mantle, whereas another set of results around 1.0 Ga and less positive ϵNd(t) values indicate that these rocks are juvenile but show crustal contamination. The high percentages of plagioclase found in the rocks, combined with high Al2O3, CaO and Na2O concentrations in total rock, indicate that the rocks of this suite derive from calc-alkaline or Al-rich basaltic magmas. The formation of the suite is in accordance with the classical petrological model of plagioclase accumulation in magma chambers and its subsequent diapiric rise. The age of the suite and its positioning indicate a correlation with an important mafic magmatic event that occurred in the Brasília Belt between 670 and 600 Ma. The interpretation of geological data on the Brasília Belt, associated with the present study, indicates that the rocks of this suite initially developed in a back-arc setting during the pre-tectonic stage of an active continental margin and that the bodies ascended to shallower regions of the crust during the post-collisional stage, through pressure relief, at approximately 650 Ma. The evolution of the Brasília Belt was marked by a constantly elevated geothermal gradient and the Córrego das Campinas massif-type anorthosite supports this inference. Therefore, we suggest that the constantly elevated geothermal gradients in the Brasília Belt were caused by multiple, concurrent geodynamic processes during its evolution, such as i) blocked mantle convection currents triggered by oceanic crust subduction, which formed an intraoceanic island arc (Goiás Magmatic Arc) between 900 and 800 Ma; this physical barrier limited the heat release from these currents, generating a “heat trap” and thus accounting for the elevated geothermal gradients; ii) thickened crust caused by collisional and accretionary events; iii) increased heat of Rodinia break-up plume; and iv) elongated microplate of the Goiás Massif.

VESIcal Part I: An Open‐Source Thermodynamic Model Engine for Mixed Volatile (H2O‐CO2) Solubility in Silicate Melts

AbstractThermodynamics has been fundamental to the interpretation of geologic data and modeling of geologic systems for decades. However, more recent advancements in computational capabilities and a marked increase in researchers' accessibility to computing tools has outpaced the functionality and extensibility of currently available modeling tools. Here, we present VESIcal (Volatile Equilibria and Saturation Identification calculator): the first comprehensive modeling tool for O, , and mixed (O‐) solubility in silicate melts that: (a) allows users access to seven of the most popular models, plus easy inter‐comparison between models; (b) provides universal functionality for all models (e.g., functions for calculating saturation pressures, degassing paths, etc.); (c) can process large datasets (1,000s of samples) automatically; (d) can output computed data into an Excel spreadsheet or CSV file for simple post‐modeling analysis; (e) integrates plotting capabilities directly within the tool; and (f) provides all of these within the framework of a python library, making the tool extensible by the user and allowing any of the model functions to be incorporated into any other code capable of calling python. The tool is presented within this manuscript, which may be read as a static PDF but is better experienced via the Jupyter Notebook version of this manuscript. Here, we present worked examples accessible to python users with a range of skill levels. The basic functions of VESIcal can also be accessed via a web app (https://vesical.anvil.app). The VESIcal python library is open‐source and available for download at https://github.com/kaylai/VESIcal, or it can be installed using pip. It is recommended to read and interact with this manuscript as an executable Jupyter Notebook, available at https://mybinder.org/v2/gh/kaylai/vesical-binder/HEAD?filepath=Manuscript.ipynb.

Warm early Mars surface enabled by high-altitude water ice clouds

Despite receiving just 30% of the Earth's present-day insolation, Mars had water lakes and rivers early in the planet's history, due to an unknown warming mechanism. A possible explanation for the >102-y-long lake-forming climates is warming by water ice clouds. However, this suggested cloud greenhouse explanation has proved difficult to replicate and has been argued to require unrealistically optically thick clouds at high altitudes. Here, we use a global climate model (GCM) to show that a cloud greenhouse can warm a Mars-like planet to global average annual-mean temperature ([Formula: see text]) ∼265 K, which is warm enough for low-latitude lakes, and stay warm for centuries or longer, but only if the planet has spatially patchy surface water sources. Warm, stable climates involve surface ice (and low clouds) only at locations much colder than the average surface temperature. At locations horizontally distant from these surface cold traps, clouds are found only at high altitudes, which maximizes warming. Radiatively significant clouds persist because ice particles sublimate as they fall, moistening the subcloud layer so that modest updrafts can sustain relatively large amounts of cloud. The resulting climates are arid (area-averaged surface relative humidity ∼25%). In a warm, arid climate, lakes could be fed by groundwater upwelling, or by melting of ice following a cold-to-warm transition. Our results are consistent with the warm and arid climate favored by interpretation of geologic data, and support the cloud greenhouse hypothesis.

Hydrogeology study and determination of aquifer distribution using geoelectrical schlumberger method in subang regency

The amount of water demand will always increase, especially in Subang Regency. Efforts to control and monitor springs and groundwater are carried out to maintain the availability of springs and groundwater. Therefore, an analysis of geology - hydrogeology of springs and groundwater is needed. The purposes of this research are to determine the interpretation of geological data to investigate groundwater, know the location and distribution of aquifers based on the resistivity value of rock types, and to assess the potential of groundwater using the Darcy equation. This research was conducted in several steps, such as collection and analysis data. The processed data was the secondary geoelectrical data with the Schlumberger method. Calculation of groundwater storage was performed by using geoelectric and Darcy’s law approach. From the calculation result, it was obtained that the predicted groundwater storage was about 5380.375 m3/day or 62.27 m3/s.

Adjustment of the Exploration Grids and its use to increase the Reliability of Geological Models of Coal Deposits

The current procedure for determining the boundaries of geological domains, the allocation of which is the mandatory element of digital geological modelling, does not entirely take into account the specifics of coal deposits. Without its improvement, it is impossible to increase the reliability of geological models used in the implementation of the “Industry 4.0ˮ strategy. A new method for analysis of geological data is supposed – the adjustment of the exploration grids method. It is to determine the corrections for values of measured parameters, the use of which eliminates the uncertainty of geological data interpretation. The correction values determined by the method of conditional measurements, which used at equalization geodetic networks. Corrections are considered as an indicator of the significance of measurement and interpolation errors which occurs in the vicinity of specific measurement points. The measured values of parameters are not corrected. Geological domains are the areas with close in values corrections, whose boundaries are corrections isolines. Separate single corrections of anomalous magnitude indicate the presence of extreme values parameters.

The Study of Sub-Bottom Sediments in Petrozavodsk Bay of Lake Onega Using Complex Geological-Geophysical Methods of Data Analysis

The results of geological interpretation of data of engineering seismic surveys obtained during the field works at Lake Onega are given. Seismic-stratigraphic units specified on processed seismograms are characterized. The survey enabled us to compile a seismic-stratigraphic column of the Quaternary sediments of Lake Onega, which may be used to analyze the structure of the open part of the lake.

Geomorfología sísmica y elementos en ambientes fluvio lacustres en un sector de los Llanos Orientales (Colombia)

Actualmente disciplinas como la Geomorfología sísmica, permite integrar datos de superficie, constituyendo una nueva visión para la interpretación de datos geológicos, especialmente en áreas donde no se hace posible obtener de manera directa información de superficie y del subsuelo. Así, métodos indirectos como la sísmica tridimensional, análogos en superficie y la estratigrafía de secuencias, han permitido determinar la geomorfología y elementos arquitecturales, en zonas del subsuelo a varios kilómetros de profundidad; presentando geometrías características, que posibilitan delinear y mapear elementos arquitecturales de depósitos de canal. Como ejemplo, en la Cuenca de los Llanos Orientales, a lo largo de toda su extensión, se presentan una serie de elementos arquitecturales, los cuales se establecen por medio de las asociaciones de facies que permiten definirlos en el subsuelo, además de ser interpretados, mediante la estratigrafía de secuencias.

Interpolation of spatially varying but sparsely measured geo-data: A comparative study

Geological properties usually vary spatially, but they are often measured sparsely in engineering geology practice, particularly for projects with medium or relatively small sizes. Spatial interpolation is, therefore, frequently performed to estimate the geological properties of interest at unobserved locations. Among a variety of interpolation methods (e.g., ordinary kriging (OK), polynomial interpolation (PI), cubic spline interpolation (CSI) and inverse distance weighting (IDW)), OK is one of the widely used methods, and it requires modeling of spatial structure of the measurement data points using a semi-variogram. However, the accuracy of the semi-variogram is affected by data size, and it may give unreliable estimates when the measurement data are sparse. This poses a challenge in applications where the measurement data are sparse, such as site characterization. To address this challenge, Bayesian compressive sampling (BCS) has been recently developed, which is able to reconstruct a complete signal from a remarkably few number of measurement data points on that signal. Unlike OK, BCS does not require characterization of spatial structure from the available measurement data before the interpolation. Therefore, the difficulties associated with modeling a semi-variogram from sparse data in OK are bypassed in BCS. A comparative study is performed in this paper to compare the effectiveness of BCS with OK, PI, CSI and IDW using simulated data and real cone penetration test data. In addition, an approach is presented in this paper to objectively select the most appropriate basis function in BCS. It is found that the BCS method is more suitable and performs better than the OK, PI, CSI and IDW methods when the measurement data are limited and sparse, such as interpretation of geological data or site characterization data.

Improving Efficiency of the Oil and Gas Sector and Other Extractive Industries by Applying Methods of Artificial Intelligence

Произошедшее за последние годы значительное снижение цен на сырье, в первую очередь на нефть, это не разовое явление, а новое равновесное состояние рынка, которое сформировалось в результате инноваций. В такой ситуации преимущество получают те производители, которые могут быстро приспособиться к низким ценам, снизив издержки и повысив эффективность. До последнего времени основной движущей силой инновационного развития энергетического сектора была «сланцевая революция». Ситуация быстро меняется, поэтому сейчас в нефтегазовой индустрии идет активный поиск новых технологических решений, которые позволили бы ей пережить период низких цен. Одно из самых обсуждаемых и быстрорастущих направлений технологии «искусственного интеллекта». В статье приведен краткий обзор наиболее распространенного метода искусственного интеллекта искусственных нейронных сетей, а также рассмотрены основные сферы их применения в нефтегазовом секторе. В своей работе авторы выделяют три основных направления использования таких технологий: интерпретация геологических данных, эксплуатация месторождений (умных месторождений smart fields) и прогнозирование цен. Привлечение методов на основе искусственного интеллекта повышает эффективность проводимых работ как в геологоразведке, так и в добыче дает возможность достигать лучшего результата с меньшими затратами. В новых рыночных условиях, сформировавшихся в энергетическом и горнодобывающем секторах, крайне важно использовать все доступные механизмы, чтобы повысить эффективность. После снижения цен на сырьевые товары добывающим компаниям нужны более точные методы прогнозирования, которые позволили бы проанализировать изменения на рынке и улучшить стратегическое планирование.

Visualization and interpretation of geologic data in 3D virtual reality

We have developed an argument and evidence from our experiences for the utility of 3D virtual reality (3DVR) systems in the interpretation of 3D geologic data. Interpretation of 3D data by geoscientists is performed in “the mind.” Visualization of 3D data in 3DVR environments is an efficient method of getting the data into the mind. Descriptions of visualization and interpretation of several different geologic data sets in 3DVR environments illustrate the advantages of 3DVR. Despite the advantages of visualization in 3DVR, several reasons exist for the present limited use of 3DVR by geoscientists. With the relatively recent availability and affordability of smaller hardware and software systems, we believe 3DVR should become commonplace on the desktops of geoscience interpreters.

Structural and Stratigraphic Interpretation of Geophysical Data of the Fenchuganj Gas Field in the Surma Basin, Bangladesh

Abstract: The Fenchuganj structure trending in NNE-SSW direction is a surface anticline (reverse faulted) in the eastern part of the Surma basin, Bangladesh. The eastern flank of the structure has steeper dip than the western one. The present study includes seismic and geological data interpretation which gives details about structure and stratigraphy of the area. Well log interpretation was done to infer lithological pattern and the hydrocarbon potential zones. Correlating the seismic interpretation and well log analysis, four gas sands have been identified at depths 2000m to 3100m. Depending on the present findings, it is concluded that further investigation can give valuable information about real sub-surface structure and hydrocarbon occurrence in this area.

Alternative 3D modeling approaches based on complex multi-source geological data interpretation

Due to the complex nature of multi-source geological data, it is difficult to rebuild every geological structure through a single 3D modeling method. The multi-source data interpretation method put forward in this analysis is based on a database-driven pattern and focuses on the discrete and irregular features of geological data. The geological data from a variety of sources covering a range of accuracy, resolution, quantity and quality are classified and integrated according to their reliability and consistency for 3D modeling. The new interpolation-approximation fitting construction algorithm of geological surfaces with the non-uniform rational B-spline (NURBS) technique is then presented. The NURBS technique can retain the balance among the requirements for accuracy, surface continuity and data storage of geological structures. Finally, four alternative 3D modeling approaches are demonstrated with reference to some examples, which are selected according to the data quantity and accuracy specification. The proposed approaches offer flexible modeling patterns for different practical engineering demands.

Обернені лінійні задачі гравіметрії та магнітометрії з уточнюючими ітераційними поправками вищого порядку

The purpose of the paper is to develop iterative methods of solving inverse problems concerning gravity and magnetic fields with high-order corrections to obtain an accurate geological data interpretation of physical fields. The iterative method has been previously used to solve linear inverse problems for gravity and magnetic fields on the basis of combining several types of parameter corrections. However, gravity and magnetometry inverse problems give inaccurate geological data, with different optimization criteria yielding various solutions. Quite often they show essential differences in some of the areas of the geometrical model. There have been developed methods for solving gravity and magnetometry linear inverse problems under Gaussian error distribution, which is connected with structural problems of detecting ore and hydrocarbon deposits. Other methods have been developed for obtaining the solution of gravity and magnetometry linear inverse problems, using iterative corrections which contain a complete set of divergences between the measured physical data and the theoretical calculations. However, the non-Gaussian errors, together with the shortcomings of the existing methods, show a low level of convergence of the iterative process and the true solution of the inverse problem. Moreover, they cause difficulties in reaching an ultimate solution, thus reducing the geological value of the inverse problem solution. New methods are suggested to raise the geological value of the inverse problem solutions with the help of high-order corrections to enhance the well-known iterative formulae and the formulae of optimization criteria. We differentiate between two types of corrections: field misfit ones and those concerning the geological medium density models. Each correction to a field misfit generates one order higher clarifying correction as to the density correction, and vice versa. Either of these corrections, though, can be used either independently in any iterative formula or together with other corrections of the same type. The most accurate field modeling is ensured by using an iterative formula with three corrections (of the same type) of the first, second and third order and a formula with three separate corrections of the other type. Each optimization criterion for such a formula has a complete set of two orders higher corrections.

The use of GIS-based 3D geological tools to improve hydrogeological models of sedimentary media in an urban environment

A software platform was developed to facilitate the development of 3D geological models of sedimentary media for hydrogeological modelling, especially for urban environments. It is composed by a geospatial database and a set of tools that enable the user to perform an accurate stratigraphic analysis. The geospatial database is used for the management of a large amount of different data types coming from different sources (geophysical logs, borehole logs, hydraulic tests, etc.). Its structure allows us to store accurate and very detailed geological borehole-log description that can be straightforwardly generalized and further upscaled. The set of stratigraphic analysis instruments, working within a Geographical Information System (GIS) environment, has been set up to facilitate the geological data interpretation. Detailed stratigraphic columns of the selected boreholes can be generated using customized queries. Creating automatically a geological profile is further possible by displaying the boreholes lithological columns and the geophysical and geotechnical field-tests’ results together with the defined stratigraphic units. Based on an interactive analysis environment is created, where the user is able to analyze and to define the possible existing correlation surfaces, units, and faults. The obtained information represented by the geological units/subunits can be then converted within a 3D environment. The resulted 3D features could be used within the same GIS environment or by external software packages for further stochastic analysis or to build up 3D geological and hydrogeological models. Starting from an accurate and very detailed geological description, the software allows us to represent in three dimensions (3D) the heterogeneity of the sedimentary media and their spatial distribution. Thus, it shows how connectivity implemented into hydrogeological models among the different sedimentary bodies plays an important role. Results are shown consisting in a case study located in the Besos River Delta, in the metropolitan area of Barcelona, on the Mediterranean coast in NE Spain.

Science, biodiversity and Australian management of marine ecosystems

The United Nations Convention on Law of the Sea (UNCLOS) (United Nations 1982) came into effect in 1994. Signatory nations have substantial management obligations for conservation of marine natural resource and ecosystems. In this paper we discuss the challenges of defining and monitoring biodiversity at scales required for management of marine ecosystems. Australia's area of immediate responsibility under UNCLOS covers an area of 11 million sq km with further linked responsibilities for an estimated area of 5.1 million sq km of continental shelf. This presents substantial data challenges for development and implementation of management. Acoustic seabed mapping is providing substantial information on seabed surface geology and topography and provides a surrogate basis for describing benthic habitat and seabed communities that have critical roles in marine food chains. The development of the Integrated Marine and Coastal Regionalisation of Australia (IMCRA 4.0, 2006) has provided a basis for planning marine biodiversity and resource management but the biological habitat interpretation of geological data is based very largely on demersal fish data. It is recognised in IMCRA 4.0 (2006) that revision and refinement of regionalisation requires further work in the areas of data coverage, ecosystem understanding and ecosystem surrogates and conceptual classification models. In this paper we discuss Australian experience highlighting problems and issues of relevance for scientifically based management of marine natural resource and ecosystems elsewhere in the world.

Perunutan Jalur Sesar Lokal di Desa Sri Mulyo Kecamatan Dampit Kabupaten Malang Berdasarkan Data Geofisika

A research has been conducted for searching local fault at Sri Mulyo Village, Malang Regency, to get the physical parameters of 3-dimension fault, which include depth, width, length, and direction. The research is based on the preliminary research that results geological data interpretation, gravity, and outcrops. The survey used resistivity parameter by applying pseudo-depth section configuration (4 electrodes). Data processing and interpretation using inverse method. By combining every pseudo depth section, 3-dimension physical parameters will be acquired square error is 2.51x10 -27 .

Do experts use idealised structural models? Insights from a deepwater fold–thrust belt

Theoretical models are often used to aid interpretation of geological data. For fold–thrust belts, structural and kinematic models have existed for over a century. While greatly contributing to our understanding of thrust systems, the usage of models can result in oversimplification and false kinematic interpretations. This paper investigates how and if experts use structural models in the interpretation of a seismic image from a deepwater fold–thrust belt. The results show that in the majority of cases experts produced interpretations that were compliant with key features in existing structural models. Those interpretations that were less compliant to existing models, better accounted for features present in natural and experimental analogues. This has implications for the general applicability of structural models in interpretation.

Dynamics of uncertainty in geological interpretation

Abstract: Interpretation of geological data is based on both personal judgement and previous experience of related scenarios. In combining such information geologists employ heuristics (rules of thumb), and are therefore subject to biases that are well known in cognitive psychology and are common to all expert judgements. Here we analyse dynamic uncertainty in an evolving geological interpretation. Through a well-designed elicitation process we show how the inclusion of multiple experts influences interpretational bias. In particular, group convergence of opinion is observed, and we show how this can be differentiated from ‘herding' behaviour similar to that observed in economic bubbles by forcing a consensus to be reached. Thus we can identify when and why the judgement of a single geological expert should be treated with caution. This process can be applied to any geological interpretational scenario.