Geological Structural Analysis Research Articles

The dynamic evolution of the Lahendong geothermal system in North-Sulawesi, Indonesia

This study uses an integrated approach to characterize the dynamic evolution of the power-producing high-enthalpy geothermal system of Lahendong, North-Sulawesi, Indonesia. Lahendong has two primary reservoirs, the southern and the northern, which have been utilised for electricity production for more than twenty years. The main focus of this study is the characterisation of heat and mass flows in the system with respect to geological structures and permeability distribution. Also, it delineates how the geothermal system has evolved and the spatial variation of the response resulting from prolonged utilization of the reservoirs. This research implemented geological structure analysis on recent surface fault mapping and pre-existing fault studies from literature. Further, the study analysed well data comprising well pressure, enthalpy, drilling program reviews and tracer tests. Hydrochemical investigation compiled new and old surface and subsurface hydrochemical evolution in both the temporal and spatial domain. The results confirm several fault trends in the study area: NE-SW and NW-SE are the major striking directions, while E-W and N-S are less dominant. The most apparent trends are NE-SW striking strike-slip faults, NW-SE thrust faults and N-S and E-W striking normal faults. The faults compartmentalize the reservoir. A comparison of the southern and the northern reservoir shows that the southern one is more controlled by faults; both reservoirs rely on fractures as permeability provider and are controlled by shallow hydrogeology, as derived from the integrated analysis of transient well data. Geochemical analysis shows that the reservoir fluids have generally a higher eelectrical conductivity and are closer to fluid-rock equilibrium, probably due to boiling, compared to spring waters. Spring waters have generally become more acidic, which is an expected result of reservoir boiling and increased steam input to near-surface waters. The spatial distribution of changes shows a permeability evolution over time and also the role of structural permeability in response to changing reservoir conditions. Observing and recording reservoir data is highly important to understand the reservoir response to production and ensure the long-term sustainability of the system. Additionally, the data is critical for making a major difference in the reservoir management strategy.

Periodicity of Earth development for forecasting the next manifestations of disaster floods

Catastrophic floods on the rivers of the Western region of Ukraine occur with a frequency of 6–12–19 years. The last two floods of 2008 and 2020 caused significant damage to landscapes, economic infrastructure, and the population. In 2008 and 2020 alone, more than 20,000 houses were destroyed in 420 settlements in Ivano-Frankivsk, Lviv, Chernivtsi, Ternopil, Zakarpattia and Vinnytsia regions. More than 300 km of roads, 600 km of fortifications and 350 bridges were washed away. In 2008, 19 people died, including 5 children. Similar floods occurred in 1911, 1927, 1941, 1955, 1969, 1980, 1988. Therefore, it is important to study the causes of floods, the possibility of forecasting and warning to prevent and overcome the devastating effects. Therefore, on January 1, 2021, a separate structural subdivision was created at the Ivano-Frankivsk National Technical University of Oil and Gas (IFNTUOG) – the Center for Forecasting and Prevention of Technogenic and Hydroecological Danger of Prykarpattia (CFPTHDP). Materials and research methods were developed even earlier, since 2008, at the Dniester Engineering-Ecological Research-Training-Production Anti-Flood Landfill IFNTUOG by the staff of the Department of Ecology under the guidance of the author of the article. This is a systematic analysis of geological structure, geophysical fields, geomorphological and paleographic features, taking into account the data of archeology, dendrochronology, chronicle, historical and instrumental epochs of observations for 1881–2020. Forecasting, ie what area will be covered by the flood; prediction of its activity, ie at what maximum height the water will rise; and the weather forecast – when it will happen. The first two parts of the triad are predicted with a probability of 75–80%, but the third – so far, only 50%.

Exploration field analysis and zone optimization of sinian, Tarim Basin, China

Carbonate rock from the Late Proterozoic to the Early Paleozoic is an important field of oil and gas exploration. The Sinian carbonate rock series in Tarim Basin are old, deep buried, with few drilling wells and various geological problems are unclear that restrict the exploration of deep carbonate rock. Based on the analysis of Sinian geological structure, by means of stratigraphic correlation and seismic prediction, the distribution of Sinian favorable source rocks, deep reservoir facies belts, and reservoir forming assemblages are studied to comb the exploration fields and favorable zones of Sinian in Tarim Basin. The findings reveal that slope-basin facies source rocks developed in Sinian. In the upper part of the Qigebulake Formation, high-quality dolomite reservoirs evolved, and mudstone from the Yuertus Formation at the foot of Cambrian can form favorable reservoir cap assemblage. The south slope of Tabei Uplift and the north slope of Tazhong Uplift are the most favorable exploration zones for Sinian dolomite, favorable exploration area of approximately 31,000 km2. The findings can provide a certain reference for the Sinian carbonate oil and gas exploration in the Tarim Basin.

The Dashui Subduction Complex in the Eastern Tianshan‐Beishan Orogen (NW China): Long‐Lasting Subduction‐Accretion Terminated by Unique Mid‐Triassic Strike‐Slip Juxtaposition of Arcs in the Southern Altaids

AbstractComprehensive studies of the tectonic nature and the formation age of the Dashui complex in the Eastern Tianshan‐Beishan Orogen may address and help to better understand the complicated accretionary tectonics of the southern Altaids. Based on our detailed geological mapping, structural analysis, and understanding of new geochemistry and detrital zircon U‐Pb dating of critical samples, the Dashui complex can be subdivided into one mélange (Central Zone) and two units of forearc basin and slope basin (Northern and Southern Zones). The Northern Zone is composed of debris flows and turbidites. The Central Zone has a “block‐in‐matrix” structure, and the blocks of basalts have E‐MORB or N‐MORB geochemical signatures. The Southern Zone is characterized by debris flows. Therefore, we name these rocks Dashui subduction complex. Detrital zircons from the three zones show a major single age peak at ca. 460–420 Ma and a minor age peak at ca. 280–260 Ma, and the maximum depositional ages from north to south are: 264, 244 and 246 Ma, respectively, indicate that the Dashui subduction complex developed independently within an overall intra‐oceanic arc until ca. 244 Ma, and there must have been a large‐scale tectonic separation between the Central Tianshan Arc to the north and the Shuangyingshan Arc to the south. The structural geometry and kinematics of the Dashui complex and adjacent areas indicate that this complex likely experienced syn‐subduction thrusting and strike‐slip deformation. In particular, the late Xingxingxia strike‐slip faulting finally juxtaposed the Central Tianshan, Mazongshan, and Shuangyingshan arcs.

Cenozoic deformation in the eastern domain of the North Qaidam thrust belt, northern Tibetan Plateau

Abstract The present topography of the northern Tibetan Plateau is characterized by the northwest-trending Eastern Kunlun Range, Qaidam Basin, and Qilian Shan, which figure importantly into the evolution and mechanism of Tibetan plateau development during Cenozoic Indo-Asian convergence. Understanding the Cenozoic deformation history and the source-to-sink relationship through time has significant implications for deciphering the growth history of the northern Tibetan Plateau. Despite decades of study, the timing, pattern, and mechanisms of deformation across the northern Tibetan Plateau are still vigorously debated. The North Qaidam thrust belt, located between the Qaidam Basin and Qilian Shan thrust belt, provides a valuable record of Cenozoic deformation in the northern Tibetan Plateau. Here, we present the results of new geologic mapping, structural and sedimentology analysis, and apatite fission track thermochronology to constrain the Cenozoic evolution history and reconstruct the paleogeomorphology of the eastern domain of the North Qaidam thrust belt and its foreland, the Wulan Basin. Our analyses reveal the North Qaidam thrust belt experienced multi-phase exhumation since the Cretaceous. A period of Eocene localized thrust-related uplift of the North Qaidam thrust belt initiated shortly after India-Asia collision, and lower erosion rates in the Oligocene allowed the thrust belt to expand along-strike eastward. Local uplift shed sediments to the southwest, directly into the Qaidam Basin. Reactivation of the proximal thrust faults and initiation of the northwest-striking right-slip Elashan fault at ca. 15–10 Ma drove the final accelerated mid-Miocene cooling and denudation to the surface. This phase of deformation established the overall framework morphology of the northeastern margin of the Tibetan Plateau, including the overall structure of the basins and ranges.

Complete deformation history of the transition zone between oblique and orthogonal collision belts of the SE Tibetan Plateau: Crustal shortening and rotation caused by the indentation of India into Eurasia

The successive indentation of India into Eurasia generated the orthogonal collisional E–W Himalaya–Tibet and the oblique collisional N–S SE Tibetan Plateau along the frontal and eastern edges of the indenter, respectively. An understanding of the complete crustal deformation history of both regions is needed to reconstruct the processes involved in this indentation. Geological mapping and structural analysis of the transitional zone between these collisional belts reveal two stages of structures with different geometries. The earlier of these stages involves structures with an unusual structural association consisting of en échelon aligned overturned dome-and-thrust pairs within a background of open folding, most likely representing the early development of a fold-and-thrust system. The later structures consist of an association of N–S-trending thrust-and-tear-faults and open folds. Combining stratigraphic data from this region with the results of previous research indicates that the earlier structures formed at 60−48 Ma, whereas the later structures formed between the early Miocene and ca. 5 Ma. This information combined with geological and paleomagnetic data for the region allows reconstruction of the complete crustal deformation history of the oblique collisional belt, which consists of early and late stages of crustal shortening separated by a middle stage involving the ∼80° clockwise rotation of the crust. The spatiotemporally variable crustal deformation of the oblique collision belt combined with the long-lived N–S crustal shortening of the orthogonal belt outline a consistent tectonic scenario within a single geodynamic system that enables the reconstruction of the indentation of India into Eurasia.

Application of Very Low Frequency (VLF) Method for Estimating Karst Underground River in Tanjungsari District

Drought is the main problem for clean water needs in Tanjungsari district. This research aims to provide information on the existence of underground river for deep well drilling. The methods used are geologic-structural analysis and application of Very Low Frequency (VLF) methods. Strike and dip measurements of 150 joints were conducted in the research area. Analysis using rosette diagram shows that the main geologic-structure orientation has a direction of Northwest - Southeast and Northeast – Southwest. Very Low Frequency (VLF) acquisition was measured across the possible occurrence of subsurface water flow directions predicted from geologic-structural analysis. The length of the VLF acquisition line is 2500 meters with 30 m spacing and 108 points acquisitions. The direction of VLF line is N 2700 E. The result shows that there are 2 locations that have high conductivity values, appearing at 1800 meters and 2200 meters. The results of this structural and VLF analyses indicate the existence of underground river at the location of 454326 N, 9105870 E.

Complex shape of the Palaeoproterozoic Serpovidny refolded mega-sheath fold in northern Fennoscandia revealed by magnetic and structural data

The Serpovidny large-scale synform located in the Arctic zone of the north-eastern Fennoscandian Shield was studied with geological mapping and structural analysis, and its core with a ground detailed magnetic survey. This is a tight to isoclinal mega-sheath fold with the strongly thinned lower limb, almost undeformed upper limb, and the ՙcat's eye՚ core. The innermost rift-related sequence of the fold core is a synformal anticline, whilst limbs are composed of Palaeoproterozoic Keivy Group (metamorphosed redeposited products of mainly deep chemical weathering) and form a syncline. The Serpovidny mega-sheath fold formed during progressive non-coaxial, high strain deformation in simple shear/general shear regimes and a northward thrusting under mid-crustal conditions. This mega-sheath fold evolved from a NNE-verging anticline originated at the base of a nappe transported north-northeastwards from the Palaeoproterozoic Imandra-Varzuga Rift-Belt during the 1.9 Ga Lapland-Kola collisional orogeny. After a thrusting of this nappe onto the Keivy Group, one anticline plunged into these rocks and was transformed into the NNE-closing Serpovidny mega-sheath fold. Its geometric parameters and/or kinematic evolution are close to those of mega-sheath folds in Cretaceous rocks in the Oman Mountains, large-scale synformal anticlines in the Helvetic nappes in the Alps, and a Caledonian nappe in northwest Ireland.

Alpine peak pressure and tectono-metamorphic history of the Monte Rosa nappe: evidence from the cirque du V\xe9raz, upper Ayas valley, Italy

The Monte Rosa nappe consists of a wide range of lithologies that record conditions associated with peak Alpine metamorphism. While peak temperature conditions inferred from previous studies largely agree, variable peak pressures have been estimated for the Alpine high-pressure metamorphic event. Small volumes of whiteschist lithologies with the assemblage chloritoid + phengite + talc + quartz record peak pressures up to 0.6 GPa higher compared to associated metapelitic and metagranitic lithologies, which yield a peak pressure of ca. 1.6 GPa. The reason for this pressure difference is disputed, and proposed explanations include tectonic mixing of rocks from different burial depths (mélange) or local deviations of the pressure from the lithostatic value caused by heterogeneous stress conditions between rocks of contrasting mechanical properties. We present results of detailed field mapping, structural analysis and a new geological map for a part of the Monte Rosa nappe exposed at the cirque du Véraz field area (head of the Ayas valley, Italy). Results of the geological mapping and structural analysis shows the structural coherency within the western portions of the Monte Rosa nappe. This structural coherency falsifies the hypothesis of a tectonic mélange as reason for peak pressure variations. Structural analysis indicates two major Alpine deformation events, in agreement with earlier studies: (1) north-directed nappe emplacement, and (2) south-directed backfolding. We also analyze a newly discovered whiteschist body, which is located at the intrusive contact between Monte Rosa metagranite and surrounding metapelites. This location is different to previous whiteschist occurrences, which were entirely embedded within metagranite. Thermodynamic calculations using metamorphic assemblage diagrams resulted in 2.1 ± 0.2 GPa and 560 ± 20 °C for peak Alpine metamorphic conditions. These results agree with metamorphic conditions inferred for previously investigated nearby whiteschist outcrops embedded in metagranite. The new results, hence, confirm the peak pressure differences between whiteschists and the metagranite and metapelite. To better constrain the prograde pressure–temperature history of the whiteschist, we compare measured Mg zoning in chloritoid with Mg zoning predicted by fractional crystallization pseudo-section modelling for several hypothetical pressure–temperature paths. In order to reach a ca. 0.6 GPa higher peak pressure compared to the metapelite and metagranite, our results suggest that the whiteschist likely deviated from the prograde burial path recorded in metapelite and metagranite lithologies. However, the exact conditions at which the whiteschist pressure deviated are still contentious due to the strong temperature dependency of Mg partitioning in whiteschist assemblages. Our pseudo-section results suggest at least that there was no dramatic isothermal pressure increase recorded in the whiteschist.

Geometry and kinematics of right‐lateral transpressional faults and growth folds, the western side of the Gulf of Suez, Egypt

Elaborated geological mapping and structural analysis of the Gulf of Suez's western side revealed two superimposed tectonic regimes; Late Cretaceous‐Early Eocene dextral transpression along ENE‐oriented deep‐seated faults and NE Oligo‐Miocene extension. Pre‐rift structures are represented by four ENE‐oriented right‐lateral strike‐slip deformation zones (DZ). Each DZ is defined by the ENE‐oriented right‐lateral strike‐slip faults, NE to ENE growth folds, and NW‐oriented normal faults. The orthogonal relation between the growth folds and NW‐oriented faults indicates their association to a strike‐slip tectonic regime. The tight overturned folds and the small angles between the growth fold axis and the principal deformation zone implies transpression rather than simple shearing. A transpressional tectonic regime with NW‐SE maximum principal stress (σ1) and NE‐SW minimum principal stress (σ3) were dominantly active during Late Cretaceous‐Early Eocene. The occurrence of three angular unconformities at different stratigraphic levels within the Upper Cretaceous‐Lower Eocene sedimentary sequences infer the deformation age. ENE anticlines have grown above the propagating deep‐seated transpressional faults, associated with continuous exhumation along their hinge zones and syntectonic deposition in the sub‐basins beyond their steep limbs.

Detailed studies of geological structure and new data analysis: Domanik-type series within southern shoulder of Mukhanovo-Erokhovsky Trough

Detailed studies of geological structure and new data analysis: Domanik-type series within southern shoulder of Mukhanovo-Erokhovsky Trough

Cenozoic structural evolution of the Catalina metamorphic core complex and reassembly of Laramide reverse faults, southeastern Arizona, USA

AbstractThis study investigates the Late Cretaceous through mid-Cenozoic structural evolution of the Catalina core complex and adjacent areas by integrating new geologic mapping, structural analysis, and geochronologic data. Multiple generations of normal faults associated with mid-Cenozoic extensional deformation cut across older reverse faults that formed during the Laramide orogeny. A proposed stepwise, cross-sectional structural reconstruction of mid-Cenozoic extension satisfies surface geologic and reflection seismologic constraints, balances, and indicates that detachment faults played no role in the formation of the core complex and Laramide reverse faults represent major thick-skinned structures.The orientations of the oldest synextensional strata, pre-shortening normal faults, and pre-Cenozoic strata unaffected by Laramide compression indicate that rocks across most of the study area were steeply tilted east since the mid-Cenozoic. Crosscutting relations between faults and synextensional strata reveal that sequential generations of primarily down-to-the-west, mid-Cenozoic normal faults produced the net eastward tilting of ∼60°. Restorations of the balanced cross section demonstrate that Cenozoic normal faults were originally steeply dipping and resulted in an estimated 59 km or 120% extension across the study area. Representative segments of those gently dipping faults are exposed at shallow, intermediate (∼5–10 km), and deep structural levels (∼10–20 km), as distinguished by the nature of deformation in the exhumed footwall, and these segments all restore to high angles, which indicates that they were not listric. Offset on major normal faults does not exceed 11 km, as opposed to tens of kilometers of offset commonly ascribed to “detachment” faults in most interpretations of this and other Cordilleran metamorphic core complexes. Once mid-Cenozoic extension is restored, reverse faults with moderate to steep original dips bound basement-cored uplifts that exhibit significant involvement of basement rocks. Net vertical uplift from all reverse faults is estimated to be 9.4 km, and estimated total shortening was 12 km or 20%. This magnitude of uplift is consistent with the vast exposure of metamorphosed and foliated cover strata in the northeastern and eastern Santa Catalina and Rincon Mountains and with the distribution of subsequently dismembered mid-Cenozoic erosion surfaces along the San Pedro Valley. New and existing geochronologic data constrain the timing of offset on local reverse faults to ca. 75–54 Ma.The thick-skinned style of Laramide shortening in the area is consistent with the structure of surrounding locales. Because detachment faults do not appear to have resulted in the formation of the Catalina core complex, other extensional systems that have been interpreted within the context of detachments may require further structural analyses including identification of crosscutting relations between generations of normal faults and palinspastic reconstructions.

An integrated approach to assessment of petroleum potential and geological characteristics of the West Siberian oil and gas basin’s eastern edge within the limits of Noyabrsk region

Background. Decline of oil and gas traditional reserves pushes companies to explore and involve in production complex reservoirs which results in exploration risks increase. That is why an exploration research has to be integrational and its’ main result has to be determination and decreasing uncertainties. Aim. The aim of this research is the planning of further exploration program within the studied territory, based on the main uncertainties and trends in geological development. Materials and methods. Several types of research methods were applied, including field observation, laboratory analysis and geological desktop studies. The results of petroleum systems modeling is the basis for source rocks maturity prediction, the main stages of hydrocarbons generation — migration and critical moment estimation. It also provided the analysis of migration distance (limits) and geological risks related to it, petroleum saturation prediction for the main plays. Great emphasis was also placed on the search and processing of additional archival data, which made it possible to significantly detail the structural-tectonic framework of the studied area. Results. Consistent progression in field observation, laboratory analysis and geological desktop studies allowed to narrow the range of uncertainties, clarify the chance of geological success (gCOS), plan the further exploration program, and highlight higher-priority license blocks. As a result, more than 60 additional prospects were identified, for each of them both the probabilistic estimation of oil and gas resources and chance of geological success evaluation were made. Moreover, the further exploration program was approved. Conclusions. Therefore, the study allowed to analyse main uncertainties and correct further exploration program on the basis of integrated analysis of geological development history and geological structure of the studied area.

Geometry, kinematics, and magnitude of extension across the Thakkhola Graben, Central Nepal Himalaya

The Thakkhola Graben has been a region of geologic inquiry for many decades. Although it is widely viewed to be in a class of structures that are important in accommodating the three-dimensional strain within the Himalayan thrust wedge, we still lack a detailed understanding of the total finite strain accommodated by graben-bounding faults, as well as their shape and cross-cutting relationships with structures deeper in the thrust wedge. Using geologic mapping and structural analysis, we show that a suite of pre-extensional shortening structures is offset by normal-oblique faults bounding the Thakkhola Graben that we use to define a piercing line. We calculate these faults to have accommodated 8.7 kilometers of vertical thinning, 7.2 kilometers of arc-perpendicular shear, and only 2.2 kilometers of arc-parallel extension. The magnitude of arc-parallel extension is quite low compared to extensional structures to the west in the Gurla Mandhata-Humla region. The cross-cutting relationships established in this study and timing constraints determined by previous works are consistent with a structural history of crustal thickening leading to foreland propagation of the locus of arc-perpendicular shortening contemporaneous with hinterland extension.

Potensi Rembesan Hidrokarbon Dan Pola Struktur Geologi Di Daerah Kabupaten Barru

The background of this study is to provide the importance of hydrocarbon seepage information that can assist in conducting a petroleum system study, the existence of seepages on the earth's surface scattered in the Barru area has never been studied in detail. Through the analysis of geological structure analysis and hydrocarbon geochemical analysis, it has provided initial information about the presence of seepage in this region. Based on the structural pattern, the seepage position appears at the lithological contact between the Barru tectonic block and the carbonate sedimentary rock of the Tonasa Formation and is also controlled by the Northwest-Southeast (NW-SE) trending direction of structural lineament. Meanwhile, seepage in Ralla, Watu, and Ullo is controlled by the Northwest-Southeast (NW-SE) trending direction of structural lineament and is placed on the sedimentary rock of the carbonate rocks of Tonasa Formation. The results of the gas chromatography and mass spectrometry (GC-MS) determination also give different indications, namely: three locations show indications of hydrocarbon seepage with the composition of the aromatic hydrocarbons benzenediol (C 8 H 10 OS) , ethanone (C 7 H 8 O 3 ) and benzenetriol (C 6 H 6 O 3 ) , two locations are including in gas seepage which is characterized by the content of ethanol (C 2 H 6 O) and phenol (C6H6O). The presence of alkane compounds (heptadecane, octadecane, and nanodecane) indicates hydrocarbon potential in Ralla Area.

Formalized Lineament Analysis of Geological Structures in the Baikal Region

Formalized Lineament Analysis of Geological Structures in the Baikal Region

Газоносность по свободным газам пород сильвинитовой и сильвинито-карналлитовой зон Верхнекамского месторождения

The results of the mine and the laboratory studies of the free gas content of the sylvinite and sylvinite-carnallite zones of the Upper Kama districts are presented. In the process of the experimental studies, the quantitative characteristics of the free gas content were obtained for sylvinite, carnallite and rock salt layers. In the process of the laboratory studies by the gas chromatography of the natural gas samples, the component composition of the free gases was assessed. Based on the geological structure analysis and the gas content study, the assessment of the composition, the volume, the location and the intensity of the natural gases release is given. Based on the experimental studies results of the free gas content, and an analysis of the locations, the volume and the intensity of the gas emissions, the probable places of the free gases accumulation are installed. The main which are the anticlinal folds inflection the rupture and the crushing, the fractures, the tectonic disturbances, the transition of the sylvinites into the carnallite and the composition changes of the layers.

Prediction method of landslide geological hazard based on AdaBoost model

Aiming at the problem of landslide geological disaster prediction, based on the analysis of geological structure and historical disaster data of a county in southwest Shaanxi, this paper puts forward a landslide geological disaster prediction model based on AdaBoost. Firstly, the data of landslide geological disasters are analyzed, and the main factors of landslide geological disasters are determined by principal component analysis and Spearman grade correlation coefficient method. Then, the main factors are used as feature data to train the model, and grid search is used to optimize the super parameters in the model. Finally, experiments on real data sets show that the prediction accuracy of AdaBoost model is 1.5% higher than the best prediction results of decision tree, logistic regression, support vector machine and k-nearest neighbor method, and AUC is 0.24% higher. It further verifies the effectiveness and feasibility of the model, which can provide a scientific basis for the prediction of landslide geological disasters.

Geothermal Well Targeting in Consideration To Geological Structures of Mataloko Field, Flores

Mataloko is one of the geothermal fields on the island of Flores, East Nusa Tenggara, which is an area of exploration, production and is expected to be able to be used for electricity generation. Geologically, Mataloko area is quite strong affected by faults and fractures geological structures. Drilling geothermal well should be considered carefully in respond to active tectonic activity in Nusa Tenggara islands in particular Flores. Directional drilling should be planned in an area where geological structures are less affection to the well drill direction. Wae Luja – Ratogesa area is an example area where geological structures should be considered accurately. Results of geological mapping have significant attention to geological structures while geophysical data analysis should be heavily considered for subsurface geological structural analysis. Exploration shallow wells have been drilled to a depth of 756.47 meters showing temperature of above 185 degrees Celsius. Using geological as well as geophysical data analysis, it is interpreted that base of cap rock is approximately at the elevation of +855 masl to +20 masl. Combining the analysis results directional drilling could be planned carefully.

Geological Structure and Tectonic Reconstruction of Botutonuo and Surrounding Areas, Gorontalo

The research aimed to reconstruct the geological structure and tectonics based on fault, shear fracture and veins data of the Botutonuo and surrounding areas. This research was conducted with DEM interpretation method to determine the lineament pattern of rock offsets and the geological structure mapping method. Geological structure analysis was carried out by using kinematic analysis method of fault, fracture and veins data using the Win Tensor program to obtain the direction and type of stress forming it. Based on the results of the analysis, extensive stress and transtensive stress trendingN-S resulted direction of Normal Fault and Slip Fault (NE-SW). Extensional stress trending (NE-SW) is the result of reorientation stress trending (N-S) in the North Sulawesi arm which is accommodated by the Gorontalo Fault regime. Normal fault and slip fault are the 2nd order faults of the 1st order faults of Gorontalo faults.