geological formation
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2022 ◽  
Vol 10 (1) ◽  
pp. 129
Author(s):  
Julia Meyer ◽  
Sheri Zakhary ◽  
Marie Larocque ◽  
Cassandre S. Lazar

Microbial communities play an important role in shallow terrestrial subsurface ecosystems. Most studies of this habitat have focused on planktonic communities that are found in the groundwater of aquifer systems and only target specific microbial groups. Therefore, a systematic understanding of the processes that govern the assembly of endolithic and sessile communities is still missing. This study aims to understand the effect of depth and biotic factors on these communities, to better unravel their origins and to compare their composition with the communities detected in groundwater. To do so, we collected samples from two profiles (~0–50 m) in aquifer sites in the Laurentians (Quebec, Canada), performed DNA extractions and Illumina sequencing. The results suggest that changes in geological material characteristics with depth represent a strong ecological and phylogenetical filter for most archaeal and bacterial communities. Additionally, the vertical movement of water from the surface plays a major role in shallow subsurface microbial assembly processes. Furthermore, biotic interactions between bacteria and eukaryotes were mostly positive which may indicate cooperative or mutualistic potential associations, such as cross-feeding and/or syntrophic relationships in the terrestrial subsurface. Our results also point toward the importance of sampling both the geological formation and groundwater when it comes to studying its overall microbiology.


Author(s):  
Fitri Mairizki ◽  
Arief Yandra Putra ◽  
Widya Adiza Putri ◽  
Ferdyansyah

Groundwater plays important role as the main water resource for human needs. The vulnerability of groundwater to contaminants both naturally and by human activities can be not avoided as a trigger for groundwater quality degradation. Hydrogeochemical become important highlights in groundwater studies because groundwater conditions in quality and quantity influenced by the geological formation of rock minerals in aquifer. Naturally, the condition of the research area which consists of peat swamps can also affect the characteristics of groundwater. The aims of this research are to determine groundwater types and groundwater facies in study area with an analytical approach using stiff diagram and piper diagram. The method used was purposive sampling by collecting data from dug wells at the research site. 5 samples from dug wells were used as representatives in the groundwater facies analysis. The groundwater facies analysis was carried out by measuring the concentration of major ions such as Na, K, Ca, Mg, Cl, SO4, and HCO3. The highest groundwater level was in the northern part of study area (7,84 m) while the lowest groundwater level was in the southwest part of study area (2,05 m). The results showed three types of groundwater based on stiff diagram as sodium chloride (NaCl), sodium sulfate (NaSO4) and magnesium sulfate (MgSO4). The lithology conditions that composed the aquifer affected the facies or origin of groundwater. The alluvium layer in the research area which rich in sodium (Na+) minerals with chloride (Cl-) or sulfate (SO42-) anions forms chloride sulfate facies (Cl+SO4) which were located in the middle to the south of the study area and sodium (potassium) chloride (sulfate) facies (Na(K)Cl(SO4)) which were distributed in the northern part of study area.


2021 ◽  
Author(s):  
Abubakar Ahmed jajere ◽  
Muhammad Bibi ◽  
Ado Usman Kibon ◽  
Usman Adamu

Abstract Understanding the availability and distribution of wetlands is key to conservation, exploitation and better management of wetlands resources. The wetlands of Kumadugu-Yobe river basin are widely spread within the sedimentary formation beyond the famous Hadejia Nguru wetlands. This study identified and map out the spatial distribution of KYRB wetlands using field observation information, the basin base map, the topographical map and high resolution Google image and Advance very High Resolution spectroradiometer (AVHRS) NDVI (Normalized Vegetation Differncial Index) data of 2018, in mapping the wetlands spatial distribution pattern. The findings of the study classified the basin wetlands in to flood plain along the river banks, surface depressions ponds and Oasis. The basin wetlands are spread all over the sedimentary geological formation of the basin. The wetlands of the mid and downstream parts of KYRB are largely spread along river Yobe, river Kumadugu-Gana, small tributaries (Alaraba, Damaturu, Budum-Gana among others), famous Hadejia-Nguru wetlands, Oases at the northern parts of the river Yobe and isolated pockets of ponds. The study recommended for effective geo data base for the wetlands.


Author(s):  
Muhd Syamir Sobri ◽  
◽  
Ahmad Khairul Abd Malik ◽  
Mohd Firdaus Md Dan ◽  
Hamzah Hussin ◽  
...  

Water supply-demand is increasing in line with the increment in population. Natural water resources are declining due to reduction of water catchment areas, river pollution and drought. This causes the raw water quantity and quality to decrease and increase water treatment costs. Groundwater usage may be able to solve this problem due to its less polluted nature which requires less treatment. The groundwater is preserved in aquifer within the geological formations, i.e., in the alluvium and fractured-rock. However, the groundwater yield of each formation is unknown unless tube well is constructed and pumping test are performed. This study aim to evaluate the tube well performance via pumping test on two different geological formations. This research focuses on the effect of transmissivity, hydraulic conductivity, and efficiency of the aquifer, which are step-drawdown test, constant-rate test and recovery test in tube well in geological formation of alluvium and fractured rock. Three well-pumping tests at each formation were conducted at IBS Universiti Malaysia Kelantan (UMK), Kelantan, Sekolah Kebangsaan Chantum, Kelantan, Sekolah Menengah Kebangsaan Agama Tok Bachok, Kelantan, FRU Wakaf Tapai, Terengganu, Kampung Dada Kering, Kuala Lipis, Pahang, and Kampung Seri Gunung Pulai, Johor, respectively. The aquifer efficiency obtained from the relationship between transmissivity and hydraulic conductivity. The suggested value of 75% efficiency is selected to present the well’s efficiency. The wells efficiency indicate that the alluvium formation has roughly uniform output between 9.39m3/h, 11.23m3/h and 23.38m3/h. Meanwhile in the fractured rock formation the efficiency was highly varied between sites, the highest is 32.33m3/h and the other two sites obtained has low output of 3.44 m3/h and 1.00m3/h respectively. The alluvium aquifer showed uniform water production compared to fractured hard rock aquifer. Meanwhile the water quantity in the fractured hard rock formation is unpredicted, which subjected to the fractured rock characteristic.


2021 ◽  
Author(s):  
Philippe Nivlet ◽  
Yunlai Yang ◽  
Arturo Magana-Mora ◽  
Mahmoud Abughaban ◽  
Ayodeji Abegunde

Abstract Overpressure refers to the abnormally high subsurface pressure that may exceed hydrostatic pressure at a given depth. Its characterization is an important part of subsurface characterization as it allows to complete drilling operations in a safe and optimal way. In dolomitic formations, however, the prediction of such overpressure is especially challenging because of (1) the high degree of lateral variability of the formations, (2) the limited effect of overpressure on tight rocks elastic parameters, and (3) the complexity of physical processes involved to form overpressure. In addition to these factors, existing experimental models generally used to relate elastic parameters to pressure are often not well calibrated to carbonate rocks. The alternative to existing purely physical approaches is a data-driven model that leverages data from offset wells. We show that due to the complexity of the characterization question to be solved, an end-to-end machine learning based approach is deemed to fail. Instead of a fully automated approach, we show a semi-supervised workflow that integrates seismic, geological data, and overpressure observations from previously drilled wells to map overpressure regions. Attribute maps are first extracted from a 3D seismic data set in an overpressured geological formation of interest. An auto-encoder is then used to learn a more compact representation of data, resulting in a reduced number of latent attributes. Then, a hand-tailored semi-supervised approach is applied, which is a combination of clustering method (here based on DBSCAN algorithm) and Bayesian classification to determine overpressure risk degree (no risk, mild, or high risk). The approach described in this study is compared to direct end-to-end models and significantly outperforms them with an error on a blind well prediction of around 25%. The overpressure probability maps resulting from the models can be used later for the optimization of drilling processes and to reduce drilling hazards.


2021 ◽  
Author(s):  
Xavier Du Bernard ◽  
Jonathan Gallon ◽  
Jérôme Massot

Abstract After two years of development, the GAIA Explorer is now ready to assist Geoscientists at Total! This knowledge platform works like a little Google, but with a focus solely on Geosciences - for the time being. The main goal of the GAIA Explorer is to save time finding the right information. Therefore, it is particularly useful for datarooms or after business acquisitions to quickly digest the knowledge, but also for feeding databases, exploration syntheses, reservoir studies, or even staff onboarding specially when remote working. With this additional time, Geoscientists can focus on tasks with added value, such as to synthesize, find analogies or propose alternative scenarios. This new companion automatically organizes and extracts knowledge from a large number of unstructured technical documents by using Machine Learning (ML). All the models relie on Google Cloud Platform (GCP) and have been trained on our own datasets, which cover main petroleum domains such as geosciences and operations. First, the layout of more than 75,000 document pages were analyzed for training a segmentation model, which extracts three types of content (text, images and tables). Secondly, the text content extracted from about 6,500 documents labelled amongst 30 classes was used to train a model for document classification. Thirdly, more than 55,000 images were categorized amongst 45 classes to customize a model of image classification covering a large panel of figures such as maps, logs, seismic sections, or core pictures. Finally, all the terms (n-grams) extracted from objects are compared with an inhouse thesaurus to automatically tag related topics such as basin, field, geological formation, acquisition, measure. All these elementary bricks are connected and used for feeding a knowledge database that can be quickly and exhaustively searched. Today, the GAIA Explorer searches within texts, images and tables from a corpus (document collection), which can be made up of both technical and operational reports, meeting presentations and academic publications. By combining queries (keywords or natural language) with a large array of filters (by classes and topics), the outcomes are easily refined and exploitable. Since the release of a production version in February 2021 at Total, about 180 users for 30 projects regularly use the tool for exploration and development purposes. This first version is following a continuous training cycle including active learning and, preliminary user feedback is good and admits that some information would have been difficult to locate without the GAIA Explorer. In the future, the GAIA Explorer could be significantly improved by implementing knowledge graph based on an ontology dedicated specific to petroleum domains. Along with the help of Specialists in related activities such as drilling, project or contract, the tool could cover the complete range of upstream topics and be useful for other business with time.


2021 ◽  
Author(s):  
Minaibim E. Abbey ◽  
Dennis E. Onyebueke ◽  
Godspower O. Ashaka ◽  
Chikanso K. Ezeife

Abstract Groundwater has remained indispensable in Enugu state Nigeria owing to industrialization, lack of surface water, and significant depth to aquifer in the area. A geophysical investigation involving vertical electrical soundings was conducted in order to evaluate groundwater potential at some locations in the Udi Local Government Area of Enugu State. With the aid of resistivity instrument ABEM Terrameter, four (4) Vertical Electrical Sounding using Schlumberger configuration were conducted, and the data acquired was interpreted using WINRESIST software. Information obtains from the survey shows that the underlying geological formation in those areas has between 5 – 7 layers. The apparent resistivity obtained in all the layers of the locations ranges from 47.1 – 6956.8 Ωm, while the aquifer was interpreted to exist at a depth between 90 – 120m. Result obtained from this geophysical investigation has shown that the survey area possesses a good groundwater potential which will go a long way in cushioning the effect associated with water scarcity in the area if exploited.


2021 ◽  
Author(s):  
Norhanim Abdul Razak ◽  

The paper applied a content analysis method to examine how myths and legends have been employed by the promotional organization in portraying New Zealand on the official tourism website. The assessment of the website uncovered six main legends which have been presented in the promotion of New Zealand to potential tourists. These traditional tales have been incorporated into the website chiefly as part of Maori heritage attributes in which purakau (the Maori term for legends) represents among crucial aspects in understanding their worldviews and cultural identities. Legends narrating fishing voyages involving demi gods offers a mythological explanation of the origin of the geological formation of islands of New Zealand were presented more than once on the website. Among the legends presented to readers on the websites encompass stories of Tane Mahuta, which depicts the tale of the sky father, the earth mother, and the creation of the world of light that humans live in today. Another unique legend, Paikea the whale rider, is featured as part of the description of a whale-watching attraction in Kaikoura, Christchurch. The overall analysis uncovered that legendary tales are incorporated into the website as the part historical origin of Maori people and in the promotion of several tourist attractions in New Zealand. From a tourism perspective, the representation of these tales enhances the appeal of destinations and make them stand out to visitors. The inclusion of the purakau offers tourists a deeper understanding of the cultural heritage of this country. Furthermore, Maori worldviews on the creation of the universe and formation of the natural environment are transpired. It is noticeable through these legends that Maori people strongly respect their ancestors and highly appreciated natural resources. Finally, the emphasis on environmental conservation and sustainability as ingrained in the tales further supported the overall promotional tagline of 100% Pure New Zealand and the inclusion of Tiaki Promise a commitment to care for New Zealand, for now, and for future generations on the official tourism website.


2021 ◽  
Author(s):  
Yuriko Furuhata

Abstract This article examines the intertwined cultural politics of geology, mining, and archival media in the context of Japan’s development as an archipelagic empire. The first Japanese geological map (1876) was completed by American geologist Benjamin Smith Lyman, who surveyed mineral deposits in Hokkaidō, Japan’s northern island, long inhabited by the Indigenous Ainu people. Following decolonial and archipelagic thoughts, the author reads across earthly archives of geological strata and colonial archives of historical documents to elucidate the conceptual duality of archipelago as a geological formation and a geopolitical territory. In tracing this formative era of Japan’s resource extraction and settler colonialism, which precedes and informs the current rush to extract rare earth minerals necessary to maintain global digital infrastructures, this article aims to both de-Westernize the methodological orientation known as media geology and offer a prehistory of contemporary rare earth mining in the Pacific Ocean.


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