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Lakes in the Dhaka city have been facing extreme deterioration both by quantity and quality due to rapid urban and population growth for several decades. The prime objective is to assess the spatiotemporal changes of water quality and water quantity of the Dhaka city lakes respectively using Sentinel 2B and Landsat satellite images. The study covers the major twelve lakes of the Dhaka city. The four seasonal water qualities such as chlorophyll-a concentration, trophic state index (TSI), Secchi disk depth (SDD) and turbidity were retrieved with the conventional algorithms using Sentinel 2B images. The results showed that the Uttara Park Lake reduced its area dramatically from 1972 to 2020 due to the rapid urbanization in this region. Although the Zoo Lakes areas increased more than three times but the Banani, Hatirjheel and Dhanmondi lakes reduced to about 60-75% from 1972 to 2020 due to the urbanization and filling up the lake’s area. On the other hand, Gulshan, Crescent and Ramna Lakes reduced their area slightly about 10-20% during the study period. The chlorophyll-a concentration from post to pre-monsoon, increased in six lakes (Uttara Park, Zoo North, Gulshan, Old Airport, Dhanmondi and Hatirjheel), declined in six lakes (Zoo South, Banani, Ramna, Uttara, Uttara South and Crescent) of Dhaka city. Although the TSI illustrated all lakes in the eutrophic states from post to pre-monsoon but the value of TSI increased in six lakes and declined six lakes of the twelve point samples within the retrieved spatial distribution of TSI using satellite images of Dhaka city. In case of Secchi depth, the SDD values declined from post-monsoon to pre-monsoon in all of the lakes, indicating the deteriorating water quality of the lakes. On the other hand, the turbidity values increased in all lakes of Dhaka city from post-monsoon to pre-monsoon. We observed pH values ranges from 7-9 in the lakes during the field works early March and May of 2021. The observed EC values of the lakes ranges from 148-730μs/cm and 130-690μs/cm respectively in winter and pre-monsoon seasons. None of the samples of the lakes meets the standard of dissolved oxygen (DO) collected in March, 2021, but Dhanmondi and Uttara Lake samples collected in May, 2021 meet the standard. Biological oxygen demand (BOD) value is extremely high and none of the samples meets the acceptable limit of BOD. Among the cations, only Hatirjheel, Gulshan, Uttara, Uttara South/W, Zoo South and North Lake exceeded the acceptable limit for K⁺. Among the anions, Hatirjheel, Gulshan, Banani, Uttara, Uttara South/W Lake exceed the standard for HCO3− and Hatirjheel, Gulshan, Banani, Old Airport, Uttara Park, Uttara South/W Lake exceed the standard limit for NO3−. Uttara Lake shows the maximum concentration of PO43− and does not meet the standard limit. All the samples meet the standard for Fe and Mn. The outputs of this study could be used to minimize the degradation of Dhaka city lakes both in terms of quantity and quality and will help take necessary measures for healthy and sustainable lake environment. The Dhaka University Journal of Earth and Environmental Sciences, Vol. 11(1), 2022, P 27-42

Soil erosion due to anthropogenic interventions is an emerging threat to the south-eastern coastal districts of Bangladesh. In the recent decade, land degradation intensified this process in this region due to the settlement of the Forcibly Displaced Myanmar Nationals (FDMNs) popularly known as ‘Rohingya’, who fled from Myanmar in 2017. The present study has attempted to quantify the regional soil loss (from 2015 to 2020) using the Revised Universal Soil Loss Equation (RUSLE) model. Results showed that the year 2015 and 2020 witnessed the mean soil erosion at a rate of around 58.2 and 59 t ha-1 yr-1, respectively in the Cox’s Bazar district in which 20 - 21% of the study area was highly subjected to soil erosion. But in the Rohingya camps mean soil erosion for these periods is 59 and 78 t ha-1 yr-1, respectively with a cumulative increase of 32%. The sub-districts adjacent to the Rohingya refugee camps (Ramu, Ukhia, and Teknaf) have experienced intense erosion compared to the others. From 2015 to 2020, a large increase of about 4.54 (6%) t ha-1 yr-1 is observed in the Palongkhali union whereas a maximum decrease of about - 8.08 (23%) t ha-1 yr-1 is observed in the Pokkhali union. In Rohingya camps, the worst soil erosion-affected areas are the camps 8E, 10, 14, 15, 16, and 17 having more than 100 t ha-1 yr-1 mean soil loss. Landuse change is the major contributing factor for soil erosion increase from 2015 to 2020 identified from the geographic detector method. The spatial variations are significantly controlled by slope and elevation factors. This work can help to understand the dynamics of soil erosion and the knowledge can be used for conservation planning in the Cox’s Bazar and Rohingya camp areas.

Beaches in estuaries and bays (BEBs) are usually distinct from open coast beaches in terms of environment, process, and morphology, and their morphodynamics remain unresolved. The present study aims to establish a relationship between profile morphology, sediment characteristics, and hydrodynamic forces. We investigated four beaches of Gamay (Botany Bay) located in the south of Sydney, SE Australia. Profiles of these beaches were measured regularly from 2016 to 2022 and sediment samples were collected from each beach. Wave data were recorded from the Sydney Waverider buoy. We used principal component analysis (PCA) to ascertain the temporal and spatial scales of the data variability, and spectral analyses to investigate the waves. Sediment samples were analyzed by Laser Diffraction Particle Size Analyzer (Mastersizer 3000).Our preliminary results indicate that different profile morphotypes are associated with different sediment characteristics and wave climates on BEBs. BEBs with the least exposure to ocean swell waves have the narrowest and steepest profiles, with BEBs more exposed to ocean swells having moderately steep profiles. BEBs containing coarser sediments show steep profiles compared to beaches with fine to very fine-grained sediments. In general, the shape of profiles changes in order from straight-through concave to convex-concave with increasing wave energy. Current research aims to parameterize these relationships with offshore and locally generated wave parameters. The insights obtained from this study will assist to understand fundamental mechanisms governing the morphological evolution of BEBs.

The urbanization processes and its keen relationship with the spatio-temporal variability of land use-land cover (LULC), land surface temperature and urban heat island (HI) within the district towns in the Rangpur division of Bangladesh has been assessed using multi-spectral Landsat satellite images from 1991 to 2021.The supervised classification approach was used to retrieve LULC types such as water body, built-up area, bare land, agricultural land and vegetation cover. The results of LULC suggest that agricultural and bare land have decreased during the last 30 years in the study areas. The vegetation cover shows an average increase and built-up area has increased progressively from 1991 to 2021. Conspicuously the water bodies, agricultural and bare lands have reduced due to the expansion and rapid growth of settlement areas or urbanization. The spatio-temporal variability of Land Surface Temperature (LST) over the study area responsible for the development of the urban heat islands (UHIs) is assessed using the mono-window algorithm. The areal extents of the UHIs are spreading out day by day and have become most extensive in 2021. Correlation of LULC types with the HI and LST indicated that lower temperature zones were found in the water bodies, vegetated and agricultural lands whereas higher temperature zones were found in the bare lands or highly built-up areas within the district towns. Ground truth data have been validated well with the image processed results with an overall 86.25% classification accuracy which indicates a good level of accuracy of the detected LULC using satellite images. Thus, the research work will help in understanding the land cover dynamics, increasing LST and heat island growth, which could be further used for mitigating the socio-economic hazards faced by the communities in and around the study areas. The Dhaka University Journal of Earth and Environmental Sciences, Centennial Special Volume June 2022: 17-28

Accumulation of microplastic in the marine environment is of great concern and has been considered to be a growing problem in the coastal sediments of Bangladesh. This research represents the large...

Coal mining areas in Bangladesh are exposing to extreme environmental problems due to the mobilization of heavy metals in the surrounding region. To assess the persisting risk, several soil samples were collected from the nearby coal mine areas. The amount of pollution of heavy metal has been calculated to determine the extent of the contamination. Soil contamination assessment was carried out using pollution evaluation indices such as heavy metal pollution index (HPI), the degree of contamination (Cd), and the contamination factor (CF). The concentration of S, As, Ba and, F exceeded the maximum concentration level in some soil samples. The HPI and the Cd yield similar results. The CF shows strong similarities with the Cd and gives a better evaluation of pollution levels. HPI indicates that about 71.42% of samples exceed the high level. Cd and CF show that about 71.42% sample is highly contaminated by trace element and 14.28% sample is highly contaminated by S, Cl, and F. Based on radioactive element analysis about 14.28% samples show medium contamination level. The findings of this research help us to assess the level of soil contamination and the extent of environmental and health concerns in the region of the Barapukuria coal mine.

The study examined the spatiotemporal variability of land use/land cover changes (LULC), land surface temperature (LST), and heat island (HI) in northwestern Bangladesh. Landsat images were used for evaluating LULC, LST, and HI for the years 1990, 2002, 2014, and 2018. Unsupervised and index-based classification approaches were used for mapping LULC. The mono-window algorithm was employed to identify the spatiotemporal variability of LST and HI. The analysis suggested that water bodies, forests, and bare land dwindled during these 28 years with an average of about 40%, 70%, and 45%, respectively. Agricultural land had been expanded from 1990 to 2002 and gradually stabilized in recent decades. Settlement areas increased alarmingly from 1990 to 2018. The water bodies, forests and bare lands were reduced due to the widening of agricultural land and rapid growth of urban area. The extents of the HI were found to be spreading out and became most extensive in 2018. LST had risen by around 5.5 °C from 1990 to 2018. The lower temperature zones prevailed in the water bodies, forests and agricultural lands whereas higher temperature zones were visible in the river sand bars and highly urbanized areas. The method used in this study is very successful in sparse built-up areas. The outputs of the study will be a great input in the city masterplan for landscape optimization and urban ecological balance in the study area and provide baseline information for future researches looking for inspecting the impacts of LULC change on a regional scale in plainland regions. Highlights • Spatiotemporal dynamics of LULC were evaluated in the northwest region of Bangladesh • Heat islands were delineated successfully indicating the rapid growth of urbanization • Enlargement of the urban area is the main cause for the increasing LST phenomenon • The rate of HI expansion validated by the changing thematic areas of LULC • Trends of urbanization and HI growth are alarming within the district town areas.

Bangladesh is a riparian country that is criss-crossed by the many tributaries and distributaries of the mighty Ganges, Brahmaputra, and Meghna river systems. Gorai-Madhumati, a distributary of the Ganges River is an example where morphological development of the river is associated with frequent channel shifting within the catchment area. The main objective of this research is to quantify the extent of channel migration, erosion-accretion, river width, sinuosity, and charland morpho-dynamics from 1972 to 2018 using geospatial techniques combined with satellite images and hydrological data. The study also addressed the impacts of Farakka Barrage construction in India on the shifting, flow behavior, and siltation of Gorai-Madhumati River. The study shows that bar surface areas have abnormally increased in both segments after 1975 due to the construction of Farakka Barrage. Water flow in the Gorai-Madhumati has dropped remarkably in the downstream and instigated huge sedimentation in this region. Analysis of the time series satellite images revealed that the morphology of the river channel experienced huge changes simultaneously with the changes in the seasonal flow and sedimentation all over the study period. Migration trend has frequently shifted and taken place in the NW and NE direction in the observed sections of the river. Throughout the study period, total amount of accretion was greater than the net percentage of erosion on both banks of the river. River discharge, bar accretion, and erosion history show that the Gorai-Madhumati River will no longer exist with the present flowing condition without attention and proper river management.

Bangladesh is a low-lying riverine country with the mighty Ganges–Brahmaputra–Meghna (GBM) major river system including their abundant tributaries and distributaries. Land erosion–accretion is a very common phenomenon in this riverine country. This process extensively erodes huge productive landmasses at the river confluence zones every year. The main objective of this study was to understand the confluence morpho-dynamics and identify the vulnerable areas near the Padma–Meghna Confluence (PMC) and Ganges–Jamuna confluence (GJC) due to confluence shifting and erosion–accretion phenomenon of those rivers. The present study utilized multi-temporal Landsat satellite images from 1972 to 2019 approximately ten years of interval. Results showed that the PMC indicated frequent variation in migration trend towards NW from 1972 to 1980, SE from 1980 to 2010, and then reversed towards NW direction from 2010 to 2019. On the other hand, the GJC confluence point moved NW direction (2.37 km) from the year 1972 to 1980, but from 1980 to 2019, the confluence shifted towards the SE direction. Due to the migration dynamics, huge changes happened in width and sand bars area of both confluences. In PMC, confluence width increased remarkably indicating erosive flow during 1972–1980, then progressively shortened up to 2019, indicating accretion. In contrast, GJC shows a significant accretional trend over the 47 years. The sand bar area of the PMC increased about 147.09 km2 throughout the study period. But, GJC shows an opposite scenario where the total sand bar area decreased about 51.02 km2 in the same period. From the vulnerability study of erosion–accretion scenarios, it is predicted that Paturia Ferry Ghat area, Aricha Ferry Ghat area, Arua, Baruria, Dashkin Saljana, Bhadiakola, Masundia, Khanganj and Nyakandi areas near GJC and Chandpur sadar, Srimandi, Sakhua, Bilaspur and char Atra near PMC are highly vulnerable zones. The outputs of the study will enable policy makers to take necessary measures to reduce the erosional severity on both confluence zones and could also provide a basis for proper land management.

Saint Martin’s is a unique island located in the Bay of Bengal where coral species are abundant due to its favorable and unique environmental conditions. Coral communities are in great danger due to global climate change, direct commercial coral extraction and unplanned tourism around the island. The present study attempts to identify the coral zone and mapping of coral reefs from the period of 1980 to 2018. The study utilized five sets of multi-temporal Landsat satellite images to examine the changes of coral reefs in Saint Martin’s Island during the study timeframe. Geospatial and image processing software was used for spatial coral colony mapping and data analysis. Satellite images processed to remove water depth impacts and supervised classification technique using the maximum likelihood decision rule suggested the spatial change of coral colonies over time. The result of the study indicates that coral colonies decreased steadily throughout the study period. A total area of 0.9342 km2 of coral colonies disappeared during the study period from 1980 to 2018. Field observations around Saint Martin’s Island indicates that destruction of coral reef habitat was basically caused by anthropogenic activities like tourism and extraction of coral by fisherman. Analysis of the historical data regarding tourism, population and households, and Sea Surface Temperature (SST) along with field observations of these parameter during 2018, suggests that anthropogenic factors are more significant than natural factors for causing coral reef degradation. It is very crucial to raise consciousness not only in the vicinity of Saint Martin’s Island but more widely regarding the significance of the biodiversity of the Island.

The rapid urbanization and industrialization along with the expansion of cities in developing countries like Bangladesh converting vegetation and bare land into built-up area that remarkably boost up the land surface temperature (LST). This study has been conducted for correlating and monitoring the changes of landuse–landcover change (LULC) and LST of rapidly expanding Chittagong metropolitan area from 1989 to 2018 utilizing four Landsat satellite images (TM, ETM+, OLI, and TIRS). The Present study combines the techniques of remote sensing and geographic information system (GIS) to find out the spatial variation of LST and identify its relationship with LULC. Supervised classification technique has been employed in ERDAS IMAGINE 14.0 software to retrieve LULC data. The images of the study area were categorized into four different classes namely vegetation, urban structures, bared lands and water bodies. LSTs were estimated using the single thermal infrared band of Landsat TM, ETM+, and the band 10 and 11 of the TIRS sensor’s image for the split-window algorithm method. Concerning the relationship between LULC and LST, it has been found that vegetation and water bodies shows lowest LST while bared lands and urban structures indicates highest LST. LULC analysis shows a dramatic increase in urban structures (from 20.83 to 58.93%), decrease in vegetation (from 56.54 to 20.24%) and bared lands (from 16.67 to 11.90%) and a further small increase in water bodies after the 80s, because of digging new ponds. LST in the study area has been increasing as high-temperature LU types have increased and low temperature LU types have decreased. Consequently, the mean annual temperature showed 6.5 °C increase, the minimum and maximum LST increased by 9 °C and 4 °C throughout the study period. The highest maximum and lowest minimum LST has found 40 °C during the years of 2010 to 2018 and 15 °C in the year of 1989, respectively. The study will assist the decision-maker to understand the impacts of unplanned urbanization for future city planning and urban management.

Dengue fever is a tropical viral disease mostly spread by the Aedes aegypti mosquito across the globe. Each year, millions of people have dengue fever, and many die as a result. Since 2002, the severity of dengue in Bangladesh has increased, and in 2019, it reached its worst level ever. This research used satellite imagery to determine the spatial relationship between urban environmental components (UEC) and dengue incidence in Dhaka in 2019. Land surface temperature (LST), urban heat-island (UHI), land-use–land-cover (LULC), population census, and dengue patient data were evaluated. On the other hand, the temporal association between dengue and 2019 UEC data for Dhaka city, such as precipitation, relative humidity, and temperature, were explored. The calculation indicates that the LST in the research region varies between 21.59 and 33.33 degrees Celsius. Multiple UHIs are present within the city, with LST values ranging from 27 to 32 degrees Celsius. In 2019, these UHIs had a higher incidence of dengue. NDVI values between 0.18 and 1 indicate the presence of vegetation and plants, and the NDWI identifies waterbodies with values between 0 and 1. About 2.51%, 2.66%, 12.81%, and 82% of the city is comprised of water, bare ground, vegetation, and settlement, respectively. The kernel density estimate of dengue data reveals that the majority of dengue cases were concentrated in the city’s north edge, south, north-west, and center. The dengue risk map was created by combining all of these spatial outputs (LST, UHI, LULC, population density, and dengue data) and revealed that UHIs of Dhaka are places with high ground temperature and lesser vegetation, waterbodies, and dense urban characteristics, with the highest incidence of dengue. The average yearly temperature in 2019 was 25.26 degrees Celsius. May was the warmest month, with an average monthly temperature of 28.83 degrees Celsius. The monsoon and post-monsoon seasons (middle of March to middle of September) of 2019 sustained higher ambient temperatures (>26 °C), greater relative humidity (>80%), and at least 150 mm of precipitation. The study reveals that dengue transmits faster under climatological circumstances characterized by higher temperatures, relative humidity, and precipitation.

Sea beaches are always a good source of heavy minerals around the world. Cox’s Bazar has 120 km of unbroken sandy sea beach. The study includes the sea beaches of 5 upazilas (Moheshkhali, Kolatoli, Ramu, Ukhia, Teknaf) in Cox’s bazaar district for studying the concentration, identification and investigation of heavy mineral deposits along the sandy beaches. This study has concentrated on the physical properties, identification, and abundance of the heavy minerals fraction in sediments collected from the study area. Satellite imagery Landsat-8 OLI was used for remote sensing verifications. The image processing and crucial analysis carried out using Environment for Visualizing Images (ENVI), Arc GIS and Erdas Imagine software. Coastal areas adjacent to Teknaf upazila has a very significant amount of heavy mineral reserves, almost 16%. The study has identified around nineteen variety of heavy minerals from the collected samples in the study area. Ilmenite, Kyanite, Garnet, Rutile, Zircon, Magnetite, Augite, Hornblende, Enstatite, Epidote, Andalusite, Hypersthene, Diopside and Cassiterite have been found the most abundant in the entire study area. The Coastline of Bangladesh was surveyed completely to map the heavy minerals which are potential resources for our national economy.

Rapid urbanization, industrialization, and development activities are posing numerous threats to the rivers of Bangladesh. In the recent decade, Turag River has been exposed to severe threats due to anthropogenic activities. The present research deals with the evaluation of water quantity–quality, landuse and landcover (LULC), and land surface temperature (LST) of Turag River and its floodplain by using an integrated approach of field study, laboratory analysis, and geospatial techniques. LULC mapping of the study area has been done using multi-temporal Landsat satellite images by unsupervised method, Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index indices (NDWI) approach. From LULC classification, the study shows that the average reduction of water bodies from 1989 to 2019 is about 60–66%, and the rate of reduction is about 14.25 ha per year. Due to anthropogenic activities and rapid urbanization, a large number of water bodies have been depleting. The average temperature of the river water from filed observed data is 30.23 °C and from image processed data is about 28.32 °C. The minimum and maximum values of pH, EC, TDS, and Eh are 6.87–8.44, 808–1192 μs/cm, 406–739 ppm, − 31 to – 150 mV, respectively. The concentration ranges of cations (Na, Ca, Mg, K, Fe, and Mn) are 85.43–247.60, 28.59–39.47, 11.1–13.58, 5.21–13.26l, .07–1.14, .006–.47 mg/l consecutively. The ranges of anions concentration (HCO3−, Cl−, SO42−, NO3−) are 165.45–388.87, 54.81–194.07, 52.49–289.63, l9.63–126.93 mg/l, respectively. It is evident that HCO3−, NO3−, and Mn exceed the standard limit of Bangladesh Water Quality Standard (BWQS) and World Health Organization (WHO), indicating that the water of the Turag River is deteriorating that is not safe for human consumption and aquaculture purposes. The study will assist to take some effective measures to control the pollution and uphold the water quality and natural riparian processes. So, the outputs of the study will contribute to the future urban landuse planning in the river floodplain area to mitigate ongoing alarming pollution and unplanned industrialization.

Since creation of spatial data is a costly and time consuming process, researchers, in this domain, in most of the cases rely on open source spatial attributes for their specific purpose. Likewise, the present research aims at mapping landslide susceptibility at the metropolitan area of Chittagong district of Bangladesh utilizing obtainable open source spatial data from various web portals. In this regard, we targeted a study region where rainfall induced landslides reportedly causes causalities as well as property damage each year. In this study, however, we employed multi-criteria evaluation (MCE) technique i.e., heuristic, a knowledge driven approach based on expert opinions from various discipline for landslide susceptibility mapping combining nine causative factors—geomorphology, geology, land use/land cover (LULC), slope, aspect, plan curvature, drainage distance, relative relief and vegetation in geographic information system (GIS) environment. The final susceptibility map was devised into five hazard classes viz., very low, low, moderate, high, and very high, representing 22 km2 (13%), 90 km2 (53%); 24 km2 (15%); 22 km2 (13%) and 10 km2 (6%) areas respectively. This particular study might be beneficial to the local authorities and other stake-holders, concerned in disaster risk reduction and mitigation activities. Moreover this study can also be advantageous for risk sensitive land use planning in the study area.

Geochemical analysis of Neogene mudrocks from Sitakund anticline, Chittagong Tripura Fold Belt (CTFB), Bengal Basin, Bangladesh, was deployed to delineate the provenance, tectonics and depositional environments. Representative samples went through mineralogical and geochemical analysis concerning major, trace and rare earth element analysis. Rigaku ZSX Primus and NITON XL3t 800 XRF instruments were utilized for the determination of major and trace elements. The experiment results reveal that the Neogene mudrocks are rich in silica having concentration of 58.10% to 62.60% with an average of 59.90%. Therefore, the geochemical response from the experiments apparently proved the existence of the active continental margin setting for the Neogene mudrocks. Different concentrations and ratios of major oxides satisfy that the mudrocks were derived from felsic source rocks. In addition, chemical index of alteration (CIA) values for the Neogene mudrocks vary from 67.81 to 77.57 with an average 74.41 indicating significant weathering at the source areas. Moreover, U/Th, Cu/Zn, Ni/Co and V/Cr ratios designate that the mudrocks were deposited in oxidizing depositional environment.

Nodular shales commonly occur in silty shales near the axial (proximity to core) regions of anticlinal structures (Sitakund anticline, Sitapahar anticline, Patharia structure, and Mirinja anticline) of eastern fold belt of Bangladesh. Stratigraphically, they are pronounced in the Surma group of Neogene succession. In many outcrops, these are found in the incompetent beds bounded by the competent ones. An initial investigation has been followed by comprehensive petrographical and geochemical studies including thin section microscopy, laser particle size analyses, X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray fluorescence (XRF) to characterize the nodular shale of Sitakund structure. From laser diffraction analysis, it is evident that nodular shales are silty in nature containing approximately 60% silt (mainly quartz). XRD pattern shows that nodular shale contains quartz, feldspar, illite, kaolinite, chlorite, and expandable mixed layer clay mineral including minor amount of calcite and siderite. Geochemical analysis shows that there is no significant variation from host rocks in context of major and trace element concentration. Microcracks within the quartz grains and squeezed clay minerals were observed in some nodular shale samples correlating the influence of regional tectonics and local structural dynamics in the axial regime of the anticline. Projection of 15 nodular shale long axes in outcrop shows their orientation in NNW-SSE that is parallel to the fold axis. The study suggests a new name of conventionally called nodular shales based on their origin, composition, and occurrence. The proposed name is “Clay Cabbage”. Diagenesis involving the conversion of montmorillonite to illite clay through a mixed layer illite/montmorillonite along with the regional and local tectonics is responsible for the formation of nodular shale. A new model naming as “Tectono-Diagenetic (TD) Model” is proposed in this study concerning the origin of nodular shale. Fluid pressure during diagenesis along with axial deformation due to folding produces hemispherical bodies by brittle and plastic flow that initiates the core of nodular shale at greater depth. Spiral geometry of the body is attained through several deformation stages with the evolution of the folded pattern.