The Control of Slope Gradient on Sedimentation by Taking Sangonghe Formation in Eastern Junggar Basin as an Example

2014 ◽  
Vol 962-965 ◽  
pp. 88-91
Author(s):  
Li Wan ◽  
Xing He Yu ◽  
Sheng Li Li ◽  
Hui Yuan Xu
Keyword(s):  
Seismic Data ◽  
Junggar Basin ◽  
Steep Slope ◽  
Slope Gradient ◽  
Delta Front ◽  
Gentle Slope ◽  
Development Experience ◽  
Lacustrine Delta ◽  
Development Area ◽  
Well Correlation

According to the cores, outcrops, seismic data and wire-line logs, the main influences exerted by slope gradient on sedimentation of lacustrine delta are as follows: 6 kinds of microfacies assemblages are recognized in the elaborate development area and 3 sequences of these assemblages are identified in the well correlation along provenance; the bars-rich delta front is developed in steep slope while the river-rich delta front in gentle slope. The exploration and development experience indicate the reservoirs formed in steep area are favorable for well-connected sandbodies and high sand-bearing ratios.

scholarly journals Facies analysis of Sunakothi Formation, Kathmandu basin, Nepal and its significance

2014 ◽  
Vol 47 (1) ◽  
pp. 57-64
Author(s):  
Mukunda Raj Paudel
Keyword(s):  
Lake Level ◽  
Facies Analysis ◽  
Flood Plain ◽  
Delta Front ◽  
Gravel Beds ◽  
Delta Plain ◽  
Facies Associations ◽  
Ripple Sand ◽  
Lacustrine Delta ◽  
Lacustrine Facies

This study decipher facies characteristic of Sunakothi Formation at southern part of Kathmandu Basin. Thick sandy and muddy sequence is found on an open lacustrine facies of the Kalimati Formation. Five facies associations have been recognized within the sandy and muddy facies. These are: (a) muddy rhythmites and silt and laminated to ripple sand bed of the prodeltaic origin (pd), (b) association of cross-stratification, rippledrift and parallel lamination in the lacustrine delta front origin (df), (c) muddy flood-plain and alteration of the fine and coarse sediments of delta-plain origin (dp), (d) sandy to silty rhythmites of the marginal shallow lacustrine origin above the delta-plain (ml), and (e) association of fluvial origin (fl ). Former three associations are interbeded by the thick gravel deposits, which is gravelly braided river origin. Transition from lacustrine to alluvial system is characterized by fluvial and deltaic system in the south. Sedimentology of the Sunakothi Formation indicates deposition during rapid lake level rise and also the thick channelized fluvial gravel beds within the sandy and muddy sequence indicate lake level fall. The cause could be climatic as well as activity of the basin margin tectonics. Sunakothi Formation is the southern counterpart of the Thimi-Gokarna Formations distributed in the northern part of the basin.

Sensitivity analysis of gully sidewall expansion to topography and rainfall factors

2020 ◽  
Author(s):  
Ma Yulei ◽  
Xu Xiangzhou
Keyword(s):  
Correlation Coefficient ◽  
Rainfall Intensity ◽  
Retaining Wall ◽  
Initial Slope ◽  
Slope Gradient ◽  
Land Loss ◽  
Remarkable Change ◽  
Gentle Slope ◽  
Rainfall Duration ◽  
Sensitivity Coefficients

<p>Gully sidewall expansion is an essential process of gully development, and its trigger condition and dynamic process are subject to multifactor effects. This study consisted of 10 sets of experiments, and three factors were considered: three rainfalls (60 mm, 48mm and 24mm), two initial slope gradients (70° and 80°) and two slope heights (1 m and 1.5 m). Then the increase-rate-analysis method was used to evaluate the variations in the changes of slope gradients of sidewall and retreat rates of gully shoulder-line with respect to changes in other causal parameters of rainfall and topography. The results are shown as follows: (1) The area of land loss of the upper gentle slope was positively correlated with the volume of gravity erosion. The correlation coefficient between the volume of gravity erosion and the area of land loss of the upper gentle slope, r<sub>1</sub>, is 0.91. The correlation coefficient between the volume of water erosion and the area of land loss of the upper gentle slope, r<sub>2</sub>, is 0.59. This shows that mass failure was the main cause to induce the land loss of the upper gentle slope in the process of sidewall expansion. (2) The rainfall duration and initial slope gradient had significant influences on the change of slope gradient of landform in the experiments. The sensitivity coefficients of rainfall intensity, rainfall duration, initial slope gradient and slope height for the change of slope gradient of the sidewall were 0.3, 2.2, 1.3 and -0.2, respectively. The increased initial slope gradient and rainfall duration may have caused the increases of the volume and number of gravity erosion, ultimately resulting in a remarkable change of slope gradient of the sidewall. (3) The most significant factor affecting the retreat rate of gully shoulder-line were rainfall intensity and initial slope gradient. The sensitivity coefficients of the rainfall intensity, rainfall duration, initial slope gradient and slope height for the retreat rate of gully shoulder-line were 3.0, 1.5, 3.0 and -0.1. As a result, the retaining wall construction was preferable to control the gully sidewall erosion. The results of this study may be referred for analyzing the mechanism of sidewall expansion and controlling the loess sidewall expansion.</p>

scholarly journals Depositional History of Paleocene Sediments in the Offshore Canterbury Basin, New Zealand

2021 ◽  
Author(s):  
◽  
Sanjay Paul Samuel
Keyword(s):  
Seismic Data ◽  
The South ◽  
Depositional History ◽  
Reservoir Rocks ◽  
The North ◽  
Late Paleocene ◽  
Shelf Slope ◽  
History Of ◽  
Well Correlation ◽  
First Time

<p>The Paleocene interval within the Canterbury Basin has been relatively understudied with respect to the Neogene and Cretaceous intervals. Within the Paleocene interval is the Tartan Formation and the Charteris Bay Sandstone, which are potential source and reservoir rocks respectively. These two formations have not been previously mapped in the offshore Canterbury Basin and their limits have not been defined. This study utilises a database of nearly 12,000km of 2D seismic data together with data from four open–file wells and sidewall core samples from three wells and newly availiable biostratigraphic information to better constrain the chronostratigraphical interpretation of seismic data. Seismic mapping together with corroboration from well correlation and core lithofacies analysis revealed new insights into the development of the offshore Canterbury Basin through the Paleocene. These include the delineation of the lateral extents and thicknesses of the Tartan Formation and Charteris Bay Sandstone and location of the palaeo shelf–slope break and also the development of a new well correlation panel that incorporates the Tartan Formation for the first time.  This study presents four new paleogeographic maps for the offshore Canterbury Basin that significantly improves our understanding of the development of the basin during the Paleocene. These maps show that during the Earliest Paleocene, the mudstones of the Katiki Formation were being deposited in the south of the study area, with the siltier sediments of the Conway Formation being deposited in the north. The coarser grained Charteris Bay Sandstone was deposited from Early to possibly Middle Paleocene in the northeast. The mudstones of the Moeraki Formation were being deposited in the south at this time. From Middle to Late Paleocene, the mudstones of the Moeraki Formation were deposited in the south and these mudstones onlapped against the Charteris Bay Sandstone which remained as a high in the north. The Tartan Formation was deposited during the Late Paleocene in the central and southern areas of the offshore Canterbury Basin, during a relative fall in sea–level. Deposition had ceased in the north of the study area or erosion possibly removed Late Paleocene sediments from there. During the Latest Paleocene, the mudstones of the Moeraki Formation were deposited over the Tartan Formation in the central and southern parts of the offshore Canterbury Basin with the northern area undergoing erosion, sediment bypass or both.</p>

scholarly journals Depositional History of Paleocene Sediments in the Offshore Canterbury Basin, New Zealand

2021 ◽  
Author(s):  
◽  
Sanjay Paul Samuel
Keyword(s):  
Seismic Data ◽  
The South ◽  
Depositional History ◽  
Reservoir Rocks ◽  
The North ◽  
Late Paleocene ◽  
Shelf Slope ◽  
History Of ◽  
Well Correlation ◽  
First Time

<p>The Paleocene interval within the Canterbury Basin has been relatively understudied with respect to the Neogene and Cretaceous intervals. Within the Paleocene interval is the Tartan Formation and the Charteris Bay Sandstone, which are potential source and reservoir rocks respectively. These two formations have not been previously mapped in the offshore Canterbury Basin and their limits have not been defined. This study utilises a database of nearly 12,000km of 2D seismic data together with data from four open–file wells and sidewall core samples from three wells and newly availiable biostratigraphic information to better constrain the chronostratigraphical interpretation of seismic data. Seismic mapping together with corroboration from well correlation and core lithofacies analysis revealed new insights into the development of the offshore Canterbury Basin through the Paleocene. These include the delineation of the lateral extents and thicknesses of the Tartan Formation and Charteris Bay Sandstone and location of the palaeo shelf–slope break and also the development of a new well correlation panel that incorporates the Tartan Formation for the first time.  This study presents four new paleogeographic maps for the offshore Canterbury Basin that significantly improves our understanding of the development of the basin during the Paleocene. These maps show that during the Earliest Paleocene, the mudstones of the Katiki Formation were being deposited in the south of the study area, with the siltier sediments of the Conway Formation being deposited in the north. The coarser grained Charteris Bay Sandstone was deposited from Early to possibly Middle Paleocene in the northeast. The mudstones of the Moeraki Formation were being deposited in the south at this time. From Middle to Late Paleocene, the mudstones of the Moeraki Formation were deposited in the south and these mudstones onlapped against the Charteris Bay Sandstone which remained as a high in the north. The Tartan Formation was deposited during the Late Paleocene in the central and southern areas of the offshore Canterbury Basin, during a relative fall in sea–level. Deposition had ceased in the north of the study area or erosion possibly removed Late Paleocene sediments from there. During the Latest Paleocene, the mudstones of the Moeraki Formation were deposited over the Tartan Formation in the central and southern parts of the offshore Canterbury Basin with the northern area undergoing erosion, sediment bypass or both.</p>

Research on Sedimentary Microfacies of Sandstone Group I in Putaohua Oil Reservoir of Gu83 Block in Gulong Oilfield

2013 ◽  
Vol 787 ◽  
pp. 618-621
Author(s):  
Yang Liu ◽  
Cheng Zhi Liu ◽  
Hui Li ◽  
Xiao Jing Liu ◽  
Yu Cong Li
Keyword(s):  
Seismic Data ◽  
Oil And Gas ◽  
Delta Front ◽  
Group I ◽  
Core Logging ◽  
Work Area ◽  
Sedimentary Microfacies ◽  
Plane Distribution ◽  
Drilling Core ◽  
Sand Bodies

The oil and gas reserves of Gu83 block in Gulong oilfield is very abundant, but the development is very difficult because the sand bodies are thin, scattered and lack of horizontal continuity. Guided by the theory of sequence stratigraphy and reservoir sedimentology, using drilling core, logging and seismic data, the researcher found that the interest area belongs to delta front subfacies deposition, which can be mainly classified by four miscrofacies types including underwater distributary channel, mouth, sheet sand and bay between distributary. The plane distribution of sedimentary microfacies are mainly controlled by the west and north provenance, the two source collected in the middle east of the work area.

scholarly journals Effects of Land Use Land Cover and Slope Gradients on Soil Fertility at Kori Sub-Watershed, East Wollega, Ethiopia

2022 ◽  
Author(s):  
Begna Tesema Bekana ◽  
Tolera Megersa Gudeta ◽  
Fedhasa Benti Chalchisa
Keyword(s):  
Land Use ◽  
Physicochemical Properties ◽  
Soil Fertility ◽  
Soil Samples ◽  
Steep Slope ◽  
Land Use Land Cover ◽  
Slope Gradient ◽  
Fertility Status ◽  
Soil Fertility Status ◽  
Effects Of Land Use

Abstract BackgroundThe complex nature of the relationship and interaction between LULC and slope gradients resulted in the decline of soil fertility parameters, which aggravate the reduction of sustainable productivity in Ethiopia in general and the study area in particular. This study was aimed to determine the effects of land use land cover and slope gradients on the physicochemical properties of soil in study area A total of 27 composite soil samples were collected from 0-20cm depth under three dominant adjacent LULC across three slope with three replications. The collected soil samples were analyzed for selected soil physicochemical properties. Two-way ANOVA was used to test the mean differences of the soil fertility parameters. ResultThe mean values of soil physicochemical parameters showed that, SOC, TN, AvP, CEC, exchangeable bases (Ca2+ Mg2+, K+, and Na+), PBS, and percentage of clay contents of cultivated land and steep slope gradient (15-30%) were low and significantly different at (P≤0.05) than forest and grad grassland of the same slope gradient.. The gentle slope (3-8%) gradients of the forest lands had the lowest BD and high TP as compared to the others.ConclusionThe overall soil fertility status of the steep slope gradient (15-30%) of cultivated lands is lower than others and cultivating the steep slope is the cause for productivity loss in the study sub-watershed. Therefore, proper land-use planning and the use of integrated soil fertility management strategy give better production and keep the soil fertility status to a better level.

scholarly journals The spatial distribution of sago palm landscape Sentani watershed in Jayapura District, Papua Province, Indonesia

2021 ◽  
Vol 22 (9) ◽  
Author(s):  
PETRUS ABRAHAM DIMARA ◽  
RIS HADI PURWANTO ◽  
SIGIT SUNARTA
Keyword(s):  
Spatial Distribution ◽  
Spatial Data ◽  
Field Survey ◽  
Steep Slope ◽  
Landsat 8 ◽  
Soil Erodibility ◽  
Slope Gradient ◽  
Sago Palm ◽  
Optimal Distance ◽  
Mediterranean Soil

Abstract. Dimara PA, Purwanto RH, Sunarta S, Wardhana W. 2021. The spatial distribution of sago palm landscape Sentani watershed in Jayapura District, Papua Province, Indonesia. Biodiversitas 22: 3811-3820. Sago palm is one of the starch sources used as local food in Papua, therefore this research aims to identify the supporting environment for the plant to grow by utilizing spatial data. The methods used were Spatial Analysis and Field Survey, where the first employed satellite imagery of Quickbird in 2012 and Landsat 8 in 2020 to distinguish between sago and non-sago palm landscape. In the process, five parameters were used, consisting of covering land elevation, slope gradient, soil type, rainfall as well as the optimal distance from the river and lake. The result showed the sago palm landscape in Sentani Watershed lies in the elevation of 0-450 m asl, while its largest habitat which lies between 0-100 m asl covering an area of 4,385.63 is found in a flat slope covering an area of 2,941.99 ha and in a very steep slope that spreads out over 41.92 ha. Generally, in Sentani Watershed, the plant grows in Mediterranean soil possessing thick solum with pH 5.0-7.0 and medium to great soil erodibility. Moreover, the largest habitat experiences a precipitation rate of 1,750 mm yr-1 covering a total of 6,846.24 ha, while the Doyo River has the largest sago palm landscape compared to other rivers.

scholarly journals Facies models of the Achimov Formation of East-Urengoiskoe license as the basis for optimizing exploration and field development patterns

Georesursy ◽  
2020 ◽  
Vol 22 (3) ◽  
pp. 55-61
Author(s):  
Alena V. Khramtsova ◽  
Sergey I. Pakhomov ◽  
Nikita Y. Natchuk ◽  
Мaria P. Kalashnikova ◽  
Sergey V. Romashkin ◽  
...  
Keyword(s):  
Seismic Data ◽  
Lower Cretaceous ◽  
Comprehensive Analysis ◽  
Core Analysis ◽  
Reservoir Properties ◽  
Development Patterns ◽  
Field Development ◽  
Submarine Fans ◽  
Well Correlation ◽  
Marine Basin

The results of sedimentological core analysis of the Achimov Formation (Upper Valanginian, Lower Cretaceous) confirm that it was formed by higher efficiency systems of submarine fans in (relatively) deep marine basin. Lithofacies models of Ach5-6 were generated, well correlation was performed based on the comprehensive analysis of core, well logging and seismic data. Distributary channels and proximal parts of depositional lobes are characterized by the best reservoir properties.

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