A reconstruction of late Pleistocene relative sea level in the south Bohai Sea, China, based on sediment grain-size analysis

2012 ◽  
Vol 281 ◽  
pp. 88-100 ◽  
Author(s):  
Liang Yi ◽  
Hongjun Yu ◽  
Joseph D. Ortiz ◽  
Xingyong Xu ◽  
Xiaoke Qiang ◽  
...  
2021 ◽  
Vol 11 (6) ◽  
pp. 2799
Author(s):  
Yanping Chen ◽  
Wenzhe Lyu ◽  
Tengfei Fu ◽  
Yan Li ◽  
Liang Yi

The Huanghe River (Yellow River) is the most sediment laden river system in the world, and many efforts have been conducted to understand modern deltaic evolution in response to anthropological impacts. However, the natural background and its linkage to climatic changes are less documented in previous studies. In this work, we studied the sediments of core YDZ–3 and marine surface samples by grain-size analysis to retrieve Holocene dynamics of the Huanghe River delta in detail. The main findings are as follows: The mean value of sediment grain size of the studied core is 5.5 ± 0.9 Φ, and silt and sand contents are 5.2 ± 2.3% and 8.2 ± 5.3%, respectively, while the variance of clay particles is relatively large with an average value of 86.4 ± 8.5%. All grain-size data can be mathematically partitioned by a Weibull-based function formula, and three subgroups were identified with modal sizes of 61.1 ± 28.9 μm, 30.0 ± 23.9 μm, and 2.8 ± 1.6 μm, respectively. There are eight intervals with abrupt changes in modal size of core YDZ–3, which can be correlated to paleo-superlobe migration of the Huanghe River in the Holocene. Based on these observations, the presence of seven superlobes in the history are confirmed for the first time and their ages are well constrained in this study, including Paleo-Superlobes Lijin (6400–5280 yr BP), Huanghua (4480–4190 yr BP), Jugezhuang (3880–3660 yr BP), Shajinzi (3070–2870 yr BP), Nigu (2780–2360 yr BP), Qikou (2140–2000 yr BP), and Kenli (1940–1780 and 1700–1650 yr BP). By tuning geomorphological events to a sedimentary proxy derived from core YDZ–3 and comparing to various paleoenvironmental changes, we proposed that winter climate dominated Holocene shifts of the Huanghe River delta on millennial timescales, while summer monsoons controlled deltaic evolution on centennial timescales.


2021 ◽  
Vol 9 ◽  
Author(s):  
Liang Chen ◽  
Hancheng Ji ◽  
Nansheng Qiu ◽  
Liang Zhang

The grain sizes of clastic rock sediments serve as important depositional indicators that are significant in sedimentology and petroleum geology studies. Generally, gamma ray, spontaneous-potential and resistivity well logs are utilized to qualitatively characterize variations in sediment grain size and determine the lithology in clastic reservoirs. However, grain size analysis of modern sedimentary samples collected from active rivers and deltas indicates that the percentage of fine depositional component has a logarithmic relationship with the average grain size in delta and river systems. Using the linear relationship to process the lithology interpretation, siltstones or mudstone is likely to be interpreted as sandstone. Therefore, a logarithmic conversion formula was built up between the gamma ray logs and measured grain size for the second member of the Xujiahe Formation of Anyue Area in the Sichuan Basin. Using the formula, the average grain size and lithology of the exploration wells were determined for the interest intervals. Furthermore, the calculated grain size gives a better understanding of the controlling factors of hydrocarbon-bearing reservoirs in the study area.


2020 ◽  
Author(s):  
Faith A. Renner ◽  
◽  
E. Christa Farmer ◽  
Moread Achek ◽  
Brandon Buchbinder ◽  
...  

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Qiao Su ◽  
Yanhui Zhu ◽  
Yalin Jia ◽  
Ping Li ◽  
Fang Hu ◽  
...  

During the last several decades, researchers have made significant advances in sedimentary environment interpretation of grain-size analysis, but these improvements have often depended on the subjective experience of the researcher and were usually combined with other methods. Currently, researchers have been using a larger number of data mining and knowledge discovering methods to explore the potential relationships in sediment grain-size analysis. In this paper, we will apply bipartite graph theory to construct a Sample/Grain-Size network model and then construct a Sample network model projected from this bipartite network. Furthermore, we will use the Mini Batch K-means algorithm with the most appropriate parameters (reassignment ratio ϵ=0.025 and mini batch = 25) to cluster the sediment samples. We will use four representative evaluation indices to verify the precision of the clustering result. Simulation results demonstrate that this algorithm can divide the Sample network into three sedimentary categorical clusters: marine, fluvial, and lacustrine. According to the results of previous studies obtained from a variety of indices, the precision of experimental results about sediment grain-size category is up to 0.92254367, a fact which shows that this method of analyzing sedimentary environment by grain size is extremely effective and accurate.


2019 ◽  
Vol 16 (2) ◽  
Author(s):  
Deny Setiady ◽  
Udaya Kamiludin ◽  
Ildrem Syafri

Daerah penelitian terletak di perairan antara Pulau Batam dan Pulau Bintan (Selat Riau), termasuk ke dalam wilayah Kotamadya Batam dan Kabupaten Bintan, Provinsi Kepulauan Riau. Metode penelitian yang dilakukan adalah pengambilan posisi (navigasi), pengukuran kedalaman dasar laut, pengamatan dan pengambilan contoh sedimen pantai, pengambilan contoh sedimen dasar laut, serta analisis laboratorium. Tujuan penelitian adalah untuk mengetahui sebaran pasir pasir laut, serta ketebalannya berdasarkan karakteristik ukuran butirannya, agar potensi bahan galian tersebut dapat diketahui. Berdasarkan analisis ukuran butir sedimen di pantai Pulau Batam dan Pulau Bintan diketahui berukuran pasir, kerikil pasiran, pasir kerikilan dan lanau pasiran, sedangkan sebaran sedimen dasar laut terdiri dari: kerikil pasiran, pasir kerikilan, pasir, pasir lanauan dan lanau pasiran. Kedalaman sedimen pasir di pantai Pulau Batam antara 1 meter sampai 2,6 meter, sedangkan ketebalan sedimen pasir di Pulau Bintan antara 0,6 meter sampai 2 meter. Kata Kunci: sedimen, ukuran butir, pasir, bahan galian, Selat RiauThe study area is located in offshore area between Batam and Bintan Islands (Riau Strait), including of Batam and Bintan regency, Kepulauan Riau Province. The research methods carried out were position taking (navigation), depth of seabed measurement (bathymetry), observation and coastal sediments sampling, seabed sediments sampling, and laboratory analysis. The objectives of the study is to know the sand beach and sea sand distribution and its thickness based on characteristics of grain size, as well as to know those construction materials. Based on sediment grain size analysis on the Batam and Bintan islands, sand beach consists of: sand, sandy gravel, gravelly sand and sandy silt, while seafloor surficial sediments distribution consist of sandy gravel, gravelly sand, sand, silty sand and sandy silt. The depth of sand sediment on Batam beach is between 1 to 2.6 meters, while the depth of sand sediment in Bintan Island coastal is between 0.6 meters to 2 meters. Keywords: sediment, grain size, sands, substrate material, Riau Strait


2016 ◽  
Vol 13 (3) ◽  
pp. 153
Author(s):  
Deny Setiady ◽  
Udaya Kamiludin ◽  
Nienu Yayu Gerhaneu

Daerah Penelitian terletak di perairan Papela dan sekitarnya yang merupakan bagian dari Selat Rote yang secara administratif merupakan wilayah dari Kabupaten Rote-Ndao, Provinsi Nusa Tenggara Timur. Di daerah penelitian pada 40 lokasi telah dilakukan pengambilan sedimen dasar laut dengan pemercontoh comot, deskripsi megaskopis dan analisis besar butir. Penelitian bertujuan untuk mengetahui jenis sedimen, sebaran sedimen dan lingkungan pengendapannya. Berdasarkan hasil analisis besar butir nomenklatur sedimen di daerah penelitian dijumpai 4 jenis sedimen yaitu: kerikil, pasir, pasir lanauan, lanau pasiran dan lanau. Sebaran kerikil terdapat di dua tempat, yaitu di utara dan selatan tepian daerah penelitian.Sebaran pasir mencapai kurang lebih 30 % dari luas perairan penelitian, pasir lanauan menutupi kurang 5 % dari luas perairan penelitian, lanau pasiran mempunyai sebaran kurang lebih 30 % dari luas perairan daerah penelitian dan sebaran lanau terdapat di muka muara sungai bagian dalam Teluk Papela dengan tutupan kurang lebih 5 % dari luas perairan penelitian.Kata kunci Sedimen permukaan dasar laut, analisis besar butir, sebaran sedimen, perairan Papela The study area is located in Papela waters area and that is part of the Rote Strait, administratively is a region of Rote-Ndao regency, East Nusa Tenggara Province. The method of research conducted is sampling seafloor sediments, megaskopis description and analysis of the grain size. The study area is located in Papela waters area and that is part of the Rote Strait, administratively is a region of Rote-Ndao regency, East Nusa Tenggara Province. The method of research conducted is sampling seafloor sediments, megaskopis description and analysis of the grain size. The purpose of research is the grain size analysis of seabed surface sediment to determine the type of sediment, sediment distribution and depositional environment. Based on nomenklature sediment grain size analysis result in the study area was found four types of sediments , there are: gravelly, sand, silty sand, sandy silt and silt Distribution of gravel found in two places, namely on the north and south banks of the study area. Distribution of sand reaches approximately 30% of the water area of research, silty sand covering approximately 5% of the water area of research, sandy silt has spread approximately 30% of the total water area of research and distribution of silt contained in the inner face of the Gulf estuaries Papela with cover approximately 5% of the water area of research. Keywords: Surficial sediment, grain size analysis, sediment distribution, Papela Waters


2015 ◽  
Vol 26 (45) ◽  
pp. 224
Author(s):  
Daniela Torrisi ◽  
Monica Kleina ◽  
Bruna Daniela de Araújo Taveira ◽  
Fabiano Antonio de Oliveira ◽  
Juliana Landolfi de Carvalho ◽  
...  

<p>O estudo da dinâmica sedimentar de um canal pode auxiliar na compreensão da evolução da paisagem e no entedimento da dinâmica fluvial em uma bacia hidrográfica. A análise granulométrica dos sedimentos permite uma aproximação inicial ao conhecimento da dinâmica sedimentar e da variação da energia do fluxo no canal. O presente trabalho objetiva identificar a variação de energia do fluxo de escoamento do canal fluvial a partir da comparação das análises granulométricas de dois perfis estratigráficos na bacia hidrográfica do rio Pirabeiraba, SC. A metodologia aplicada foi baseada em análises granulométricas e estatísticas desenvolvidas em amostras coletadas em campo. Os principais resultados obtidos demonstraram que os perfis apresentaram-se muito semelhantes, indicando que, apesar de ocorrerem variações de energia dos fluxos, os perfis se mantiveram equivalentes nas duas amostras estudadas. Desta forma, pode-se relatar que os eventos ocorridos foram homogêneos nesta parte da bacia.</p><p><strong>Palavras-Chave:</strong> Análise granulométrica, Fluxo fluvial, Rio Pirabeiraba.</p><p><strong>Abstract</strong></p><p>The study of sediment dynamics of a river may help to understand the evolution of the landscape and to comprehend the fluvial dynamics in a watershed. One useful tool is the sediment grain size analysis (granulometry / granulometric analysis). The granulometric analysis allows to understand sediment dynamics as well as energy changes in a river flow. This paper aims to identify the energy change of a river channel by means of the comparison of particle size analysis of two stratigraphic profiles in the Pirabeiraba river watershed, Santa Catarina, Brazil. The applied methodology was based on grain size and statistical analysis from the collected samples. The main results show that both profiles are very similar, despite the variations that occurred in the river flows, what means that the fluvial process were uniform in this part of the watershed. <strong> </strong></p><p> </p><p><strong>Keywords:</strong> Grain size analysis, Fluvial flow, Pirabeiraba river.</p>


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