A Study of Engineering Geological Conditions of Late Quaternary Sedimentary Layers in Coastal Areas of China

2008 ◽  
pp. 139-139-10
Author(s):  
C Li ◽  
G Xu
Keyword(s):  
Late Quaternary ◽  
Coastal Areas ◽  
Geological Conditions

scholarly journals Circum-Antarctic coastal environmental shifts during the Late Quaternary reflected by emerged marine deposits

1998 ◽  
Vol 10 (3) ◽  
pp. 345-362 ◽  
Author(s):  
Paul A. Berkman ◽  
John T. Andrews ◽  
Svante Björck ◽  
Eric A. Colhoun ◽  
Steven D. Emslie ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Late Quaternary ◽  
Marine Species ◽  
Coastal Areas ◽  
The Arctic ◽  
Marine Habitat ◽  
Marine Deposits ◽  
Quaternary Climate ◽  
Antarctic Marine ◽  
The Antarctic

This review assesses the circumpolar occurrence of emerged marine macrofossils and sediments from Antarctic coastal areas in relation to Late Quaternary climate changes. Radiocarbon ages of the macrofossils, which are interpreted in view of the complexities of the Antarctic marine radiocarbon reservoir and resolution of this dating technique, show a bimodal distribution. The data indicate that marine species inhabited coastal environments from at least 35 000 to 20 000 yr BP, during Marine Isotope Stage 3 when extensive iceberg calving created a ‘meltwater lid’ over the Southern Ocean. The general absence of these marine species from 20 000 to 8500 yr BP coincides with the subsequent advance of the Antarctic ice sheets during the Last Glacial Maximum. Synchronous re-appearance of the Antarctic marine fossils in emerged beaches around the continent, all of which have Holocene marine-limit elevations an order of magnitude lower than those in the Arctic, reflect minimal isostatic rebound as relative sea-level rise decelerated. Antarctic coastal marine habitat changes around the continent also coincided with increasing sea-ice extent and outlet glacial advances during the mid-Holocene. In view of the diverse environmental changes that occurred around the Earth during this period, it is suggested that Antarctic coastal areas were responding to a mid-Holocene climatic shift associated with the hydrological cycle. This synthesis of Late Quaternary emerged marine deposits demonstrates the application of evaluating circum-Antarctic phenomena from the glacial-terrestrial-marine transition zone.

scholarly journals Possibility of using RIT technology in the ground conditions of Vietnam

2020 ◽  
Vol 177 ◽  
pp. 02005
Author(s):  
Yury Kharin
Keyword(s):  
Soil Structure ◽  
High Efficiency ◽  
Field Tests ◽  
Physical And Mechanical Properties ◽  
Coastal Areas ◽  
Geological Conditions ◽  
Ground Conditions ◽  
Coastal Soils ◽  
Bored Piles ◽  
Water Saturated

The article compares engineering and geological conditions in the coastal areas of Vietnam and Tunisia. A sufficiently high similarity of soil structure and their physical and mechanical properties was noted. Both in Vietnam and in Tunisia, foundations for responsible buildings and structures are arranged on bored piles of the same length of 40-60 meters and a diameter of 600 to 1600 mm. The article provides examples of using super-piles of small-size RIT using recharge impulse technology in conditions of weak water-saturated coastal soils of Tunisia. The high efficiency and cost-effectiveness of the new recharge impulse technology were noted. The article presents photographic materials of the test stand for conducting field tests of piles, presents and analyzes the results of testing piles with vertical static load. The low precipitation of the tested piles and their high load-bearing capacity prove the promise of using super-piles of RIT in the conditions of weak soils of Tunisia and, consequently, in the coastal areas of Vietnam.

scholarly journals Groundwater characteristics of the Saga Plain, Japan

2000 ◽  
Vol 22 ◽  
Author(s):  
Lin Wang ◽  
Yushiro Iwao
Keyword(s):  
Saltwater Intrusion ◽  
Single Layer ◽  
Seasonal Fluctuation ◽  
Coastal Areas ◽  
Young Age ◽  
Tritium Concentration ◽  
Chemical Components ◽  
Deep Aquifers ◽  
Groundwater Head ◽  
Geological Conditions

The Saga Plain is located in the west of Kyushu Island, Japan. The area is seriously affected by overdraft of groundwater. Land subsidence has been evident since 1957, and it was quite significant in 1960. The groundwater head varies seasonally depending on discharge and precipitation. According to the geological properties of the Saga Plain, a single layer two-dimensional plane model was adopted to simulate the seasonal fluctuation of the groundwater head. Based on the Darcy's Law and continuity principle, the following differential equation was used to describe the groundwater flow: (Tꝺ2h)/ ꝺx2 + (Tꝺ2h)/ ꝺy2 = Sꝺh/ꝺt + Q(x,y,t) where, T is the transmissivity of aquifer; S is the storage coefficient; Q is the net recharge; and h is the groundwater head. By comparing the pattern of the Hexa diagram in different areas and different aquifers, it was found that saltwater intrusion occurred in the Saga Plain due to over-pumping. Water quality and quantity are affected not only by the recharge and soil utilisation but also by the surrounding geological conditions. Tritium concentration analysis was used for estimating the age of groundwater in the Saga Plain. The Saga Plain is divided into the Saga District and Shiroyishi District. In the Saga District, the groundwater showed a young age in the shallow wells of inland as well as coastal areas. The young age in the inland areas was attributed to the recharge of groundwater from the northern mountains. For the coastal areas, it was thought as the effect of saltwater intrusion from the Ariake Sea. Meanwhile, measurements showed that the groundwater in deep aquifers was of old age in the Saga District. Those results were also supported by the chemical analyses of the components of groundwater in the Saga Plain. In the Shiroyishi District, the old groundwater was encountered both in deep and shallow aquifers. The analyses of chemical components showed that the groundwater is affected mainly by the fossil water in the Shiroyishi District.

scholarly journals Geological Characteristics and Distribution of Granite Geothermal Reservoir in Southeast Coastal Areas in China

2021 ◽  
Vol 9 ◽  
Author(s):  
Herong Zheng ◽  
Jun Luo ◽  
Ying Zhang ◽  
Jianyun Feng ◽  
Yan Zeng ◽  
...  
Keyword(s):  
Seismic Data ◽  
Hot Springs ◽  
Sedimentary Basins ◽  
Coastal Areas ◽  
Geothermal Reservoir ◽  
Thermal Springs ◽  
Granitic Rocks ◽  
Geothermal System ◽  
Geothermal Resources ◽  
Geological Conditions

The southeast coastal areas in China have distributed lots of granite outcrops of different periods. Previous research has shown that granite geothermal reservoirs are also distributed under sedimentary basins in these areas, such as in Zhangzhou basin. Therefore, granites with fractures buried in deep can be used as a potential deep geothermal reservoir in these areas. In order to study geological conditions of the deep granite reservoir and discuss the genesis of the deep granite geothermal system, rock geochemistry and zircon U-Pb chronology from outcrop and parts of the drilling cores of granitic rocks have been analyzed, combined with the anatomy of the deep seismic data and electromagnetic detection data in selected area. Based on the results of geochemistry and zircon U-Pb chronology, most granites in this area are of Yanshanian periods. Based on the seismic data, the thickness of the overlying strata on granite in Huangshadong area of Huizhou City is up to 1.5 km. According to the regional geological survey, multi-stage joints are developed in the granite, and most of hot springs rise from intersection of fracture with different directions to the surface. The heat source in the study area mainly comes from the mantle carried up by the deep NNE-trending faults. There are a large number of thermal springs at the intersection of the surface and the NW-trending fault, and the NW-trending fault provides the drainage conditions for the upwelling of underground thermal springs. There is a huge amount of deep granite geothermal resources in the southeast coastal area. The analysis of deep granite geological conditions and genetic models can provide guidance for the evaluation of deep granite geothermal resources and the further optimization of favorable zones in these areas.

scholarly journals ALTERNATIF BANGUNAN AIR UNTUK PENYEDIAAN AIR BAKU DI PULAU GILI-GILI, NUSA TENGGARA BARAT

2018 ◽  
Vol 6 (2) ◽  
Author(s):  
Diah Affandi
Keyword(s):  
Water Supply ◽  
Rainy Season ◽  
Building Materials ◽  
Water Structure ◽  
Coastal Areas ◽  
Dry Season ◽  
Rain Water ◽  
Small Islands ◽  
Local Conditions ◽  
Geological Conditions

In order to meet water needs during the dry season in West Nusa Tenggara (NTB), particularly on small islands in the NTB area needed a facility that can accommodate the rain water in the rainy season, so water supply can be used during the dry season. Characteristics of land in coastal areas in particular, other than flat land also contains sand, so the soil tends to have relatively high permeabilities. To build waterworks facilities suitable to local conditions then, required an assessment of alternative types of water structure adapted to the geological conditions and availability of building materials to be used. Keywords : Karakteristik Tanah, Alternative Bangunan Air

Characterization and evolution of spearfishing in Madeira archipelago, Eastern Atlantic

2020 ◽  
Vol 33 ◽  
pp. 15
Author(s):  
Roi Martínez-Escauriaza ◽  
Claudio Vieira ◽  
Lídia Gouveia ◽  
Nuno Gouveia ◽  
Margarida Hermida
Keyword(s):  
Fish Species ◽  
Young Men ◽  
Coastal Areas ◽  
Teleost Fishes ◽  
The North ◽  
Southeast Coast ◽  
Madeira Archipelago ◽  
First Time

Data obtained from licenses of spearfishers and surveys conducted in 2004 and 2017 allowed for the analysis, for the first time, of the practice of spearfishing in the Madeira archipelago. Only a small percentage of the population practices spearfishing, mostly local young men. Most of them practice the activity with a partner throughout most of the year and along most of the island's coastal areas, although preferentially along the North and Southeast coast. Results show how, in recent years, despite the population of spearfishers decreasing, the abundance in the annual catch potentially increased, probably due to the higher investment of time in this activity. It has been observed that many fishers complement their catches with manual collecting of invertebrates. Overall, 40 teleost fishes and also 4 crustaceans and 8 molluscs were identified. The most frequently captured fish species were parrotfish and white seabream, while limpets were the most collected invertebrates in both selected periods.

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