笔者在琼州海峡西口第四系松散沉积物中新发现碳酸盐胶结岩,通过生物碎屑AMS14C同位素定年、全岩X衍射定量分析、扫描电镜、阴极发光、全岩主微量元素地球化学测试等方法对其进行了年代学和成因研究。结果显示,碳酸盐胶结岩的成岩时代...笔者在琼州海峡西口第四系松散沉积物中新发现碳酸盐胶结岩,通过生物碎屑AMS14C同位素定年、全岩X衍射定量分析、扫描电镜、阴极发光、全岩主微量元素地球化学测试等方法对其进行了年代学和成因研究。结果显示,碳酸盐胶结岩的成岩时代为早—中全新世,具有等厚纤柱状环边胶结、重力悬挂胶结、马牙状胶结、(似)共轴增生胶结、非等轴胶结等5种胶结物特征;阴极发光环带具有广泛发育、环带密集,可见淡水和海水相互作用的咸淡水混合带,说明其成岩环境包括淡水渗流带、咸淡水混合带、海水渗流带、海水潜流带;结合其沉积主微量元素特征,其赋存层位的沉积环境为海岸沉积环境,滨岸沉积相障壁岛亚相,属于海滩岩。综合雷州半岛西南部灯楼角珊瑚礁的海平面记录,重建了全新世琼州海峡西口地区海平面演化历史:9.9~6.7 ka BP海侵期、6.7~6.2 ka BP海退期、6.2~4.2 ka BP海侵期和4.2 ka BP至今的稳定期等四个阶段。展开更多
Nesting behaviour of sea turtles remains a subject to study, due to their enigmatic pattern of seasonal breeding activities. In the present study, characteristics of the breeding turtle, Olive Ridley (Lepidochely...Nesting behaviour of sea turtles remains a subject to study, due to their enigmatic pattern of seasonal breeding activities. In the present study, characteristics of the breeding turtle, Olive Ridley (Lepidochelys olivacea) at Ramnagar along N-E coast of North Andaman Islands were investigated, for the nesting periods 2016-2017. Olive Ridley is the dominant sea turtles, with more than 300 individuals nesting every season with at least a 75% hatching success rate. It is one of the conducive, highly protective and undisturbed nesting sites for Olive Ridley on North Andaman coast. In the present study an initiative is made, to identify nature’s cues and the biological characteristics of Olive Ridley, which leads it to nest at Ramnagar beach, with a high hatchling success rate.展开更多
The nesting behaviour of sea turtles remains a subject to study, due to their enigmatic pattern of seasonal breeding activities. Over a period of time, several reports have been made in this context associated with th...The nesting behaviour of sea turtles remains a subject to study, due to their enigmatic pattern of seasonal breeding activities. Over a period of time, several reports have been made in this context associated with the nesting behaviour of the Olive Ridley turtles. In the present study, characteristics of the breeding beach and nesting pattern of Olive Ridley (Lepidochelys olivacea) at Ramnagar along N-E coast of Andaman Islands were investigated, during the nesting periods 2016-2017. The study area hosts Olive Ridley, the dominant sea turtles with more than 300 individuals nesting each year. For this study, the number of sea turtles visited, nested, the sediment characters, salinity, and temperature were taken. The exposed sandy nesting beach characteristics are prone to varying degrees of morphological changes every day. The results depict that even though similar grain size (Coarse Sand to Fine Sand and Very well sorted to Poorly Sorted), with an ambient incubating temperature, pH and salinity with wide nesting area, the selective nesting in the particular location of the beach identified because of comfortable energy conditions in the waters (1.5 m/s) favours the female turtles to reach the beach at the preferable site of Ramnagar and nest.展开更多
This paper deals with the floral components and soil nutrient dynamics and their relationship in Vatica mangachapoi forest on the tropical sandy beach .The results are : 1 The floral components of Vatica mangachapoi f...This paper deals with the floral components and soil nutrient dynamics and their relationship in Vatica mangachapoi forest on the tropical sandy beach .The results are : 1 The floral components of Vatica mangachapoi forest are different from that of other forest at the same climatic regions. 2 The plant species increase from 6 of which to 137 species ,especially 64 are tropical rain forest species, although the Simpson and Shannon-weiner indexes(species diversity indexes) are 2.19 and 2.34 respectively. Though the contents of the elements such as nitrogen, potassium, phosphorus etc. are extremely low, the contents of the soil nutrients increase appreciably along with the progressing of the forest community succession.展开更多
滩海地区含油层系通常深度跨度大、原油物化性质变化快,稠化机理复杂,造成研究难度大,同时在增储上产和节约成本的形势下,需要开展滩海浅层稠油物理化学特征及稠化机理方面的研究。稠油物理性质、族组分、碳同位素、甾萜类标志物等特征...滩海地区含油层系通常深度跨度大、原油物化性质变化快,稠化机理复杂,造成研究难度大,同时在增储上产和节约成本的形势下,需要开展滩海浅层稠油物理化学特征及稠化机理方面的研究。稠油物理性质、族组分、碳同位素、甾萜类标志物等特征进行了全面分析。物性分析发现原油凝固点低,说明受到了强烈的次生蚀变作用,含硫量一般较小,具备低硫的生物降解稠化环境;族组分随着距凹陷中心越远,沥青质含量越高,异构烷烃含量增大、姥植比降低;三、四环萜烷、甾烷含量增加,粘度大于1 000 m Pa?s甾、萜烷也被降解。最后认为,稠油成因与水洗、氧化和降解这一系列油藏次生作用有关。通过成藏机理分析,认为大幅抬升背景、丰富的断裂系统及地层水,是浅层稠油油藏形成的必备要素。展开更多
文摘笔者在琼州海峡西口第四系松散沉积物中新发现碳酸盐胶结岩,通过生物碎屑AMS14C同位素定年、全岩X衍射定量分析、扫描电镜、阴极发光、全岩主微量元素地球化学测试等方法对其进行了年代学和成因研究。结果显示,碳酸盐胶结岩的成岩时代为早—中全新世,具有等厚纤柱状环边胶结、重力悬挂胶结、马牙状胶结、(似)共轴增生胶结、非等轴胶结等5种胶结物特征;阴极发光环带具有广泛发育、环带密集,可见淡水和海水相互作用的咸淡水混合带,说明其成岩环境包括淡水渗流带、咸淡水混合带、海水渗流带、海水潜流带;结合其沉积主微量元素特征,其赋存层位的沉积环境为海岸沉积环境,滨岸沉积相障壁岛亚相,属于海滩岩。综合雷州半岛西南部灯楼角珊瑚礁的海平面记录,重建了全新世琼州海峡西口地区海平面演化历史:9.9~6.7 ka BP海侵期、6.7~6.2 ka BP海退期、6.2~4.2 ka BP海侵期和4.2 ka BP至今的稳定期等四个阶段。
文摘Nesting behaviour of sea turtles remains a subject to study, due to their enigmatic pattern of seasonal breeding activities. In the present study, characteristics of the breeding turtle, Olive Ridley (Lepidochelys olivacea) at Ramnagar along N-E coast of North Andaman Islands were investigated, for the nesting periods 2016-2017. Olive Ridley is the dominant sea turtles, with more than 300 individuals nesting every season with at least a 75% hatching success rate. It is one of the conducive, highly protective and undisturbed nesting sites for Olive Ridley on North Andaman coast. In the present study an initiative is made, to identify nature’s cues and the biological characteristics of Olive Ridley, which leads it to nest at Ramnagar beach, with a high hatchling success rate.
文摘The nesting behaviour of sea turtles remains a subject to study, due to their enigmatic pattern of seasonal breeding activities. Over a period of time, several reports have been made in this context associated with the nesting behaviour of the Olive Ridley turtles. In the present study, characteristics of the breeding beach and nesting pattern of Olive Ridley (Lepidochelys olivacea) at Ramnagar along N-E coast of Andaman Islands were investigated, during the nesting periods 2016-2017. The study area hosts Olive Ridley, the dominant sea turtles with more than 300 individuals nesting each year. For this study, the number of sea turtles visited, nested, the sediment characters, salinity, and temperature were taken. The exposed sandy nesting beach characteristics are prone to varying degrees of morphological changes every day. The results depict that even though similar grain size (Coarse Sand to Fine Sand and Very well sorted to Poorly Sorted), with an ambient incubating temperature, pH and salinity with wide nesting area, the selective nesting in the particular location of the beach identified because of comfortable energy conditions in the waters (1.5 m/s) favours the female turtles to reach the beach at the preferable site of Ramnagar and nest.
文摘This paper deals with the floral components and soil nutrient dynamics and their relationship in Vatica mangachapoi forest on the tropical sandy beach .The results are : 1 The floral components of Vatica mangachapoi forest are different from that of other forest at the same climatic regions. 2 The plant species increase from 6 of which to 137 species ,especially 64 are tropical rain forest species, although the Simpson and Shannon-weiner indexes(species diversity indexes) are 2.19 and 2.34 respectively. Though the contents of the elements such as nitrogen, potassium, phosphorus etc. are extremely low, the contents of the soil nutrients increase appreciably along with the progressing of the forest community succession.
文摘滩海地区含油层系通常深度跨度大、原油物化性质变化快,稠化机理复杂,造成研究难度大,同时在增储上产和节约成本的形势下,需要开展滩海浅层稠油物理化学特征及稠化机理方面的研究。稠油物理性质、族组分、碳同位素、甾萜类标志物等特征进行了全面分析。物性分析发现原油凝固点低,说明受到了强烈的次生蚀变作用,含硫量一般较小,具备低硫的生物降解稠化环境;族组分随着距凹陷中心越远,沥青质含量越高,异构烷烃含量增大、姥植比降低;三、四环萜烷、甾烷含量增加,粘度大于1 000 m Pa?s甾、萜烷也被降解。最后认为,稠油成因与水洗、氧化和降解这一系列油藏次生作用有关。通过成藏机理分析,认为大幅抬升背景、丰富的断裂系统及地层水,是浅层稠油油藏形成的必备要素。
