Seismic Evidence for Widespread Possible Gas Hydrate Horizons on Continental Slopes and Rises
Seismic Evidence for Widespread Possible Gas Hydrate Horizons on Continental Slopes and Rises
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DOI：
10.1306/2f91890a-16ce-11d7-8645000102c1865d
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发表时间：
1979-12
期刊：
影响因子：
3.5
通讯作者：
T. Shipley;M. H. Houston;R. Buffler;F. J. Shaub;K. Mcmillen;J. Ladd;J. L. Worzel
中科院分区：
文献类型：
--
作者：
T. Shipley;M. H. Houston;R. Buffler;F. J. Shaub;K. Mcmillen;J. Ladd;J. L. Worzel
在陆坡区海洋地震反射资料中，异常反射常与气水化沉积岩基底相关。对得克萨斯大学海洋科学研究所反射数据的研究表明，沿着美国东海岸、墨西哥湾西部、哥伦比亚北方和巴拿马北方海岸以及中美洲太平洋一侧从巴拿马延伸到墨西哥阿卡普尔科附近的地区可能存在这种天然气水合物。疑似水合物存在于700至4 400米的水深中，并从100至1 100米的海底延伸。几何关系、反射系数、反射极性和压力-温度关系都支持异常反射作为气体水化沉积物基底的识别。在大多数地方，天然气水合物伴生与构造异常（背斜、倾斜地层）有关，这可能使天然气富集并向上倾斜迁移到适合水合物形成的压力和温度条件。天然气水合物边界可用于估算热梯度。通常，从气体水合物相边界估计的热梯度高于通过常规手段测量的报告的热梯度。
Anomalous reflections in marine seismic reflection data from continental slopes are often correlated with the base of gas hydrated sedimentary rocks. Examination of University of Texas Marine Science Institute reflection data reveals the possible presence of such gas hydrates along the east coast of the United States, the western Gulf of Mexico, the coasts of northern Colombia and northern Panama, and along the Pacific side of Central America in areas extending from Panama to near Acapulco, Mexico. Suspected hydrates are present in water depths of 700 to 4,400 m and extend from 100 to 1,100 m subbottom. Geometric relations, reflection coefficients, reflection polarity, and pressure-temperature relations all support the identification of the anomalous reflections as the base of gas hydrated sediments. In most places, gas hydrate association is related to structural anomalies (anticlines, dipping strata), which may allow gas to concentrate and migrate updip into pressure and temperature conditions suitable for hydrate formation. The gas hydrate boundary can be used to estimate thermal gradients. In general, thermal gradients estimated from the gas hydrate phase boundary are higher than reported thermal gradients measured by conventional means.