Regional stratigraphy and subsurface geology of Cenozoic deposits, Gulf Coastal Plain, south-central United States
Regional stratigraphy and subsurface geology of Cenozoic deposits, Gulf Coastal Plain, south-central United States
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美国中南部墨西哥湾沿岸平原新生代矿床的区域地层学和地下地质
DOI：
10.3133/ofr9166
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
R. Hosman
中科院分区：
文献类型：
--
作者：
R. Hosman
墨西哥湾沿岸区域含水层系统分析包括阿肯色州、伊利诺伊州、肯塔基州、路易斯安那州、密西西比州、密苏里州、田纳西州、德克萨斯州的墨西哥湾沿岸平原新生代沉积物的所有主要含水层系统，以及阿拉巴马州和佛罗里达州（西部狭长地带）的小区域（面积约 290,000 平方英里）。墨西哥湾沿岸地槽和密西西比湾是构成含水层系统框架的第三纪和第四纪沉积物的主要沉积中心。墨西哥湾沿岸地槽和密西西比湾的形成始于古生代末期的下翘和下断层。沉积作用导致地槽在整个中生代和新生代持续下沉。白垩纪晚期，中生代末期，海水向北推进，最终淹没了密西西比河海湾。海洋循环持续存在于第三纪的古新世和始新世，海水在密西西比湾上空交替前进和后退。由此产生的沉积物形成一系列被陆源沙分隔开的致密海洋粘土。在海湾海退期间，墨西哥湾沿岸地槽仍然被淹没。始新世末期，最后一片第三纪海从密西西比湾撤出后，在非海洋、海洋、近海洋和三角洲环境的变化下，沉积物沿着墨西哥湾沿岸平原继续进行。第四纪期间，密西西比河湾的沉积作用恢复，形成了与冰川相关的阶地和溪流的加积。河流沉积仍在继续。墨西哥湾沿岸平原和密西西比湾的构造特征对新生代沉积有显着影响。例如，德沙盆地是阿肯色州东南部一个明显的第三纪向斜沉积中心。三个大型隆起大致沿路易斯安那州北部边界的纬度排列。从西到东，它们是萨宾隆起、门罗隆起和杰克逊隆起。由卢陵-墨西哥-塔尔科、阿肯色州和皮肯斯-吉尔伯敦这三个主要断裂带组成的带，通常沿着墨西哥湾沿岸平原的沉积物走向，或多或少地形成了墨西哥湾沿岸地槽的北部上倾范围。一系列平缓的向斜和背斜交替排列，垂直于德克萨斯州墨西哥湾沿岸的海岸线。从西南端开始，这些是里奥格兰德海湾、圣马科斯拱门、休斯顿海湾和萨宾拱门。威金斯背斜大致沿着密西西比州南部沉积物的走向。墨西哥湾沿岸平原的盐丘数量众多，可能会穿透数千英尺的沉积物。尽管盐侵入的程度可能非常大，但对邻近地层的破坏仅限于穹顶附近。墨西哥湾沿岸平原的地貌是地表地层性质和作用在地层上的物理力的直接结果。不同的地形代表了它们下面的岩性。沙子和粘土各自产生独特的地貌图案；沙子往往会产生山脊，粘土会产生地形低洼。尽管新生代矿床的分化并不均匀，但整个地区普遍建立了主要古新世和始新世单元的州际关联。较新的存款的差异化程度不高。一些在地表暴露处做出的地层名称不能扩展到地下，并且不同地质层位的稀缺阻碍了区域尺度的区分。渐新世和较年轻的沿海沉积物相发育的复杂性阻碍了地层应用所需的广泛可识别层位的发育。沿海沉积物是三角洲、泻湖、湖泊、沼泽、风成、河流碎屑相和局部钙质礁相的非均质组合。即使是地质系列之间的主要时间界限也没有完全解决。地表第四纪沉积物覆盖在第三纪地层的截断亚层之上，并且通常是可区分的，尽管更新世和底层上新世沉积物之间的一些接触一直是争议的历史根源。与冰川相关的阶地是更新世的特征，而侵蚀河流的冲积层是全新世的特征。
The Gulf Coast Regional Aquifer-System Analysis includes all major aquifer systems in Cenozoic deposits in the Gulf Coastal Plain in Arkansas, Illinois, Kentucky, Louisiana, Mississippi, Missouri, Tennessee, Texas, and in small areas in Alabama and Florida (western panhandle area), an area of about 290,000 square miles. The Gulf Coast geosyncline and the Mississippi embayment were the major depocenters for the Tertiary and Quaternary deposits that form the framework for the aquifer systems. Formation of the Gulf Coast geosyncline and the Mississippi embayment began with downwarping and downfaulting at the end of the Paleozoic Era. Sedimentation caused the geosyncline to continue to subside throughout Mesozoic and Cenozoic time. During the Late Cretaceous, at the close of the Mesozoic Era, the sea advanced northward and eventually inundated the Mississippi embayment. Marine cycles persisted throughout the Paleocene and Eocene Epochs of the Tertiary Period, as the sea alternately advanced and retreated over the Mississippi embayment. The resulting sediments form a series of dense marine clays separated by terrigenous sands. The Gulf Coast geosyncline remained submerged during marine regressions in the embayment. After withdrawal of the last Tertiary sea from the Mississippi embayment at the end of the Eocene Epoch, deposition continued along the Gulf Coastal Plain under a shifting variety of nonmarine, marine, nearmarine, and deltaic environments. Deposition resumed in the Mississippi embayment during the Quaternary with glacially related terraces and aggradation of streams. Fluvial deposition continues. Structural features in the Gulf Coastal Plain and Mississippi embayment significantly affected Cenozoic deposition. The Desha basin, for example, is a pronounced Tertiary synclinal depocenter in southeastern Arkansas. Three large uplifts are approximately aligned along the latitude of the northern boundary of Louisiana. These are, from west to east, the Sabine, Monroe, and Jackson uplifts. A belt of three major fault zones, the Luling-Mexia-Talco, Arkansas, and Pickens-Gilbertown, generally follows the strike of sediments across the Gulf Coastal Plain and more or less forms the northern updip extent of the Gulf Coast geosyncline. An alternating series of gentle synclines and anticlines is oriented perpendicular to the coastline along the Gulf Coast in Texas. Beginning at the southwestern end, these are the Rio Grande embayment, San Marcos arch, Houston embayment, and Sabine arch. The Wiggins anticline is oriented approximately along strike of the sediments in southern Mississippi. Salt domes are numerous in the Gulf Coastal Plain and may penetrate thousands of feet of sediments. Although the degree of salt intrusion can be very great, disruption of adjacent strata is limited to the vicinity of the dome. The physiography of the Gulf Coastal Plain is a direct result of the nature of the strata at land surface and physical forces that act upon them. Different terrains typify the lithologies that underlie them. Sands and clays each produce characteristic geomorphologic patterns; sands tend to produce ridges, and clays produce topographic lows. Although Cenozoic deposits are not uniformly differentiated, interstate correlations of major Paleocene and Eocene units are generally established throughout the area. Younger deposits are not as well differentiated. Some stratigraphic designations made at surface exposures cannot be extended into the subsurface, and the scarcity of distinct geologic horizons has hampered differentiation on a regional scale. The complexities of facies development in Oligocene and younger coastal deposits preclude the development of extensive recognizable horizons needed for stratigraphic applications. Coastal deposits are a heterogeneous assemblage of deltaic, lagoonal, lacustrine, palustrine, eolian, and fluvial clastic facies and local calcareous reef facies. Even major time boundaries, as between geologic series, are not fully resolved. Surficial Quaternary deposits overlie the truncated subcrops of Tertiary strata and generally are distinguishable, although some contacts between Pleistocene and underlying Pliocene deposits have been a historical source of controversy. Glacially related terraces are characteristic of the Pleistocene Epoch, and alluvium of aggrading streams typifies the Holocene.