Structure Contour of the Top of the Middle Miocene Sequence, Gulf Coast

The structure contours were created using biostratigraphic data in the Paleo-Data, Inc., Tenroc Regional Geologic Database. The depths of the microfossil locations were associated with the wells data provided by the Louisiana Department of Natural Resources. Because of the proprietary nature of the Tenroc database, no actual data can be shown and only those data points contained in the Louisiana State wells database are included in the control points layer. Contouring was accomplished in Dynamic Graphics, Inc., EarthVision modeling software (v.5) using minimum tension gridding. Three custom programs were used to convert contour lines generated from grids in EarthVision to Arc/Info coverages and then to shapefiles. The data are provided as both lines and polygons (mmtoplg.shp and mmtoppg.shp), and the public wells that penetrate the top of the Middle Miocene (MM) sequence are provided in a point shapefile (mmtopptg.shp).

These datasets contain basic data and interpretations developed and compiled by the U.S. Geological Survey's Framework Studies and Assessment of the Gulf Coast Project. Other major sources of data include publicly available information from state agencies as well as publications of the U.S. Geological Survey and other scientific organizations. In cases where company proprietary data were used to produce various derivatives such as contour surfaces, the source is cited but the data are not displayed.

本数据集的构造等值线（structure contours）基于Paleo-Data, Inc.公司的Tenroc区域地质数据库（Tenroc Regional Geologic Database）中的生物地层数据（biostratigraphic data）生成。微化石点位（microfossil locations）的深度数据与路易斯安那州自然资源部（Louisiana Department of Natural Resources）提供的井数据（wells data）完成关联。由于Tenroc数据库具有专有属性（proprietary nature），无法展示其原始数据，因此控制点图层（control points layer）仅纳入路易斯安那州井数据库中的数据点。等值线生成工作由动态图形公司（Dynamic Graphics, Inc.）的EarthVision建模软件（EarthVision modeling software，v.5版本）通过最小张力网格化法（minimum tension gridding）实现。另有三款定制程序（custom programs）用于将EarthVision中生成的网格等值线转换为Arc/Info覆盖图层（Arc/Info coverages），并进一步导出为形状文件（shapefiles）。数据集以线要素与面要素形式提供（对应文件为mmtoplg.shp与mmtoppg.shp），同时附带了揭露中中新统（Middle Miocene，简称MM）序列顶部的公共井位数据的点形状文件（point shapefile，对应文件为mmtopptg.shp）。

本数据集包含由美国地质调查局（U.S. Geological Survey）墨西哥湾沿岸项目框架研究与评估工作开发并汇编的基础数据与解译成果。其他主要数据来源包括州级机构公开可获取的信息，以及美国地质调查局与其他科研机构的正式出版物。若在生成等值面等衍生数据产品时使用了企业专有数据，将标注其来源但不展示原始数据。