Graphic Representation of Subsurface Data by Computer: ABSTRACT

Abstract

A subsurface stratigraphic study of terrigenous Miocene sediments along the south Texas Gulf coast was undertaken to determine the possible existence of a major, uranium-bearing, fluvial system that may be related to a paleo-Nueces River. The Nueces River in south Texas flows in a southeasterly direction toward the Texas Gulf coast. In southeastern LaSalle County, the Nueces River makes an abrupt 90° turn and flows northeast for 56 mi (90 km). The Neuces River joins with the Frio and Atascosa Rivers to flow southeasterly, End_Page 696------------------------------ debouching in Corpus Christi Bay. It has been theorized that the Neuces River once flowed southeasterly crossing northwest Webb and central Duval Counties and then into Baffin Bay. A subsurface stratigraphic study was initiated to determine the existence of stacked fluvial sequences within the confines of the proposed former course of the Neuces River. Four hundred and three electric logs were examined to determine the formation tops, bottoms, thickness, percent sand, net sand, and maximum sand of both the Oakville and Catahoula Formations. The electric log data were reduced to acceptable form for use with the University of Rhode Island SYMAP program. The SYMAP program is capable of producing a map of any dimension using a conventional line printer. Data base, cross section location, percent sand, net sand, and maximum sand maps were produced by this method. An advanced University of Rhode Island program known as SYMVU was used in conjunction with a CalComp plotter to display the data as a colored, graphic, three-dimensional map. End_of_Article - Last_Page 697------------