APRIL 2016 LUNCHEON MEETING

APRIL 2016 LUNCHEON MEETING

James R. (Rick) Turner
Geologist, Barrow-Shaver Resources Company
presents
Application of Terrain Slope Maps (S1 Maps) for the Recognition of Buried Geologic Features

11:30 AM Wednesday, April 20, 2016
at the Cascades
4511 Briarwood Road
Tyler, TX 75709

BIOGRAPHY

Mr. James R. (Rick) Turner, a native of East Texas, lives in his hometown of Marshall, Texas. Upon completion of high school, he attended Stephen F. Austin University and graduated in 1973 with a B.S. degree in Geology. After graduation, he served three years in the U.S. Army as an Ordinance Officer and as an Engineering Officer. Following his tour of active duty, Mr. Turner entered the graduate school at Texas A&M University and earned a Master of Science Degree in Geology in 1977. After graduation, he joined Gulf Oil Company in Houston as an Exploration Geologist working the Mesozoic of the Gulf Coast. In 1981, he returned to East Texas and worked for several years in Shreveport with Braddock Exploration and Pruet Oil Company of Jackson, Mississippi. In 1990, he began working for Fina Oil and Chemical Company in Tyler, Texas, and later for Enron Oil and Gas. In 1998, he joined Barrow-Shaver Resources Company in Tyler where he serves as chief geologist.

While in Shreveport, Mr. Turner served on the Board of Directors of the Shreveport Geological Society including serving as President of the Society. He also served on the Board of Directors and as President of the Shreveport Chapter of the Society of Professional Well Log Analysts. In Tyler, Mr. Turner works on the Scholarship Committee of the East Texas Geological Society, as well as serving as Vice President of the Society and as Chairman of the Mesozoic Sandstone Gas Symposium. He is a frequent speaker at Geological Society meetings in Shreveport, Tyler, and Dallas. He has published several papers in the Transactions of the Gulf Coast Association of Geological Societies on numerous topics that include the environment of deposition of the Woodbine at Kurten Field in Brazos County, Texas; the petrophysical character of the Smackover at Bayou Middlefork in Claiborne Parish, Louisiana; a model for the creation of salt diapirs in the East Texas Basin; recognition of low resistivity production in the Travis Peak and Cotton Valley of East Texas; evidence for strike-slip faulting in Northeast Texas; and petrophysical answers for producibility in the Bossier Sandstone in East Texas. Mr. Turner’s geological experience includes exploration and production in the Smackover of South Arkansas and East Texas, the Paluxy of East Texas, the Cotton Valley and Travis Peak of East Texas, and salt domes in East Texas and North Louisiana. Mr. Turner is also interested in applying surface geo-chemistry and topographic analysis as exploration tools.

ABSTRACT

Application of Terrain Slope Maps (S1 Maps) for the Recognition of Buried Geologic Features

James R. Turner
Barrow-Shaver Resources Company

Buried geologic features influence surface conditions in an indirect manner through mechanisms that are not fully understood.  Some mechanisms that have been proposed and studied include differential loading, renewed or continued movement, differential compaction, disruption of near surface ground water flow, and earth tide movements.  In part, surface expression occurs because low gradient streams are sensitive to conditions near buried features.  This results in locally perturbed drainage patterns, abrupt changes in channel and floodplain width, deflection or circumnavigating of streams, and areas of increased drainage density or topographic dissection. 

Three common relationships are developed among subsurface features and topography.  The first is the positive relief stage where there is a direct relationship between relief and structure.  This phase is characterized by a central topographic high with circumnavigating drainage and radial drainage away from the crest.  The second phase is the breached stage characterized by an inverse relationship between relief and structure.  The central topographic high is lowered by headward erosion and scarp slopes face the center of the structure.  The third phase is the obliterative stage where the relationship between structure and relief has been reduced to a large scale embayment.   This phase occurs when headward erosion extends beyond the rim of the structure, the high is split into two halves, and the floodplain begins to widen over the crest.

In locations where subsurface structure or stratigraphic configuration creates a petroleum trap, a microseepage plume will reach the surface.  In the seepage chimney, sediments become hardened with calcium carbonate cement through the action of anaerobic bacteria that feed on the hydrocarbons.  Examples are shown from fields in North Louisiana, East Texas, and South Arkansas that illustrate the effect that the indurated sediments have on local erosional patterns.  Erosion of the indurated strata develops topography with steeper slopes, the hardened area is more intensely dissected by streams, and drainage patterns develop that are similar to those over buried structures.  Iron oxide and iron carbonate cements, produced from a ground water solution of carbon dioxide, hydrogen sulfide, and iron result in the creation of siderite, limonite, hematite, pyrite, and magnetite.  As erosion proceeds these sediments are often exposed at the surface over the seepage plume. 

The Terrain Slope map is one the best ways to display the topographic and drainage data for a study of surface expression.  The Terrain Slope map is a contour map of the slope, in degrees, from zero (horizontal) to 90 (vertical) calculated at each node in a grid file.  Topographic data is usually taken from a DEM file (Digital Elevation Model).  The map consists of isolines of steepest slope from a grid node.  In this presentation, the displays are termed “S1 Maps” because they are the first derivative of topographic slope.  The vertical scale relative to the horizontal scale is exaggerated by a factor of 3.28 which amplifies the surface features.  The maps are contoured with color fill and invisible contour lines, contour lines below 2 degrees are not plotted.                    

Fields in North Louisiana, East Texas, and South Arkansas have been selected to illustrate various aspects of surface expression.  The field example list includes Black Lake in Natchitoches Parish; Sugar Creek in Claiborne Parish; BSR in Madison County, Texas; Horsehead in Columbia County, Arkansas; Corney Bayou in Union Parish, Louisiana; and Lassater-Cedar Springs in Marion and Upshur Counties, Texas; and Brookeland Field, Newton, Jasper, and Tyler Counties, Texas.