Virtual Landscapes of Texas

60

Grand Saline

LOCATION: NE Van Zandt Co. 32° 39' 58" N; 95° 42' 34" W

RESIDUAL GRAVITY EXPRESSION: -56 G units

DEPTH: Depth to Cap Rock: 171 ft (52 m) Depth to Salt Stock: 213 ft (65 m) Depth to Top of Louann Salt (approximate): 20,000 ft (6,100 m)

ORIENTATION AND MAXIMUM LATERAL DIMENSIONS OF SALT STOCK: Major Axis: Length: 1.6 mi (2.6 km) Orientation: 050° Minor Axis: Length: 1.5 mi (2.4 km) Area: 2.1 mi 2 (5.4 km 2 ) Area of Planar Crest: 1.8 mi 2 (4.6 km 2 ) Percentage Planar Crest: 86%

SHAPE OF SALT STOCK: General: Piercement stock Plan: Circular (axial ratio = 1.07) at -100 ft (-30 m); elliptical (axial ratio = 1 .3) at -3,000 ft (-91 4 m) Cross Section: Axis: Axial plunge 74°; tilt direction 339°; tilt distance 2,112 ft (644 m) Approximate Overall Symmetry: Monoclinic

Crest: Planar Sides: Parallel above -7,500 ft (-2,286 m); deepest data -7,500 ft (-2,286 m) Overhang: Minor overhang on SE flank, elevation -6,500 ft (-1,981 m); maximum lateral overhang 500 ft (1 52 m); percentage overhang 10%; axial tilt produces apparent overhang on NW flank of 2,640 ft (805 m)

CAP ROCK: Maximum Stratigraphic Thickness: 61 ft (19 m) Minimum Stratigraphic Thickness: 5 ft (2 m) Composition: Anhydrite, gypsum, calcite

GEOMETRY OF ADJOINING STRATA: Lateral Extent of Rim Syncline: None above -7,500 ft (-2,286 m) Lateral Extent of Drag Zone: 21,000 ft (6,401 m) Vertical Variation in Maximum Dip of Strata: A = -5° at -6,000 ft (-1 ,829 m) (Washita) A = +5° at 0 ft (0 m) (Wilcox) Angle Between Salt and Surrounding Strata: 5 = 85° at -8,600 ft (-2,621 m) (Glen Rose) <5 = 3O°atOft(Om) (Wilcox) Contact fault below Wilcox Group Oldest Planar Overburden: Wilcox Group

FAULTING OF ADJACENT STRATA: Faults at Flanks: Small graben on NE flank Crestal Faults: None Youngest Faulted Strata: Woodbine Group Oldest Strata at Surface: Wilcox Group: no stratigraphic evidence of doming at surface

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