Regional Groundwater Flowpath in Trans-Pecos, West Texas

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Regional Groundwater Flowpath in Trans-Pecos,
West Texas

• Thandar Phyu
• CE 394K-GIS in Water Resources
• 12/05/2000

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Outline

• Introduction
• Isotopes
• 87Sr/86Sr
• Procedure
• Summary and Further Work
• Acknowledgement

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Location Trans-Pecos
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DEM
Rustler Hills
Wild Horse Flat
Apache Mtn.
Elevation Range In meters
Star Mtn
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87Sr/86Sr

• Used as a flowpath tracer
• Sr isotopes
• no significant fractionation during mineral-water
  interaction
• 87Sr/86Sr reflects the Sr composition of mineral
• Daughter product of 87Rb
• Stable
• higher 87Sr/86Sr with age

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General Geology
Uliana, 2000
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Procedure 87Sr/86Sr Distribution

• from (x,y) to decimal degrees
• .dbf add event theme create TIN from
  features

87Sr/86Sr Range
0.714-0.715 0.713-0.714 0.712-0.713 0.711-0.712 0.
711-0.711 0.710-0.711 0.709-0.710 0.708-0.709 0.70
7-0.708
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Convert To Grid
87Sr/86Sr Range
0.707-0.708 0.708-0.709 0.709-0.710 0.710-0.711 0.
711-0.711 0.711-0.712 0.712-0.713 0.713-0.714 0.71
4-0.715 No data
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87Sr/86Sr Contour Lines

• Exported as a .shp from SURFER 7.0

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Composite
0.707-0.708 0.708-0.709 0.709-0.710 0.710-0.711 0.
711-0.711 0.711-0.712 0.712-0.713 0.713-0.714 0.71
4-0.715 No data
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ComparisonArcView 3.2, Surfer 7.0 - Macromedia
FreeHand 7.0
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Conceptual Groundwater Flowpath
regional flowpath
Uliana, 2000
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Summary and Further Work

• Created Sr grid
• Sr contours (SURFER 7.0)
• Limitation not enough data
• Potentiometric Surface Map

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Acknowledgement

• Mathew Uliana
• Ph.D Candidate
• Dept. of Geological Sciences
• UT - Austin