Changes

  | part    = Predicting the occurrence of oil and gas traps

  | part    = Predicting the occurrence of oil and gas traps

  | chapter = Value of geological fieldwork

  | chapter = Value of geological fieldwork

  | frompg  = 19-1

  | frompg  = 19-37

  | topg    = 19-42

  | topg    = 19-37

  | author  = Denise M. Stone

  | author  = Denise M. Stone

  | link    = http://archives.datapages.com/data/specpubs/beaumont/ch19/ch19.htm

  | link    = http://archives.datapages.com/data/specpubs/beaumont/ch19/ch19.htm

==Outcrop gamma-ray logging==

==Outcrop gamma-ray logging==

Outcrop gamma-ray logging can be a valuable technique for stratigraphic correlation. It allows a quantitative tie between surface and subsurface using a measurement common to both: the gamma-ray curve. This kind of tie can be more credible than “jump correlating” (identifying events on noncontiguous seismic records or lithologic horizons on well logs, separated by distance, as the same or correlative interfaces in the earth), particularly when significant distance is involved.

[http://www.merriam-webster.com/dictionary/outcrop Outcrop] gamma-ray logging can be a valuable technique for stratigraphic correlation. It allows a quantitative tie between surface and subsurface using a measurement common to both: the gamma-ray curve. This kind of tie can be more credible than “jump correlating” (identifying events on noncontiguous seismic records or lithologic horizons on well logs, separated by distance, as the same or correlative interfaces in the earth), particularly when significant distance is involved.

Two methods of outcrop gamma-ray logging are currently in use:

Two methods of outcrop gamma-ray logging are currently in use:

==Shallow coring==

==Shallow coring==

Surface outcrop samples of a given formation are assumed to be the best available example of that same formation at depth. If this isn't the case, though, another approach exists. A shallow coring program is a cost-effective way to obtain surface geologic data in areas of limited outcrops, severe surface weathering, thick vegetation, and/or thin alluvial cover. A seismic shot hole or water well drilling rig can be strategically positioned for collecting such samples.

Surface [http://www.merriam-webster.com/dictionary/outcrop outcrop] samples of a given formation are assumed to be the best available example of that same formation at depth. If this isn't the case, though, another approach exists. A shallow coring program is a cost-effective way to obtain surface geologic data in areas of limited outcrops, severe surface weathering, thick vegetation, and/or thin [[alluvial]] cover. A seismic shot hole or water well drilling rig can be strategically positioned for collecting such samples.

==External links==

==External links==

[[Category:Predicting the occurrence of oil and gas traps]]  

[[Category:Predicting the occurrence of oil and gas traps]]  

[[Category:Value of geological fieldwork]]

[[Category:Value of geological fieldwork]]