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{{publication
 | name    = Problems in Exploration Seismology and their Solutions
 | image   = [[File:897.Def.Lz-cropped.png|frameless|180px|link=Problems in Exploration Seismology and their Solutions]]
 | width   = 120px
 | series  = Geophysical References Series
 | title   = [[Problems in Exploration Seismology and their Solutions]]
 | part    = 
 | chapter = 10
 | pages  = 367 - 414
 | author  = [[Lloyd P. Geldart]] and [[Robert E. Sheriff]]
 | doi     = 10.1190/1.9781560801733
 | pdf     = 
 | store   = https://shop.seg.org/shop/products/detail/897
 | isbn    = ISBN 9781560801153
}}
== Problem ==
How do you reconcile the contradictory dips between the 5- and 6-km marks at the top of the migrated section in Figure 10.4a? What [[structural style]] is represented? How would you draw faults?

=== Background ===
[[Structural style]] is discussed in problem 10.3.

When a burst of energy occurs on only a few traces, it migrates into a wavefront shape, called a ''smile''; the pattern on Figure 10.4a below 3 s is mainly one of intersecting smiles.

[[file:Ch10_fig10-4a.png|thumb|{{figure number|10.4a.}} Ardmore Basin (Oklahoma) section.]]

[[file:Ch10_fig10-4b.png|thumb|{{figure number|10.4b.}} Interpretation of Figure 10.4a.]]

=== Solution ===
This section has been migrated, as is evident from the many “smiles” in the lower portion of the section. Migration generally assumes that

# the line is in the dip direction so that there are no data from off to the side of the line 
# the velocities used are correct 
# all of the data arise from primary reflections or diffractions. 

If some of these assumptions are not true, the result is conflicting dips, which are abundant on this section. There is no obvious correlation of events at opposite sides of the section.

This structure can be interpreted as a flower structure (solid lines in Figure 10.4b), a structure resulting from a compressional component (or extensional component for a negative flower structure) of strike-slip [[faulting]]. If this is the case, the [[structural style]] would be classed as basement-involved wrench [[faulting]]. The structure may also be interpreted as thrust [[faulting]] (dashed line in Figure 10.4b), in which case it would be classed as basement-detached thrusting.

Knowledge of the [[structural style]] from other data would help in properly interpreting this line.

== Continue reading ==
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! style="background: #426580; color: white;" | Previous section
! style="background: #E5D75F;" | Next section
|-
| align="center" | [[Structural style]]
| align="center" | [[Mapping faults using a grid of lines]]
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| align="center" | [[:Category: Data processing|Data processing]]
| align="center" | [[:Category: Refraction methods|Refraction methods]]
|-
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[[Problems_in_Exploration_Seismology_and_their_Solutions|Table of Contents (book)]]
|}

== Also in this chapter ==
* [[Improvement due to amplitude preservation]]
* [[Deducing fault geometry from well data]]
* [[Structural style]]
* [[Faulting]]
* [[Mapping faults using a grid of lines]]
* [[Fault and stratigraphic interpretation]]
* [[Interpretation of salt uplift]]
* [[Determining the nature of flow structures]]
* [[Mapping irregularly spaced data]]
* [[Evidences of thickening and thinning]]
* [[Recognition of a reef]]
* [[Seismic sequence boundaries]]
* [[Unconformities]]
* [[Effect of horizontal velocity gradient]]
* [[Stratigraphic interpretation book|Stratigraphic interpretation book]]
* [[Interpretation of a depth-migrated section]]
* [[Hydrocarbon indicators]]
* [[Waveshapes as hydrocarbon accumulation thickens]]

== External links ==
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[[Category:Problems and Solutions]]
[[Category:Publications]]
[[Category:Geologic interpretation of reflection data]]