| dc.contributor.advisor |
Steel , R . J . |
|
| dc.contributor.advisor |
Mohrig , David |
|
| dc.contributor.committeeMember |
Kim , Wonsuck |
|
| dc.creator |
Armstrong , Christopher Paul |
|
| dc.date.accessioned |
2012 -07 -20T20 :08 :30Z |
|
| dc.date.accessioned |
2012 -11 -29T20 :50 :44Z |
|
| dc.date.available |
2012 -07 -20T20 :08 :30Z |
|
| dc.date.available |
2012 -11 -29T20 :50 :44Z |
|
| dc.date.created |
2012 -05 |
|
| dc.date.issued |
2012 -07 -20 |
|
| dc.date.submitted |
May 2012 |
|
| dc.identifier.uri |
http : / /hdl .handle .net /2152 /ETD -UT -2012 -05 -5646 |
|
| dc.description.abstract |
This study uses a 1375 km2 3D seismic dataset located in the late Miocene to Pliocene Mississippi River Delta in order to investigate the external characteristics , lithology , and evolution of channelized deposits within the seismic survey . Fluvial thicknesses range from about 11 m to 90 m and widths range from about 100 m to 31 km . Channel fill can be generalized as sandy with low impedance and high porosity ( ~ 35 % ) , though heterogeneity can be high . Three distinct fluvial styles were recognized : incised valleys , channel -belts , and distributive channel networks . Fluvial styles were interpreted as a result of changes in sea -level and a speculative late Miocene to Pliocene Mississippi River Delta sea -level curve constructed using these relationships . Additionally , a characteristic interval between the major changes in fluvial style was found . These fluvial systems interact with and are affected by other elements in the landscape . Growth faults in particular are common within the survey area ; however , the dynamic between fluvial systems and growth fault related subsidence has been poorly understood and so was also a focus of this project . Previous work as well as this study found little evidence that growth faults are able to affect the course or geometry of the majority of small (with most < 500 m in width and < 20 m in depth ) channels . However , the relationship between growth faults and larger scale channel -belt systems (between 1 km and 5 km in width and > 25 m in depth ) has not been previously evaluated in this area . In contrast to the majority of small distributary channels found within the survey , channel -belts appear to be steered by growth faults . Fluvial response or insensitivity to fault induced subsidence is related to the relative timescales of avulsion and faulting . Channel -belts are longer lived features than more ephemeral small distributary channels . Channel -belts , due to their relatively low mobility compared to small channels , are more likely to experience punctuated faulting events which results in greater apparent sensitivity to faulting than seen in small channels . |
|
| dc.format.mimetype |
application /pdf |
|
| dc.language.iso |
eng |
|
| dc.subject |
Seismic geomorphology |
|
| dc.subject |
Fluvial |
|
| dc.subject |
Stratigraphy |
|
| dc.subject |
3D seismic |
|
| dc.subject |
Faults |
|
| dc.subject |
Mississippi River Delta |
|
| dc.title |
3D seismic geomorphology and stratigraphy of the late Miocene to Pliocene Mississippi River Delta : fluvial systems and dynamics |
|
| dc.description.department |
Geological Sciences |
|
| dc.type.genre |
thesis |
* |
| dc.type.material |
text |
* |
| thesis.degree.name |
Master of Science in Geological Sciences |
|
| thesis.degree.level |
Masters |
|
| thesis.degree.discipline |
Geological Sciences |
|
| thesis.degree.grantor |
University of Texas at Austin |
|
| thesis.degree.department |
Geological Sciences |
|
| dc.date.updated |
2012 -07 -20T20 :09 :00Z |
|
| dc.identifier.slug |
2152 /ETD -UT -2012 -05 -5646 |
|