Paleogene sedimentation patterns and basin evolution during Andean orogenesis, Middle Magdalena Valley basin, Colombia

Show simple item record


dc.contributor.advisor Horton , Brian K . , 1970 -
dc.contributor.committeeMember Steel , Ronald J .
dc.contributor.committeeMember Milliken , Kitty L .
dc.creator Moreno , Christopher John
dc.date.accessioned 2010 -12 -23T18 :36 :37Z
dc.date.accessioned 2010 -12 -23T18 :37 :02Z
dc.date.accessioned 2014 -02 -19T22 :48 :21Z
dc.date.available 2010 -12 -23T18 :36 :37Z
dc.date.available 2010 -12 -23T18 :37 :02Z
dc.date.available 2014 -02 -19T22 :48 :21Z
dc.date.created 2010 -08
dc.date.issued 2010 -12 -23
dc.date.submitted August 2010
dc.identifier.uri http : / /hdl .handle .net /2152 /ETD -UT -2010 -08 -1959
dc.description.abstract The Central Cordillera and Eastern Cordillera of the northern Andes form the western and eastern flanks of the north -trending Middle Magdalena Valley basin . Previous estimates for the timing of initial exhumation of the two cordilleras range from ~100 to ~10 Ma . Accurately constraining the spatial and temporal distribution of deformation in Colombia has implications for the shortening history of the Andean convergent margin and the prediction of rapid lateral facies changes in sedimentary basins in close proximity to sediment sources . This study applies sandstone petrographic point counts , field sedimentological analyses of basin fill , and paleocurrent measurements of trough cross -stratification , clast imbrication , and flute casts to provide new insights into the tectonic history of the flanks of the Middle Magdalena Valley basin . Between the lower and upper Paleocene strata of the Lisama Formation , paleocurrent orientations show a shift from northward to eastward transport . This change in sediment dispersal coincides with a shift from a cratonic (Amazonian ) to orogenic (Andean ) sediment source , as recorded by published U -Pb detrital zircon geochronological results (Nie et al . 2010 ) , suggesting initial uplift of the Central Cordillera by mid -Paleocene time . Later in the basin’s history , establishment of an alluvial -plain system with meandering -channel deposits is recorded in lower–middle Eocene strata of the lower La Paz Formation . Consistent eastward paleocurrents characterize mid -Paleocene through uppermost Eocene strata , indicating a continuous influence of western sediment source areas . However , within the upper middle Eocene succession ( ~40 Ma ) , at the boundary between the lower and upper La Paz Formation , sandstone compositions show a dramatic decrease in lithic content . This compositional change is accompanied by a facies shift to amalgamated fluvial channels , reflecting changes in both the composition and proximity of the western sediment source . We attribute these changes to the growing influence of the exhumed La Cira /Infantas paleohighs off the western flank of the present -day Nuevo Mundo syncline . In the uppermost Eocene strata of the Esmeraldas Formation , paleocurrents show a switch to dominantly westward transport that persisted through the Neogene . In addition , deposits show a contemporaneous decrease in the amount of coarse -grained channel deposits . These changes are interpreted to reflect the onset of exhumation in the Eastern Cordillera . The lack of a significant change in sandstone compositions at this boundary suggests a compositional similarity between strata uplifted by the Lisama structure and the Eastern Cordillera . These data support and further refine previous thermochronologic and provenance studies which suggest that uplift -induced exhumation of the Central Cordillera and Eastern Cordillera commenced by mid -Paleocene and late Eocene–early Miocene time , respectively .
dc.format.mimetype application /pdf
dc.language.iso eng
dc.subject Palogene
dc.subject Sedimentation
dc.subject Basin evolution
dc.subject Sedimentology
dc.subject Tectonics
dc.subject Sandstone petrography
dc.subject Colombia
dc.subject Andes
dc.subject Middle Magdalena Valley basin
dc.subject Cordillera
dc.subject Cenozoic
dc.title Paleogene sedimentation patterns and basin evolution during Andean orogenesis , Middle Magdalena Valley basin , Colombia
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 2010 -12 -23T18 :37 :02Z

Citation

Paleogene sedimentation patterns and basin evolution during Andean orogenesis, Middle Magdalena Valley basin, Colombia. Master's thesis, University of Texas at Austin. Available electronically from http : / /hdl .handle .net /2152 /ETD -UT -2010 -08 -1959 .

Files in this item

Files Size Format View

There are no files associated with this item.

This item appears in the following Collection(s)

Show simple item record

Search DSpace

Advanced Search

Browse