Simulation of stochastic chronological ordering of channelized paleo-evidences.

in: 2017 RING Meeting, pages 440--451, ASGA

Abstract

Modeling consistent channelized systems requires to account for different gradual processes (e.g. outer-bank erosion, inner-bank deposition) and abrupt natural processes (e.g. meander cutoff, avulsion). The latter mainly consists in meander abandonment. When the witnesses of these events survive the posterior reworking of the channel belt, these geobodies are generally brought out on seismic images. In this case, they are valuable clues for recovering the past evolution of a channelized system and can be considered as conditioning data. To reconstruct channelized systems that honor these type of data we have proposed a reverse migration simulation method. The modeling starts from the last observed channel path and migrates it back in time while integrating paleo-evidences such as oxbow lakes according to their likely abandonment age. This technique relies on the knowledge of the abandonment meanders chronology, but only local relative chronologies can be deduced from clear cross-cutting relationships between paleo-evidences. We propose a new method to simulate abandoned meander chronologies at each step of the reverse migration modeling. This semi-automatic technique takes into account local relative chronologies, and generates a range of possible global chronologies of paleo-evidences. Local chronologies are semi-automatically detected through intersections between digitized paths of oxbow lakes inside a group. Then, a stochastic procedure orders the isolated oxbow lakes and the relationships between groups. The sampling is guided by the distance and the orientation of the oxbow lakes toward the current channel. The proposed method also uses the distribution of the number of cutoffs per unit length that can be observed in a specific time period in an analog database. Our tool is demonstrated on a seismic stratal slice of the McMurray Formation in Canada, and provides various consistent global chronologies. Introduction

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BibTeX Reference

@INPROCEEDINGS{Parquer2017c,
    author = { Parquer, Marion and Caumon, Guillaume and Collon, Pauline },
     title = { Simulation of stochastic chronological ordering of channelized paleo-evidences. },
 booktitle = { 2017 RING Meeting },
      year = { 2017 },
     pages = { 440--451 },
 publisher = { ASGA },
  abstract = { Modeling consistent channelized systems requires to account for different gradual processes (e.g. outer-bank erosion, inner-bank deposition) and abrupt natural processes (e.g. meander cutoff, avulsion). The latter mainly consists in meander abandonment. When the witnesses of these events survive the posterior reworking of the channel belt, these geobodies are generally brought out on seismic images. In this case, they are valuable clues for recovering the past evolution of a channelized system and can be considered as conditioning data. To reconstruct channelized systems that honor these type of data we have proposed a reverse migration simulation method. The modeling starts from the last observed channel path and migrates it back in time while integrating paleo-evidences such as oxbow lakes according to their likely abandonment age. This technique relies on the knowledge of the abandonment meanders chronology, but only local relative chronologies can be deduced from clear cross-cutting relationships between paleo-evidences. We propose a new method to simulate abandoned meander chronologies at each step of the reverse migration modeling. This semi-automatic technique takes into account local relative chronologies, and generates a range of possible global chronologies of paleo-evidences. Local chronologies are semi-automatically detected through intersections between digitized paths of oxbow lakes inside a group. Then, a stochastic procedure orders the isolated oxbow lakes and the relationships between groups. The sampling is guided by the distance and the orientation of the oxbow lakes toward the current channel. The proposed method also uses the distribution of the number of cutoffs per unit length that can be observed in a specific time period in an analog database. Our tool is demonstrated on a seismic stratal slice of the McMurray Formation in Canada, and provides various consistent global chronologies. Introduction }
}