Provenance Modelling as a Technique for Analysing Source Terrane Evolution and Controls on Foreland Sedimentation

  1. P. A. Allen and
  2. P. Homewood
  1. S. A. Graham1,
  2. R. B. Tolson1,
  3. P. G. Decelles1,
  4. R. V. Ingersoll2,
  5. E. Bargar3,
  6. M. Caldwell4,
  7. W. Cavazza2,
  8. D. P. Edwards5,
  9. M. F. Follo6,
  10. J. F. Handschy7,
  11. L. Lemke8,
  12. I. Moxon1,
  13. R. Rice9,
  14. G. A. Smith10 and
  15. J. White11

Published Online: 5 MAY 2009

DOI: 10.1002/9781444303810.ch23

Foreland Basins

Foreland Basins

How to Cite

Graham, S. A., Tolson, R. B., Decelles, P. G., Ingersoll, R. V., Bargar, E., Caldwell, M., Cavazza, W., Edwards, D. P., Follo, M. F., Handschy, J. F., Lemke, L., Moxon, I., Rice, R., Smith, G. A. and White, J. (1986) Provenance Modelling as a Technique for Analysing Source Terrane Evolution and Controls on Foreland Sedimentation, in Foreland Basins (eds P. A. Allen and P. Homewood), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444303810.ch23

Author Information

  1. 1

    School of Earth Sciences, Stanford University, Stanford, California 94305, USA

  2. 2

    Department of Earth and Space Sciences, University of California, Los Angeles, California 90024, USA

  3. 3

    SOHIO Petroleum, 5420 LBJ Freeway, Dallas, Texas 75240, USA

  4. 4

    Department of Geology, Western Michigan University, Kalamazoo, Michigan 49008, USA

  5. 5

    Department of Geology, Northern Arizona University, Flagstaff, Arizona 86001, USA

  6. 6

    Department of Geological Sciences, Harvard University, Cambridge, Massachusetts 02138, USA

  7. 7

    Department of Geology and Geophysics, Rice University, Houston, Texas 77251, USA

  8. 8

    Department of Geosciences, University of Arizona, Tuscon, Arizona 85719, USA

  9. 9

    Department of Geology, McMaster University, Hamilton, Ontario L8S 4M1, Canada

  10. 10

    Department of Geology, Oregon State University, Corvallis, Oregon 97331, USA

  11. 11

    Department of Geological Sciences, University of California, Santa Barbara, California 93106, USA

Publication History

  1. Published Online: 5 MAY 2009
  2. Published Print: 22 DEC 1986

ISBN Information

Print ISBN: 9780632017324

Online ISBN: 9781444303810

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Keywords:

  • provenance modelling - technique for analysing source terrane evolution and controls on foreland sedimentation;
  • Southern face of Sphinx Mountain, Madison Range, Montana - upward coarsening and thickening sequence;
  • conceptual basis for provenance modelling of conglomerates;
  • provenance modelling to Sphinx Conglomerate;
  • error analysis in provenance modelling fraught with difficulty;
  • fill of foreland basin reflecting evolution of fold-thrust belt linked genetically

Summary

Tectonism and climate are widely viewed as principal controls on alluvial-fan sedimentation in foreland and other fault-bounded basins. For example, upward coarsening and thickening sedimentary sequences often are interpreted as responses to cratonward propagation of thrust-fault systems in foreland basins. Source-rock lithology is recognized as influencing gross fan morphology (e.g. sandy versus gravelly fans), but the impact of time-varying provenance has not been assessed. The Sphinx Conglomerate of south-western Montana clearly displays the controlling role of changing provenance in an eroding foreland thrust belt on sedimentary style in the adjacent foreland basin. The Maastrichtian Sphinx Conglomerate crops out atop the 3315 m high Sphinx Mountain in the Madison Range as an erosional remnant, over 1000 m thick, of the proximal realm of a Laramide foreland basin. Conglomerate clasts define an unroofing sequence: recognizable Cretaceous to Cambrian clasts appear progressively upward in the Sphinx. Conglomerate units increase upward in abundance and thickness, and the Sphinx Conglomerate is overridden by a foreland thrust fault, implying that conglomerate distribution is a progradational sedimentary response to faulting. However, the Mesozoic section exposed in the Madison Range is largely muddy and contains few units capable of producing conglomerate clasts. In contrast, the middle and lower Palaeozoic section consists largely of carbonates capable of generating great volumes of cobbles in a temperate climate. Thus, the inverted stratigraphy seen in clasts, apparent overall upward coarsening, and increasing abundance and thickness of conglomerate beds suggest that sedimentary style in the Sphinx is determined largely by the lithology of units exposed at specific times in the encroaching thrust plate. To test this hypothesis, we tabulated thicknesses of resistant lithologies capable of yielding gravel clasts for each Phanerozoic unit exposed in the Madison Range, as compared to total unit thickness. Conglomerate clast counts of the Sphinx Conglomerate permitted the identification of units eroding in the adjacent thrust plate at specific times. Comparison of the composition of hypothetical conglomerates eroded from particular suites of source units with the actual composition of Sphinx Conglomerate samples yielded striking results. Modelled compositions closely match actual compositions in several instances. These results suggest that changing provenance can produce bedding trends in foreland basins that are often otherwise attributed to tectonic or climatic controls. Provenance modelling can aid in evaluating these alternative interpretations.