Lacustrine Carbonates: Facies Models, Facies Distributions and Hydrocarbon Aspects

  1. P. Anadón,
  2. Li. Cabrera and
  3. K. Kelts
  1. N. H. Platt1 and
  2. V. P. Wright2

Published Online: 14 APR 2009

DOI: 10.1002/9781444303919.ch3

Lacustrine Facies Analysis

Lacustrine Facies Analysis

How to Cite

Platt, N. H. and Wright, V. P. (1991) Lacustrine Carbonates: Facies Models, Facies Distributions and Hydrocarbon Aspects, in Lacustrine Facies Analysis (eds P. Anadón, Li. Cabrera and K. Kelts), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444303919.ch3

Author Information

  1. 1

    Geologisches Institut, Universität Bern, Baltzerstrasse 1, CH-3012 Bern, Switzerland

  2. 2

    Postgraduate Research Institute for Sedimentology, University of Reading, Reading RG6 2AB, UK

Publication History

  1. Published Online: 14 APR 2009
  2. Published Print: 6 SEP 1991

ISBN Information

Print ISBN: 9780632031498

Online ISBN: 9781444303919

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Keywords:

  • Lacustrine carbonates, biogenic or bio-induced precipitates;
  • progradation of marginal fades, resulting from carbonate production;
  • bench-type lake margin sequence;
  • basal Cretaceous Rupelo Formation;
  • alluvial fan, dominating Lower Freshwater Molasse of Switzerland;
  • Lacustrine carbonates - facies models, facies distributions and hydrocarbon aspects

Summary

Lacustrine carbonates are dominantly biogenic or bio-induced precipitates. While lake basinal carbonates may be modelled in terms of hydrological factors, marginal lacustrine carbonate facies show great variability. At low-energy lake margins, bioturbated micrites dominate. At high-energy margins, lenticular carbonate sands and coated grains are developed. Lakes with low-gradient (‘ramp’-type) margins show dominantly marginal lacustrine facies; lakes with high-gradient (‘bench’-type) margins display greater development of basinal facies. Progradation of lake margins commonly leads to the deposition of regressive sequences, which may be modelled in four categories according to the morphology and energy of lake margins. These categories are: low-energy ‘bench’; high-energy ‘bench’; low-energy ‘ramp’; high-energy ‘ramp’.

Carbonate deposition in lakes is sensitive to climatic and tectonic influences and dependent upon lake hydrology and morphology. Climate controls the rate and nature of biogenic productivity, influences chemical weathering, erosion, and runoff rates in the catchment area, and thus determines carbonate supply.

Lake carbonates may form in a variety of structural settings, especially where the catchment area geology is dominated by carbonates or calcic basement rocks. Tectonic controls determine the rate of subsidence and thus influence sedimentation rates. High-gradient, bench-type lake margins commonly occur at faulted boundaries of rapidly subsiding rift basins where subsidence exceeds sedimentation. At more slowly subsiding rift borders, in larger strike-slip basins, in foreland settings, and in sag basins, low-gradient, ramp-type lake margins dominate. Tectonic factors also influence patterns of continental drainage and the location of clastic sediment input, each of which condition facies distributions within lake basins. Carbonate facies are deposited in areas of low alluvial clastic supply, either in central basin areas away from major bounding faults or prograding thrust fronts, or at basin margins starved of clastic input.

Carbonate lacustrine systems may have hydrocarbon potential. Good source rock prospects occur in deeper, stratified lakes, where anoxic bottom conditions and low detrital input permit the deposition of laminated organic-rich sediments. Reservoirs are more problematic; although reservoirs with primary and secondary porosity may occur in lake marginal bioherms and shoals, most reservoir potential is likely to occur in intercalated alluvial or sublacustrine clastic facies. The extreme lateral variability of lacustrine systems, particularly in rift and strike-slip basins and in high-energy settings, may make accurate prediction of source rock and reservoir facies distributions difficult.