Skip to Main Content
Skip Nav Destination

Stratigraphy of lacustrine deposits

M. D. Picard and L. R. High
Stratigraphy of lacustrine deposits
AAPG Bulletin (May 1979) 63 (5): 837-838


The major stratigraphic aspects of lacustrine rock units are geometry (thickness and lateral extent), facies patterns, and vertical sequence. Sizes and shapes of modern lakes show wide ranges, but many large ones are subcircular to elongate. In cross section most thick lacustrine units are broadly lenticular with maximum thickness near the center of the basin where subsidence is greatest. Bottom sediments of modern lakes encompass a wide variety of lithofacies. If clastic sediments dominate, there may be concentric belts of gravel, sand, sandy marly mud, and mud, which are controlled by wave base and overall energy gradients. Facies patterns in chemical and organic sediments are not so easily predicted. However, two carbonate models are recognized, one with increasing carbonate content toward the center of the lake and the other with higher carbonate concentrations near the margins. The former results from nearshore dilution by terrigenous sediment and the latter from greater carbonate productivity in shallower water. Similarly, two organic facies patterns predominate. Offshore increase in organic matter results from deposition and preferred preservation below wave base. In contrast, nearshore concentrations of organic matter are mostly caused by in-place accumulations of organic remains. Few ancient lacustrine sequences are either sufficiently well preserved or studied in sufficient detail for construction of even general facies maps. One obvious exception is the Green River Formation of Peleocene(?) to Eocene age, the most extensively studied lacustrine rock unit in the world. In the Green River Formation, the general facies pattern in northeast Utah and northwest Colorado is one of marginal coarse clastics and centralized organic-rich mudstone; a general basinward increase in carbonate rock is also notable. Most lakes pass through more than one cycle of expansion and retreat. The resulting vertical sequence is a composite of many complete and incomplete cycles. Lacustrine rocks display a variety of allocyclic sequences: glacial and nonglacial varves, transgressive-regressive cycles, and various composite groupings represented by bundles of varves or other cyclic deposits.

ISSN: 0149-1423
EISSN: 1558-9153
Serial Title: AAPG Bulletin
Serial Volume: 63
Serial Issue: 5
Title: Stratigraphy of lacustrine deposits
Affiliation: Univ. Utah, Salt Lake City, Utah, United States
Pages: 837-838
Published: 197905
Text Language: English
Publisher: American Association of Petroleum Geologists, Tulsa, OK, United States
Meeting name: AAPG-SEPM-EMD Rocky Mountain sections, 28th annual meeting
Meeting location: Casper, Wyo., USA, United States
Meeting date: 19790603June 3-6, 1979
Summary: Y
Accession Number: 1979-033207
Categories: Sedimentary petrology
Document Type: Serial Conference document
Bibliographic Level: Analytic
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2019, American Geosciences Institute.
Update Code: 1979
Close Modal

or Create an Account

Close Modal
Close Modal