Superimposed platform carbonate cycles
The Middle Triassic Latemar carbonate buildup of the Dolomites (Italy) records high-frequency stratigraphic cyclicity (fourth and fifth order) superimposed on low-frequency (third order) cyclicity. The Latemar platform contains four facies stacked vertically: (1) lower platform facies (LPF), 250 m of subtidal grainstones with abundant early marine diagenesis, noncyclic, subaerial exposure horizons every 10-15 m; (2) lower cyclic facies (LCF), 90 m of meter-scale cycles each composed of subtidal deposits overlain by a vadose diagenetic cap; (3) tepee facies (TF), 120 m of meter-scale cycles periodically interrupted by tepee zones depicting extended subaerial exposure; (4) upper cyclic facies (UCF), 210 m of meter-scale cycles similar to the LCF. High-frequency cyclicity is represented by at least 500 meter-scale cycles (average 0.65 m/cycle) occurring within the LCF, TF, and UCF, each of which records subaerial exposure on a 10/sup 4/ year scale (approximately 20,000 years average). Five meter-scale cycles (fifth order) are grouped into asymmetric megacycles (fourth order). This 5:1 ratio of the superimposed high-frequency orders and the asymmetry of the 10/sup 5/ year fluctuation are predicted by a Milankovitch glacio-eustatic mechanism. Lower frequency cyclicity (third order) is expressed by the Latemar facies succession (LPF in equilibrium LCF in equilibrium TF), which records progressive increase in platform subaerial exposure and decrease in cycle thickness, reflecting a progressive decline in relative subsidence rate.
- OSTI ID:
- 6592380
- Report Number(s):
- CONF-880301-
- Resource Relation:
- Conference: Annual meeting of the American Association of Petroleum Geologists, Houston, TX, USA, 20 Mar 1988
- Country of Publication:
- United States
- Language:
- English
Similar Records
Sequence stratigraphy and systems tract development of the Latemar platform, Middle Triassic of the dolomites: Outcrop calibration keyed by cycle stacking patterns
Identification of Milankovitch Signals in Middle Triassic Platform carbonate cycles using a super-resolution spectral technique
Related Subjects
03 NATURAL GAS
DOLOMITE
CATAGENESIS
NATURAL GAS DEPOSITS
PETROLEUM DEPOSITS
CARBONATE ROCKS
EXPLORATION
GEOLOGIC HISTORY
PETROLEUM GEOLOGY
SANDSTONES
STRATIGRAPHY
TRIASSIC PERIOD
ALKALINE EARTH METAL COMPOUNDS
CALCIUM CARBONATES
CALCIUM COMPOUNDS
CARBON COMPOUNDS
CARBONATE MINERALS
CARBONATES
GEOLOGIC AGES
GEOLOGIC DEPOSITS
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MAGNESIUM CARBONATES
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MINERAL RESOURCES
MINERALS
OXYGEN COMPOUNDS
RESOURCES
ROCKS
SEDIMENTARY ROCKS
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030200 - Natural Gas- Reserves
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