Identification of Milankovitch Signals in Middle Triassic Platform carbonate cycles using a super-resolution spectral technique

Conference · Fri Jan 01 04:00:00 EST 1988

OSTI ID:6591669

Hinnov, L; Goldhammer, R K

The Middle Triassic Latemar carbonate buildup of the Dolomites (northern Italy) contains 500 meter-scale cycles (average 0.65 m/cycle) each composed of subtidal deposits overlain by a thin vadose diagenetic cap. The cycles record depositional and early diagenetic responses to glacio-eustatic sea level oscillations with superimposed -- 20,000 year and -- 100,000 year periodicities. Previously, documentation of these Milankovitch periodicities was limited to autocorrelation analyses of truncated sequences (i.e. less than or equal to 45 consecutive cycles) of cycle thicknesses and modeling sedimentation dynamics. To improve the resolution and statistical measure of nonrandom variability in cycle thicknesses, the authors approach Latemar cyclicity using a spectral technique that produces super-resolution spectra of discrete time series. The technique differs from other spectrum estimation procedures in that the time series is ''multitapered'' as a consequence of expanding its Fourier transform by an ordered set of spheroidal functions. The resulting high-resolution spectrum estimates have a greatly enhanced statistical stability that permits the detection of extremely narrow-band signals in noisy data sets that are likely to be missed by traditional spectral analysis. The application of this multitapering algorithm on 140 consecutive Latemar cycles reveals nine statistically significant harmonies controlling cycle development, all with periodicities corresponding to those of Berger's modeled series for the Earth's orbital eccentricity and axial tilt. The authors believe this to be the first report of evidence for multiple, superimposed high-resolution Milankovitch spectra in the pre-Pleisocene shallow marine, platform carbonate record.

• OSTI ID: 6591669
• Report Number(s): CONF-880301-
• Country of Publication: United States
• Language: English

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03 NATURAL GAS
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99 GENERAL AND MISCELLANEOUS
990220 -- Computers
Computerized Models
& Computer Programs-- (1987-1989)
ALGORITHMS
ALKALINE EARTH METAL COMPOUNDS
CALCIUM CARBONATES
CALCIUM COMPOUNDS
CARBON COMPOUNDS
CARBONATE MINERALS
CARBONATE ROCKS
CARBONATES
CATAGENESIS
CENOZOIC ERA
COMPUTERIZED SIMULATION
DEPOSITION
DOLOMITE
EXPLORATION
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC MODELS
GEOLOGY
MAGNESIUM CARBONATES
MAGNESIUM COMPOUNDS
MATHEMATICAL LOGIC
MESOZOIC ERA
MINERAL RESOURCES
MINERALS
NATURAL GAS DEPOSITS
OXYGEN COMPOUNDS
PETROLEUM DEPOSITS
PETROLEUM GEOLOGY
PLEISTOCENE EPOCH
QUATERNARY PERIOD
RESOURCES
ROCKS
SEDIMENTARY ROCKS
SEDIMENTATION
SIMULATION
SOURCE ROCKS
SPECTRA
TRIASSIC PERIOD