The Geologic Column records the Milankovitch cycles

[LanceH]

I only recently learned this and I'm sure this has already been posted:

Empirical evidence for stability of the 405-kiloyear Jupiter–Venus eccentricity cycle over hundreds of millions of years

"Rhythmic climate cycles of various assumed frequencies recorded in sedimentary archives are increasingly used to construct a continuous geologic timescale. However, the age range of valid theoretical orbital solutions is limited to only the past 50 million years. New U–Pb zircon dates from the Chinle Formation tied using magnetostratigraphy to the Newark–Hartford astrochronostratigraphic polarity timescale provide empirical confirmation that the unimodal 405-kiloyear orbital eccentricity cycle reliably paces Earth’s climate back to at least 215 million years ago, well back in the Late Triassic Period"

Also...

Milankovitch Cyclicity in the Eocene Green River Formation of Colorado and Wyoming

"The Eocene Green River Formation is a classic example of cyclic lacustrine sediments. Following Bradley (1929, U.S.G.S. Prof. Paper 158-E), many descriptive studies suggested precession and eccentricity as the probable climatic forcing to produce the cyclic pattern. Here we report spectral analysis results that confirm this hypothesis. Furthermore, we have identified the presence of a surprisingly large amplitude obliquity cycle, the long-period eccentricity cycle (400 k.y.) and the long period modulators of obliquity. Spectral analyses of data from Colorado were undertaken on an outcrop section and core data using two different proxies for lake depth. "

[LanceH]

Pretty amazing stuff.

 

One of these days they'll probably work out the time of Chixalub impact down to a few centuries maybe even a few years.

Edited May 13, 2023 by LanceH

[Mikrogeophagus]

I saw some paper awhile back mentioning Milankovitch cycles correlating with sea level changes that translate to changes from marl to chalk in the Austin Chalk (if I remember correctly) but I didn’t have access to the article. Need to go back to digging for it some time soon…

[Missourian]

Pennsylvanian cyclothems were likely caused by Milankovitch cycles, at least in part.

 

My interpretation of cycles of strata of my area in Kansas City, Missouri, as caused by sea-level changes:

 

 

Each lithologic change from thick limestone to thick shale (limestone formation to shale formation in most cases here) probably record one or more Milankovitch cycles. The Winterset limestone represents at least two cycles, and as many as four.

 

Note that the thickness of units of strata here are not necessarily equivalent in time. I.e., thin black shales may represent more time than some thick limestones and shales.

[doushantuo]

Lance,I don't think the the spelling of the astrobleme you mentioned is correct. 

[doushantuo]

Revealing the hidden Milankovitch record from Pennsylvanian  cyclothem successions and implications regarding late Paleozoic
chronology and terrestrial-carbon (coal) storage
Frank J.G. van den Belt, Thomas B. van Hoof, and Henk J.M. Pagnier

Geosphere (2015) 11 (4): 1062–1076.

2,1 MB

1062.pdf

[doushantuo]

A&A 428, 261–285 (2004)
DOI: 10.1051/0004-6361:20041335

Astronomy & Astrophysics
A long-term numerical solution for the insolation quantities of the Earth
J. Laskar, P. Robutel, F. Joutel, M. Gastineau, A. C. M. Correia, and B. Levrard

(2.9 Mb)

laskarinsolationTOP100aa1335.pdf

[doushantuo]

some of you may like:

A strategy for cross-calibrating U–Pb chronology and astrochronology of sedimentary sequences: An example from the Green River Formation, Wyoming, USA

Earth and Planetary Science Letters 413(2015)70–78

 

malka machlus,Jahandar Ramezani , Samuel A. Bowring , Sidney R. Hemming ,Kaori Tsukui  William C. Clyde 

(1,3Mb)

recommended

Machlus etal15 (1).pdf

 

zircons/tuff/phenocrysts/sanidine/chronostratigraphy/silicic volcanic eruption

acronyms: CA-TIMS

 

Edited May 14, 2023 by doushantuo