Some more work relating the 405k cycle:
Scientists show solar system processes control the carbon cycle throughout Earth's history
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Using chemical data from ancient mudstone deposits in Wales, an international team involving scientists from Trinity College Dublin discovered that periodic changes in the shape of Earth's orbit around the Sun were partly responsible for changes in the carbon-cycle and global climate during and in between the Triassic-Jurassic Mass Extinction (around 201 million years ago, when around 80% of the species on Earth disappeared forever) and the Toarcian Oceanic Anoxic Event (around 183 million years ago).
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"Our work shows that for the 18 million years or so in between the Triassic-Jurassic mass extinction and the Toarcian Oceanic Anoxic Event, Earth's global carbon-cycle was in a constant state of change."
"Periodic changes in the shape of Earth's orbit around the sun impacted on the amount of energy received by Earth from the sun, which in turn impacted climatic and environmental processes, as well as the carbon-cycle, on local, regional and global scales."
"Although this phenomenon is well known for having caused the glacial cycles in more recent times, the present study shows that these external forcing mechanisms on Earth's systems were also operating, and controlling Earth's carbon cycle in the distant past, even during non-glacial times when Earth was marked by hot-house climate conditions."
https://www.sciencedaily.com/releases/2020/02/200210153341.htm*
Orbital pacing and secular evolution of the Early Jurassic carbon cycle
Cyclic variations in Earth’s orbit drive periodic changes in the ocean–atmosphere system at a time scale of tens to hundreds of thousands of years. The Mochras δ13CTOC record illustrates the continued impact of long-eccentricity (405-ky) orbital forcing on the carbon cycle over at least ∼18 My of Early Jurassic time and emphasizes orbital forcing as a driving mechanism behind medium-amplitude δ13C fluctuations superimposed on larger-scale trends that are driven by other variables such as tectonically determined paleogeography and eruption of large igneous provinces. The dataset provides a framework for distinguishing between internal Earth processes and solar-system dynamics as the driving mechanism for Early Jurassic δ13C fluctuations and provides an astronomical time scale for the Sinemurian Stage.
https://www.pnas.org/content/early/2020/02/04/1912094117And this article is about the same cycle but just putting the link here so i can find it later.
The articles introduction is a nice introduction to the cycles with a whole bunch of links to research.
https://www.sciencedirect.com/science/article/pii/S1674987119301197