Dr Micha CampbellJan 23, 2025

The #PaperClub pick this fortnight is a recent-ish one from Columbu et al. - interesting use of a speleothem hydroclimate record to contextualise the decline of Neanderthals in Italy. Early days yet, and I'm no hominin expert, but I was just struck by how recently Neanderthals became extinct - only ~42 ka! Imagine the world if they had managed to survive...

https://www.nature.com/articles/s41559-020-1243-1

Speleothem record attests to stable environmental conditions during Neanderthal–modern human turnover in southern Italy - Nature Ecology & Evolution

Unstable and harsh climates have been implicated as partial causes of Neanderthal demise. Here a speleothem palaeoenvironmental record spanning the Middle to Upper Palaeolithic transition attests to stable and moderate conditions in the Mediterranean during this time suggesting a more complicated picture than previously thought.

Nature
Dr Micha CampbellJan 9, 2025

#PaperClub is back for the start of 2025, and we're kicking off with Patterson et al (2024), who present a PCP-corrected stalagmite d18O record from Vietnam, spanning 45-4 ka. Interesting paper, and the whole 'PCP impacts on d18O' thing has been getting quite a lot of airtime in recent years. Hopefully without sounding like a hater, I remain a bit skeptical. In this instance, the model assumptions include a feeding stalactite drip rate of 1 drip/second, which seems too high for LGM (where PCP effect on the stal was greatest). For stalactite PCP to be recorded in a stalagmite, there must not be sufficient residence time for re-equilibration to occur. I would love to see a sensitivity test of the drip rate on the model.

Growth rates during the 'peak PCP' period were also extremely low (<5 um/yr), which suggests to me that growth was likely not continuous over the period. d18O vals were high, I assume there was greater opportunity for disequilibrium to drive the signal rather than PCP?

Anyway, I'm definitely no expert in d18O kinetics, and I'm looking forward to hearing the opinions of the group, and anyone else who has read the paper :) I am really happy to be wrong about this, as there are lots of clever people on the paper who know more than me about this stuff!

#Paleoclimate #Speleothems #speleology
https://www.nature.com/articles/s41467-024-53422-y

Local hydroclimate alters interpretation of speleothem δ18O records - Nature Communications

This study finds that in-cave processes affect speleothem oxygen isotope records. Correcting for these processes improves agreement with other regional records and climate models, providing a more accurate reflection of past hydroclimate change.

Nature
Dr Micha CampbellNov 29, 2024

This fortnight's paper club offering is this banger by Tremaine and Frohlich (2013). Picked by me, as my group is moving towards doing more TE work, so I'm trying to share the foundational TE papers. It's been a minute since I've read this paper closely, and it's still thoroughly enjoyable (if you're interested in the interactions between host rock chemistry, hydrology, climate, and trace element concentrations, but aren't we all!).

#PaperClub #geochemistry

https://www.sciencedirect.com/science/article/pii/S0016703713004067

Speleothem trace element signatures: A hydrologic geochemical study of modern cave dripwaters and farmed calcite

Trace element variations in ancient cave speleothems are often interpreted as indicators of changes in paleo-rainfall and hydrologic conditions. Howev…

Matthias SchröterNov 5, 2022

3/3 We have been reading this paper yesterday in goeml, the #Goettingen #MachineLearning #paperclub.

The majority opinion was: unexpected, but not so surprising result, once you think about it. The vote on the scientific quality of the paper was 4.94 (with 7 being best).

In two week from now we will discuss: Statistical Physics through the Lens of Real-Space Mutual Information, https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.127.240603

DM me if you are interested to join (goeml is Zoom only, 14:00 MET)