New Holocene geological subdivisions. The Anthropocene nowhere to be found.

I wrote about it here:

https://judithcurry.com/2017/09/15/nature-unbound-v-the-elusive-1500-year-holocene-cycle/

You should read my articles. Here is what I had to say about it:

The 4.2 kyr event

At about 4,200 yr BP an abrupt climate change took place that had a strong aridity effect at middle and low latitudes in Africa, the Middle East and southern Asia. The intense drought reduced precipitation by about 30% for about 100-200 years likely causing the end of the Egyptian Old Kingdom, the collapse of the Akkadian Empire in Mesopotamia, and initiated the dispersion of the urban Harrapan civilization in the Indus Valley. The 4.2 kyr event is also seen throughout the Northern hemisphere but in a more complex and irregular manner, unlike most Holocene cold events. Although intense cooling is detected in Iceland lake sediments at 4.2 kyr BP (Geirsdottir et al., 2013), it is brief and completely reversed in about 100 years. Glacier advances are also recorded at the time in Central Asia, the Southern Hemisphere and North America (Mayewski et al., 2004). Interestingly, the 4.2 kyr event is also seen in the GISP2 Greenland ice core. It shows as a significant drop in chlorides (sea salt) concentration (a sea ice proxy; Mayewski et al., 2002), unlike most cold events of the Holocene, suggesting that the cold might have been accompanied by reduced precipitation.

Proxies indicate that the 4.2 kyr event is centered in the Arabian sea region, affecting the East African and Asian monsoons, the Mediterranean and Southern Europe, with a smaller effect on the North Atlantic region and South America, while the cooling appears global. A Kilimanjaro (East Africa) ice core presents a 200-fold increase in dust particles at the time (Thompson et al., 2002; figure 74 a), while a marine sediment core in the Gulf of Oman presents a 10-fold increase in wind transported dolomite from the Mesopotamian region (Cullen et al., 2000; figure 74 b).

Figure 74. The 4.2 kyr event. a) 50-year average of the Holocene dust history from Kilimanjaro ice core NIF3. Dust concentration measured as 0.63-16.0 µm diameter particles per ml sample. Source: L.G. Thompson et al. 2002. Science 298, 589-593. b) Gulf of Oman core M5-422 changes in dolomite which reflect eolian mineral supply from Mesopotamian sources. Source: H.M. Cullen et al. 2000. Geology 28, 379-382. c) Deuterium changes in sedimentary plant leaf wax δDwax measured as ‰ vs. Vienna standard, as a proxy for East African monsoon strength at Lake Challa (Kenya). Source: J.E. Tierney et al. 2011. Quat. Sci. Rev. 30, 798-807.

Tierney at al. (2011) analyzed in detail the hydrology of Lake Challa, close to Kilimanjaro. One of the proxies they used was the proportion of deuterium in lake sediment plant leaf waxes, interpreted as a proxy for the strength of the East African monsoon. While other proxies indicate Lake Challa did not have low lake levels at the time, δDwax indicates the monsoon decoupled at the time from the total rainfall amount in the local basin. The East African monsoon showed at the time its weakest values in the entire Holocene (Tierney et al., 2011; figure 74 c). The 4.2 kyr event coincides also with a period of great weakness of the Asian monsoon (figure 54 f). The general monsoonal weakness during the 4.2 kyr event must have contributed to its unusual aridity.

We must conclude that the 4.2 kyr event is a uniquely abrupt regional arid event that also caused global cooling. The proxies that show it best do not display a clear periodicity (figure 74), indicating that Holocene climate cycles were not the cause. The very strong monsoon weakening and severe aridification are different to the rest of Holocene cooling events and underscore a primary atmospheric manifestation. Its cause is a complete mystery. Most authors talk about shifts and thresholds in oceanic/atmospheric systems. No big volcanic eruption or asteroid impact capable of such global effect has been convincingly linked to the event, although the abruptness, nature and development of the arid-cold event is compatible with a big tropical volcanic eruption or asteroid impact. Since 1998 soil scientist Marie-Agnès Courty has been defending that soil micro-fabrics bear the signature of a cosmic impact at the time (Courty et al., 2008). However, the lack of more substantive evidence, like iridium, nickel or platinum spikes, or a well-dated crater, has made her research largely ignored.

Whatever its cause, the 4.2 kyr event had a brutal impact on human societies, wiping out the most advanced civilizations at the time and changing the course of history. The world is now 100 times more populated and, despite civilization advances, no less vulnerable to the effects of the changes described. The success of the Akkadian empire was partly due to the sophisticated measures (at the time) they implemented to cope with recurrent droughts in the region. They were just unprepared for the unimaginable scale of what came their way.