| NGRIP, GISP2 & GRIP Ice Cores | Greenland | 12,896 to 11,703 b2k (c. 10,900–9,700 BCE) | Global stratotype for GS-1 onset and Holocene onset; δ18O drop, dust spike, and 20-year Pt anomaly in GISP2 | Pt spike cited for extraterrestrial/volcanic input; exact temporal alignment with terrestrial black mats debated within ±30–100 yr ice-core uncertainty |
| Murray Springs & Lehner Ranch | San Pedro Valley, Arizona, USA | ~12,800 cal BP (c. 10,850 BCE) | Classic Clovis hunting camps and mammoth kill sites directly capped by Stratum F2 wetland "black mat" | Magnetic spherules, Pt and iridium reported at base of black mat (Firestone 2007); independent replication and synchroneity questioned by Holliday et al. (2023) |
| Blackwater Draw (Clovis Type Site) | New Mexico, USA | ~12,900–12,750 cal BP | Stratified mammoth bones and Clovis fluted points beneath diatomaceous pond deposits and Folsom layers | Reported microspherule and nanodiamond peaks at the Clovis/Folsom transition; critics argue wetland authigenesis and reworking |
| Arlington Springs & Daisy Cave | Channel Islands, California, USA | ~12,900–12,800 cal BP | Human femora (Arlington Springs Man), pygmy mammoth extinction horizon, and charcoal-rich dark sediment layers | Hexagonal lonsdaleite/nanodiamonds and spherules reported (Kennett et al. 2009); mineral identification disputed by Daulton et al. |
| Sheriden Cave & Topper | Ohio & South Carolina, USA | ~12,850 cal BP | Sheriden Cave yielded extinct giant short-faced bear, stag-moose and two Clovis bone points in a charcoal-rich layer; Topper has a distinct Clovis quarry floor | Platinum, microspherules and nanodiamonds reported directly on the Clovis floor; critics question single-year synchroneity across Bayesian radiocarbon widths |
| Abu Hureyra | Euphrates Valley, Syria | ~12,800 cal BP (c. 10,850 BCE) | Late Epipalaeolithic pit-dwellings transitioning to early cereal cultivation during YD cooling and drying | Meltglass (>1,700°C) and Pt peak reported (Moore et al. 2020); 2023 shock-quartz follow-up paper retracted in 2025 |
| Pilauco | Los Lagos, Chile | ~12,800 cal BP | Peat/wetland boundary with extinction of Notiomastodon, horses and megafaunal dung fungi (Sporormiella) | Pt/Pd anomaly, Cr-rich spherules and biomass-burning peak reported in Southern Hemisphere (Pino et al. 2019) |
| Southern Sweden YDB sequence | Southern Sweden | ~12,850 cal BP (~150 yr above ~13,006 cal BP Laacher See tephra) | Late-glacial sediment sequence with dated Laacher See volcanic tephra marker ~150 years below the YDB onset | Leading Edge (Moore et al., Sept 30, 2026): Pt peak and Fe/Si-rich microspherules (mostly terrestrial impact-melt + minor extraterrestrial component) chronologically separated from the Laacher See eruption |
| Göbekli Tepe (Layer III) & Karahan Tepe | Şanlıurfa, Türkiye | ~11,600–10,800 cal BP (c. 9600–8800 BCE) | Earliest monumental T-pillar enclosures built immediately at the Younger Dryas–Holocene warming boundary | Sweatman & Tsikritsis (2017) read Pillar 43 as a 10,950 BCE comet record; DAI excavators read the reliefs as local PPNA cosmology and note Layer III postdates YD onset by ~1,200 yr |
