A Story of the Planet Venus
Looking For The Planet Venus Prior to 1200 BC
by John M. Collins Sarnia, Ont., Canada 2021
Appendix 5
Venus & Platinum
Analysis of Materials in The Greenland Ice Samples
Contents
Summation
Abstracts:
Petraev, M. I. et al 2013 Large platinum anomaly in the Greenland ice core points to a cataclysm at the onset of Younger Dryas
Moore, C. R. et al 2017 Widespread platinum anomaly documented at the Younger Dryas onset in North American sedimentary sequences
Mario Pina et al 2019 Sedimentary record from Patagonia, southern Chile supports cosmic-impact triggering of biomass burning, climate change, and megafaunal extinctions at 12.8 ka
VENUS COMET & MENTIONS OF PLATINUM
FOUND IN ICE CORES AND BLACK MAT
Summation
The findings in these three papers are described as metal contaminants deposited at the time of the Younger Dryas Boundary (YDB). Abstracts of these papers are given below.
The Abstract of the first paper (Petaev, M.I. et al 2013) describes research on the NOAA samples of Greenland ice cores. The date is given as 12,888 calendar years Before Present on a single sample.
The Abstract of the second paper (Moore, C.R. et al 2017) deals with 11 soil samples taken North America-wide. The dating given is ~12,800 calendar years Before Present.
Also attached is the Abstract of a third paper (Mario Pino et al 2019) describing field research in Chile on >50 samples from the "black mat" from the 13kYA catastrophe which led to the Younger Dryas Boundary. The dating given is ~12,800 calendar years Before Present.
The entire articles are cited to allow reference to them if desired.
All studies show that a Platinum (Pt) spike found in the samples, has little association with other elements, such as Iridium (Ir), Hafnium (Hf) and Aluminium (Al) usually found with it in Earth-sourced samples. This suggests an extra-terrestrial source for this material.
The discussion in "Venus; The Late - Arriving Planet" by John M. Collins describes this particulate material as being transported in the Venus Comet but from where is not known. No assumption is made that it is sourced from the planet Venus. Conversely that planet can not be ruled out as the source.
Additionally the Petaev et al paper (see abstract on following pages) provides readings on other features of the YDB event based on contaminants found in the ice.
- Severe emissions of SO4- dated 12,982, 12,817 and 12,782 calendar years BP likely related to volcanic or other Earth ruptures (Great Rift Valley/ Dead Sea system?) caused by the close proximity of the Venus planet and its comet.
- Severe emission of NH4+ dated 12,857 calendar years BP likely caused by huge fires on the Earth.
While the analysis methods of the particles is not worrisome, the dating of the samples is. From the work done in "Venus; The Late - Arriving Planet", this author is aware that the Earth - Venus Comet encounter that initiated the Younger Dryas was a singular event. The above dates span a 200 year time frame. He is aware that while the varves in the ice column represent individual years, trying to extract an adequate sample from a single year in that 13,000 YA time frame, was not possible. The NOAA data for that period show that multiple years were grouped to obtain enough sample to test. The results were reported with the average date of the grouping, and the test data as an average for that range of sample.
Recent work on the analysis of 'black mat' material found in the Pilauco Bajo site near Osorno, Chile(1) , is discussed in "The Venus Story" text in the entry on 13,000 YA, and in Appendix. 1 - Dated Events - 11,053 BCE. Researchers found a Pt., Au and Pd peak anomaly claimed to be a derivative of airbursts or impacts. It also contains chromium spherules that match the material in those Andean mountains indicating them as its source. Multiple large volcanoes in the immediate vicinity, such as Osorno, have erupted violently in the past(2) and therefore could have thrown the chromium ore particles up and into the Venus Comet maelstrom.
Large Platinum anomaly in the Greenland ice core points to a cataclysm at the onset of Younger Dryas
Michail I. Petaev, Shichun Huang, Stein B. Jacobsen, and Alan Zindler
PNAS August 6, 2013 110 (32) 12917-12920; https://doi.org/10.1073/pnas.1303924110
• Edited by Mark H. Thiemens, University of California, San Diego, La Jolla, CA, and approved June 26, 2013 (received for review February 28, 2013)
Abstract
One explanation of the abrupt cooling episode known as the Younger Dryas (YD) is a cosmic impact or airburst at the YD boundary (YDB) that triggered cooling and resulted in other calamities, including the disappearance of the Clovis culture and the extinction of many large mammal species. We tested the YDB impact hypothesis by analyzing ice samples from the Greenland Ice Sheet Project 2 (GISP2) ice core across the Bølling-Allerød /YD boundary for major and trace elements. We found a large Pt anomaly at the YDB, not accompanied by a prominent Ir anomaly, with the Pt/Ir ratios at the Pt peak exceeding those in known terrestrial and extraterrestrial materials. Whereas the highly fractionated Pt/Ir ratio rules out mantle or chondritic sources of the Pt anomaly, it does not allow positive identification of the source.
Circumstantial evidence such as very high, superchondritic Pt/Al ratios associated with the Pt anomaly and its timing, different from other major events recorded on the GISP2 ice core such as well-understood sulphate spikes caused by volcanic activity and the ammonium and nitrate spike due to the biomass destruction, hints for an extraterrestrial source of Pt. Such a source could have been a highly differentiated object like an Ir-poor iron meteorite that is unlikely to result in an airburst or trigger wide wildfires proposed by the YDB impact hypothesis.
• meteorite impactclimate changeICP-MS analysisPGE
The Younger Dryas (YD), a millennium-long cooling period amid postglacial warming well documented in the Greenland ice cores (e.g., refs. 1, 2), is thought to result from an abrupt change in atmospheric and oceanic circulation (3). Whether such a change was caused by a catastrophic event or it is an integral, although still poorly understood, feature of the deglaciation process remains unclear (4).
Among testable catastrophic hypotheses, the most popular, attractive, and long-lasting idea of a sudden discharge of fresh water from the proglacial Lake Agassiz into the Arctic Ocean (5⇓–7) eventually was found inconsistent with geomorphological and chronological data (4, 8). The long-term effect of the proposed “volcanic winter” in the northern hemisphere induced by the catastrophic eruption of the Laacher See volcano 12,916 calendar years before 1950 (cal BP) (9) is not clear as the Laacher See tephra, found in many European lacustrine deposits, is absent in the Greenland ice cores (10). The impact hypothesis (11), once declared dead (12, 13), recently gained new support from the discovery of siliceous scoria-like objects (SLOs) with global distribution, which provide strong evidence for processing at high temperatures and pressures consistent with a cosmic impact (14).
The ever-controversial impact hypothesis was initially invoked to explain the disappearance of the Clovis culture and the extinction of many mammal species, including mammoths, by a cometary airburst that resulted in massive wildfires and, ultimately, the YD cooling. A C-rich layer exposed at many sites in North America and Europe at or near the YD boundary (YDB layer), which is enriched in magnetic grains with Ir, magnetic microspherules, charcoal, soot, carbon spherules, glass-like carbon with nanodiamonds, and fullerenes with extraterrestrial He (11), has been interpreted as documenting this event. Ammonium and nitrate spikes at the onset of the YD in Greenland Ice Core Project (GRIP) and Greenland Ice Sheet Project 2 (GISP2) ice cores, perhaps resulting from biomass burning, are taken as further support for the impact hypothesis. Subsequent studies (13, 15, 16) questioned the origins of many impact markers cited by ref. 11, but the discovery of the SLOs alongside abundant, compositionally similar microspherules in three YDB sites in North America and Asia is difficult to explain by anything other than a cosmic impact. In its latest incarnation, the impact hypothesis calls for three or more epicentres of an impact or airburst (14). However, the invoked markers have never been supported by a clear geochemical impact signature such as a sharp increase in Ir or other platinum group element (PGE) concentrations at the YDB.
We have tested the YDB impact hypothesis by measuring trace and major element concentrations in ice samples from the GISP2 ice core across the Bølling-Allerød/YD boundary (depth of 1,709–1,720 m, 12,279–13,064 cal BP) with a spatial resolution of ∼12.5 cm, corresponding to a time resolution of 2.5–4.6 y (17). The elemental concentrations in melted ice samples were measured by inductively coupled plasma mass spectrometry (ICP-MS) that is known to have possible interferences of LuO and HfO peaks with Ir and Pt peaks. This issue was resolved by measuring Lu and Hf oxide formation in well-calibrated standards (details in Materials and Methods).
The major finding of this study (Fig. 1 and Table S1) is the lack of a striking Ir anomaly in the analyzed ice samples. Instead, we found a large Pt anomaly in the middle of the Bølling-Allerød–YD transition that is contemporaneous with a sharp drop in the δ18O values (Fig. 1B and Fig. S1). The Pt peak (Fig. 1) is unlikely to be a mass-spectrometry artifact because (a) it is smoothly defined by seven ice samples; (b) the HfO interferences (178Hf16O, 179Hf16O, 180Hf16O) on 194,195,196Pt isotopes, respectively, were carefully assessed; (c) the 178,179,180Hf signals in sample 63 with the highest Pt concentration are at least a factor of 10 lower than those of 194,195,196Pt; and (d) there is no linear correlation between Hf concentrations and Pt concentrations in the ice samples.
<img class=“highwire-fragment fragment-image" alt="Fig. 1."
src="https://www.pnas.org/content/pnas/110/32/12917/F1.medium.gif" width="345" height="440"/>
Fig. 1.
(A and B) Ir (A) and Pt (B) variations in the GISP2 ice samples across the Bølling-Allerød/YD boundary. Open symbols indicate upper limits. During the transitional period the annual rate of ice accumulation changes from high to low values (1). The Ir contents in the ice (A) show some variations with no clear substantial anomalies. On the contrary, a large Pt anomaly (B) occurs in the middle of the Bølling-Allerød–YD transition period. The anomaly coincides with a sharp drop in the δ18O values in ice (black curve). The δ18O curve is calculated from the data of ref. 18 averaged for 40 cm of ice thickness. (C) The time of the Pt anomaly differs from those of the volcanic SO42− spikes (19) and the Laacher See eruption (LSE) (9) and precedes the onset of the NH4+ spike (2) by ∼30 y.
The Pt concentrations gradually rise by at least 100-fold over ∼14 y and drop back during the subsequent ∼7 y. The decay of the Pt signal is consistent with the ∼5-y lifetime of dust in the stratosphere. The observed gradual ingrowth of the Pt concentration in ice over ∼14 y may suggest multiple injections of Pt-rich dust into the stratosphere that are expected to result in a global Pt anomaly.
The Pt anomaly is accompanied by extremely high Pt/Ir and Pt/Al ratios (Fig. 2), indicative of a highly unusual source of Pt in the ice. Such a source is unlikely to be laboratory contamination because (a) all samples defining the anomaly are from the same ice core samples (Fig. S2) and were collected using the same set of tools and latex gloves, (b) three peak samples are from a single continuous chunk, and (c) the samples were randomly dissolved and analyzed. Contamination during ice coring and subsequent slicing is also unlikely because PGEs are essentially insoluble in pure acids, let alone in water (Materials and Methods).
<img class="highwire-fragment fragment-image" alt="Fig. 2." src="https://www.pnas.org/content/pnas/110/32/12917/F2.medium.gif" width="439" height="440"/>
Fig. 2.
(A and B) Pt/Ir (A) and Pt/Al (B) ratios in the GISP2 ice samples across the Bølling-Allerød/YD boundary vary between the chondritic and continental crust values. The only exception is the Pt anomaly with both Pt/Ir and Pt/Al ratios greatly exceeding chondritic and crustal values, with three top points also exceeding Pt/Ir ratios of low-Ir iron meteorites. Such a large fractionation of both Pt/Ir and Pt/Al ratios within the anomaly most likely results from atmospheric processing of the Pt-rich material.
Materials with high Pt/Ir ratios and essentially no Al are known among magmatic iron meteorites (20, 21). Finding a terrestrial Pt-rich and Ir-, Al-poor source is difficult. Most volcanic rocks have elevated Pt/Ir ratios, although not as high as in iron meteorites, but Pt/Al ratios are very low (e.g., refs. 22, 23). Mantle rocks are depleted in Al, but have essentially unfractionated Pt and Ir (24). The only known terrestrial material with Pt/Ir ratios comparable to those in iron meteorites is the Pt-rich sulphides from the Sudbury Footwall (25). However, both terrestrial and extraterrestrial high-Pt sources have substantially lower Pt/Ir ratios than those at the top of the Pt peak, implying either Pt-Ir fractionation during atmospheric processing of the Pt-rich materials or multiple injections of materials with different Pt/Ir ratios not sampled so far.
Thus, the highly fractionated Pt/Ir ratio rules out mantle or chondritic sources of the Pt anomaly (Fig. 2). A further discrimination between Pt-rich crustal materials like Sudbury Footwall ore (25) and fractionated extraterrestrial sources such as Ir-poor iron meteorites like Sikhote-Alin (26) is difficult because of the comparable magnitude of the Pt/Ir fractionation in these materials. Circumstantial evidence hints at an extraterrestrial source of Pt, such as very high, superchondritic Pt/Al ratios at the Pt anomaly and its timing, which is clearly different from other major events recorded in the GISP2 ice core, including well-understood sulphate spikes caused by volcanic activity and the ammonium and nitrate spikes associated with biomass destruction (Fig. 1C).
Until the question about the nature of Pt-rich material and the means of its delivery to the ice is resolved, an extraterrestrial source of Pt appears likely. For example, the Pt anomaly could be explained by multiple impacts of an iron meteorite like Sikhote-Alin or Grant (21, 26); the former is a large crater-forming meteorite shower. Assuming a global anomaly, the 62.5-cm-thick ice layer with the average Pt concentration of 30 parts per trillion (ppt) (Fig. 1) would require an iron meteorite like Sikhote-Alin of ∼0.8 km in diameter to account for the Pt budget at the YDB. Because complete disintegration of such a large iron meteorite during its atmospheric passage seems unlikely, the event is expected to form a crater of a few kilometres in diameter. No such crater at YDB has been found so far.
The main conclusion of our study is the detection of an unusual event during the Bølling-Allerød–YD transition period that resulted in deposition of a large amount of Pt to the Greenland ice. The Pt anomaly precedes the ammonium and nitrate spike in the GISP2 ice core (2) by ∼30 y and, thus, this event is unlikely to have triggered the biomass burning and destruction thought to be responsible for ammonium increase in the atmosphere and the Greenland ice (11). Although the data do not allow an unambiguous identification of the Pt source, they clearly rule out a chondritic origin of Pt. One of the plausible sources of the Pt spike is a metal impactor with an unusual composition derived from a highly fractionated portion of a proto-planetary core.
Scientific Reports
Widespread platinum anomaly documented at the Younger Dryas onset in North American sedimentary sequences
Moore, Christopher R.; West, Allen; LeCompte, Malcolm A.; Brooks, Mark J.; Daniel, I. Randolph; Goodyear, Albert C.; Ferguson, Terry A.; Ivester, Andrew H.; Feathers, James K. (2017-03-09)
Sci Rep. 2017; 7: 44031. Published online 2017 Mar 9. doi: 10.1038/srep44031
Abstract
Previously, a large platinum (Pt) anomaly was reported in the Greenland ice sheet at the Younger Dryas boundary (YDB) (12,800 Cal B.P.). In order to evaluate its geographic extent, fire-assay and inductively coupled plasma mass spectrometry (FA and ICP-MS) elemental analyses were performed on 11 widely separated archaeological bulk sedimentary sequences. We document discovery of a distinct Pt anomaly spread widely across North America and dating to the Younger Dryas (YD) onset. The apparent synchroneity of this widespread YDB Pt anomaly is consistent with Greenland Ice Sheet Project 2 (GISP2) data that indicated atmospheric input of platinum-rich dust. We expect the Pt anomaly to serve as a widely-distributed time marker horizon (datum) for identification and correlation of the onset of the YD climatic episode at 12,800 Cal B.P. This Pt datum will facilitate the dating and correlating of archaeological, paleontological, and paleoenvironmental data between sequences, especially those with limited age control.
In 2013, Petaev et al.1 discovered an anomalously large platinum (Pt) peak in ice core samples from the Greenland Ice Sheet Project 2 (GISP2), thus providing the most compelling evidence to date for a catastrophic extraterrestrial event coincident with the onset of the Younger Dryas (YD) climate episode. In the study by Petaev et al., high-resolution (2.5–4.6 y) time-series of ice core samples were analyzed for trace and major element concentrations using inductively coupled plasma mass spectrometry (ICP-MS). Petaev et al.1 reported the presence of a Pt peak anomaly at the Bølling-Allerød/Younger Dryas Boundary (YDB), coincident with a large shift in δ18O values, confirming the onset of cooler conditions at the beginning of the YD interval. This peak interval is represented by a rise in Pt concentrations over 14 years and subsequent drop during the following 7 years, consistent with the known residence time of stratospheric dust1. This sharply defined Pt anomaly at the YD onset in GISP2 is coeval with other YDB impact-related proxies, including nanodiamonds and melted spherules, found in Greenland and across four continents and is proposed by Petaev et al. to have resulted from a highly fractionated, Ir-deficient, iron-rich, extraterrestrial impactor. However, ten additional YDB studies have reported different concentrations and ratios of Pt and other platinum group elements (PGE), including iridium (Ir), osmium (Os), ruthenium (Ru), and rhodium (Rh), all of which usually co-vary (Supplementary Information, “Summary of PGE Occurrence in the YDB”). These other studies do not rule out an extraterrestrial impactor as source of the PGE anomalies, but do not support the conclusion that it was highly fractionated and Ir-deficient, leaving open the question of the exact nature of the Pt source (see Supplementary Information, “Potential Sources of YDB Platinum”).
Sawlowicz2 notes that PGE anomalies may result from multiple processes of enrichment, including: a) cometary or meteoritic influx [Supplementary Table 7]; b) impactites from an extraterrestrial impact event [Supplementary Table 7]; c) volcanoes [Supplementary Table 10]; d) mantle material, e.g., from tectonic motion or in cratons [Supplementary Table 7]; e) exhal-ative-hydrothermal processes; f) precipitation from seawater; g) post-depositional transport and precipitation at redox boundaries; and h) reduction from intermediate and low-temperature solutions. In this study, we evaluate evidence of PGE enrichment from archaeologically-stratified sedimentary sequences across North America that date to the YDB in order to test the implications of Petaev et al.1 who suggested the likelihood of a global Pt anomaly. Results are discussed below and in Supplementary Information.
The Younger Dryas impact hypothesis proposed a causal link between a cosmic impact event and a) the onset of the YD climate cooling episode at ~12,800 calendar years BP, b) a peak in continental-scale biomass burning, c) extinction of more than 35 genera of North American Pleistocene megafauna, and d) the demise of the Paleoindian Clovis technocomplex3. In support of those links, several studies3,4,5,6,7 have reported an exotic assemblage of impact-related proxies in a widely-distributed layer at the YDB, dating to 12,800 ± 150 Cal B.P. Impact proxies reported for YDB sites include but are not limited to high-temperature iron and silica-rich magnetic spherules, nanodiamonds, aciniform carbon (soot), high-temperature melt-glass, and elevated, above-background concentrations of nickel, osmium, and iridium3,4,5,6,7. Researchers have also hypothesized a human population decline or demographic shift immediately following the disappearance of the Clovis technocomplex at the YD onset8,9,10,11.
A number of other studies have made critical assessments of the evidence for a YD impact event. Specifically, questions have been raised regarding the nature or replicability of the reported impact proxies, the accuracy of the established chronology, and its purported effects on humans and animals at the YD onset12,13,14,15,16,17,18. All of these criticisms have been addressed by additional and independent studies replicating the original findings of Firestone et al.3,7,19,20. Another investigation demonstrated the synchroneity of the YDB layer throughout its geographic range based on Bayesian modeling of data from 23 stratigraphic sections and 354 dates from 12 countries21. The modeled YDB age range is 12,835–12,735 Cal B.P. (at 95% probability). In one study critical of the YDB hypothesis, Paquay et al.22 reported small YDB PGE peaks in Pt, Ir, and Os at Murray Springs, AZ and Lake Hind, AB, Canada, co-occurring with peaks in YDB microspherules and nanodiamonds. That study, claiming the PGE anomalies merely resulted from natural authigenic enrichment, dismisses an extraterrestrial origin, but without citing evidence. Instead, even though their Pt anomalies are small, their results are consistent with the independent impact-related Pt study by Petaev et al.1.
Of particular relevance to our study, Andronikov et al.23,24,25 investigated sediments from Belgium, the Netherlands, Lithuania, and NW Russia near Finland, reporting sharp YDB enrichment in Pt at the YD onset, as well as other meteoritic elements such as nickel, chromium, copper, and iridium. In a separate study, Andronikov et al.19 analyzed YDB magnetic microspherules from Blackwater Draw, New Mexico using scanning electron microscopy (SEM), electron probe microanalysis (EPMA), X-ray diffraction (XRD), and laser-ablation inductively coupled-plasma mass spectrometry (LA-ICP-MS). They reported an abundance peak in YDB microspherules that display melted, dendritic textures, confirmed through a combination of SEM and energy dispersive spectroscopy (EDS). These results confirm those for YDB spherules from Blackwater Draw by Firestone et al.3 and LeCompte et al.20, and contradict the spherule results of Surovell et al.18, who found no peak, but neglected to perform the SEM analyses required to correctly identify YDB spherules.
In the same study of Blackwater Draw, Andronikov et al.19 reported that four of six YDB spherules contained very high Pt abundances, ranging from 18.2 to 460 ppb, up to 900× crustal abundance of 0.5 ppb26, consistent with the finding of elevated YDB Pt in the Greenland ice core by Petaev et al.1 (Supplemental Table 8). For two spherules, Pt was below detection. In addition, five of the six Blackwater Draw YDB spherules contained elevated concentrations of Ir at >230× crustal abundance of 0.022 ppb26, supporting the findings of Firestone et al.3. They also found high concentrations of YDB Os at >240× crustal abundance of 0.03126, supporting the findings of Wu et al.27. The presence of PGE-enriched spherules heterogeneously distributed throughout any given YDB sample could account for the highly variable PGE concentrations reported by Firestone et al.3, who proposed that variability to result from a PGE-rich “nugget effect”.
Andronikov et al.19 reported that Pt, Ir, and Os values were near detection limits for spherules, and therefore, have high uncertainties. For comparison, they analyzed six YDB magnetite and ilmenite grains, which showed undetectable Ir in grains compared to an average of 2.2 ppb in YDB spherules, undetectable Os versus 4 ppb, and an average of 16.2 ppb of Pt in non-YDB grains compared to 145 ppb in the YDB. Such large compositional differences between grains and spherules suggest that PGE enrichments in the YDB spherules are real and that the spherules did not derive from the melting of local magnetic and/or ilmenite grains, but rather are of non-local origin. Even though Pt has been shown to be present in YDB spherules, they may not be the only Pt source. There is currently no evidence to preclude the possibility that high Pt concentrations may also be present in non-spherulitic YDB grains and dust.
Sedimentary record from Patagonia, southern Chile supports cosmic-impact triggering of biomass burning, climate change, and megafaunal extinctions at 12.8 ka
Mario Pino,1,2 Ana M. Abarzúa,1,2 Giselle Astorga,1,2 Alejandra Martel-Cea,1,2 Nathalie Cossio-Montecinos,1 R. Ximena Navarro,3 Maria Paz Lira,4 Rafael Labarca,1,2 Malcolm A. LeCompte,5 Victor Adedeji,6 Christopher R. Moore,7 Ted E. Bunch,8 Charles Mooney,9 Wendy S. Wolbach,10 Allen West,11 and James P. Kennett12
Sci Rep. 2019; 9: 4413.
Published online 2019 Mar 13. doi: 10.1038/s41598-018-38089-y
PMCID: PMC6416299
PMID: 30867437
Abstract
The Younger Dryas (YD) impact hypothesis posits that fragments of a large, disintegrating asteroid/comet struck North America, South America, Europe, and western Asia ~12,800 years ago. Multiple airbursts/impacts produced the YD boundary layer (YDB), depositing peak concentrations of platinum, high-temperature spherules, meltglass, and nanodiamonds, forming an isochronous datum at >50 sites across ~50 million km² of Earth’s surface. This proposed event triggered extensive biomass burning, brief impact winter, YD climate change, and contributed to extinctions of late Pleistocene megafauna.
In the most extensive investigation south of the equator, we report on a ~12,800-year-old sequence at Pilauco, Chile (~40°S), that exhibits peak YD boundary concentrations of platinum, gold, high-temperature iron- and chromium-rich spherules, and native iron particles rarely found in nature. A major peak in charcoal abundance marks an intense biomass-burning episode, synchronous with dramatic changes in vegetation, including a high-disturbance regime, seasonality in precipitation, and warmer conditions. This is anti-phased with northern-hemispheric cooling at the YD onset, whose rapidity suggests atmospheric linkage. The sudden disappearance of megafaunal remains and dung fungi in the YDB layer at Pilauco correlates with megafaunal extinctions across the Americas.
The Pilauco record appears consistent with YDB impact evidence found at sites on four continents.
(1) Mario Pino et al, "Sedimentary record from Patagonia, southern Chile supports cosmic-impact triggering of biomass burning, climate change, and megafaunal extinctions at 12.8 kYA" Scientific Reports (2019). DOI: 10.1038/s41598-018-38089-y : https://phys.org/news/2019-03-geologic-evidence-theory-major-cosmic.html#jCp
(2) VolcanoDiscovery.com - Osorno noted 2019-03-23