[meteorite-list] New Investigation of a Greenland ice core platinum anomaly near the Bølling-Allerød/Younger Dryas boundary

From: Paul <etchplain_at_meteoritecentral.com>
Date: Thu, 14 May 2020 13:14:41 -0500
Message-ID: <1d1f8542-3ed6-e2e6-f5e3-4980789791ae_at_att.net>

Green, C. E., 2019. Investigating the origin of a Greenland ice
core geochemical anomaly near the B?lling-Aller?d/Younger
Dryas boundary (Doctoral dissertation, Durham University).
http://etheses.dur.ac.uk/13490/
http://etheses.dur.ac.uk/13490/1/C_Green_thesis_final_CORRECTIONS.pdf

Green (2019) noted:

"The source of a platinum peak identified in the Greenland
Ice Sheet Project 2 (GISP2) ice core associated with high
platinum/iridium (Pt/Ir) and platinum/aluminium (Pt/Al)
ratios, and previous research attributed the anomaly to an
unusual iron-rich Ir-poor meteorite impact."

Green (2019) concluded:

I. the Laacher See eruption is not the Pt spike source because:
A. the Laacher See tephra has low Pt concentrations,
B. the Laacher See tephra?s geochemical ratios are dissimilar
to the GISP2 Pt spike and
C. conversion of the Pt spike timing to the newest ice core
age-depth model shows a chronological offset of ~60 years
between the two events.

II. The event resulting in the Pt spike occurred ~60 years
after GS-1 cooling, and was therefore not the primary
trigger.

III. and the Pt spike origin is interpreted as either:
A. a noncataclysmic impact of an undiscovered iron meteorite
B. or an unidentified Pt-rich volcanic eruption contemporaneous
with the anomaly, whose aerosol fractionated in the atmosphere
or ice.

Yours,

Paul H.
Received on Thu 14 May 2020 02:14:41 PM PDT