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GEOREF RECORD

Did the black-mat impact/airburst reach the Antarctic? Evidence from New Mountain near the Taylor Glacier in the Dry Valley Mountains

W. C. Mahaney, David H. Krinsley, Michael W. Milner, Robert Fischer and Kurt Langworthy
Did the black-mat impact/airburst reach the Antarctic? Evidence from New Mountain near the Taylor Glacier in the Dry Valley Mountains
Journal of Geology (May 2018) 126 (3): 285-305

Abstract

Detailed microscopic investigations of horizons in a surface paleosol, part of a pedostratigraphic stack of tills at New Mountain, Antarctica, dated to the middle Miocene climatic optimum event (ca. 15 Ma), suggest not only that the paleoclimate history of the continent can be read from stratigraphic layers within paleosols but also that records of cosmic events may lie embedded in coatings on sand clasts resident in paleosols. Recent microscopic and chemical data from sands in the upper horizons of a surface paleosol (Ant-828), adjacent to the Taylor Glacier, contain Fe and Na coatings surfaced with cosmic signatures including welded and shock-melted grains, opaque carbon coatings, microfeature stack of cards, Fe spherules, solubilized grain surfaces with streams of melted skin, a grain carrying an Ir signature, rare earth elements elevated above crustal averages, and slightly elevated Pt/Pd ratios. The projected link to the probable black-mat event of 12.8 ka is reinforced by the presence of fresh opaque carbon and other cosmic signatures on grain surfaces that overlie well-weathered grain features, presumably weathering from middle Miocene time near today. Evidence of CO (sub 2) and NO (sub x) accumulations dated to 12.9 ka in the Taylor Ice Dome suggest that the black-mat impact/airburst of the same time line as the Younger Dryas boundary may have reached across South America and the Pacific Ocean to the Dry Valley Mountains of Antarctica.


ISSN: 0022-1376
EISSN: 1537-5269
Coden: JGEOAZ
Serial Title: Journal of Geology
Serial Volume: 126
Serial Issue: 3
Title: Did the black-mat impact/airburst reach the Antarctic? Evidence from New Mountain near the Taylor Glacier in the Dry Valley Mountains
Affiliation: Quaternary Surveys, Thornhill, ON, Canada
Pages: 285-305
Published: 201805
Text Language: English
Publisher: University of Chicago Press, Chicago, IL, United States
References: 82
Accession Number: 2018-096136
Categories: Stratigraphy
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. strat. col., 1 table, sketch map
S78°00'00" - S77°00'00", E161°00'00" - E167°00'00"
Secondary Affiliation: University of Oregon, USA, United StatesNWM Consulting, CAN, Canada
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2023, American Geosciences Institute.
Update Code: 201851
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