Novel Applications of Meteoric- and In Situ-Produced Beryllium-10 in the East Antarctic
This work comprises three novel applications of in situ- and meteoric-produced beryllium-10 (Be-10) in East Antarctica. Sampled deposits cover a wide spatiotemporal transect through the Dry Valleys, from an inland, middle elevation location of Quaternary age, to a mid-valley, high elevation location...
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ftunivpenn:oai:repository.upenn.edu:dissertations-14141 2023-05-15T13:40:32+02:00 Novel Applications of Meteoric- and In Situ-Produced Beryllium-10 in the East Antarctic Valletta, Rachel D 2017-01-01T08:00:00Z https://repository.upenn.edu/dissertations/AAI10273262 ENG eng ScholarlyCommons https://repository.upenn.edu/dissertations/AAI10273262 Dissertations available from ProQuest Geology|Paleoclimate Science|Geochemistry text 2017 ftunivpenn 2021-01-04T22:20:16Z This work comprises three novel applications of in situ- and meteoric-produced beryllium-10 (Be-10) in East Antarctica. Sampled deposits cover a wide spatiotemporal transect through the Dry Valleys, from an inland, middle elevation location of Quaternary age, to a mid-valley, high elevation location of Miocene age, and finally to an offshore, submarine location of Pliocene age. Each research chapter we present is a unique project unto itself, but all chapters utilize the cosmogenic radionuclide Be-10. In the first application, we present "Difference Dating,'' a new approach to date glacial moraines in regions where traditional exposure age dating is fraught with complications. Difference Dating allows for the construction of deglaciation chronologies in regions where they are frequently precluded by inheritance issues. We use Difference Dating to constrain the ages of Quaternary moraines in an alpine glacial cirque, Wright Valley, Dry Valleys. The second and third applications use meteoric-produced Be-10 in two different depositional settings. In marine sediments, we recast the Be-10/Be-9 ratio as a proxy for East Antarctic Ice Sheet freshwater discharge during mid-Pliocene interglacials. Using this record, we suggest that zones of deep water formation may be significant in funneling Be into the global thermohaline circulation belt. We also apply the meteoric-produced Be-10 system to paleolake sediments, where extremely low concentrations are used to construct an age model extending to 14-17.5 Ma. This range is commensurate with lake sediment deposition during the Middle Miocene Climatic Optimum, a rare Antarctic terrestrial deposit of this globally significant warming event. Text Antarc* Antarctic Antarctica East Antarctica Ice Sheet University of Pennsylvania: ScholaryCommons@Penn Antarctic East Antarctica East Antarctic Ice Sheet Wright Valley ENVELOPE(161.833,161.833,-77.517,-77.517) |
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Open Polar |
collection |
University of Pennsylvania: ScholaryCommons@Penn |
op_collection_id |
ftunivpenn |
language |
English |
topic |
Geology|Paleoclimate Science|Geochemistry |
spellingShingle |
Geology|Paleoclimate Science|Geochemistry Valletta, Rachel D Novel Applications of Meteoric- and In Situ-Produced Beryllium-10 in the East Antarctic |
topic_facet |
Geology|Paleoclimate Science|Geochemistry |
description |
This work comprises three novel applications of in situ- and meteoric-produced beryllium-10 (Be-10) in East Antarctica. Sampled deposits cover a wide spatiotemporal transect through the Dry Valleys, from an inland, middle elevation location of Quaternary age, to a mid-valley, high elevation location of Miocene age, and finally to an offshore, submarine location of Pliocene age. Each research chapter we present is a unique project unto itself, but all chapters utilize the cosmogenic radionuclide Be-10. In the first application, we present "Difference Dating,'' a new approach to date glacial moraines in regions where traditional exposure age dating is fraught with complications. Difference Dating allows for the construction of deglaciation chronologies in regions where they are frequently precluded by inheritance issues. We use Difference Dating to constrain the ages of Quaternary moraines in an alpine glacial cirque, Wright Valley, Dry Valleys. The second and third applications use meteoric-produced Be-10 in two different depositional settings. In marine sediments, we recast the Be-10/Be-9 ratio as a proxy for East Antarctic Ice Sheet freshwater discharge during mid-Pliocene interglacials. Using this record, we suggest that zones of deep water formation may be significant in funneling Be into the global thermohaline circulation belt. We also apply the meteoric-produced Be-10 system to paleolake sediments, where extremely low concentrations are used to construct an age model extending to 14-17.5 Ma. This range is commensurate with lake sediment deposition during the Middle Miocene Climatic Optimum, a rare Antarctic terrestrial deposit of this globally significant warming event. |
format |
Text |
author |
Valletta, Rachel D |
author_facet |
Valletta, Rachel D |
author_sort |
Valletta, Rachel D |
title |
Novel Applications of Meteoric- and In Situ-Produced Beryllium-10 in the East Antarctic |
title_short |
Novel Applications of Meteoric- and In Situ-Produced Beryllium-10 in the East Antarctic |
title_full |
Novel Applications of Meteoric- and In Situ-Produced Beryllium-10 in the East Antarctic |
title_fullStr |
Novel Applications of Meteoric- and In Situ-Produced Beryllium-10 in the East Antarctic |
title_full_unstemmed |
Novel Applications of Meteoric- and In Situ-Produced Beryllium-10 in the East Antarctic |
title_sort |
novel applications of meteoric- and in situ-produced beryllium-10 in the east antarctic |
publisher |
ScholarlyCommons |
publishDate |
2017 |
url |
https://repository.upenn.edu/dissertations/AAI10273262 |
long_lat |
ENVELOPE(161.833,161.833,-77.517,-77.517) |
geographic |
Antarctic East Antarctica East Antarctic Ice Sheet Wright Valley |
geographic_facet |
Antarctic East Antarctica East Antarctic Ice Sheet Wright Valley |
genre |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet |
op_source |
Dissertations available from ProQuest |
op_relation |
https://repository.upenn.edu/dissertations/AAI10273262 |
_version_ |
1766136579439460352 |