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:edissertations-4406 2023-05-15T13:59:23+02:00 Novel Applications Of Meteoric- And In Situ-Produced Beryllium-10 In The East Antarctic Valletta, Rachel Don 2017-01-01T08:00:00Z application/pdf https://repository.upenn.edu/edissertations/2620 https://repository.upenn.edu/cgi/viewcontent.cgi?article=4406&context=edissertations en eng ScholarlyCommons https://repository.upenn.edu/edissertations/2620 https://repository.upenn.edu/cgi/viewcontent.cgi?article=4406&context=edissertations Publicly Accessible Penn Dissertations Antarctica beryllium-10 cosmogenic radionuclides Dry Valleys East Antarctic Ice Sheet exposure age dating Climate Geochemistry Geology Paleontology text 2017 ftunivpenn 2021-01-04T22:00:57Z 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) |
institution |
Open Polar |
collection |
University of Pennsylvania: ScholaryCommons@Penn |
op_collection_id |
ftunivpenn |
language |
English |
topic |
Antarctica beryllium-10 cosmogenic radionuclides Dry Valleys East Antarctic Ice Sheet exposure age dating Climate Geochemistry Geology Paleontology |
spellingShingle |
Antarctica beryllium-10 cosmogenic radionuclides Dry Valleys East Antarctic Ice Sheet exposure age dating Climate Geochemistry Geology Paleontology Valletta, Rachel Don Novel Applications Of Meteoric- And In Situ-Produced Beryllium-10 In The East Antarctic |
topic_facet |
Antarctica beryllium-10 cosmogenic radionuclides Dry Valleys East Antarctic Ice Sheet exposure age dating Climate Geochemistry Geology Paleontology |
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 Don |
author_facet |
Valletta, Rachel Don |
author_sort |
Valletta, Rachel Don |
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/edissertations/2620 https://repository.upenn.edu/cgi/viewcontent.cgi?article=4406&context=edissertations |
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 |
Publicly Accessible Penn Dissertations |
op_relation |
https://repository.upenn.edu/edissertations/2620 https://repository.upenn.edu/cgi/viewcontent.cgi?article=4406&context=edissertations |
_version_ |
1766267923668664320 |