10Be exposure ages of erratic boulders in southern Norway and implications for the history of the Fennoscandian Ice Sheet
Permanent citation URL:
http://hdl.handle.net/1957/2298
|
| Title: | 10Be exposure ages of erratic boulders in southern Norway and implications for the history of the Fennoscandian Ice Sheet |
| Authors: | Goehring, Brent M. |
| Advisors: | Brook, Edward J. |
| Committee Members: | Clark, Peter U. Hostetler, Steven W. |
| Keywords: | Fennoscandian ice sheet Beryllium-10 Cosmogenic nuclide |
| LCSH Keywords: | Beryllium -- Isotopes Ice sheets -- Norway Boulders -- Norway Radioisotopes in glaciology -- Norway |
| Issue Date: | 28-Jun-2006 |
| Abstract: | This thesis focuses on the application of the cosmogenic nuclide Beryllium-10 (10Be) in an effort to better constrain the thickness history of the Fennoscandian Ice Sheet (FIS) at the Last Glacial Maximum (LGM) and into the Holocene, as well as begin to answer the long-standing question regarding the age
and interpretation of periglacial weathering features in southern Norway. 10Be exposure ages of glacially transported boulders have been measured along three vertical transects (Skåla, Blåhø, and Elgåhogna) in southern Norway. At the LGM, 10Be ages indicate that ice at Blåhø and Elgåhogna was thicker than that based on reconstructions using blockfield-weathering limits, and better agrees with models based on ice physics or isostatic rebound inversion. Ice surface elevation at Skåla was likely no greater than ~1440 m at the LGM, agreeing well with the mapped trimline in that region, as well as high resolution models for Nordfjord. At all three sites, rapid deglaciation begins at approximately 12 10Be ka, and deglaciation is
complete by approximately 9 10Be ka. A progressive and large divergence between boulder and bedrock exposure ages is observed at the easternmost site (Elgåhogna), indicating that the bedrock has experienced minimal erosion under cold-based ice. Therefore, blockfields are not young features (< ~10 kyr), but rather have survived beneath regions of coldbased ice, possibly through multiple glacial-interglacial cycles. |
| Description: | Graduation date: 2007 |
| URI: | http://hdl.handle.net/1957/2298 |
| Appears in Collections: | Theses, Dissertations and Student Research Papers (Geology) Electronic Theses and Dissertations |
This item is licensed under a Creative Commons License
Items in ScholarsArchive are protected by copyright, with all rights reserved, unless otherwise indicated.
