مورد إلكتروني
Magnetic record of deglaciation using FORC-PCA, sortable-silt grain size, and magnetic excursion at 26 ka, from the Rockall Trough (NE Atlantic)
| العنوان: | Magnetic record of deglaciation using FORC-PCA, sortable-silt grain size, and magnetic excursion at 26 ka, from the Rockall Trough (NE Atlantic) |
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| المصدر: | Geochemistry Geophysics Geosystems (1525-2027) (Amer Geophysical Union), 2016-05 , Vol. 17 , N. 5 , P. 1823-1841 |
| بيانات النشر: | Amer Geophysical Union 2016-05 |
| تفاصيل مُضافة: | Channell, J. E. T. Harrison, R. J. Lascu, I. Mccave, I. N. Hibbert, F. D. Austin, W. E. N. |
| نوع الوثيقة: | Electronic Resource |
| مستخلص: | Core MD04-2822 from the Rockall Trough has apparent sedimentation rates of ∼ 1 m/kyr during the last deglaciation (Termination I). Component magnetization directions indicate a magnetic excursion at 16.3 m depth in the core, corresponding to an age of 26.5 ka, implying an excursion duration of ∼350 years. Across Termination I, the mean grain size of sortable silt implies reduced bottom-current velocity in the Younger Dryas and Heinrich Stadial (HS)-1A, and increased velocities during the Bølling-Allerød warm period. Standard bulk magnetic parameters imply fining of magnetic grain size from the mid-Younger Dryas (∼12 ka) until ∼ 8 ka. First-order reversal curves (FORCs) were analyzed using ridge extraction to differentiate single domain (SD) from background (detrital) components. Principal component analysis (FORC-PCA) was then used to discriminate three end members corresponding to SD, pseudo-single domain (PSD) and multidomain (MD) magnetite. The fining of bulk magnetic grain size from 12 to 8 ka is due to reduction in concentration of detrital (PSD+MD) magnetite, superimposed on a relatively uniform concentration of SD magnetite produced by magnetotactic bacteria. The decrease in PSD+MD magnetite concentration from 12 to 8 ka is synchronized with increase in benthic δ13C, and with major (∼70 m) regional sea-level rise, and may therefore be related to detrital sources on the shelf that had reduced influence as sea level rose, and to bottom-water reorganization as Northern Source Water (NSW) replaced Southern Source Water (SSW). |
| مصطلحات الفهرس: | magnetic granulometry, FORC-PCA analysis, sortable silt, magnetic excursion, termination I, Rockall Trough, text, Publication, info:eu-repo/semantics/article |
| DOI: | 10.1002.2016GC006300 |
| URL: | info:eu-repo/grantAgreement/EC/FP7/320750/EU//NANOPALEOMAG |
| الإتاحة: | Open access content. Open access content 2016 American Geophysical Union info:eu-repo/semantics/openAccess restricted use |
| ملاحظة: | application/pdf English |
| أرقام أخرى: | FRMER oai:archimer.ifremer.fr:44456 https://archimer.ifremer.fr/doc/00333/44456/44128.pdf https://archimer.ifremer.fr/doc/00333/44456/44129.pdf DOI:10.1002/2016GC006300 https://archimer.ifremer.fr/doc/00333/44456/ 1248914684 |
| المصدر المساهم: | ARCHIMER From OAIster®, provided by the OCLC Cooperative. |
| رقم الأكسشن: | edsoai.on1248914684 |
| قاعدة البيانات: | OAIster |
| DOI: | 10.1002.2016GC006300 |
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