کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1045837 | 944836 | 2011 | 12 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Pleistocene-Holocene environmental change in the Canary Archipelago as inferred from the stable isotope composition of land snail shells
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
زمین شناسی
پیش نمایش صفحه اول مقاله

چکیده انگلیسی
The isotopic composition of land snail shells was analyzed to investigate environmental changes in the eastern Canary Islands (28-29°N) over the last ~ 50 ka. Shell δ13C values range from â8.9â° to 3.8â°. At various times during the glacial interval (~ 15 to ~ 50 ka), moving average shell δ13C values were 3â° higher than today, suggesting a larger proportion of C4 plants at those periods. Shell δ18O values range from â1.9â° to 4.5â°, with moving average δ18O values exhibiting a noisy but long-term increase from 0.1â° at ~ 50 ka to 1.6-1.8â° during the LGM (~ 15-22 ka). Subsequently, the moving average δ18O values range from 0.0â° at ~ 12 ka to 0.9â° at present. Calculations using a published snail flux balance model for δ18O, constrained by regional temperatures and ocean δ18O values, suggest that relative humidity at the times of snail activity fluctuated but exhibited a long-term decline over the last ~ 50 ka, eventually resulting in the current semiarid conditions of the eastern Canary Islands (consistent with the aridification process in the nearby Sahara). Thus, low-latitude oceanic island land snail shells may be isotopic archives of glacial to interglacial and tropical/subtropical environmental change.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Quaternary Research - Volume 75, Issue 3, May 2011, Pages 658-669
Journal: Quaternary Research - Volume 75, Issue 3, May 2011, Pages 658-669
نویسندگان
Yurena Yanes, Crayton J. Yapp, Miguel Ibáñez, MarÃa R. Alonso, Julio De-la-Nuez, MarÃa L. Quesada, Carolina Castillo, Antonio Delgado,