کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1045697 944829 2008 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Evidence of temperature depression and hydrological variations in the eastern Sierra Nevada during the Younger Dryas stade
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
پیش نمایش صفحه اول مقاله
Evidence of temperature depression and hydrological variations in the eastern Sierra Nevada during the Younger Dryas stade
چکیده انگلیسی

Sediment records from two lakes in the east-central Sierra Nevada, California, provide evidence of cooling and hydrological shifts during the Younger Dryas stade (YD; ~ 12,900–11,500 cal yr BP). A chironomid transfer function suggests that lake-water temperatures were depressed by 2°C to 4°C relative to maximum temperatures during the preceding Bølling–Allerød interstade (BA; ~ 14,500–12,900 cal yr BP). Diatom and stable isotope records suggest dry conditions during the latter part of the BA interstade and development of relatively moist conditions during the initiation of the YD stade, with a reversion to drier conditions later in the YD. These paleohydrological inferences correlate with similar timed changes detected in the adjacent Great Basin. Vegetation response during the YD stade includes the development of more open and xeric vegetation toward the end of the YD. The new records support linkages between the North Atlantic, the North Pacific, and widespread YD cooling in western North America, but they also suggest complex hydrological influences. Shifting hydrological conditions and relatively muted vegetation changes may explain the previous lack of evidence for the YD stade in the Sierra Nevada and the discordance in some paleohydrological and glacial records of the YD stade from the western United States.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Quaternary Research - Volume 70, Issue 2, September 2008, Pages 131–140
نویسندگان
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