A speleothem record of glacial (25-11.6 kyr BP) rapid climatic changes from northern Iberian Peninsula

作者：Moreno Ana^*; Stoll Heather; Jimenez Sanchez Montserrat; Cacho Isabel; Valero Garces Blas; Ito Emi; Edwards R Lawrence

来源：Global and Planetary Change, 2010, 71(3-4): 218-231.

DOI：10.1016/j.gloplacha.2009.10.002

• speleothems
• northern Iberian Peninsula
• Marine Isotope Stage 2
• last deglaciation
• stable isotopes
• trace elements
• rapid climate change

Low and high frequency climatic fluctuations in northern Iberian Peninsula during the last glacial maximum (LGM) and deglaciation are documented in a stalagmite using delta O-18 and delta C-13 and hydrologically sensitive trace metal ratios Mg/Ca and Ba/Ca. U/Th dating indicates speleothem growth commenced at 25 kyr BP (Present = year 1950) and extended to 11.6 kyr BP making this one of few European speleothem growing during the last glacial period. Rapid climatic fluctuations as Heinrich event 2 (H2) and Greenland Interstadial (GI-) 2 are well characterized in this record by more arid and cold conditions and by more humid conditions, respectively. Speleothem growth ceased from 18.2 to 15.4 kyr BP (the so-called Mystery Interval) likely reflecting the driest and potentially coldest conditions of this record, coincident with the 2 kyr duration shutdown of the North Atlantic Meridional Overturning Circulation (MOC). A major gradual increase in humidity and possibly in temperature occurred from 15.5 to 13.5 kyr BP, beginning in the Bolling and culminating in the Altered period. This gradual humidity change contrasts with more abrupt humidity shifts in the Mediterranean, suggesting a different climate threshold for Mediterranean vs. Atlantic margin precipitation.

• 出版日期2010-4