Universidad Complutense de Madrid
E-Prints Complutense

Younger Dryas to Early Holocene paleoclimate in Cantabria (N Spain): Constraints from speleothem Mg, annual fluorescence banding and stable isotope records

Impacto

Downloads

Downloads per month over past year

Rossi Nieto, Carlos and Bajo, Petra and Lozano, Rafael P. and Hellstrom, John (2018) Younger Dryas to Early Holocene paleoclimate in Cantabria (N Spain): Constraints from speleothem Mg, annual fluorescence banding and stable isotope records. Quaternary Science Reviews, 192 . pp. 71-85. ISSN 0277-3791, online ISSN: 1873-457X

[img] PDF
Restringido a Repository staff only

6MB

Official URL: https://www.sciencedirect.com/science/article/pii/S0277379118300763



Abstract

The Younger Dryas (YD) stadial represents the most abrupt climate change of the Earth's recent history. Thus, understanding its causes and different local responses is relevant for Quaternary paleoclimatology. We present a speleothem high-resolution proxy record of the Lateglacial to Early Holocene paleoclimate of the Cantabrian Cordillera (N Spain), a strategic location to evaluate the influence of North Atlantic events such as the YD on South-Western Europe. Fluorescence lamination, growth-rate, stable-isotope, and [Mg] records from stalagmite SIR-1 were dated using an age-depth model constrained by U-Th dates and annual-lamina counting. The YD is recorded as a prominent positive δ13C excursion whose chronology (12.95 ± 0.14 to 11.62 ± 0.16 ka) and shape closely agree with the GS-1 stadial as defined in Greenland ice, supporting the event synchronicity in both areas. A colder and drier YD climate limited soil productivity and dripwater availability, leading to higher δ13C and [Mg], reduced growth rate, and virtually absent fluorescence lamination. The early YD record (until ∼12.5 ka) reflects increasing aridity, whereas the late YD (from ∼12.2 ka on) shows the opposite trend. At the YD boundaries, temperature changes influenced the [Mg] record by modifying the Mg partition into calcite. However, this effect was superseded by major changes in dripwater Mg/Ca linked to rainfall variations. During the Early Holocene, the Arnero Sierra was forested and had a relatively warm and humid seasonal climate, indicated in SIR-1 by higher growth rates, lower δ13C and [Mg], and well-developed fluorescent lamination. Similar to other high-resolution stalagmitic records of the Cordillera, from ∼8.5 to 8.0 ka SIR-1 reflects a temporary trend of increasing aridity.


Item Type:Article
Uncontrolled Keywords:Younger dryas, Early holocene, Speleothems, Magnesium concentration, Annual fluorescence lamination, Stable isotopes, Northern Spain
Subjects:Sciences > Geology > Stratigraphic geology
Sciences > Geology > Geochemistry
ID Code:49849
Deposited On:30 Oct 2018 17:50
Last Modified:30 Oct 2018 17:50

Origin of downloads

Repository Staff Only: item control page