Project

Back to overview

High-resolution palynology and climate change in the Late Glacial-Holocene of Colombia

English title High-resolution palynology and climate change in the Late Glacial-Holocene of Colombia
Applicant Gorin Georges
Number 124721
Funding scheme Project funding
Research institution Département des sciences de la Terre Université de Genève
Institution of higher education University of Geneva - GE
Main discipline Geology
Start/End 01.04.2009 - 31.03.2012
Approved amount 190'640.00
Show all

Keywords (8)

ENSO; global change; ITCZ; paleoecology; South America; geochemistry; tropics; vegetation belts

Lay Summary (English)

Lead
Lay summary
Records of climate change in the tropics are particularly important, because it is at these latitudes that major thermal energy interchanges take place between oceans and atmosphere. Climatic events like the El Niño-Southern Oscillation (ENSO) and the migration of the Intertropical Convergence Zone (ITCZ) are typically associated with the tropics, but influence the global climate. Good-quality, high-resolution palynological studies over the last 15'000 years are rare in this country and in tropical South America. The main investigated site in this project, the Páramo de Frontino, is a high plateau with various wet zones located in the Western Cordillera, at the northwestern termination of the Colombian Andes. It is anthropogenically-undisturbed and is strategically situated to understand the biota interchanges between Central and South America: being located close to the Pacific and Atlantic oceans, it is susceptible to receive dry influences from the Caribbean zone, meanwhile it is exposed on its western side to the influence of El Niño. Good-quality C14 datations show that it contains a continuous Lateglacial and Holocene sequence which provides a unique sedimentary record of at least the last 17'000 years. These sediments consist of peat, organic, organo-mineral and diatomeous muds, with several intercalations of diatomites, volcanic ash and paleosoils. The main goal of this project is to provide a high-resolution study of the vegetation and climate changes over the last 17'000 years, using palynology and geochemistry (microfluorescence X) as the main proxies. It will test climate variability in the Holocene, for which high-quality data are missing in the tropics and provide a valuable data base to compare tropical with higher latitude climate variations and validate the outcome of climate models.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
A well-dated, continuous record of Lateglacial-Holocene climate in a high-altitude wet zone from northwestern Colombia
Muñoz Paula, Monsalve Carlos, Jojoa Marcela, Gorin Georges (2010), A well-dated, continuous record of Lateglacial-Holocene climate in a high-altitude wet zone from northwestern Colombia, in Parra, Norberto, Velasquez, Cesar.
Late Holocene climatic record from a middle-mountain wet zone in Central Colombia
Gorin Georges (2009), Late Holocene climatic record from a middle-mountain wet zone in Central Colombia, in Muñoz, Paula.
Middle and Late Holocene climate in the tropics : a high-resolution palynological and geochemical record from a páramo in northwestern Colombia exposed to both Pacific and Atlantic climate influences
Muñoz Paula, Jojoa Marcela (2009), Middle and Late Holocene climate in the tropics : a high-resolution palynological and geochemical record from a páramo in northwestern Colombia exposed to both Pacific and Atlantic climate influences, in Velasquez, Cesar, Gorin, Georges.

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
XIV Congreso Latinoamericano de Geologia 29.08.2011 Medellin, Colombie
18th International Sedimentological Congress 28.09.2010 Mendoza, Argentina
American Geophysical Union (AGU) Meeting Las Americas 08.08.2010 Foz de Iguazu, Brésil
18th Meeting of Swiss Sedimentologists 27.02.2010 Fribourg, Suisse
American Geophysical Union (AGU) Fall Meeting 14.12.2009 San Francisco, USA
ECORD Summer School 23.07.2009 Urbino, Italy


Awards

Title Year
2nd Prize Poster (out of 77), ECORD Summer School, Urbino (Italy) 2009
Outstanding Student Paper Award, 2009 AGU Fall Meeting 2009

Associated projects

Number Title Start Funding scheme
112320 Etude des bassins sédimentaires: A) Matière organique sédimentaire: un outil paléoécologique de haute résolution; B) Processus glaciaires anciens dans les environnements périglaciaires 01.04.2006 Project funding
112320 Etude des bassins sédimentaires: A) Matière organique sédimentaire: un outil paléoécologique de haute résolution; B) Processus glaciaires anciens dans les environnements périglaciaires 01.04.2006 Project funding

Abstract

This project is a continuation of the ongoing SNF project 200020-112320.Because climate oscillations in the Holocene occurred under conditions similar to those of today, i.e., in a time of overall warmth and in the absence of large-scale Northern Hemisphere ice sheets, they can contribute more efficiently to our understanding of contemporary climate change than do the events of the last glacial period. Among all palaeoclimate proxies in the terrestrial realm, continental organic fossils (e.g., pollen, spores, fungal remains, plant macrofossils, etc.) deposited in lakes or wetlands have been used extensively in the Pleistocene and Holocene to study variations in terrestrial ecosystems and to try to understand their relation with climatically-induced environmental changes. Records of climate change in the tropics are particularly important, because it is at these latitudes that major thermal energy interchanges take place between oceans and atmosphere. Climatic events like the El Niño-Southern Oscillation (ENSO) and the migration of the Intertropical Convergence Zone (ITCZ) are typically associated with the tropics, but influence the global climate. In the last 60 years, Colombia has been one of the best studied tropical countries with respect to climate changes and associated variations in the distribution of vegetation, and palynology has been the main tool for these investigations. Nevertheless, good-quality, high-resolution palynological studies over the last 15'000 years, which can provide good proxies for climate variations, are rare in this country and in tropical South America. The main investigated site in this project, the Páramo de Frontino, is a high plateau with various wet zones located in the Western Cordillera, at the northwestern termination of the Colombian Andes. It is strategically situated to understand the biota interchanges between Central and South America: being located close to the Pacific and Atlantic oceans, it is susceptible to receive dry influences from the Caribbean zone, meanwhile it is exposed on its western side to the influence of El Niño. It is located in the paramo/subparamo vegetation belt, in a zone where the vegetation is practically undisturbed by anthropogenic influences. The steep slope gradients that surround it make it very sensitive to register past vegetation changes linked to vertical species migration (migration of vegetation belts) and resulting from climate change. Previous investigations at this site have shown that one of its wet zones (called Llano Grande, at an altitude of 3460m amsl) contains a continuous Lateglacial and Holocene sequence which can be cored over 13 meters. This provides a unique sedimentary record of the last 15’000 years.The main goal of this project is to provide for this selected site a high-resolution (less than 50-yr time resolution) study of the vegetation and climate changes over a time interval spanning the Lateglacial to Middle Holocene, using palynology as the main proxy. These results can be combined with existing high-resolution palynological data covering the Late Holocene at the same location. The latter study has detected and characterized the duration and amplitude of high-frequency changes in the Late Holocene vegetation and climate The palynological investigation proposed in this project is associated to sedimentological (mineralogy, facies analysis) and geochemical (microfluorescence X) observations that can provide other proxies for climate change.Several cores have already been taken in the Páramo de Frontino using a “Russian” corer, which has the great advantage of not compacting the soft sediments. The cored sediments consist of peat, organic, organo-mineral and diatomeous muds, with several intercalations of diatomites, volcanic ash and paleosoils. The existing 14C datations show the absence of hiatuses in the sequence. Below this organic-rich section, a core acquired in the framework of the ongoing SNF project has encountered a varved sequence that will be evaluated in this project continuation. This basal sequence might go back to the Pleniglacial. Palynological observations in the high-altitude Páramo de Frontino can be complemented by two similar types of investigations carried out at lower altitudes in the Late Holocene of Central (at an altitude of 2’100m) and Southern (at an altitude of 2760m) Colombia.The final objective of this project is to compile, for the first time in the tropics, a palynologically-derived, continuous record of climate variations over the last 15’000 years with a time resolution of 20-40 years. It will provide a test of the climate variability in the Holocene, for which high-quality data are missing in the tropics. Because the Páramo de Frontino is close to the Pacific where climate variability influences the migration of the ITCZ, the identification of dry/humid and warm/cold cycles might be looked at in relation with the ITCZ and ENSO-type variations. Results will provide a valuable data base to compare tropical with higher latitude climate variations and validate the outcome of climate models.
-