← Search

Archive · collection · 2017

Fe/K-ratios and pollen analysis of ODP Site 202-1239

Listed in PANGAEA

Vegetation and climate change in nortwestern South America were studied using pollen analysis in combination with XRF scanning on marine sediments of ODP Site 1239 from the East Equatorial Pacific comprising the interval between 4.7 and 4.2 Ma.

Description

The study site is sensitive to latitudinal shifts of the Intertropical Convergence Zone (ITCZ) shifts insofar as a southward (northward) shift would result in increased (decreased) precipitation over Ecuador.

The presented pollen record (46 samples) comprises representatives from five ecological groups: lowland rainforest, lower montane forest, upper montane forest, páramo, and broad range taxa. A broad tropical rainforest coverage persisted in the study area throughout the early Pliocene, without significant open vegetation below the forest line. Between 4.7 and 4.42 Ma, humidity increases, reaching its peak around 4.42 Ma, and slightly decreasing again afterwards.

Read the rest (1 more)

The stable, permanently humid conditions are rather in agreement with paleoceanographic data indicating a southward shift of the ITCZ, possibly in response to closure of the Central American Seaway. The presence of páramo vegetation indicates that the Western Cordillera of the northern Andes had already reached considerable elevation by the early Pliocene. The trend in iron/potassium-ratios (Fe/K) is similar to the pattern of humidity inferred from the pollen spectrum, showing the highest values around 4.46 Ma, thus supporting the hydrological interpretation of the pollen record.

Links

Where it is published

Catalogue records · 1

Topics

Provenance · 1 source records, 8 field assertions
SourceKeyLast seenRaw
PANGAEAoai:pangaea.de:doi:10.1594/PANGAEA.88428514 d agoJSON v1
FieldAssertionExtractorEvidence
access_levelsource · PANGAEAconnector:pangaea@1.0.0
concepts[field].anzsrc:group:3709enrichment · PANGAEAtaxonomy-embedding@1.1.0title+keywords+description (72%)
concepts[field].local:field:earth-environmentalmapping · PANGAEAconnector:pangaea@1.0.0
descriptionsource · PANGAEAconnector:pangaea@1.0.0/metadata/dc/description
licensesource · PANGAEAconnector:pangaea@1.0.0/metadata/dc/rights
publication_datesource · PANGAEAconnector:pangaea@1.0.0
spatialsource · PANGAEAconnector:pangaea@1.0.0
titlesource · PANGAEAconnector:pangaea@1.0.0/metadata/dc/title