Palynological PV borehole dataset
Description
Quantitative palynological data – proxy data – from the PV borehole (onshore Valdés Basin) together with the statistical treatment of data, offer key information for regional paleoclimatic, paleoenvironmental and paleogeomorphic reconstructions for the Miocene of the southwestern Atlantic Ocean. Data show the stratigraphical distribution of palynomorphs (number of specimens) and environmental variables of 60 samples from a 580 m-thick section. Quantitative changes in the palynological assemblages may indicate shifting of the coastline, related — in part – to fluctuations of the relative sea level and in turn, interpreted as successive regional transgressive - regressive cycles occurred during the Miocene in the southwestern Atlantic margin.
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Steps to reproduce
The database contain: 1) raw palynological data - proxy data from cutting samples of an exploratory borehole. Counting were done using transmitted light microscope; 2) These quantitative data were statistically evaluated, based on four paleoenvironmental variables selected to conduct a multivariate analysis. Paleoenvironmetal variables are based on selected ecologically important individuals, or groups of taxa of dinoflagellate cysts as well as categories of palynomorphs. The variables used include: warm-water dinocyst taxa; outer neritic to oceanic dinocyst taxa; acritarch over total dinocysts (a/ dx100); terrestrial/marine ratio (t/m ratio); 3) log 10 transformed variables used for the Principal Component Analysis (PCA) as well as the PC scores are stratigraphically ordered from the top to bottom through the borehole. The dissimilarity between the samples, obtained by PCA in the PV borehole, was performed using the XLSTAT software.