Article
NATURAL SEEPAGE IN THE GULF OF PARIA AND ITS RELATION WITH BEACH TAR ALONG THE SOUTHEASTERN COAST OF THE PARIA PENINSULA, VENEZUELA
Autor
G. MÁRQUEZ1, F. GALARRAGA2, R. FERNÁNDEZ2, K.A. DE FREITAS2, E. LORENZO1, M. ESCOBAR3, C. SIERRA4, J.R. GALLEGO4
Institución
Resumen
Tar residues are frequent on the south-eastern coastline of the Paria Peninsula. Here
we studied tarballs along approximately 14 km of shoreline by means of a systematic
monthly sampling conducted over a two-year period on beaches between the villages
of Macuro and Mapire. More than 70% of the tarballs sampled were included in the
same group on the basis of their physical and organoleptic properties. This group was
then fingerprinted using biomarkers (hopanes, steranes, alkanes, aromatic steroids,
phenanthrenes, and dibenzothiophenes) by gas chromatography coupled to flame
ionization detection, and by gas chromatography/mass spectrometry. Sulfur and trace
elements were also determined to complete the geochemical characterization. Our
results showed that these beach tar residues do not have an anthropogenic origin and
that they may have originated from carbonate source rocks within the Naparima Hill
Formation via shallow offshore seepage. Therefore, we have established a
geochemical background for tar residues that will be very helpful to distinguish
natural from anthropogenic beach tar contamination along the south–eastern shoreline
of the Paria Peninsula.