Zemes un vides zinātnes Earth and Environment Sciences - Latvijas ...
Zemes un vides zinātnes Earth and Environment Sciences - Latvijas ...
Zemes un vides zinātnes Earth and Environment Sciences - Latvijas ...
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100 ADVANCES IN PALAEOICHTHYOLOGY<br />
from the Pavāri site were for the first time excavated by Lyubov Lyarskaya in 1970, <strong>and</strong><br />
the geological setting of the Ketleri Formation was defined <strong>and</strong> stratigraphical<br />
conclusions were made together with Lyudmila Savvaitova (Lyarskaya <strong>and</strong> Savvaitova<br />
1974). In subsequent years excavations were organised by L. Lyarskaya (in 1973), <strong>and</strong><br />
by E. Lukševičs in cooperation with palaeontologists from the Natural History Museum<br />
of Latvia, Museum of Natural History (London), Palaeontological Institute (Moscow),<br />
Cambridge University, Institute of Petroleum Geology (Novosibirsk), in 1988, 1989,<br />
1991, 1995, <strong>and</strong> finally in 2001, adding significantly to the vertebrate material. Some<br />
palaeoecological clues analysing the fa<strong>un</strong>al composition <strong>and</strong> taphonomical features of<br />
the Ketleri <strong>and</strong> Pavāri localities have been made previously (Lukševičs 1992), <strong>and</strong><br />
notes on the fa<strong>un</strong>al composition were published together with the first description of<br />
Ventastega (Ahlberg, Lukševičs <strong>and</strong> Lebedev 1994). The fossil assemblage of the Pavāri<br />
site is important for the <strong>un</strong>derst<strong>and</strong>ing of palaeoecology of the Late Devonian vertebrates<br />
in the Baltic palaeobasin. Now the Pavāri locality is a Nature Monument still <strong>un</strong>der<br />
active study; some sedimentological <strong>and</strong> taphonomical studies were carried out there<br />
in 2001, 2002 <strong>and</strong> 2004 by the authors of this article. The present paper pro<strong>vides</strong> a<br />
more complete description of the geology, taphonomy <strong>and</strong> fa<strong>un</strong>al composition of the<br />
Pavāri site.<br />
Material <strong>and</strong> methods<br />
The Ketleri Formation is distributed only in southwestern Latvia <strong>and</strong> northwestern<br />
Lithuania, cropping out only along the northern margin of its distribution in Latvia.<br />
Two localities of the Ketleri Formation are particularly rich in vertebrate fossils: the<br />
Ketleri site at the river Venta near the former Ketleri hamlet <strong>and</strong> the Pavāri site at the<br />
river Ciecere opposite the former Pavāri hamlet. The Pavāri site is located in the southern<br />
corner of the Kuldīga district, in western Latvia (Fig. 1). The best fossils come from the<br />
Pavāri site, where more than a thous<strong>and</strong> specimens of fossil vertebrates were excavated<br />
during several field seasons. Vertebrate fossils were collected mainly to examine the<br />
fa<strong>un</strong>al composition of the assemblage <strong>and</strong> the morphology of the various taxa, but in<br />
1988 <strong>and</strong> 2001, also to collect taphonomic <strong>and</strong> sedimentological information. More<br />
than 900 specimens have been determined to the generic/species level. The distribution,<br />
sorting, orientation, state of preservation, <strong>and</strong> wearing of vertebrate remains have also<br />
been studied. Data on spatial distribution, sorting <strong>and</strong> azimuthal orientation of fossil<br />
bones <strong>and</strong> skeletal fragments were collected in 1988 <strong>and</strong> 2001; totally 325 measurements<br />
of the orientation of fossil bones were taken. More than 800 specimens stored at the<br />
Natural History Museum of Latvia were examined to detect the state of preservation<br />
<strong>and</strong> wearing of bones.<br />
A complete grain size analysis of seven rock samples from the Ketleri Formation<br />
was carried out. The content of clay <strong>and</strong> silt was detected using the pipette method at<br />
the Laboratory of Quaternary <strong>Environment</strong> <strong>and</strong> Laboratory of Soil Research at the<br />
Faculty of Geographic <strong>and</strong> <strong>Earth</strong> <strong>Sciences</strong> of University of Latvia. S<strong>and</strong> particles were<br />
sieved at the laboratory of the Institute of Silicate Technology at the Riga Technical<br />
University using a set of „Fritsch” sieves „Analysette 3PRO”. MS Excel was used to<br />
r<strong>un</strong> the statistical analysis of the data. Variation <strong>and</strong> cumulative curves were drawn to<br />
illustrate the granulometric composition of the rocks, <strong>and</strong> the coefficient of sorting <strong>and</strong>