High Pinaceae pollen concentrations in the air and on the surface of puddles before the main pollen season started were observed in Kraków (southern Poland) in May 2013. The paper presents the results of detailed studies of the composition and source of the "yellow rain" in 2013, and as a comparison, the Pinaceae pollen concentrations and samples collected from the ground surface in 2014 were considered. The air samples were collected using the volumetric method (Hirst-type device), while pollen grains sampled from the ground surface were processed using a modified Erdtman acetolysis method. Finally, all samples were studied using a light microscope. In 2013, the period of higher Abies, Picea and Pinus pollen concentrations was observed from the 5 to 12 of May, earlier than the main pollen season occurred. The presence of rainfall on the 12 and 13 of May 2013 caused the pollen deposition on the ground surface, where the prevalence of Pinaceae pollen was found. The synoptic situation and the analysis of the back-trajectories and air mass advection at the beginning of May 2013 indicated that Pinaceae pollen grains could have been transported from Ukraine, Romania, Hungary and Slovakia. In contrast, Pinaceae pollen grains deposited on the ground surface as a "yellow" film in May 2014, originated from local sources.
The valley of the lower San river downstream from town of Jaros³aw is filled with the alluvial sediments of the thickness 15-19 m which form the Vistulian terrace (8-12 m above the river level) as well as system of the terraces of the Late Vistulian and the Holocene (5-8 m, 3-5 m and 1-3 m above the river level). Radiocarbon datings supplemented with palynological and sedimentological analyses made possible to distinguish the alluvial fill of the decline of the Upper Plenivistulian (15,600-14,000 BP) occurring within the Vistulian terrace as well as system of the paleochannels and the alluvial fills of the Late Vistulian, Preboreal, Boreal and the Subatlantic phases occurring within the Holocene terraces. Some of the Late Vistulian large paleomeanders of the San river could have been subsequently used by flood waters and finally filled up with peat sediments during the Subboreal phase. Under the Late Vistu- lian and the Holocene paleochannel fills, at the depth 3.5-5.0 m member of the sand alluvia of the decline of the Upper Plenivistulian (15,100-14,200 BP) were recorded, similarly to the Vistulian terrace. It can indicate the shallow incision of the Plenivistulian and/or the Late Vistulian sediments and rewor- king of the channel alluvia within the Holocene terraces of the San river. The aggradation of the thick overbank sediments upon the channel alluvia dated at 15,000 BP (within the left-side part of the valley) is probably connected with the alluvial fan of the Wis³ok river.
PRELIMINARY DATA ON THE AGE OF THE DEPOSITS IN THE VISTULA RIVER VALLEY, NEAR TARNOBRZEG
Summary
The purpose of this paper is to present the preliminary results of geomorphological studies made in 1964 within the Vistula River valley, along the sector Baranow-Sandomierz. The series of the deposits distinguished within the valley are shown in the profile (Fig. 1). In the lowermost part of the river bed there rests a thin layer of quartz with an admixture of local and Carpathian rocks, directly on the substratum of the pre-Quaternary rocks. This layer is cemented by iron compounds. Higher up, there are found sands with gravels and large blocks of northern rocks. This layer, in turn, is covered by an arenaceous series 10 m in thickness. Here are found traces of old channels, frequently filled up with plant detritus. In a close contact with the arenaceous series are dune forms, in which traces of the Neolithic culture have been observed. Mud deposits represent the last layer uniformly covering the whole area of the overflood terrace.
In the light of palaeobotanical and stratigraphical analyses it appears to be possible that the deepest channel of the Vistula River was formed at the time of the Eemian Interglacial. Here, at the decline of the glaclal period, arenaceous-gravelly and arenaceous series were deposited. The top of the arenaceous series probably belongs to the Holocene. The dunes had been formed during the Sub-boreal period and shortly after that time the overoflood terrace was covered by mud deposits.
The paper presents the results of the latest radiocarbon dating and the palynological analyses of organic sediments found in the alluvia of the Wisłok River valley between the towns of Łańcut and Przeworsk. The study conducted in the gravel pit made possible the dating of several alluvial fills of the 7–8 m high Holocene terrace and the 5–6 m high floodplain. The oldest channel alluvia and palaeochannel sediments of the 7–8 m high terrace were dated at 10 100–9300 BP (11 960–10 500 cal BP). According to the anthracological analysis the top cover of clay overbank alluvia, which bears charcoal fragments, was deposited in the Subboreal and/or the Subatlantic Phases. In the sequence of the 5–6 m high floodplain, the bottom fills of palaeochannels, dated at 10 195–9885 cal BP (probability level: 68.2%; GdS-3233: 8900 ± 95 BP ) and 11 095–10 755 cal BP (probability level: 68.2%; GdS-3228: 9575 ± 95 BP), were truncated by erosion and covered by alluvia of palaeomeanders, which were active in the 19<sup>th</sup> century. Preservation of the erosional bench of the Early Holocene organic sediments indicates the predomination of lateral migration of the river channel during the last 200 years and the formation of wide erosional floodplain that has been aggraded with recent flood alluvia. In the 20<sup>th</sup> century the floodplain aggradation was simultaneous with the deepening of the Wisłok riverbed.
