Mirosław Błaszkiewicz - Academia.edu (original) (raw)

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Papers by Mirosław Błaszkiewicz

World geomorphological landscapes, 2024

Climate of The Past, May 31, 2018

Timescale uncertainties between paleoclimate reconstructions often inhibit studying the exact tim... more Timescale uncertainties between paleoclimate reconstructions often inhibit studying the exact timing, spatial expression and driving mechanisms of climate variations. Detecting and aligning the globally common cosmogenic radionuclide production signal via a curve fitting method provides a tool for the quasi-continuous synchronization of paleoclimate archives. In this study, we apply this approach to synchronize 10 Be records from varved sediments of Tiefer See and Lake Czechowskie covering the Maunder, Homeric and 5500 a BP grand solar minima with 14 C production rates inferred from the IntCal13 calibration curve. Our analyses indicate best fits with 14 C production rates when the 10 Be records from Tiefer See were shifted for 8 (−12/+4) (Maunder Minimum), 31 (−16/ + 12) (Homeric Minimum) and 86 (−22/+18) years (5500 a BP grand solar minimum) towards the past. The best fit between the Lake Czechowskie 10 Be record for the 5500 a BP grand solar minimum and 14 C production was obtained when the 10 Be time series was shifted 29 (−8/ + 7) years towards present. No significant fits were detected between the Lake Czechowskie 10 Be records for the Maunder and Homeric minima and 14 C production, likely due to intensified in-lake sediment resuspension since about 2800 a BP, transporting "old" 10 Be to the coring location. Our results provide a proof of concept for facilitating 10 Be in varved lake sediments as a novel synchronization tool required for investigating leads and lags of proxy responses to climate variability. However, they also point to some limitations of 10 Be in these archives, mainly connected to in-lake sediment resuspension processes.

Catena, Mar 1, 2021

Paleosols can widely be used as chronometric markers, and the so-called Finow soil is reported to... more Paleosols can widely be used as chronometric markers, and the so-called Finow soil is reported to be a supraregional marker in the sandy deposits in northern central Europe and Siberia. The Finow soil is thought to be associated with pedogenesis between the Allerød and the Younger Dryas with subsequent fossilization by eolian activity. The formation of the 5-to 15-cm-thick brownish Finow soils is often explained by brunification and some minor illuviation of clay. Although the Finow soil has been described at several distant sites, the lack of an entire soil sequence consisting of a topsoil and a subsoil recently raised doubts about the formation of the Finow soil. We present a micromorphological approach together with grain size analysis from two sites in northeastern Germany (Glashütte and Jänschwalde in Brandenburg) and one site in Poland (Błędno) where purported Finow soils have been reported and were dated in earlier studies to investigate the processes that led to the formation of the Finow soil. Our findings show that the three studied Finow soils are characterized by clay migration, rather than brunification, and that the Finow soils are situated below well-drained sandy deposits at hydrological barriers. Whereas at Glashütte, the soil organic matter of an Usselo soil acts as a hydrological barrier, at Jänschwalde and Błędno, changes in the granulometry of the sandy deposits presumably act as a hydrological barrier. At Jänschwalde, the illuvial horizon is the least developed of the three sites and the eluvial horizon has a depth of only 40 cm, but at Glashütte, the Finow soil below the 330-cm-thick sandy deposit shows extensive features of clay illuviation. Hence, we propose that the thickness of the eluvial horizon strongly influences the degree of clay illuviation in the Finow soil. Further, we propose that due to the well-drained character of the sandy substrates, the formation of the Finow soil is limited to the supply of clay for the clay migration rather than being time limited. Therefore, the clay illuvial features of the Finow soil are indicative of neither the suggested pre-Holocene soil development nor of the lack of the eluvial and topsoil horizons of the supposedly truncated Finow soil due to late Quaternary soil erosion or landscape activity. Indeed, the clay illuviation that causes the formation of the Finow soil can visually accentuate sedimentological changes, but because the clay illuviation is a postsedimentary process, the indicative potential of the Finow soil is site specific. Hence, we conclude that the use of the Finow soil as a supraregional chronometric or pedostratigraphic marker should be avoided.

EGU General Assembly Conference Abstracts, Apr 1, 2017

Land Degradation & Development

The rapid climate changes of recent decades are causing rapid glacier recession in the high Arcti... more The rapid climate changes of recent decades are causing rapid glacier recession in the high Arctic and the loss of large patches and blocks of dead ice. Their temporally differentiated melting is very significantly transforming the relief of marginal zones, creating dead‐ice landscapes. The article focuses on dead‐ice degradation processes in the forelands of two glaciers (Erikkabreen and Haakenbreen) on Oscar II Land in Spitsbergen. Detailed in‐field geomorphological mappings have been conducted twice (in 1989 and 2022) in the two glaciers' forelands. These were combined with analysis of available photogrammetry and Digital Elevation Models, allowing the authors to describe the dynamics of dead‐ice melting processes within various landforms and the effect of those processes on the forms' ultimate morphology. This provided a broad view of the trajectory of melt processes depending on local geomorphological and hydrological conditions. Particular attention was paid to the int...

The Holocene

In this work, we studied the course of climatic fluctuations at the beginning of the Preboreal pe... more In this work, we studied the course of climatic fluctuations at the beginning of the Preboreal period using multiproxy analyses (Chironomidae, pollen, diatoms, Cladocera, stable isotopes, macrocharcoal, microlithofacial) combined with varve chronology of sediments. The results showed a decrease in the mean July temperature and stronger continentalism followed by climate wetting at the start of the Preboreal period. This was reflected in the remodeling of the vegetation cover from birch forests to more open spaces with grass vegetation dominance, as well as that of the species composition of Cladocera and diatoms, and the high variability of isotopic composition. In addition, the results showed the impact of local conditions (fires and relict permafrost) on the amplification of environmental responses due to climate cooling. The environmental transformations presented here correspond temporally to the changes that are well documented in other parts of Europe as the Preboreal Oscillat...

European Glacial Landscapes

DEUQUA Special Publications

The young moraine area to the southeast of Berlin was repeatedly overrun and covered by Scandinav... more The young moraine area to the southeast of Berlin was repeatedly overrun and covered by Scandinavian ice sheets (SISs). The last glaciation took place during the Last Glacial Maximum (LGM), when the last/most recent SIS reached its furthest southern extent. An incompletely formed chain of terminal moraines marks the Brandenburg ice stage. The most recent glacier had its greatest environmental impact due to the large quantities of released meltwaters. Many subglacial channels, massive proglacial sands and huge meltwater streamways (Urstromtäler) were formed at that time. During the Holocene, the landscape was finally shaped mainly by the rivers Dahme and Spree.

EGU General Assembly Conference Abstracts, Apr 1, 2016

EGU General Assembly Conference Abstracts, Apr 1, 2018

To revise the chronology for the Lake Gościąż record, sediment cores were retrieved during two fi... more To revise the chronology for the Lake Gościąż record, sediment cores were retrieved during two field campaigns in 2015 and 2018. Four overlapping sections were collected using a UWITEC Piston Corer (Ø 90 mm) in the deepest part of Lake Gościąż, Poland (52.583022 N, 19.339946 E). The chronology was obtained by triple varve counting on petrographic thin sections that was complemented by 137Cs measurements and 14C AMS dating of terrestrial plant remains. Additionally, part of the chronology between 520-758 cm was obtained through age-depth modelling. Pollen analysis was performed for seventy one samples, prepared according to standard procedure, and analyzed in three intervals: i) from 1859.9 cm to 1874.4 cm with 2 cm resolution, ii) from 1880.2 cm to 1896.7 cm with 1-2 cm resolution and iii) from 1741.4 cm to 1798.4 cm with 0.5-3 cm resolution. The record is mostly varved and the bottom of the composite profile coincides with the onset of lacustrine sedimentation in the late Allerød a...

These datasets provide data for the lowest part of a new composite profile GOS18 from Lake Gością... more These datasets provide data for the lowest part of a new composite profile GOS18 from Lake Gościąż in central Poland. The composite profile was established using sediment cores recovered in 2015 and 2018 with an UWITEC Piston Corer at 19.6-21.5 m water depth (Bonk et al., in press). Our data covers the time interval from the onset of lacustrine sedimentation in the late Allerød to the early Preboreal. Since Lake Gościąż comprises a continuous, seasonally resolved (varved) and exceptionally well-preserved archive of the Younger Dryas (YD) climate variation, it is highly suitable for detailed investigations of lake system responses during periods of rapid climate cooling (YD onset) and warming (YD termination), respectively. Chironomidae head capsules (hc) were utilized to reconstruct the mean July air temperature from the late Allerød to the early Preboreal in Lake Gościąż (central Poland). Sample resolution ranges from 0.5 to 6 cm. Two different training sets were used for the recon...