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News older than one year.
What factors determine which part of the cliff will be “eaten” by salt crystals?
Numerous small pits on cliff surfaces have been noted by almost everyone who visited some of the sandstone rock cities. These pits are called honeycombs. Long ago, they were believed to form by wind erosion. For some time already, they have been understood to be shaped by a different mechanism: their origin is largely contributed by the crystallization of salts from groundwater/pore waters. A paper on this topic was released in the February issue of the Geomorphology journal: it brings additional evidence for the origin of honeycombs and, using dye experiments, documents the crucial role of the reach of hydraulic field in this process. This field, or, more exactly, its margin (i.e., the evaporation front) controls the sites of salt crystallization hence also the way the cliff surface is shaped by the salts. More information can be found in the paper, which was also contributed by scientists of the Institute of Geology: Michal Filippi as a co-author, and Jan Rohovec and Šárka Matoušková as analysts.
In memory of Jiří Fiala
This week, we learned a very sad news about the death of our colleague ing. Jiří Fiala, CSc.
Jirka graduated from University of Chemistry and Technology in Prague in 1961. His whole professional life was connected with the Academy of Sciences. He completed his post-graduate studies in the Institute of Geochemistry and Mineral Resources of the Czechoslovak Academy of Sciences. After the re-organization of the Czechoslovak Academy of Sciences, he was working in the Institute of Geology until his death. He was the Director of this institute in years 1991–1993. From the year 2008, he was an emeritus scientist of the Czech Academy of Sciences.
Jirka was a very successful scientist, measured by his publications. He specialized in geochemistry and petrology of metamorphic and magmatic rocks. In his research, he collaborated with many colleagues from abroad. Besides others, he can be credited for the foundation of the laboratories of mineral separation at the Institute of Geology.
Jirka had very open and friendly relationships with his colleagues, always willing to share his broad field experience and scientific knowledge.
With Jirkaʼs decease, the Institute of Geology as well as Czech science are losing a significant scientist and an outstanding personality. May the memory of him be honoured.
The last respect will be paid in the Church of the Most Sacred Heart of Our Lord in the main cemetery of Vimperk at 1 p.m. on Friday, February 16, 2018.
Climatic record of Marine Isotope Stage 3 in Moravia
The Last Ice Age, was not “icy” at all times. During this period, certain climatic variations occurred, being characterized by warming and higher precipitation rates. The interpretation of sedimentary record from the Last Ice Age is subject to change based on new observations from the field and new interpretations of the climatic curve. A possible definition of climatic events in this period in central Moravia is presented in the paper: „Podhradem Interstadial; A critical review of the middle and late MIS 3 (Denekamp, Hengelo) in Moravia, Czech Republic“ published in Quaternary Science Reviews (IF: 4.747). The paper was contributed by scientists of the Institute of Geology CAS, v.v.i.
Honorary professional medal
Assoc. Prof. Jozef Michalík, DrSc. of the Earth Science Institute of the Slovak Academy of Sciences was awarded the František Pošepný honorary professional medal for his achievements in the field of geosciences on January 18, 2017. This award was nominated by the Institute of Geology CAS, v.v.i. Congratulations!
A documentary on rock arches
In the first week of this year, the Czech Television presented a documentary called “Arches”, dealing with sandstone weathering and the origin of sandstone arches. Both the documentary and the preceding research were contributed by scientists of the Institute of Geology: Michal Filippi, Radek Mikuláš and Jiří Adamovič. For more, click here.
A new database of rockfall phenomena in Czech sandstones
Sandstones are porous rocks extremely sensitive to temperature and humidity changes. Climatic extremes of the last decades therefore induce accelerated destruction of sandstone outcrops in the whole Bohemian Cretaceous Basin. These events have not been registered yet. Now, a database of rockfall events, both recent and fossil, has been established with the support of the Geohazards Programme within Strategy AV21. Descriptions of individual objects are accompanied by photos taken at different times after – and before – the event. The database is fully open to contributions from professional and lay public. Annotation of the Kokořínsko – Máchův kraj PLA in 2016 and Bohemian Paradise PLA in 2017 will be followed by other sandstone areas. To enter the application, click HERE.
Registration of users: Mgr. Jiří Adamovič, CSc., adamovicgli [dot] cas [dot] cz
An endemic ichnoassemblage from Tertiary paleolake in SE Iceland
In Þórisdalur valley in southeastern Iceland, a small relict of unique sedimentary body was identified. It probably represents a remnant of a deep, tectonically arranged paleolake (Late Miocene, 8–9 Ma), filled with volcaniclastic material from the nearby active volcanic centers. Trace fossils of the newly described endemic ichnoassemblage (e.g., Thorichnus ramosus igen. et isp. nov., T. corniculatus igen. et isp. nov., Mammillichnis jakubi isp. nov., Vatnaspor jachymi igen. et isp. nov.) were identified in the sedimentary section. The results of the study, actively participated by Assoc. Prof. RNDr. Lukáš Krmíček, Ph.D. of the Institute of Geology of the Czech Academy of Sciences, are currently published in Palaeogeography, Palaeoclimatology, Palaeoecology.
Conspicuous Research of the Tunguska Explosion
X-ray scans over wood disks collected in the Tunguska region in 2008 partly unveiled the mystery of the Tunguska explosion. Several trees survived the event. While the trees contain a record of this event in the form of anomalous Ca concentration (and other elements), the size of the Ca anomaly also shows the direction towards the explosion epicenter. Figure: Four identical images of the larch anual rings, each showing the direction towards the TE epicenter (arrow in the compass rose). Graphical inset on top of each image shows the relative concentration of Ca across the wood section along a transect shown by the bottom edge of each inset. The x-axis distance scale on the Ca graphs has a 2-mm grid spacing, and the y-axis is the relative concentration of Ca. (A) North-south transect; black arrows show the extent of fire damage along the 1908 tree ring. (B) East-west transect; (C) Northwest-southeast transect; (D) Southwest-northeast transect.
Research results were published (Kletetschka et al. 2017: Survival Response of Larix Sibirica to the Tunguska Explosion) in the Tree-Ring Research journal.
An exhibition to the Photogenic Science photo competition
Much like in the years before, staff members of the Institute of Geology, Czech Academy of Sciences, participated in the Photogenic Science photo competition with their best shots. Some of them were chosen for the shortlist, and finally one photo by Michal Filippi and two photos by Pavel Lisý were nominated. One of the two photos, titled "Nobody was at home" ended up second in the "Scientists in photography" category.
Open Days 2017
Open Days 2017 were held on the 3rd, 9th and 10th November 2017 in the Institute of Geology. The visitors, about 80 in number, were dominated by children. Besides experiences, they took away some 150 copies of journals issued for a broad public by the Czech Academy of Sciences. See also Week of Science and Technology.