CONTENTS & ABSTRACTS

In English. Summaries in Estonian

Proceedings of the Estonian Academy of Sciences.

Geology

Volume 54 No. 2 June 2005

Harmonic and disharmonic soil-type interference on Late Pleistocene and Holocene sediments in Northeast Germany; 75–86

Gerhard Reuter

Abstract. Using colour photos and a specific horizon nomenclature, soil profiles in Northeast Germany are presented, which show characteristic features of harmonic development under recent climatic conditions, and disharmonic development with the joint appearance of Lessivé, BrownEarth, Podzol, and Pseudogley features on till. Taking into account studies in other climatic regions, the disharmonic development is interpreted as resulting from changing climate during the Holocene. Furthermore, in the relatively low-precipitation coastal area, a relict Chernozem (from the Boreal) has been subject to BrownEarth development. So-called Iron-Humus Podzols on older dune sands are reinterpreted as resulting from disharmonic development with ferralluviation during the Preboreal period.

Key words: soil types, soil development, change in climate, Holocene, Northeast Germany.

Chitinozoans of the Margachitina margaritana Biozone and the Llandovery–Wenlock boundary in West Estonian drill cores; 87–111

Viiu Nestor

Abstract. The succession of chitinozoan taxa in the uppermost Llandovery and lowermost Wenlock of the Viki, Ohesaare, Kaugatuma, and Ruhnu drill core sections is described and correlated with the global stratotype section of the basal Wenlock in Hughley Brook, Shropshire, England. The most important biomarkers for the identification of the Llandovery–Wenlock boundary in Estonian sections are the disappearance levels of Ramochitina nestorae, Conochitina acuminata, C. cf. flamma, and Angochitina longicollis. In the West Estonian cores this boundary corresponds to a level in the middle or upper part of the Margachitina margaritana Biozone. In the Viki and Ohesaare cores it coincides with the bentonite layers above the accepted boundary between the Adavere and Jaani regional stages and correlates with a level in the middle of the murchisoni graptolite Biozone. Three new species, Belonechitina oeselensis, Ancyrochitina mullinsi, and Eisenackitina inanulifera, are described.

Key words: chitinozoans, correlation, Llandovery, Wenlock, Silurian, Estonia.

Thermal behaviour of bone apatite of Recent pike (Esox lucius L.); 112–118

Jüri Nemliher and Toivo Kallaste

Abstract. Thermal properties of bioapatite of Recent pike (Esox lucius L.) vertebrae were studied by means of the whole-pattern-fitting XRD technique. The sample was gradually heated up to 900 °C. Weight loss of the sample heated up to 900 °C was about 3.05 wt%. The apatite heated up to 900 °C had lattice parameters a = 9.419 Å and c = 6.881 Å. Recrystallization of crystallites took place during heating, being the strongest at temperatures higher than 600 °C. At the temperature of 900 °C crystallites achieved the dimensions over 1000 ´ 1000 Å.

Key words: bioapatite, XRD whole-pattern-fitting, thermal behaviour, fossilization.

Development and protection of the coasts in the Tallinn area; 119–136

Heino Levald and Ain Valdmann

Abstract. The paper deals with the protection of the coastal areas of Tallinn and their primary development into harbours. The coast and coastal buildings are endangered by strong storm waves, especially in case of a high sea accompanying the storm. Due to the influence of waves, the coastal terrace recedes towards the land; in the bays the sands are whether deposited or swept away. Storms have caused major destruction to the coasts of Aegna Island and the Kakumäe Peninsula. The coastal area owners, the local authorities, and the organs of the state should take measures to protect the coasts through mutual cooperation and improvement of the valid legislation. The coasts and harbours within the boundaries of Tallinn are predominantly state-owned. In planning the development of the harbours it is necessary to reckon with the increase in passenger transport and sea tourism, environmental protection, safety and economic interests of the city, which have so far been somewhat neglected. Tallinn Municipality has begun to rearrange the administration of the coasts and harbours located within the city borders. Muuga Harbour plays a special role in further protection of coasts and development of harbours and could take over a major part of cargo transport within the boundaries of Tallinn. To ensure the safety of the harbour, a breakwater has to be constructed, however, it is a complicated and expensive task due to difficult geological conditions. The research conducted shows that the breakwater would increase considerably the safety of the harbour and is economically cost-effective.

Key words: Tallinn, coast, coastal reinforcement, harbour, breakwaters, environmental impact, cost-benefit analysis.

Comment on “Application of OSL and ¹⁰Be techniques to the establishment of deglaciation chronology in Estonia” by Anto Raukas (2004); 137–138

Vincent R. Rinterknecht and Peter U. Clark

Instructions to authors; 139–141

Copyright Transfer Agreement; 142