Cement Stone Blocks at Kopgalis in the Curonian Spit: Origin and Formation Background

摘要

On the basis of experimental and archive research as well as on historical photo-graphs, the article analyzes the composition, origin and formation background of cement stone blocks (the blocks of hardened Portland cement paste) laid along the southern breakwater of Klaipeda port on the seaside of the Curonian Spit at Kopgalis and periodically uncovered during big storms. The surface condition, internal structure and chemical and mineral composition of these blocks provide sufficient evidence for an assessment that the blocks were formed from Portland cement hydrated in sea water without mixing (in dormant state) over a long time. The archive documents of Klaipeda port and investigation into the press publications of that period in question have evidenced that these barrel-shaped cement stone blocks relate to the shipment of Portland cement that was delivered from Gotland Island, most probably from Slite cement factory on the boat Grisslan that sank in the port entrance channel in 1924. The shipment (about 340 tons) was ordered by Lithuanian company Sand?lis. The composition of Portland cement shipped from Sweden is similar to that of modern Portland cement, however, it has a relatively higher content of chrome oxide; cement stone blocks also display the stripes of lime. These are the features characteristic of Portland cement produced at the turn of the 20th century. A long-term contact of the block with sea water resulted in higher salt content in the blocks. The motor sailing-boat sank due to technical reasons – low engine capacity and rigging not suitable for the stormy weather. During investigation into sinking accident, neither the captain and the crew nor the pilots and other port services were found at fault. The accident, its causes and response to the effects were immediately and precisely, however not in sufficient detail, covered by Klaipeda periodicals of different political orientation in 1924. The similarity of offi-cial reports on boat sinking accident delivered to the Ministry of Transport and Communication and articles in Klaipeda newspapers reveal close cooperation between port administration and reporters. Article in Lithuanian