278 Twenhofel — Notes on Black Shale in the Making. 



fine-grained black slime heavily charged with sulphur gas. 

 The reeds growing on the surface, both above and beneath the 

 water, ultimately appear to leave no microscopic signs of 

 their presence, since a few inches below the surface nothing 

 but black mud occurs. Later the bay was crossed by a boat 

 and it was found to be so shallow that the boat was propelled 

 by a pole and the entire bottom was seen to be covered with a 

 similar black slime which also contained sulphur gases. Land- 

 ing was effected by wading from the boat and it was learned in 

 an extremely disagreeable way that the upper layers of the 

 slime were very soft and permeable and that one sunk nearly 

 to the hips before reaching a bottom firm enough to hold the 

 weight of a man. That compact slime of this kind probably 

 underlies the greater portion of the swampy land on each side 

 of the bay for a considerable depth below the surface is 

 extremely probable. 



Farther to the south are the two islands of Oesel and Moon, 

 separated by a body of water with a minimum width of about 

 one mile. It is known as the Little Sound and is open at both 

 ends. The water is quite shallow and at one place the two 

 islands have been joined by a road. Many parts of each 

 shore have extensive deposits of the black slime and it also 

 covers some parts of the bottom and probably most of it. 



Near the town of Arensburg on the southwestern corner of 

 the island of Oesel, there is a large bay which has only a 

 narrow connection with the Baltic. At the time of the build- 

 ing of Arensburg Castle (1334), this bay was open to the sea 

 and afforded an excellent harbor. At the present time it is 

 almost completely filled with slime of the same character as 

 that of Lyckholm Bay and is accessible from the sea only to 

 small rowboats. In the town the slime is extensively used for 

 baths, at least three establishments exploiting it for this 

 purpose. The healing properties are said to be very great, 

 but the odor and general appearance would appear to be some- 

 what repellent. The writer was informed that it is also used 

 at Hapsal for bathing, but this statement has not been verified. 



Between the Sworbe, the long southwestern peninsula 

 extension of Oesel, and Oesel proper, there is another narrow 

 sound which is almost completely filled with a similar slime. 

 The width of this body of water is not great and it is not 

 shown on any map which the writer has seen. 



Schmidt has briefly referred to these slimes (loc. cited, p. 89) 

 and he states that, they are deposited in protected bays in 

 apparent independence of the character of the sea floor and 

 are made from the decomposed remains of animals and plants. 

 He gives as localities additional to those named many parts of 

 the long stretch of coast between Pernau and Hapsal and 



