MINBU. 43 



50 x 20 feet, filled with a watery mud of about 82 F. Inside 

 this basin there are numerous independent vents, which emit gas 

 continuously, some of them with a hissing noise ; the surface of the 

 mud was covered with a thick film of petroleum. The principal basin 

 is surrounded by numerous vents, some of which emit gas only, while 

 others eject a very viscous mud, mixed with petroleum. The tem- 

 perature varied from 79 F. to 82 F. 



Several vents of this same kind are found a short distance north 

 of this one ; in all cases a more or less circular basin is filled with 

 a watery mud in which numerous gas bubbles rise. The northern- 

 most of these holes, just at the foot of the hill, is remarkable for its 

 comparatively high temperature, which was repeatedly measured and 

 found to be 97°. I first attributed it to the heating influence of the 

 sun, but after having found the same temperature early in the morn- 

 ing, before sunrise, it must be considered as the actual tempera- 

 ture of this mud well. 



3. — General features. 



So far it appears that the mud volcanoes have little in common in 

 general shape, but we shall eventually see that the basin shaped 

 mud wells and the conical mud volcanoes are only modifications of 

 one and the same phenomenon. 



The features in common are : they all produce a greyish blue 

 mud, of varying consistency, more or less saturated with petroleum, 

 and emitting an inflammable gas in smaller or greater quantities. It 

 appears unquestionable that the mud volcanoes of Minbu are more or 

 less intimately connected with subterraneous petroliferous strata, 

 and their position on the west of the anticlinal arch is therefore by 

 no means accidental. The mud brought up by the mud volcanoes 

 resembles in fact so much the debris baled out of the drilled wells at 

 Kodoung, that samples of both cannot be distinguished. 



The source from which the mud and gas rises cannot possibly be 

 very deep below the surface ; this is indicated by the low temperature 

 of the ejected mud. Except one well in the northern group, which 



( 89 ) 



