1^)4 PROCEEDINGS OF SECTION C. 



Occurrences of Petroleum and Natural Gas Vents. 



The chief occurrences of petroleum are to be seen at Akauda, about 2 

 miles north of the village on either side of the Vailala River, near Opa 

 village, a few miles east of the river and south of the former occur- 

 rences, and near Aro-Aro village, a few miles west, between the Vailala 

 and Purari Rivers, 



Associated with the petrolevim are series of natural gas vents and 

 mud volcanoes. At Akauda, Opa, and Aro-Aro there is a petroliferous 

 brown-coloured scum seen on the surface of the water in some of the 

 vents. As a matter of fact, the odour of petroleum is discernable at 

 almost every vent. 



The oil itself, in all cases where it occurs, is seen oozing from the 

 mudstoue, and usually in small creeks where there are exposures of 

 shattered rock. The best occurrence is at a point about 2 miles above 

 the Akauda village, in a small creek on the left hand bank of the river. 

 Following this creek up for about 200 yards, in which outcrops of sand- 

 stone and mudstone occur, the oil is seen, not only seeping through the 

 mudstone, but also bubbling up through the water and floating on the 

 surface in dark-brown fluorescent globules. About 250 c.cs were 

 collected for analyses. Bubbles and vents were seen in the creek bed 

 near the oil occurrences. About 100 yards to the right of this creek 

 there is a large circular gas vent filled with jnineralized water, about 

 22 yards in diameter, containing much of the brown-coloured petro- 

 liferous scum and the odour of petroleum. With the exception of a 

 few small mud volcanoes, the general character of the vents throughout 

 the district is as follows : — An inflammable gas bubbling through 

 mineralized or muddy water, burning with a luminous flame, with a 

 bluish fringe. The ebulition is at times fairly %agorous. At Akauda a 

 can of water was boiled in one of the ignited jets projected by means 

 of a bamboo spouting. The ground near the springs is very soft and 

 swampy, and in some cases dangerous. The vents themselves are, 

 in some cases, very deep, and at Aro-Aro, in one particular instance, 

 was not sounded at 35 feet. 



The principal occurrences of the phenomena connected with the 

 oil deposits are as follows : — At Akauda, on either side of the river 

 near Opa village, near Aro-Aro village, at Pairi Jiear Hipcri village, a 

 few miles east from the Purari River, and at four or five minor localities 

 near the coast-line of Orokolo Bay, between the Vailala and Purari 

 Rivers. 



A considerable amount of detailed geological work not included 

 in this paper has been done in the country in the immediate neigh- 

 bourhood about the occurrences. Dips and strikes have been taken 

 wherever possible, and placed upon the full-scaled geological sketch map 

 prepared with the report* for the Papuan Government by the author. 



* Eeport on tha Geology of the Petroleum Area, Gulf Division. P.apua, by Evan K. 

 Stanley, Oovernmeat Geologist, 1012. 



