282 mk. a. J. c. molyneux ojs t the [May 1903, 



Twenty-five miles to the west is the Lubu Coalfield, where 

 at the time of writing no work has been done. The seams crop out 

 in the river-bed, and are 8£ feet thick. The area of this field 

 exceeds 30 square miles. 



The Sebungu Coalfield, 20 miles still farther west, has also 

 been neglected in development. There are many seams in the 

 river-bed, one of 4 feet and others totalling 5J feet. The area of 

 the exposed coal-bearing strata is 100 square miles. 1 



The Tuli Coalfield lies 190 miles south of Bulawayo, near 

 the Limpopo River. It is several square miles in extent, but only 

 about 1500 acres have been proved by development. The coal is 

 semi-bituminous, on an average 3| feet thick. 



The Massabi Coalfield lies 6 miles south-west of the foregoing. 

 It covers an area of 10,000 acres, and is now undergoing development. 

 So far two seams, respectively 4 feet and 6 feet 1 inch thick, have 

 been struck. The coal differs greatly from other Rhodesian coals in 

 being clean, with metallic lustre, and does not soil the fingers. 



On the Sabi River in the south-east, another coalfield has 

 recently been found, and is yielding good coal. 



VI. The Thermal Springs and Travertine-Beds. 



A special feature of the northern districts is the prevalence of 

 mineral springs, varying from steam-jets and fumaroles, as at Zongala, 

 and streams of boiling w r ater of several hundred gallons per minute, 

 as at Tchabi's, to mere percolations of saline water, yielding the salt 

 collected from the soil by a process of lixiviation by the natives 

 at Selayo, Nkoka's, Sitanga's and Tchabi's — and indeed at many 

 places along the area of the coal-bearing beds. 



While the gently-rising springs depositing saline matter, and the 

 warmer ones (as at Sitanga's) which contain sulphuretted hydrogen, 

 are charged with substances taken up in solution from the under- 

 lying coal-bearing beds, the majority of the hot springs deposit sheets 

 of siliceous travertine, and are the moribund phases of volcanic- 

 action represented by the extinct craters of the Wankie district. 



They are but a remnant of a vast number that, in fairly recent 

 times, sprang up among the sandstones of the Forest Series, for in 

 the valleys of the Shangani, Pupa, Kama, and Golongolo Rivers, along 

 the Great Escarpment, up the Sengwe River, and at the edge of the 

 Sikonyaula basalt-sheet, there are innumerable heaps of travertine — 

 rounded quartz-grains cemented together by silica, often assuming 

 the shapes of roots, and enclosing shells of Pupa, Limncea, Planorbis, 

 and Unio. There are now no other signs of these springs, as they 

 are quite extinct ; but the travertine left by them protects the 

 underlying sandstones, and forms the capping of small rises. 



Near these mounds are fragments of silicified trees, sometimes 

 6 feet long, and showing root-stumps and circles of exogenous 



1 With regard to the Wankie Coalfield, see 'Colliery Gruardian 

 vol. lxxxiii (February 21st, 1902) p. 390. 



