KAKKOO KOCKS IX THK MAFIXGABUSI. 40 1 



sufficient for correlation. Cone in cone limestone beds occurs 

 near the Gasue Eiver and at Masenga in the Bume. A Loreliole 

 was put down in Matabola beds in the Inyoka basin in 1899. 

 It commenced at the foot of a hill of o-rit and conolomerate 

 overlying- shales and clays of coal beds that continued to 

 310 feet, when they clianged at 316 feet to fine grey sandstone 

 with specks of carbonaceous matter and pyritic concretions two 

 inches across. Coarse sandstone and grit, angular and mica- 

 ceous supervened to 319 feet, below which the rock would not 

 core. This might be relative to the Upper Wankie sandstone. 



The nodiilar ironstones in these beds lie in deep red masses 

 of turtle shape, 10 feet in diameter, that sometimes coalesce 

 to form a bed over a considerable area (1273/4). Internally 

 the colour is red-grey — the iron being masked by carbonaceous 

 matter. Veins of yellow calcite and chalybite form a central 

 network . 



The thickness is shown in the table at a minimum of 

 320 feet, measured in the borehole, and taking* the sandstone 

 found at the bottom as being* the base of the grou]). xlt 

 Wankie the figure is given as 750 feet (variable). 



In the liunie Eiver, three miles from Masosoni village. 

 is a fissure in the clay filled with wax-like coal. 



Another similar fissure among blue-grey clays contains 

 a light red pisolitic ferruginous clay or botryoidal concretions, 

 around centres of colloidal coal. Others are filled with iron, 

 or both coal and iron. 



YI. — Relationship of Karroo to Arcii.3-:ais' Floor, 



As in the areas already described by previous Mriters, the 

 KaiToo rocks lie as an overlap on the ancient fioor. In regard 

 to its eastern margin, the rocks of that floor will probably l)e 

 found to belong to the IiOmag*undi system. There is no evidence 

 that a fault forms the contact, tliough there is likely to be 

 some structural line that favoured the direction of the Umniati 

 river in its i)resent course. How far the Karroo system may 

 have extended eastward there is no evidence to say, but its 

 curtailment, as seen to-day, has been brought about by tlie 

 erosive action of the Umniati and its tributaries. 



REFERENCES. 



1. MOLYNEUX, A. J. C. — 



The Sedimentary Deposits of Southern Rhodesia. — 

 Quart. Joiirn. Geo] . Soc, vol. lix (1903). 

 pp. 2GG-291. 



2. Parsons, C. E.— 



Notes on a Geological Sectif)n from Gwelo to the 

 Zambezi River. — Proc. lihod. Sci. Assn., vol. iv 

 (1903-4), p. 48, plate v. 



