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THE SALT PAN NEAR HAAGENSTAD.-^\ 



By G. W. Cook, B.Sc. >. — i i-^ 



The Salt Pan is situated about thirty miles from Bloemfon- 

 tein, in a direction north-west by north, and is about four miles 

 to the north-west of Lombaard's Drift, over the Modder River. 

 It forms a portion of several farms, among which are Haagen- 

 stad on the east, Rietfontein and Vaalbank on the south, 

 Poortje on the west and Yeelgeluk and Rondefontein on the 

 north. 



The pan itself is heart-shaped and forms a depression sur- 

 rounded on all sides excepting the south by rising ground, 

 composed of shales, sandstones and intrusive dolerites. 



The beds of the entire district consist of sandstones and 

 shales, which exhibit the lithological characters of the lower 

 Karroo or Ecca series. 



Fossils appear to be rare, the only one I have found appear- 

 ing to be a poorly-preserved specimen of Glossopteris. 



The sandstones abound with spherical formations, which at 

 first sight appear to be ordinary concretionary nodules. These 

 are found in all horizons in the Ecca series. I have found 

 them on Naval Hill, whose beds are above those at the Salt 

 Pan, and in still more marked quantities in the higher strata 

 near Senekal. The unweathered spheres contain a hard, 

 closely-grained, dark limestone. 



I have not been able to collect sufficient data upon which to 

 urge a hypothesis as io their formation, but I may be per- 

 mitted to throw out the suggestion for what it is worth, that 

 they are old pot-holes in which calcium carbonate has been 

 deposited from solution. 



The dip of the beds, except where disturbed by intrusions, 

 is uniformly to the south-east. 



The pan then lies on the north-western edge of a synclinal 

 fold, whose axis runs north-east to south-west, and wdiose 

 south-eastern edge outcrops in Natal and the north of the 

 Cape Colony. 



The beds underlying the pan consist of dark grey shales, 

 wdiich dip uniformly to the south-east. On the higher parts 

 round the pan these beds are over-laid by grey sandstones, 

 which are well exposed on the farm, which derives from them 

 its name — Vaalbank. This sandstone is occasionally ripple- 

 marked. 



The shale is very compact, almost impervious, and is cut bv 

 two main cleavages almost at right angles to each other and 

 to the plane of bedding. It often weathers in conchoidal 

 fashion and eventually disintegrates into thin, splintery frag- 

 ments. When in contact with the dolerite intrusions this 

 shale is found very indurated and very much resembles in 

 appearance the overlying sandstone. 



