Notices of Memoirs — H. B. Maufe — S. Rhodesia. 417 



are produced on a flint when flaking, and which, are not found upon 

 implements which have been exposed to atmospheric conditions, 

 these fragments would in time, by thermal effects, ' weather out ' 

 and leave a clean-cut groove behind. 



When I proceeded to test my theory by examining a series of 

 striated flints in ray collection I found various specimens which seem 

 to me to show striae in different stages of weathering. Thus one 

 black glossy flint given me by Mr. E. St. H. Lingwood, of Westleton, 

 Suffolk, and found by him on a ploughed field at that place, showed 

 a shattered scratch extending for about 1:^ inches across its surface. 

 To prove that such, a scratch could easily be deepened I attacked part 

 of it with a steel probe and found that I could easily remove the 

 thin plates of flint which were produced when the initial shattering 

 took place. I then took a pointed flint flake and cleared away the 

 remaining splinters of flint in the groove I had made, and this 

 specimen, therefore, now exhibits a shattered line over half its 

 length, and the other half a deepish groove. 



This question of the ' weathering out' of scratches appears to me 

 to be of some importance, because what we have looked upon as deep 

 strise caused by great pressure are in all probabilitj'^ merely * weathered 

 out ' scratches, the initial stage of which would not require any very 

 great pressure to produce. I give it as my opinion that every scratch 

 imprinted upon a flint must have a shattered portion on the sides and 

 floor of the scratch, and, further, this shattered portion, if exposed 

 long enough to thermal effects, must ' weather out ' and the scratch 

 alter in depth and appearance until all the thin fragments are gone. 

 If a flint gets striated, and then becomes covered by some impervious 

 material such as clay, then it will be protected from thermal changes 

 and no ' weathering out' of the scratches take place. This perhaps 

 offers an explanation for the smallness of the strise on the flints from 

 the Chalky Boulder-clay, as compared with those showing on stones 

 from below the E,ed Crag. The latter were scratched and then 

 exposed on the pre-Crag land surface, and consequently got ' weathered 

 out ', while those in the Boulder-clay have been protected by the 

 nature of the material in which they lie, and many of them exhibit 

 typical unweathered out, shattered, scratches. In this note I refer 

 solely to the strise which are developed upon the hard portion of the 

 flints, not to those upon the softer cortex. 



ITOTIOES OIF 3yLE]VCOIB,S- 



Geological Sukvey or SouTHEEisr Hhodesia. 

 rriHE following is an abridged statement from the Report of the 

 i. Director, Mr. H. B. Maufe, for the year 1912 (fol. ; Salisbury, 

 Rhodesia, 1913) : As a result of the detailed work amongst the 

 metamorphic rocks, it is becoming increasingly clear tliat they are 

 divisible into three series, one of which, consists of three groups : 

 {a) a greenstone schist group, including epidiorite, (b) a banded iron- 

 stone group, and (c) a conglomerate and grit group. The second series 

 consists of ultra-basic rocks, some of which contain chromite and 

 asbestos. The third series comprises a very variable group of fine- 

 grained and frequently schistose acid rocks, which have not hitherto 



decade v. — VOL. X. — NO. IX. 27 



