160 ME. J. B. SCRIYENOR ON [June I912. 



writing (September 1911), a year has elapsed since the greater 

 part of the information contained in the paper was collected, and 

 since the paper was despatched a considerable amount of supple- 

 mentary information has been obtained, strengthening my con- 

 clusions. I embody this in the following short appendix.] 



(a) Absence of Schistosity in the Mass of the 

 Gopeng Beds. 



There is now a very clear section exposed at the Tekka Ltd. 

 Mine, showing the junction of the Gopeng Beds and the granite. 

 Por a distance of about 10 feet from the granite along part of the 

 junction the Gopeng Beds are distinctly schistose, and there are 

 quartz-veins parallel to the planes of schistosity. The passage 

 from schists to red clay is gradual ; and it would appear that the 

 hot granite so far hardened the clays and robbed them of their 

 plasticity at the junction, as to render them capable of taking on a 

 schistose structure. This is not the case, however, in the big 

 Chinese mine on the south. There the clays show nothing that 

 can be called schistosity, and the veins, which are abundant, do 

 not appear to follow any physical feature in the clay. One vein of 

 tourmaline-rock can be traced for 40 feet. 



"While the phyllites and quartzites are clearly distinct from the 

 Gopeng Beds, it is possible that some pale-grey rocks, resembling 

 phyllites, but much weathered, exposed on the road at the top of 

 a hill not far from Tekkah Sungei Eaia, are really grey Gopeng 

 clay retaining a structure imposed by the earth-movements at the 

 time of the granite irruption. I cannot regard this as proved, 

 however, until boulder-clay showing the same structure has been 

 found. 



{b) Clayey Fault-Breccia. 



A very remarkable rock is seen at the Tekka Mine, close to the 

 granite junction. This is a dark-red clay full of angular fragments 

 of tourmaline-rocks, siliceous rocks, and ironstone. These may 

 have formed veins originally, but there can be little doubt that the 

 rock is a fault-breccia in the Gopeng Beds. A photograph was 

 obtained, showing a sharp junction between this breccia and 

 ordinary red clay with small boulders. A smooth face with a 

 surface like that of a slickenside has been seen in this breccia. 



(c) The Intrusive Veins. 



There are now very clear sections on the Kinta Tin-Mines 

 property and on the Gopeng Mining Company's property, showing 

 the kaolin veins cutting the Gopeng Beds. The big vein described 

 on the Kinta Tin-Mines property has been cut down to a lower 

 level, and is now clearly exposed in a ditch : its width is about 

 60 feet, and it contains a considerable quantity of quartz. In part 



