184 C. W. MANN. 



Overlying this felsite at Hatton's Corner, is a band of 

 eight feet of metamorphosed rock, mainly indurated shales 

 and sandstones. This is capped with a thin sill of felsite 

 about six feet or seven feet in thickness, from which at 

 least two apophyses inject the overlying shales. These 

 latter are also considerably indurated. The actual junc- 

 tion between the sill and the main mass of porphyry is not 

 apparent, there being a considerable amount of alluvium 

 covering the outcrop. 



Not far from this occurrence and in the Marchmont 

 Paddocks on the way to Hatton's Corner, is an important 

 intrusion in which the magma has caught up large frag- 

 ments of fossiliferous limestone, some specimens measuring 

 up to 5 cm. in diameter. The felspar is considerably 

 decomposed and large grains of quartz are still abundant. 

 The magma which included the limestone lias a strong 

 resemblance to the decomposed fragments of the main mass 

 and is probably a direct apophysis from the main mass of 

 the Laidlaw porphyry. Associated with these direct effects 

 from the intrusion is an extensive formation of silicifled 

 limestone and a large intrusion of quartz rock. 



At Derrengullen Creek, some five miles from the above 

 mentioned occurrence, is a thin sill of quartz porphyry some 

 six feet in thickness interhedded with the shales. This 

 occurs above the upper surface of the Laidlaw porphyry. 

 {These features are shown in the section, fig. II.) 



The features on the western eOge of the Douro porphyry 

 are similar to those recounted above. (See Plate X.) Sills 

 of felsite are present and associated with them is a con- 

 siderable amount of contact breccia. Silicifled limestone 

 and quartz rock are also present. 



At the southern end of the Laidlaw intrusion and in the 

 Golf Links Paddock, the mass peters out in a tongue-shaped 

 plan (See Plate X). Here is a large formation of quartzite, 



