BY T. STEPHENS. 765 



practically level, being fringed along the coast-line by sand dunes, 

 except where low rocky rises intervene. From the Detention to 

 Crayfish Creek the rocks exposed along the beach are altered 

 slates, schists, and flaggy sandstones, the last-named being thickly 

 traversed by joints crossing the bedding planes at all angles 

 (Plate xx vi., fig. 2). There is much foliation on the line of strike } 

 the mean of which is about N.E. and S.W. The dip is northerly. 

 For the next three miles the same rocks show themselves at 

 frequent intervals, but the strike is more nearly E. and W., and 

 the dip southerly, suggesting the neighbourhood of a low anticlinal 

 fold. Near Brickmakers' Bay there are small veins and pockets 

 of iron pyrites in the slates, which are noted on an old map of 

 Tasmania as " copper ore." Near the mouth of the Black River 

 are the same slates and sandstones with a northerly dip, and 

 strong bands of quartzite crop out here and there on the east bank 

 for about a mile southerly. From the mouth of the river westerly 

 for the next three miles is a sandspit crowned with dunes and 

 flanking East Bay or Inlet. The original track followed the 

 beach to the wide mouth of the Inlet, the bar of which was 

 at one time easily fordable at low tide. Some changes in the 

 tidal currents have deepened the channel, and a traveller who has 

 survived the crossing of it will in future prefer to strike inland 

 after fording the Black River, and lengthen his journey by a mile 

 or two. On the west bank of the river, a mile from the sea, is a 

 rocky ridge, the lowest exposed member of which is a strong band 

 of quartzite on which lies a band of quartzose conglomerate, and 

 on this again a band of light-coloured altered limestone, which is 

 occasionally used by limeburners. The coast-line here has a 

 northerly trend and the old rocks are almost entirely covered by 

 a wide expanse of drift sand and gravel, except at a point about 

 three miles from the river, where a sheet of basalt is exposed. 

 This probably extends under the drift to Green Hills at the 

 narrowest part of the peninsula, being continuous from there to 

 the north point some four miles distant. There are occasional 

 outcrops of the ancient rocks from under the basalt along the 

 shore line of the Western Plains. The junction of this basalt 

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