Geo(jra'phy of North- Western Tasmania. 1 79 



The upper, or eastern part of this pene-plain, is comparatively 

 narrow. It is bounded on the south by some woody hills, which 

 run northward from the King River, and on the north by 

 Crown Hill and the mountain known as the Professor. These 

 hills must, at one time, have formed the banks of the river which 

 eroded this part of the pene-plain. This river rose on the Cent- 

 ral Plateau, near the Eldon Range, and flowed first through the 

 upper part of the valley of the King River, and then along the 

 Sedgwick Valley and through the gap between Mounts Sedgwick 

 and Lyell, over the site of the Queen River valley. As the river 

 flowed westward its valley became wider. It was joined by tribu- 

 taries from the south, which drained country now included in 

 the lower basin of the King River ; it was also joined by the 

 Henty and other rivers from the north. As most of this area is 

 now drained by the Henty, I suggest for it the name of tne 

 Henty pene-plain. Near the sea this pene-plain joins with those 

 of other rivers, and they together form the continuous pene-plain 

 which backs the western coast of Tasmania. 



The eastern part of the Henty pene-plain, between the lower 

 King River and the Professor, has the features of the lower 

 valley of a large river. This aspect of the country is especially 

 well seen from Mount Lyell. The slopes on either side have the 

 contours characteristic of the sides of an old river valley, and 

 not of cliffs formed by marine denudation. If the pene-plain 

 had been formed by the sea, some remains of old clitis and 

 beaches might be expected to occur round it, and some traces of 

 marine deposits on its floor. I am not aware that any such have 

 been found or recorded, while I am told by Mr. Huntley Clarke, 

 Engineer of Supplies at Mount Lyell, that some of the hills are 

 capped by river gravels. 



Montgomery has described the occurrence of rounded, water- 

 worn gravel upon this pene-plain, and has described the area as a 

 plain of marine erosion.^ He says, " At the Nine Mile Plain 

 on the road from Strahan, a good deal of well-rounded waterworn 

 gravel is seen lying on the bed-rock beneath the surface soil, at 

 an elevation of from 700 to 800 feet above sea level, and pretty 

 well on the top of a watershed." 



1 A. Montgomery : " Notes on the Queen River and Mount Lyell Mining District," Pari. 

 Pap., Tasmania, 9th .July, 1804. 



