Taking a section across the Murray River Valley, in South Australia, for a distance of about forty miles from west to east, we have (as shown in the accompanying diagram) two parallel ranges, and on the outer flank of the western range there are at some places micaceous strata (A), having a steep inclination, resting against the contorted strata of the range, sections of which are seen in gaps and gullies, with steep sides, in some instances 800 to 1000 feet deep. These hills are partly granitic; the granite is reddish, very readily decomposed, and worn by the rain and weather here and there into strange grotesque figures. There are well-defined metallic lodes in this range. East of these hills are three terraces leading down to the river. The first is the broadest, extending about two-thirds the distance, and falls twenty feet to the river. It is composed chiefly of sand; but rocks similar to those of the western rock crop out here and there. The second terrace averages about two-ninths of the distance between the range and the river: it falls about thirty feet; sometimes not more than ten or fifteen feet; at places, however, more than fifty feet. The third or lowest terrace is only one-ninth of the distance, and nearly level with the river: in fact, it is overflowed when the water is up. The river itself flows slowly, having a fall of about one foot a mile.
