times indicated by earthquakes, and the amount by geologi- cally “recent” shore forms of unmistakable identity only mod- erately eroded since their uplift.
As we sailed southward from Coloso, with the land in view, there could be seen everywhere along the coast signs of recent uplift. By this I do not mean necessarily uplift in the human period but in recent geological times, and the shells and marine débris that one finds on some of the raised beaches are exactly like those that one may pick up on the active beaches today. At the mouth of the Copiapó valley is a terrace that stands about 150 feet above sea level and stretches up and down the coast, appearing to correspond to the 150-foot terrace at Anto- fagasta and Coloso. Going up the Copiapó valley one can trace the terrace far inland. Six kilometers from Caldera at the station called Carpa No. 1, at an elevation of over 400 feet, is a terrace whose surface is literally a solid mass of marine shells deposited in hollows of a rock-cut surface—evidence that the sea floor and the land are here parting company along the edge of the continent and that the uplift of the land may be called a continuing process. The actual movement of the crust at the moment may not be upward; the coast may be station- ary or it may even be sinking, but the trend of the coastal movement is distinctly upward and has been upward in the later stages of geological history.
At the port of Paita in northwestern Peru one may obtain a very clear notion of the recency of the crustal movements that have affected the land thereabout. On the left of Figure 43 a cut terrace only a few feet above sea level may be ob- served. It runs up each of the reëntrants and rounds all the spurs with even contour. Its materials are of exactly the same sort as those in the existing beach below it, and the shells oc- curring in it are likewise identically like those on the present shore. It appears to have been formed but yesterday, so fresh are its details of structure and relief. Just outside the port, at the Punta de Foca, are wider terraces cut into the rock as well as the soft sands and gravels that overlie the rock. It is now being scored by the intermittent streams dependent on the so- called ‘‘seven-year rains’’ and is being cut off on the seaward
