The Willamette Sound. 59 



one hundred feet in thickness as now seen in 

 some of these bluffs that, for instance, near 

 the North river would require more than 

 that depth of water to place it there; and this 

 sediment is so fine in material as to warrant 

 the conviction that it once existed evenly dis- 

 tributed over the whole region, bay and all. 

 The upper layers, too, have in them the finest 

 materials and the fewest fossils; both facts in- 

 dicating increasing depth of water as the up- 

 per beds were deposited. 



Yet another plain truth is legibly written 

 here the changes indicated in depth of water 

 over the place were quiet changes. Any sud- 

 den catastrophe would have signs of violence 

 and consequent strong current, but nothing 

 of the kind appears here. The fragile cone 

 of the spruce tree period, buried in that sedi- 

 ment, is found to-day among these shells as 

 little marred by time as the shells themselves. 

 The line of deposit along the sheltered bay, 

 just as it was at its deepest stage of water, 

 is now as unbroken as it was then. Neither 

 the violence of earthquake nor the suddenness 



