80 Kansas Academy of Science. 



The earth, therefore, in the Tertiary was a fair and lovely 

 world ; it was a garden, a paradise ; but this condition of things 

 could not last forever. As the Tertiary began to wane a change 

 came over the fair face of nature, more terrible than we have 

 language to describe. The sun was nearing Sirius in his 

 western journey, the earth's axis had become inclined to prob- 

 ably thirty degrees, an ice-cap had begun to form, the great 

 difference in temperature between summer and winter and 

 between the equator and the frigid zones, the great change of 

 atmospheric pressure from summer to winter and from the 

 tropics to the poles, and, furthermore, the great difference of 

 the sun's attraction and also of the moon's on the higher lati- 

 tudes between summer and winter, caused a tremendous strain 

 upon the earth's crust, a strain that the earth's crust could 

 not withstand; and as a consequence, it yielded in all its 

 weakest points. This event ushered in the Pliocene Tertiary. 



To use the words of Professor Le Conte (Elements of Geol- 

 ogy, p. 567) : "At the end of the Miocene, i. e., the begin- 

 ning of the Pliocene, there occurred the greatest event of the 

 Tertiary period, one of the greatest in the history of the Ameri- 

 can continent. At that time the sea bottom off the then 

 Pacific coast was crushed together into the most complicated 

 folds and upswollen into the coast chain, and at the same time 

 the fissures were formed in the Cascade range, with the out- 

 pouring of the great lava sheet of the northwest, covering 

 150,000 square miles with a lava sheet from three thousand 

 to four thousand feet in thickness. Coincidently with this 

 there was a settling down of the basin region and the plains. 

 Then after a short lapse of time, speaking geologically, there 

 was a general upheaval of the continent. Coincident with 

 this general uplift, mountain-making by crust-block tilting 

 occurred on a grand scale. The Sierra, the Wasatch, and the 

 Basin ranges assumed their present form and height ; and the 

 great north-and-south fault cliffs of the plateau region were 

 formed. At the same time there were great disturbances in 

 the Old World. The Himalayas were raised above the sea ; the 

 great Deccan lava flow, covering 200,000 square miles with a 

 lava sheet 6000 feet thick, occurred; Europe assumed its 

 present form; Asia added much of her southern lands; and 

 large parts of the African continent were raised above the sea ; 

 the Pacific ocean continent went down, and most likely the 



