THE MOUNTAINEER G3 



disappearance of the glaciers has left to view a vast rock-scoured country. 

 In going up the divide between the Elwha and the Quiniault, the section 

 may be studied in detail. The strata are not only tilted, but they are 

 squeezed and contorted and made to fold upon themselves. In areas only a 

 few feet in diameter, the individual strat.a may be seen folded back and 

 forth and even faulted to a minor degree. Quartz veins are numerous and 

 represent fissures and cracks which have since been filled with silica. In 

 general the veins are nearly parallel to the strike of the strata and lie 

 nearly parallel to the bedding planes. They are not persistent; that is. 

 they do not continue with the same thickness for any great distance, but 

 taper out and either entirely disappear or become merely thin stringers 

 which may or may not coalesce to form again a well-defined vein. One of 

 the most remarkable features in this region of high mountain ridges is the 

 increased proportion of quartzite laj'ers. They generally have a light color 

 and are extremely hard and upon weathering break up into huge blocks. 

 They are much more resistent to weathering than the softer schists and 

 shales, and. as a result, make up the major portion of the ridges and high, 

 rugged peaks. The highest peak of ]\Iount Olympus is for the most part 

 composed of this quartzite. From ]\Iount Olympus to the north, east, south 

 and west the country rock appears to be composed of this same metamorphic 

 material ; namely, quartzite, schists, slates, etc. How far to the south it 

 extends is not certain. No attempt has been made to study this region and 

 no accurate data are available. The Tertiary rocks are known to occur on 

 the Humptulips, "Wynooehe and the Satsop rivers and it is probable that the 

 contact wliere tlie Tertiary beds overlie the metamorphic rocks is somewhere 

 near, but to the south of the JefPerson and Chehalis county line. To the east 

 the metamorphic rocks appear to extend at least as far as ]\Iount Constance 

 and the Sawtooth range, and to the west probably far down into the low- 

 lying country near the Pacific ocean. In one place it is known that they 

 extend even to the ocean itself. The general dip of the strata, or the angle 

 which their plane makes with that of the horizon, is about 45 degrees. 

 Where the strata are first exposed near ^McDonald the dip is lowest, but it 

 gradually increases until in the high Olympics the beds stand nearly vertical 

 or are even reversed. The dip is not con.stant, however, and at one or two 

 localities near the headwaters of the Quiniault repeated folding or possible 

 faulting is suggested. Viewed from IMount Olympus the dip appears to be 

 reversed on the north side of the Hoh river valley, which, if true, means a 

 broad fold or syncline between ]\rount Olympus and the Hoh valley. To 

 the north the metamorj^hic formations may ho seen nearly to Lake Crescent 

 and to the north side of the canyon of the Soleduck. Beyond this they are 

 covered with strata of Tertiary age. 



The rocks belonging to the Tertiary are divided into three periods. 

 knoAvn as the Eocene. ^Miocene and Pliocene. The oldest is the Eocene. 

 They ai'o all represented by sandstones, shales and conglomerates. In 

 these rocks may be found the remains of foi-mer marine life, consisting of 

 clam shells, siuiil shells, sea urchins, etc. Such remains are petrified and are 

 known as fossils. It is bv means of the difi'erent species of fossils that we 

 know tlie rock to ])e of Tertiary age, and l)y comparing the characteristic 

 species with tbo^e of other areas, wliere the ages of the rocks are well known, 

 Ave are enabled to divide the Tertiary into the Eocene, IMiocene and Pliocene. 

 The main nmss of the Olympic mountains is made up of metamorjjhic rocks, 

 which might be styled the Olympic ftu'iiiation. No rocks of known Tertiarv 



