THE SPOKANE GLACIATIOX 



583 



rived by glacial plucking of the decayed granite on the northern flanks 

 of Moran Peak and Mica Peak. They are boulders of decomposition and 

 doubtless were easily quarried by the ice. Their abundance in the gravel 

 and the little rubbed condition are clear indications that the front of the 

 ice-sheet did not advance far beyond this place. 



Despite the fresh appearance of the gravel at Pantops, the topography 

 gives no clue to its presence. From Mdiat can be seen now, it is difficult 

 to determine whether the Pantops gravel is a kamey deposit or is a rem- 

 nant of a valley train or outwash plain. It blends into the loAver slopes 

 of Moran Peak and the basalt plateau. 



There are other gravel deposits on the plateau immediately south of 

 Spokane, similar to that at Pantops in altitude, bedding, freshness of 

 material, and absence of fluvio-glacial forms, but none possess the 

 granitic boulders of decomposition. 



Vicinity of Spangle. — The village of Spangle is 12 miles almost di- 

 rectly south of Pantops and 15 miles south of the eastern part of Spo- 

 kane. Maturely dissected driftless country lies to the east and south, a 

 scabland plain to the west (figure 6). Striated erratics have been found 

 ■ here as high as 2,500 feet above tide, on the slopes which face the scab- 

 land, and within 100 feet of the hill tops. 



The drainage of this part of the Palouse country is northwestward, 

 toward the scabland tract. When glacial ice stood at the limit marked 

 approximately by the north-south line between Pantops and Spangle, 

 this drainage was blocked and a lake was formed for which another dis- 

 chargeway was necessary. The waters of Latah (Hangman) Creek and 

 its tributaries, Eock Creek, California Creek, Mica Creek, etcetera, aug- 

 mented by a great volume of Avater from the ice, spilled over the divide 

 west of Latah Creek, about 6 miles southeast of Spangle, and entered 

 North Pine Creek, a minor tributary of Pine Creek, flowing thence 

 southwestward 20 miles across the unglaciated Palouse hill land to enter 

 the scabland region at the north end of Rock Lake. The prominent spill- 

 ways were eroded across the divide into North Pine Creek Valley.-^ The 

 floor of each of the cols is on basalt at about 2,450 feet above tide and is 

 essentially a scabland tract. The glacial waters back of this double spill- 

 way doubtless were ponded in Latah and Rock Creek valleys. 



During the occupation of the spillways these waters eroded deeply iii 

 the basalt. The larger spillway is half a mile wide at the col. Both are 

 well shown on the Oakesdale topographic map and on the Spokane 

 County soil map. Near the junction of North Pine Creek and Pine 



= Thomas Large : The glaciation of the Cordilleran region. Science, vol. 50. no. 1447, 

 3 022, p. 335. 



