434 J. S. Emerson — Some Character istics of Kau. 



Until such proof of marine origin is found, we cannot accept 

 the theory of upheaval as proven or even as a working hyj3oth- 

 esis. To speak of the Kau dust as an "alluvial formation "^ 

 only removes the question of its origin one step further back. 

 Whence came it ? The process of disintegration has scarcely 

 begun in much of the Kau bed rock. The most casual study 

 of its soil shows that it is not decomposed rock. It is totally 

 unlike the soil of Hilo or Kona, and certainly was not washed 

 down from the aa diudi pahoehoe of upper Mauna Loa. 



Evidently it is a formation similar to that which covers a 

 large portion of the slopes of Vesuvius and overwhelmed the 

 ancient city of Pompeii. This volcanic ash is the evidence of 

 a series of explosive eruptions in Kau on the grandest scale, 

 probably far surpassing anything of a similar nature of which 

 we have any evidence in this group. We must then look to 

 the medium of the atmosphere rather than to the action of 

 water to explain the remarkable distribution of this dust which 

 has been sifted down on the ridges, as well as in the hollows,. 

 in a manner far more regular and uniform than could have 

 been accomplished by the action of running water. 



To locate the source or sources of this aerial eruption is a 

 problem not yet fully solved, but some light may be thrown 

 upon it. We need hardly look to Mokuaweoweo, the summit 

 crater of Mauna Loa, as a source. For had such an explosion 

 occurred there, the dust would also have been carried in the 

 direction of Kona. But as a fact, neither in Kona nor on any 

 side of the great dome of Mauna Loa is this dust found in 

 quantity, until we reach the wood belt of Kau. Kilauea, the 

 only remaining active volcano, may be looked to as a possible 

 source with slightly greater probability. But between the 

 district covered by the Kau dust and Kilauea lies the Kau 

 Desert with an area of "many miles" of a totally different 

 formation, while nothing is to be seen of the dust anywhere 

 around the volcano. The writer has examined "fissures in the 

 Kau Desert to a depth of perhaps thirty feet and failed to see 

 any of the dust. If then Kilauea were the real source of the 

 dust eruption, the evidences of it have been covered most com- 

 pletely by these later eruptions. 



The supposition is barely possible, but extremely improbable. 

 Another possible source in this enumeration should not be over- 

 looked. It is the vicinity of Puu o Keokeo, greatest of all the 

 offsprings of Mauna Loa, with an elevation of 6870 feet; it 

 appears to those who sail around South Point as another grand 

 mountain, the rival of its mighty parent. It is located on the 

 great fissure, or rift, in Mauna Loa, extending from Pohaku 

 Hanalei to the vicinity of South Cape. This fissure, probably 

 as old as the mountain itself, lies in the direction of the line 



