EXTINCT VOLCANOES, 51 
give a milky appearance to the sea for some distance around. <A 
number of the masonry houses of Agaiia were destroyed, and those 
left standing were so badly injured as to be unfit for habitation. The 
old bell tower of masonry near the church, built in 1669, was seamed 
with large cracks. In the other towns of the island nearly all masonry 
houses, churches, and rectories were ruined. The collier -/ustin was 
sent the day after the disaster with an officer to the German island of 
Saipan, 120 miles to the northward, to ascertain the damage done and 
offer aid. They found no casualties, though the earthquake had also 
violently shaken the island. Fortunately the disaster occurred in the 
daytime, as did the hurricane of 1890, and the casualties included but 
one child killed and a few of the townspeople of Agafa hurt. The 
total cost of repairs to government buildings was estimated at $22,100 
gold. 
A summary of the earthquake phenomena of 1902 is included in 
Doctor Abbe’s report, published in Terrestrial Magnetism and Atmos- 
pheric Electricity, 1904, page 81. 
EXTINCT VOLCANOES.—AI] of the mountain peaks of Guam are 
undoubtedly of voleanic origin. In some of them the outlines of the 
craters may still be traced and the lava presents the same appearance 
as in recent volcanoes.” Surrounding the bases of the mountains are 
ancient coral reefs, the margins of which, in contact with the volcanic 
products, have in many places been converted into crystalline lime- 
stone, showing evidence of volcanic activity after the whole island 
had been raised from the sea. The heights of the principal mountains 
are approximately as follows: Santa Rosa 265 meters, Tiyan (Barri- 
gada) 205 meters, Makahnag 215 meters, Chachao 320 meters, Tengho 
310 meters, [licho (Humuyong-manglo) 390 meters, Sasalaguan (Hell 
mountain), at the southern end of the island, 340 meters. 
ANCIENT CORAL REEFS.—The entire northern portion of the island is 
a raised coral platform penetrated in several places by the low volcanic 
peaks already referred to. On the west side of the island between the 
mesa and the sea several distinct flat terraces occur, showing succes- 
sive upheavals. During the recent earthquakes the general level of 
the whole island was raised. It would require only a very slight ele- 
vation to convert into dry land the very extensive reef flats along the 
west coast which are covered at high tide by only a few feet of water. 
The bottom between the shore and the barrier reef is perfectly level 
and covered with very fine sand resembling flour in consistency. 
MINERALS. — With the exception of thin layers of iron-ore, no metal- 
yielding deposits occur on the island. An inferior lignite is found in 
one or two places. There is also a volcanic rock called homén, which 
is used for fire places, and a soft pale-green mineral called lauka which 
@ This is especially true of Santa Rosa, in the northern part of the island. 
