392 The American Geologist. December, i904. 
group or archipelago of islands, forming a part of the very long Pa- 
cific volcanic belt. The archipelago contains twenty well-kno-.s i, ai d 
recent volcanic cones, twelve of which are more or less active, rang- 
ing in hight from a few hundred feet up to about 10,300 fet;c. 
Earthquakes are frequent in large parts of the island group, in- 
cluding the n'^ighborhood of Manila, slight shocks occurring at in- 
tervals of every few days or weeks ; while more severe shocks, doing 
injury to property and life, happen in sortie part of the archipelago al- 
most every year. Seismographic records have shown that somj af 
these earthquakes, even though not destructive at their origin or epi- 
center, send their waves or earth tremors entirely around or across 
the globe. 
In Mainila very violent and destructive earthquakes occurred in the 
years i6oOj 1645, 1658, 1665, 1728, 1796, 1824, 1852, i86;5, and 1880. The 
earthquake of June 3, 1863, destroyed the Manila cathedral, burying 
many persons in its ruins, and also threw down 25 public and 570 
private buildings. The average annual number of days having earth- 
quakes at that city is twelve, with a minimum, for the years 1880 to 
1897, of five, and a maximum of twenty-six. w. u. 
Mount Stuart Folio, JVasltington. By George Otis SmitS. Geologic 
Atlas of the United States, Folio No. 106. Pages 10; with four 
maps, and six sections. Washington, D. C, 1904. 
The quadrangle which is here mapped and described extends half 
a degree in latitude and longitude, lying on the eastern slope of the 
Cascade range. On the north, it includes Mount Stuart, rising 9,470 
ieet above the sea, fifteen miles east from the main Cascade range, 
of which an eastern spur, named by Russell the Wenatchee mountains, 
culminates in this rugged peak. Southward the quadrangle reaches to 
Ellensburg, in a broad flat expansion of the Yakima valley. Thus it 
cortiprises a great range of geologic formations, from the oldest to 
the youngest rocks known in the region of the northern Cascades. 
The oldest formations, constituting the Mount Stuart massif and 
the lower peaks near it, are metamorphic sedimentary and eruptive 
rocks, probably of Paleozoic age. 
In the south and east parts of the quadrangle are strata of Ter- 
tiary age, partly sediments, but most conspicuously represented by the 
Miocene basaltic eruptions, in which thousands of cubic miles of lava 
welled up from the earth's interior through numerous vents. 
During late Pliocene and early Pleistocene time a great uplift of 
the belt forming the Cascade mountains took place, and subsequently 
streams and weathering have sculptured the mountains into their 
present outlines. Glaciers in the valleys about Mount Stuart, and. west 
of this quadrangle, on the headwaters of the Yakima river, largely aided 
in supplying extensive alluvial deposits of gravel and sand in the 
Teanaway and Yakima valleys, making the principal lands of agricul- 
tural value. w. V. 
