23,5 Dickerson: Baguio Plateau 425 



above, these beds might be younger still. After much searching 

 a species of Pecten was found in the sandy matrix of the con- 

 glomerate, so the conglomerate is thus proven to be marine. 

 Both Doctor Smith and the writer regard these strata at Klon- 

 dike's Springs as being of Malumbang-Pliocene age and as hav- 

 ing been formed contemporaneously with Malumbang-Pliocene 

 limestone; that is, as a pebble beach equivalent of a coral reef 

 of Malumbang time rather than later deposits. 



The strata at Klondike's Springs dip 25° west and strike north 

 38° west and are in the middle of a well-exposed section, 

 excellently dissected by Bued River. At least 300 meters of 

 conformable strata are above this locality, and apparently a 

 minimum of 450 meters below it. 



The Malumbang limestone has a much greater distribution 

 than was previously recognized. The belt extending from a 

 locality about 3 kilometers south of Mount Mirador to a point 

 about 3.2 kilometers north of Trinidad Valley is the striking 

 and well-known exposure. In a reconnaissance trip to the top 

 of Mount Santo Tomas, Mr. Graham B. Moody, Mr. Palmer 

 Beckwith, Dr. W. D. Smith, and the writer discovered several 

 small blocks of Malumbang limestone. The tuffs of the Baguio 

 formation were noticed aj; kilometer 5, but a short distance 

 beyond and at kilometer 6, elevation 1,820 meters, aneroid, 

 limestone was found. At locality 42x a fine specimen of Lep- 

 toria sp. was collected. A small collection of corals was made 

 at 7.75 kilometers from Baguio, elevation 1,536 meters (5,120 

 feet). At locality 43x a branching coral, of a species that is 

 common in the Malumbang formation, was collected. Between 

 localities 42x and 44x the hill tops are composed of coralline 

 limestone, but at 1,560 meters (5,200 feet), a short distance 

 beyond locality 44x, an abrupt change in topography occurs; 

 andesitic conglomerate is found, and the trail zigzags up a very 

 steep face. This is caused by a comparatively recent fault at 

 that point. Farther on, andesite is found at kilometer 11, 

 elevation 1,950 meters (6,500 feet, aneroid) ; and a short dis- 

 tance beyond, about halfway between posts 11 and 12, coralline 

 limestone again occurs, on top of the hill, locality 45x. From 

 this point the trail descends slightly, and between posts 12 and 

 13 andesite again outcrops in a steep hillside. The contact be- 

 tween the last-named localities is marked by a fault (Plate 6, 

 figs. 1 and 3). Resting upon the andesite is a considerable 

 thickness of andesitic conglomerate. The slope then changes, 

 and for a short distance the ascent is gradual. Suddenly, the 



