Resistivity soundings on sand and gravel deposits in Malaya, Pililla, Rizal were taken during the period from September 7 to October 15, 1967, as a project of the Bureau of Mines. The survey was carried out to determine the approximate thickness of the deposit and to test the applicability of the electro-ground resistivity instrument (MICHIM0 Model 274) to such problems.

The area (Plate I) is approximately 70 kilometers south-southeast of Manila and is accessible either by road from the City or by motor boat from any town along the coast of Laguna de Bay.