Limestone Resource Assessment of Eastern Rizal Province: Inputs for Regional Development Planning

L. Bron-Sikat, K.R. Sandoval, and C.J.C. Manipon

School of Graduate Studies, Mapua Institute of Technology

Abstract

Rapid urbanization and industrialization in the metropolis is synonymous with the sprouting of various structures such as commercial buildings, factories, residential units, highways, road networks, and bridges. In Metro Manila and nearby provinces, the evidence of urbanization is very clear as various subdivisions and infrastructures are being constructed almost everywhere. Cement, being the most common construction and building material, has been in demand since. Limestone is the main ingredient in the manufacture of cement and has been mined actively in the Philippines since the 1950’s. At present there are 20 cement plants all over the country, 11 of which are in Luzon. The limestone raw materials for the cement supply of Metro Manila come from six (6) quarry sites of local cement plants of Rizal and Bulacan. If the demand continues in the future, it is necessary to be able to locate areas containing sufficient limestone resources that do not entail much transportation costs.

Eastern Rizal, being proximal to Metro Manila and encompassing substantial amount of limestone resources which are mostly untouched, is strategically situated and aptly suited as a source of raw materials for cement. Among the limestone deposits found in the area are the limestone members of Maybangain Formation, Kinabuan Formation, and Binangonan Formation, which occur as separate bodies within the study area. These resources are situated within the protected area stipulated in Proclamation 1636 (Kaliwa Watershed) and the proposed protected area under the DAO No. 33 (Masungit Rock Reservation). Estimates of the remaining limestone resources were computed using Geographic Information System (GIS) techniques. The geologic model of the area was adapted from the geologic map published by the Mines and Geosciences Bureau. The locations of protected areas were also plotted and a one-kilometer buffer zone was created around the proposed Laiban Dam reservoir. Based on the GIS analyses, a maximum of 17B MT of limestone resources are available from the study area. In anticipation of the demand for cement by a growing metropolis due to a likely increase in infrastructure development in the future, it is suggested that the government reconsider the current protected status of the limestone areas and relevant clearances be requested to and approved by appropriate authorities. The limestone resources should be mapped in detail and their chemical quality should be analyzed to establish if it is economically minable.