Here's why:

* Geological Formation: The province primarily lies within the Central Luzon Basin, which is characterized by sedimentary rocks, mainly composed of sandstone, shale, and limestone. These rock formations are not typically associated with the formation of metallic ores.

* Mining History: There is no historical or current mining activity for metals in Nueva Ecija.

* Government Data: The Mines and Geosciences Bureau (MGB) of the Philippines, the government agency responsible for managing mineral resources, does not list any significant metallic deposits in Nueva Ecija in their database.

However, it's important to note:

* Potential for Exploration: While metallic deposits are not currently known, there's always the possibility of undiscovered mineral resources. Further geological exploration could reveal potential deposits in the future.

* Other Minerals: Nueva Ecija does have deposits of other minerals, such as limestone, used for cement production, and sand and gravel for construction.

Therefore, while it's safe to say that Nueva Ecija is not known for its metallic deposits, there's always a chance of discovering them in the future.