HolesThese holes are very shallow. With about 3m of overburden, and 3m of targeted ore, these holes will only take about ten minutes each to drill. Depending on the grid size and ground terrain another two - ten minutes to move and setup for the next hole. 30 to 50 holes easily each day.
Geologists would be hard pressed to keep up logging the core.
So its very possible that a great number of holes could be drilled already.
As far as bulk samples three meters of overburden can be moved with a small track hoe, or even a good sized back hoe. Not sure of what the nature of the phosphate is ( hard or soft rock). But if soft it can be scraped and gouged with the hoe bucket. If hard a jack hammer attachment will work.
So in my opinion this work could proceed really quickly.
But I didnt take into account poisoness blow darts or machete wielding terrorists.