The drilling bit designed to remove large debris for use in geological analysis, by raising it to the surface without furtehr grinding by means of the drilling fluid, comprises a tool body, connected to the rotary drive elements, with a central flared cavity at the bottom with a shape having a surface of revolution of decreasing diameter the further it is from the base of the drilling bit. The drilling bit has diamonds embedded in a solid matrix (a) positions prepd. on the surface of the central cavity for attacking the rock, and providing for removal of the debris by shearing (b) a system of irrigating the cutting front with drilling fluid which ensures that the debris is carried away from the central cavity to the annular space between the drill and the walls of the borehole; the irrigation system itself comprises at least one feed channel for drilling fluid opening into a flow channel for distributing fluid from the periphery of the drill to the points of attack, by means of one or more orifices near the periphery of the drill bit, at least one debris-collecting channel and at least one channel for the removal of debris formed in the central cavity of the drilling bit and directly connecting the collecting channels to at least one orifice in the drilling bit opening into the annular space between the drill bit body and the borehole lining.
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