Patagonia Lithium (ASX:PL3) said that the well 4 in the north east section of the Formentera concession in Argentina, drilled to a depth of 401.5 meters, was surveyed with an nuclear borehead magnetic resonance tool and recorded an average specific yield porosity of 9%, and a maximum of 40%, according to a Monday Australian bourse filing.

The survey confirmed the high porosity from 87 meters to 401 meters, and the well, which was drilled to test the limit of the lithium mineralization to the east, was still open at depth.

It said that four brine zones were identified and delineated by brine conductivity.

Its shares fell 5%, to an all-time low.