20210921 09375600 1.0 TRUE Block and sub-block The Block Identification System is a geographic grid pattern using the basic unit (a block) defined as five minutes of latitude by five minutes of longitude. The sub-unit (a sub-block) is one minute of latitude by one minute of longitude. The blocks are numbered between 1 and 3456 inclusive. The sub-blocks are labelled between 'A' and 'Z', excluding 'I'. The blocks are grouped by 1:1 000 000 sheet areas (the basic map unit for description) referred to as Block Identification Map (BIM). Each BIM contains 3456 blocks and each block is divided into 25 sub-blocks. © State of Queensland (Department of Resources) 2024 A grid used to describe exploration tenures.