It was so named by the New Zealand Geological Survey Antarctic Expedition (1958–59) because its shape resembles the pyramidal ceremonial platforms used by the Aztec and Maya civilizations.
[1][2] As shown in McPherson's 1975 Figure 2.1, approximately 85-metre (279 ft) of sedimentary strata of the Beacon Supergroup are exposed on the eastern flank of Aztec Mountain.
[3][4] The Permian Weller Coal Measures consists largely of fine to medium-grained, graded sandstone beds interstratified with laminated siltstone and carbonaceous mudstone.
These cross-beds, which are interpreted to be the foresets of a Gilbert delta, grade downward into and interfinger with very fine-grained beds of lacustrine sandstones, siltstones and mudstones.
At its type locality, the Aztec Siltstone consists of 56-metre (184 ft) of coarse-grained, quartzose, braided river and stream and Gilbert delta deposited sandstone.