[1] The geology was reassessed in 2007 with the separation out from the geologically named Pilbara Craton of a thick succession of interbedded clastic or chemical sedimentary rocks and volcanic rocks forming the Fortescue, Hamersley, and Turee Creek basins that are usually aged from 2.78–2.42 billion years old and the younger volcano-sedimentary Ashburton Basin aged from 2.21–1.79 billion years ago.

[3][4][5] Biogenic sedimentary structures (microbialites) such as stromatolites and MISS were described from tidal, lagoonal and subtidal coastal settings that can be reconstructed from the Dresser stratigraphy as well.

[16][17][18][19] Consequently, many alternative abiotic explanations have been proposed for the filamentous microstructures including carbonaceous rims around quartz spherules and rhombs,[14][15] witherite self-assembled biomorphs[20] and haematite infilled veinlets.

[21] The carbonaceous matter composing the filaments has also been repeatedly examined with Raman spectroscopy[14][22][21] which has yielded mixed interpretations of results and is therefore regarded by many to be unreliable for determining biogenicity when used alone.

Carbonaceous structures appearing to be of biological origin have also been discovered in the 3.47 billion year-old Mount Ada Basalt, a rock layer that is a few million years older than the Apex chert.