Stratigraphic column, log and H₂ content in % from the well PTRA-1. H₂ amounts are derived from five samples. Two of these samples are listed in Table 1, obtained during the well test (860 to 912 m depth), with the reference depth (886 m) representing an average of the depth interval. They appear superimposed in the figure due to being from the same depth interval and exhibiting similar H₂ values. The remaining three samples correspond to isojar samples collected from 1419, 1455, and 1491 m depth; therefore, the accuracy of their value is questionable as discussed in item 3 of the Appendix. However, after air correction, these values are included in the graph to indicate that the Espinhaço Sequence also holds H₂ shows. GR corresponds to gamma ray, RLA_3 to resistivity, DT Vp to sonic, RHOZ to density and NPHI to neutron log.