Table 1 Chemical bulk rock and varnish analyses of samples used in this study compared to rock analyses by Geosciences Australia and published by Donaldson [1] and the mineral paragenesis of the varnish and bulk rock, determined by Raman spectroscopy, XRD, and from thin sections, respectively. PRXF was used for bulk rock and varnish analysis

SiO₂

50.25

34.50

70.23

32.71

Al₂O₃

17.03

20.95

12.35

11.23

Fe₂O₃

8.86

16.64

4.69

11.36

MgO

7.55

n.a

1.82

n.a

CaO

10.95

2.66

0.69

0.93

Na₂O

n.a

n.a

n.a

n.a

K₂O

0.45

0.79

2.57

1.16

TiO₂

0.48

0.74

0.54

0.71

MnO

0.15

6.42

0.07

2.60

Varnish

Hematite, magnetite, albite, clinochlore, clinozoisite, quartz, anatase, and organic matter

Hematite, magnetite, albite, microcline, kaolinite, quartz, anatase, and calcite

Bulk rock

Plagioclase, quartz, mica, pyroxene, hornblende, and ore minerals

Alkali feldspar, pyroxene (incl. needle-like pyroxene), fine matrix of quartz, feldspar, and ore minerals