Table 2 Percentages of identified sterols in the meltwater ponds, lagoon, and in the relict microbial mat

1

0.957

22-trans-24-norcholesta-5,22E-dien-3β-ol

Diatoms^31,34,38; Dinoflagellates³⁸

3.2

2

0.970

5α-cholest-22E-en-3β-ol

Dinoflagellates³⁵

1.3

3

0.979

5β-cholestan-3β-ol

Diagenesis of cholest-5-en-3β-ol

6.2

2.2

7.5

4

0.982

Unknown Steroid

n.a.

1.5

5

0.988

27-nor-(24S)-cholesta-5,22E-dien-3β-ol

Diatoms^31,32,33; Microalgae^32,37

0.2

0.3

0.3

3.3

1.8

6

0.990

Unknown Steroid

n.a.

2.4

7

0.993

cholesta-5,22E-dien-3β-ol

Diatoms^23,31,32; Red algae^23,40; Sponges³⁶

2.6

2.7

2.1

1.5

1.9

2.0

2.1

5.1

2.3

13.0

4.7

1.7

8

0.996

Unknown Steroid

n.a.

0.6

0.4

0.997

Unknown Steroid

n.a.

0.6

10

1.000

cholest-5-en-3β -ol(²H₇)

n.a.

n.i.

n.i.

n.i.

n.i.

n.i.

n.i.

n.i.

n.i.

n.i.

n.i.

n.i.

n.i.

n.i.

n.i.

n.i.

n.i.

11

1.001

cholest-5-en-3β-ol

Animals²³; Fungi²³; Microalgae^23,32; Diatoms^30,31,32; Red algae³²; Green algae³²; Dinoflagellates^32,34

15.0

18.2

25.7

21.8

11.5

33.7

17.2

18.7

19.5

38.6

24.8

19.6

16.7

21.8

26.5

17.3

12

1.006

5α-cholestan-3β-ol

Diagenesis of cholest-5-en-3β-ol

5.0

2.5

3.3

3.6

1.2

3.3

0.9

2.3

3.1

3.4

2.2

2.1

10.7

7.1

13

1.008

Unknown Steroid

n.a.

0.7

14

1.012

24-methylcholesta-5,22E-dien-3β-ol

Diatoms^30,31,34,39; Cercozoa³²; Dinoflagellates³⁵; Microalgae²³

10.8

14.6

4.4

8.7

5.4

15.5

6.6

7.1

8.8

12.7

12.0

9.2

20.5

34.0

18.8

17.8

15

1.018

5α-cholest-7-en-3β-ol

Diatoms^33,34

5.5

11.8

4.5

7.2

0.9

1.3

trace

5.9

2.9

2.8

trace

16

1.026

24-methylcholesta-5,24(28)-dien-3β-ol

Diatoms^31,34; Sponges³⁶

8.4

5.0

6.6

14.4

8.9

6.1

6.1

7.8

11.4

9.1

14.9

5.6

17

1.026

(24R)-ethyl-5β-cholestan-3β-ol

Diagenesis of (24S)-ethylcholesta-5,22E-dien-3β-ol

5.4

co.e.

co.e.

co.e

co.e.

co.e.

18

1.028

(24R)-methylcholest-5-en-3β-ol

Diatoms^31,32; Green algae^32,40

7.2

9.6

6.2

8.5

18.4

16.9

7.0

8.4

15.6

11.8

7.0

7.9

7.1

2.8

10.2

7.4

19

1.030

(24R)-methyl-5α-cholestan-3β-ol

Diagenesis of (24R)-methylcholest-5-en-3b-ol

2.2

1.2

1.7

1.4

1.3

0.8

1.5

1.1

20

1.035

(24S)-ethylcholesta-5,22E-dien-3β-ol

Diatoms^31,34,41; Cercozoa³²; Microalgae^23,32

7.0

4.1

6.4

8.7

13.2

10.1

5.3

7.5

7.7

11.8

6.6

6.5

8.8

4.0

10.6

13.8

21

1.037

23,24-dimethyl-5α-cholest-22E-en-3β-ol

Diatoms^23,34; Dinoflagellates^35,36

2.1

3.0

1.3

1.1

2.0

21

1.037

Unknown Compound

n.a.

co.e.

co.e.

co.e.

co.e.

co.e.

22

1.043

24-methyl-5α-cholest-7-en-3β-ol

Green Algae³²; Diatoms^34,39; Fungi²³

1.5

3.2

2.3

2.9

3.8

4.4

10.9

2.2

trace

2.8

2.6

23

1.045

Unknown Steroid

n.a.

0.6

0.2

0.9

trace

trace

1.0

0.8

0.9

1.2

24

1.048

(24R)-ethylcholest-5-en-3β-ol

Diatoms^31,34,39; Green algae^32,41

15.7

14.1

24.6

16.2

23.3

23.8

35.4

27.6

16.0

25.1

25.6

18.3

10.4

11.7

23.2

22.0

25

1.051

(24R)-ethyl-5α-cholestan-3β-ol

Diagenesis of (24R)-ethylcholest-5-en-3β-ol and (24S)-ethylcholesta-5,22E-dien-3β-ol

4.0

3.4

3.4

4.1

3.6

2.6

1.6

3.0

2.1

8.0

0.1

0.9

25

1.051

24-ethylcholesta-5,24(28)Z-dien-3β-ol

Algae^32,36,40; Sponges³⁶; Green algae^23,32,41; Diatoms³³

co.e.

co.e.

co.e.

26

1.057

4α,23,24-trimethylcholest-22E-en-3β-ol

Dinoflagellates^23,36,38; Diatoms^30,31,39

0.9

26

1.057

See table description

n.a.

co.e.

27

1.060

Unknown Steroid

n.a.

3.7

28

1.064

(24S)-ethyl-5α-cholesta-7,22E-dien-3β-ol

Green algae⁴⁰; Microalgae³²

1.1

3.5

3.3

2.3

2.4

3.2

5.5

1.9

1.1

1.5

0.6

29

1.069

Unknown Steroid

n.a.

2.3

30

1.072

Unknown Steroid

n.a.

3.7

3.7

4.0

trace

4.3

1.4

1.7