Table 1.

Overview of Samples and Analyses Performed

Location	Cave name	Sample nature	Sample color	Analyses performed	Relevant figures
Microbial mats
Hawai‘i	Bird Park	Microbial mat	White and yellow	Molecular and SEM
Hawai‘i	Epperson's	Microbial mat	White and yellow	Molecular and SEM
Hawai‘i	Kaumana	Microbial mat	White and yellow	Molecular
Hawai‘i	Kula Kai	Microbial mat	White and yellow	Molecular and SEM
Azores	Branca Opala	Microbial mat	White and yellow	Molecular	Fig. 2
Azores	Balcões	Microbial mat	White and yellow	Molecular	Fig. 2
Azores	Achada	Microbial mat	White and yellow	Molecular	Fig. 2
Azores	Principiantes	Microbial mat	White and yellow	Molecular	Fig. 2
New Mexico	ELMA2	Microbial mat	White and yellow	Molecular and SEM
New Mexico	ELMA3	Microbial mat	White and yellow	Molecular and SEM
New Mexico	ELMA4	Microbial mat	White and yellow	Molecular
New Mexico	Four Windows	Microbial mat	White and yellow	Molecular and SEM
Secondary mineral deposits
Hawai‘i	Maelstrom	Copper silicate	Blue-green	Molecular and SEM	Figs. 3, 9, 11
Hawai‘i	Thurston	Gold-colored veins	Gold	Molecular and SEM	Figs. 8, 9, 12
Hawai‘i	Epperson's	Pointillistic colonies	White	SEM	Fig. 4
Azores	Algar do Carvão	Hexagons	Pink	Molecular and SEM	Figs. 7, 9, 13
Azores	Buracos	Fe oxide	Red	Molecular	Figs. 5, 9
Azores	Principiantes	Organic ooze	Butterscotch	Molecular	Figs. 6, 9
New Mexico	Four Windows	Gold-colored veins	Gold	Molecular and SEM	Figs. 8, 9, 12