Fig. 5

Microfabric features of the modern microbial carbonates in the hypersaline lakes of atoll of Kiritimati, Pacific Ocean: presence of mold holes and crusts. Diameters are marked by red dots. a Modified from Fig. 6-E of Arp et al. (2012), of a hand specimen collected from the hypersaline lake of atoll of Kiritimati, showing an orange microbial mat in the upper part, dead microbes in the middle part, and white reticulate microbial carbonate in the lower part; b Modified from Fig. 13-B of Arp et al. (2012), of a sample collected from the same location as a, showing white netlike microbial carbonate; c Modified from Fig. 13-F of Arp et al. (2012), photomicrograph of thin section, of a specimen collected from the same place as a; d Enlargement of the red box in c, showing that the microbial carbonate consists of mold holes (H) with the carbonate (C) in between, and the mold holes are round or wormlike, 10–19 μm in diameter