"Geyser Eggs" from Te Whakarewarewatangaoteopetauaawahiao, North Island, New Zealand

Abstract

Waikorohihi and Mahanga, two geysers located on Geyser Flat at Te Whakarewarewatangaoteopetauaawahiao, New Zealand, discharge chloride waters with a pH of 8.5-9.25 at 100؇C. Many large (up to 10 ؋ 8 ؋ 5 cm) coated grains composed of amorphous silica (opal-A), that are informally termed ''geyser eggs'', surround the vent of Waikorohihi, whereas smaller (Ͻ 3 cm) geyser eggs are present in the proximal outflow channel of Mahanga. The geyser eggs have nuclei of detrital sinter or rhyolitic tuff. Their cortices are formed of thin concentric laminae and (or) spicular geyserite. Most cortical laminae contain a low-diversity biota that includes filamentous microbes (three types) and scattered spherical microbes. Silicified grains of Pinus radiata pollen are common in some laminae. Multiple phases of silica encrustation around the filamentous microbes disguised most features that are needed to confidently identify them. Most filaments are probably cyanobacteria. Variations in the microporosity and (or) microbe concentrations define individual cortical laminae.Growth of the geyser eggs in the pool around Waikorohihi vent was controlled by the eruptive behavior of the geyser. The eggs are submerged by boiling water during eruptions. During dormant phases, the geyser eggs are subaerially exposed. While exposed, their surfaces may remain moist from steam or rainwater, or they may desiccate. The low microbial diversity in the geyser eggs is probably related to their periodic inundation by boiling water and the highly variable conditions. The abundant microbial laminae in the geyser eggs confirm that microbial templates are found in siliceous coated grains from almost all environmental settings in siliceous thermal-spring systems.

Cool water geyser travertine: Crystal Geyser, Utah, USA

“…The internal structure of pisoids ranges widely, although they generally display a nucleus and a concentric cortex composed of radiating crystals, similar to those previously described by many authors (Baker & Frostick, ; Jones & Wilkinson, ; Braithwaite, ; Risacher & Eugster, ; Schreiber et al ., ; Abreau, ; Jones & Renaut, ; Jones et al ., ; Bonny & Jones, ; Jones, ). The Crystal Geyser pisoids exhibit some unusual aspects, for example, one pisoid displayed an entire cortical layer composed of diatom moulds, an oncoid according to the classification of Logan et al .…”

Biomolecules from Fossilized Hot Spring Sinters: Implications for the Search for Life on Mars

“…Second, a Subrecent sample from Te Puia is an opal-A sinter with distinct microbial palisade texture (e.g., Campbell et al, 2015a) and is from a part of the terrace with a pH 8.5-9.15 ( Jones et al, 2001b). Palisade textures occur when fine filaments are densely packed in vertical pillar structures .…”

Sedimentology and geochemistry of Archean silica granules

“…Some modern and ancient sinter deposits contain siliceous oncoids 1-10 cm in diameter (Guidry and Chafetz, 2003;Jones and Renaut, 1997;Jones et al, 1999Jones et al, , 2001Lynne et al, 2008;Renaut et al, 1996) or pisoids (Lowe and Braunstein, 2003;Walter, 1976;Walter et al, 1996). These large siliceous grains are not appropriate analogues for silica granules: Apart from their size discrepancy, these grains are irregular in shape and often contain relatively insoluble impurities (e.g., organic matter, iron oxides, clays) that distinguish the wrinkly or irregular concentric internal laminations visually and geochemically.…”