K. A. Rodgers

TL;DR: In this article, the authors describe the evolution of silica sinters over the last 10,000 to 50,000 years, from non-crystalline opal-A particles to poorly crystalline Opal-CT and/or opalC.

TL;DR: The Umukuri silica sinter is a large, late Pleistocene hot-spring deposit exposed along the eastern upthrown block of the Ulukara Fault, one kilometer southwest of the active Orakei Korako geothermal area, Taupo Volcanic Zone as discussed by the authors.

TL;DR: In this paper, the authors used X-ray powder diffraction operating parameters indicate silica lattice order/disorder using untreated, dry, <106 μm powders scanned at 0.6° 2θ/min with a step size of 0.0±0.1 mg sinter samples at a heating rate of 20°C/min in dry air.

TL;DR: In this paper, a position-sensitive detector system was used to identify the moganite pattern in the presence of a large proportion of quartz, and semiquantitative estimates of the different silica phases present in bulk sinter samples of ~450 mg.

TL;DR: A silica-carbonate deposit is forming from the dilute alkali chloride waters of Pavlova spring, a small thermal pool and outflow channel (85 to ǫ 10 times lower accumulation rates than typical siliceous sinters in the TVZ), and deposition of both silica and calcite is controlled by microchemical conditions and local temperature gradients, rather than by bulk spring water chemistry as mentioned in this paper.