Studies on bedded cherts

  title={Studies on bedded cherts},
  author={Diana Thurston},
  journal={Contributions to Mineralogy and Petrology},
  • Diana Thurston
  • Published 1 December 1972
  • Environmental Science
  • Contributions to Mineralogy and Petrology
Radiolarian cherts from two localities in North-western Italy have been studied by optical and scanning electron microscopy, X-ray diffraction and X-ray fluorescence analysis. The quality of preservation of the radiolarians decreased from dark red to pale cherts. The effect of diagenetic processes (solution, reprecipitation and recrystallization) was least in red cherts where contained hematitic and clay material inhibited the movement of pore solutions, and greatest in the pale cherts… 
The origin and diagenesis of cherts from Cyprus
The Troodos Massif of Cyprus is overlain by a variety of cherts in pelagic chalks, volcanogenic sediments, radiolarites and radiolarian mudstones, all of Campanian to Upper Eocene age. There
Thermal Alteration of Chert in the Ophiolite Basement of Southern Central America
Radiolarian chert and volcaniclastic-rich siliceous rocks of the Nicoya Complex were studied by optical mineralogy, X-ray diffractometry, and SEM. Various phenomena of thermal alteration occur due to
Triassic bedded cherts in central Japan are not pelagic
Although the origin of bedded radiolarian cherts in orogenic belts has been widely debated1–15, their geochemistry is still poorly understood. Triassic bedded radiolarian cherts occur extensively in
On the origin of cherts
SummaryA new classification scheme for non-detrital siliceous rocks is proposed, facts and problems coneerning the origin of cherts are discussed, and a new genetic model is presented. The


Inorganic bedded cherts from the Magadi area, Kenya
The High Magadi beds can be divided into a lower and an upper sequence, separated by a bed rich in Tilapia nilotica remains. The lower sequence contains one or more magadiite horizons. Through
Carboniferous Cherts, Turbidites, and Volcanic Rocks in Northern Independence Range, Nevada
Rocks of eugeosynclinal origin in the northern Independence Range, Elko County, Nevada (Wildhorse and Bull Run quadrangles) compose the Schoonover Formation which includes eight named and two unnamed
Radiolarian Skeletons: Solution at Depths
Radiolarian skeletons were placed at several depths on the taut mooring wire of a buoy in the central Pacific for 4 months; Tripyleans seemed to be less resistant than polycystins and Acantharia dissolved completely at all depths.
Environments of generation of some base-metal ore deposits
The origin of the ore fluids, their dissolved constituents, the force that drives them, and the causes for deposition of their constituents are reviewed for five districts: Providencia, Mexico;
Chert and its sodium-silicate precursors in sodium-carbonate lakes of East Africa
Chert has formed from two sodium-silicate minerals, magadiite (NaSi7,O13(OH)3·3H2O) and kenyaite (NaSi11O20.5(OH)4·3H2O), in uppermost Pleistocene deposits of lakes Magadi and Natron in Kenya and
Summary Experimental investigation shows that amorphous silica is converted into quartz through cristobalite under hydrothermal conditions. The rate of transformation, essentially dependent on the
Franciscan-Knoxville Problem
Franciscan and Knoxville rocks are widely distributed and attain a great thickness in the Coast Ranges of California and southwestern Oregon. In California they crop out in a known area of at least
Silica Solubility, 0°-200° C., and the Diagenesis of Siliceous Sediments
The data on solubility of amorphous silica and quartz at low temperatures are reviewed. Determinations of the metastable equilibrium solubility of amorphous silica at 25° C. in distilled water and