...V. L. Sharpton; B. C. Schuraytz Abstract Reports of shock-deformed phenocrysts from the Toba ignimbrite deposits, Sumatra, have prompted considerable debate over whether shock-deformation products are clear evidence of a meteorite impact origin for the Cretaceous/Tertiary (K/T) boundary deposits...

...Neville L. Carter; Charles B. Officer; Craig A. Chesner; William I. Rose Abstract Plagioclase and biotite phenocrysts in ignimbrites erupted from the Toba caldera, Sumatra, show microstructures and textures indicative of shock stress levels higher than 10 GPa. Strong dynamic deformation has...

... in Malaysia were dated at 68 ±7 ka by the isothermal plateau fission-track technique. These new determinations, in conjunction with previous ages for the two oldest tuffs at Toba, establish the chronology of four eruptive events from the Toba caldera complex over the past 1.2 m.y. Ash-flow tuffs were erupted...

... rather than biogenic origin for the Opal-CT in the study area, and X-ray fluorescence data reveals higher percentages of silica which is comparable to the Toba Ash of Toba Caldera, Indonesia of about 75,000 B.P. Kaolinite Chrysotile Opal-CT Barind Tract Bangladesh A major portion...

...Fig. 11. Vertical seismic sections for three subduction zones. A : Toba caldera, Sumatra; B : Mount Merapi, Central Java; C : across Central Andes, at 23° S. Projections of earthquakes are shown as asterisks in A and B and as black dots in C . Arrows show possible migration paths...