VOLCANIC ASH FROM MT. PINATUBO (1991) LUBAO, PAMPANGA, PHILIPPINES

MOUNT PINATUBO ERUPTION FROM CLARK AIRFORCE BASE USGS Photograph

I am revisiting some old samples donated to me by Ward's Scientific when they abandoned their sand collections. The representative gave me the identification samples from their collections! This was many years ago. Since then, I have improved my techniques, and want to refphotograph these samples. If the "0X Sample" is a circle, it is a Ward's sample.

GRAIN DISTRIBUTION CHARACTERISTICS (AGI CHART)

GRAIN SHAPE CHARACTERISTICS

(PREPARED BY GAMMA ZETA CHAPTER , SIGMA GAMMA EPSILON, KENT STATE UNIVERSITY - AGI CHART))

Roundness is the degree of smoothing due to abrasion of sedimentary particles. It is expressed as the ratio of the average radius of curvature of the edges or corners to the radius of curvature of the maximum inscribed sphere.

The sphericity of a particle is: the ratio of the surface area of a sphere (with the same volume as the given particle) to the surface area of the particle.

0X IMAGE

1X IMAGE (BACKGROUND IMAGE)

3X IMAGE