Passage II
A lahar is a flow of water-saturated volcanic ash and rock. A lahar deposit, formed once the flow stops, consists of clasts (rocks having diameters ≥ 16 mm) embedded in a matrix (a mixture of particles having diameters ≤ 8 mm).
A sample of a lahar deposit was collected at each of 7 distances from a volcano's crater. For each sample, Figure 1 shows the percent by mass of the clasts by composition, and Figure 2 shows the percent by mass of the matrix by particle size class. For the 7 samples combined, Figure 3 shows the cumulative percent by mass of clasts and matrix particles, or of clasts alone, as diameter decreases.
8. According to Figure 3, clasts and matrix particles having diameters greater than or equal to 0.5 mm made up approximately what percent of the total mass of the combined samples?
Your Answer is
Correct Answer is H
Explanation
Read the picture title, see figure 3, the abscissa corresponds to 0.5 mm, and the ordinate is about 63%