5. Examine the two green sands in the photos below Green sand, Floreana Island G

Question

5. Examine the two green sands in the photos below Green sand, Floreana Island Galapagos Islands (Scale in millimeters.) Green sand, Big Island, Hawaii (Scale in millimeters.) a. What is the green mineral in these two sands? b. What do you think the black grains are? c. Interpret the source area lithology. Name two types of rock that contain this green mineral d. Interpret the tectonic activity in the source area. e. What is the stage of textural maturity? f. Interpret the energy levels in the depositional environment. g. Have these grains been in the depositional environment for a long time or a short time? How did you come to this conclusion?

Explanation / Answer

a ) the green crystal in both the cases is olivin gem variety peridot.

b) the black grain may be the pyroxene on the beach.

c) the source area is mafic composition. two rocks are basalt, gabbro.

d) the source area has a hot spot volcanic activity.

e) by seeing the image , the textural matuarity is good in floreana while poor in big beach.

f) the depositional environment is low energy in floreana and moderately high energy in big beach as it has larger grains.

g) these grains are for a short time because weathering will take place and these may weather easily as their formation pt condetions are more differ than the surface condetions.

Related Questions

Navigate

• Browse (All)
• Browse 5
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.