ANSWER: Correct Chapter 1 Question 7 Â­ True/False Part A A scientific theory is a tentative or untested explanation that is proposed to explain scientific observations. This preview has intentionally blurred sections.
Gravel /ËÉ¡rÃ¦vÉl/ is a loose aggregation of rock fragments. Gravel is classified by particle size range and includes size classes from granule- to boulder-sized fragments. In the Udden-Wentworth scale gravel is categorized into granular gravel (2 to 4 mm or 0.079 to 0.157 in) and pebble gravel (4 to 64 mm or 0.2 to 2.5 in).
Limestone does not form gravel beds very frequently either; unless they are close to the source rock. Older gravel beds are more likely to be composed of harder igneous and metamorphic rocks such as dolerite, basalt, porphyry, hornfels. Granite often weathers down to a fine gravel, high in feldspar and quartz.