8th Grade Multiple Choice Study Guide for MONDAY'S BENCHMARK

• Brachiopods and coral fossils are ocean creatures.
• Fossils show evidence about the history of rocks and climate of an area.
• The principle of uniformitarianism is the principle that the answers to the past can be found in the present, meaning that everything is uniform in how it works. Such as a volcano erupting today would be the same as it would have been a billion years ago. Or rain would fall the same was today as it would in the time of the dinosaurs.
• Fossils most often form in sedimentary rock.
• The Earth is 4.5 billion years old.
• Uplifting forces can raise or elevate layers of the Earth.
• Earth’s features are constantly being built up AND worn down.
• The Grand Canyon is a result of erosion due mainly to water.
• Steep cliffs that remain were probably more resistant to erosion than surrounding rocks.
• Sandstone layers were likely formed from wind blown sand.
• The principle of superposition states that in a sequence of undisturbed sedimentary layers or lava flows, the oldest layers are at the bottom.
• Geologists study rocks.
• Rock layers were formed from layers of sediments that are deposited and transformed into rock over millions of years.
• Weathering breaks down rocks.
• Erosion transports rock pieces.
• Gravity produces avalanches and landslides.
• Physical weathering – caused by natural forces such as water freezing and thawing inside rocks
• Mechanical weathering – same as physical weathering
• Chemical weathering – happens when chemical reactions dissolve minerals.
• Variation of steepness in hill slopes is probably due to the softness and hardness of rock layers.
• Soil is formed over time – rock weathers, plants add organic materials and rain spreads minerals through the layers.
• Soil is a mixture of weathered rock, water, decayed organic matter, oxygen and mineral fragments.
• The top layer of soil contains the most organic matter.