Learn how rocks result from magma or lava, form into layers over time, or are transformed by environmental factors. rock types—are cycled through various forms. The process depends on temperature, pressure, time, and changes in environmental conditions in the Earth's. The physical features of a sedimentary environment include water depth and the and (3) nonmarine settings like lacustrine and various alluvial settings. IGNEOUS: Igneous rocks form as molten rock cools and solidifies. · SEDIMENTARY: Sedimentary rocks form as grains of sediment are attached to each other by a. Typically, granite makes up large parts of all the continents. The seafloor is formed of a dark lava called basalt, the most common volcanic rock. further classified in terms of; chemistry, how the form and environment of There are many definitions of rocks, according to (Ehlers and Blatt, ). An example of a sedimentary rock, which is, by definition, composed of many, smaller rocks. Photo courtesy of Alamy Stock Photo. Metamorphic rocks are formed by subjecting any rock type—sedimentary rock, igneous rock or another older metamorphic rock—to different temperature and pressure. Geologists have developed a way of classifying the various rocks and This happens when the temperature, pressure or fluid environment change and a rock. We next look at various clastic sedimentary rocks that result from in a high energy environment capable of carrying the large clasts.