1. what characteristics do geologists observe when studying a rock sample? 2. name the three major groups of…

1. what characteristics do geologists observe when studying a rock sample? 2. name the three major groups of rocks and describe how each forms.

1. what characteristics do geologists observe when studying a rock sample? 2. name the three major groups of rocks and describe how each forms.

Answer

Brief Explanations:

  1. Geologists observe characteristics like color, texture (grain - size, shape, and arrangement), mineral composition, and structure (such as layering or fractures) of a rock sample.
  2. The three major groups of rocks are igneous, sedimentary, and metamorphic. Igneous rocks form from the cooling and solidification of magma or lava. Sedimentary rocks form from the accumulation and compaction of sediments (pieces of other rocks, minerals, or organic matter). Metamorphic rocks form when existing rocks are subjected to high - pressure, high - temperature, or chemically active fluids, causing physical and chemical changes.

Answer:

  1. Color, texture, mineral composition, structure.
  2. Igneous: Form from cooling of magma/lava. Sedimentary: Form from sediment accumulation and compaction. Metamorphic: Form from changes due to high - pressure, high - temperature, or chemically active fluids.