11.2: What Are Sedimentary Rocks and Why Are They Important?

What Are Sedimentary Rocks and Why Are They Important?

Sedimentary rocks are rocks that form at the Earth’s surface via the processes of weathering, erosion, and lithification. They are unique in that they record surface conditions and contain evidence of life, like fossils Links to an external site.. Sedimentary rocks are the pages in which Earth’s history is written and can inform us about a wealth of subjects from the occurrence of ancient catastrophes to the productivity of life.

The identification of sedimentary rocks is more than applying names, since each name is a loaded term that conveys information regarding its history, where it was formed, potentially when it was formed, and the processes that led to its formation. Each sedimentary rock is a puzzle, and by identifying a set of rocks, how they are layered, the fossils contained within, and patterns in the rocks, a geologist can reconstruct an entire environment and ecosystem. Solving these puzzles can be useful to better understand the world around us. Additionally, important mined resources like fossil fuels, water, and salt are typically contained within sedimentary rocks.

Those who study sediments, sedimentary rocks, and their fossils may go by many titles: sedimentologist, sedimentary petrologist, or paleontologist. A sedimentary petrologist is a geoscientist who specializes in sedimentary rocks and their conditions of formation. Like many other geoscientists, working with other disciplines is common, with a heavy influence from both math and technology. Many are employed by universities where they teach and/or do research, and state and federal agencies, including geological surveys, like the California Geological Survey Links to an external site. or United State Geological Survey (USGS) Links to an external site.. Additional career pathways are available in the private sector including in mining and natural resource extraction. Many of these career options require a college degree and postgraduate work. If you are interested, talk to your geology instructor for advice. We recommend completing as many math and science courses as possible (chemistry is incredibly important for mineralogy). Also, visit National Parks Links to an external site., CA State Parks Links to an external site., museums, gem & mineral shows, or join a local rock and mineral club. Typically, natural history museums will have wonderful displays of rocks, including those from your local region. Here in California, there are a number of large collections, including the San Diego Natural History Museum Links to an external site., Natural History Museum of Los Angeles County Links to an external site., Santa Barbara Museum of Natural History Links to an external site., and Kimball Natural History Museum Links to an external site.. Many colleges and universities also have their own collections/museums.