Basic Geology 101 is that rocks are formed in 3 ways-sedimentary, igneous and metamorphic.

But did you know there are actual fields of scientific study who specialize in exploring, studying and understanding each of these formations?

Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles. The mineral or organic particles is transported to the place of deposit by water, wind, ice or mass movement. Sedimentary rock covers about 73%s of the Earth's crust, and it is the most common type of rock.

Sedimentology (also known as Sedimentary Petrology)  is a branch of geology that focuses exclusively on the study of sedimentary rocks and the processes involved in their formation.  It involves the examination of sediments, their characteristics, and the environments in which they are deposited. So why would people want to study sedimentary rocks so intensively?

Well, understanding sedimentary rocks provides a wealth of information about past environments, geological processes and climate conditions, which may help us to understand future changes in our planet. This information can help us predict and mitigate natural disasters such as landslides, floods and coastal erosions. Another reason to study sedimentology is to in the exploration for natural resources such as oil, gas, and minerals. Scientist can learn to identify potential reservoirs and predict the distribution of these resources.

IN the 18^th and 19^th century scientist began exploring the thought that geological processes that have formed the Earth for millions of years are still occurring today. Techniques developed on the 20^th century expanded the world of Sedimentology.  Radiometric dating, seismic imagining, and satellite remote sensing have help geologist study sediment rocks in detail and given us a better understanding of how the Earth’s surface is formed by tectonic and climatic forces

There are 3 main types of sedimentary rock:  clastic (which includes sandstone and shale) -composed of pre-existing fragments of rock transported by wind, water or ice; chemical (which includes limestone and dolomite)-formed through the precipitation of minerals from water solutions; and organic (such as coal)-formed from the accumulation of organic materials such as plants or shells.

Sedimentologist go deeper into these processes, studying things like flow velocity, sediment size, sediment sources, sediment transport, sediment load, sediment sorting, and sediment entrainment.

A deeper understanding of these items can help scientist understand more the history of the Earth. Other clues on what was happening during formation include thickness of layers, cross bedding, ripple marks, cracks, etc. Ripple marks suggest water, cracks suggest a dry environment.

Surprisingly, sedimentology is important for sustainability too! Sediment pollution is a significant environmental issue that affects water quality, aquatic ecosystems, and even human health. Sediment pollution, often caused by human activity, can decrease oxygen levels, transport dangerous heavy metals or pesticides, endanger ecosystems and pose health risk to aquatic life, wildlife and humans. Erosion can cause great damage or even landslides. Sedimentologist can recommend ways to prevent these issues, from monitoring to dredging out excess sediments.

By examining sedimentary rocks for evidence of past glacial activity, sea level fluctuations, changes in ocean currents, etc., sedimentologist can predict future climatic changes and the potential impacts on society. Modern day sedimentology uses high resolution imaging techniques such as LiDAR and ground-penetrating radar, geochemical analysis, computational modeling, satellite imagery and aerial photographs, sea floor mapping, and isotropic dating methods and we are learning so much more everyday about this planet we live on!

Happy hunting!