Classification of Sedimentary Rocks Part 1: Terrigenous/Siliciclastic Rocks

The video tutorial provides an in-depth exploration of sedimentary rocks, focusing on their classification into terigenous, biogenic, and chemogenic categories. It delves into siliciclastic rocks, emphasizing grain size as a key classification factor. The tutorial further examines sandstone characteristics, including composition and maturity, and explains conglomerates and breccias. Finally, it explores mudstones and shales, highlighting their properties and significance in geological studies.

Which category of sedimentary rocks is derived from the erosion of preexisting rocks?

• Volcanogenic

• Terigenous

• Chemogenic

• Biogenic

What is the primary basis for classifying siliciclastic rocks?

• Color

• Grain size

• Mineral composition

• Chemical composition

In a ternary diagram for classifying rocks, what does each corner of the triangle represent?

• A different color

• 100% of one component

• A different rock type

• A different mineral

What is the term for the empty space between sand grains in a sandstone?

• Pore space

• Cement

• Framework

• Matrix

Which mineral is most commonly found in the framework of sandstones?

• Mica

• Gypsum

• Quartz

• Calcite

What type of sandstone is rich in quartz and has little to no matrix?

• Lithic wacky

• Quartz arenite

• Arkosic arenite

• Feldspathic wacky

What indicates a texturally mature sandstone?

• Angular grains

• Presence of feldspar

• Well-rounded and well-sorted grains

• High matrix content

What is the main difference between conglomerates and breccias?

• Mineral composition

• Color

• Grain size

• Shape of clasts

Which type of sedimentary rock is most likely to be deposited in low-energy environments?

• Breccia

• Conglomerate

• Sandstone

• Mudstone

Why are mudstones often associated with high levels of radioactivity?

• They are formed in volcanic environments

• They contain high amounts of quartz

• They are rich in organic carbon

• They have a high iron content