Final answer:
Biogenous sediments are primarily composed of biological material, not weathered rock or volcanic materials, making the initial statement false. Sediments from weathering and erosion form clastic sedimentary rocks, whereas sediments from biological sources form biogenous or organic sedimentary rocks.
Step-by-step explanation:
The statement that sediments derived from weathered rock and volcanic activities are called biogenous sediments is false. Sediments are indeed derived from the processes of weathering and erosion of pre-existing igneous, metamorphic, and sedimentary rocks. When rock particles settle out of water or air, they form what are known as clastic sedimentary rocks, for example, sandstone or mudstone. These rocks are formed from physical remnants of older rocks that have been transported and laid down by wind, water, ice, or gravity. Conversely, when minerals precipitate directly from water, the resulting rocks are called chemical sedimentary rocks, like limestone or gypsum.
Moreover, the term 'biogenous sediment' specifically refers to sediments made up of material of biological origin, such as the shells and bones of marine organisms. This type of sediment is often composed of calcium carbonate or silica. Organic sedimentary rocks are a subset of this category and include materials like coal, which forms from the accumulated plant debris that has been buried and subjected to geological processes.
To summarize, biogenous sediments are not the result of weathered rock and volcanic activity material; instead, they are predominantly composed of the remnants of biological organisms. The formation of sedimentary rocks involves many processes and encompasses various types of sediments depending on the origin and method of deposition, whether it is clastic, chemical, or organic. The correct categorization and understanding of these processes are fundamental in the study of geology and Earth's history.