lava or molten rock or magma, are not sediments.
sediments are grains of mineral or powdery minerals that have been weathered from any rocks.
I have previously asked you, do you know what WEATHERING is, but you had never replied to me with an answer.
as I don’t care to explain what weathering to again, all I will say that wind, water and debris can break minerals from igneous rocks, and these minerals are the “sediments“.
so whenever you hear of sediments, they means the deposits of minerals, eg usually minerals like feldspar, quartz or mica.
When animals are buried in the ground of topsoil, about 45% are made of these sediments of minerals, about 5% are composed of organic matters (eg any wastes from animals and from plants, and bacteria, etc), and the rest of the rest of topsoil are just pores of the soil, often filled with either water or gases. But over time new layer of soil (becoming the new “topsoil”), while the original layer (the one where animals are buried), becomes layer of subsoil. As more layers buried the original soil, the less porous this soil become and the more dense it become, water, gases and any organic matters will drain away, even leaving only the sediments of minerals and skeletal remains of the animals or the hard shells of invertebrates.
over more than 10,000 years, but more like 10s or 100s of thousands of years, the sediments will become dense enough to turn into sedimentary rocks.
if the shell or skeletal remains of animals are not destroyed by the buildup of pressures in the sediments or not destroyed by acidity in the soil or by the enzyme from fungi or from bacteria, then it could lead to remains becoming fossilize.
Although I was never taught anything about fossils, I did learn about geology during my civil engineering course, learning some basics about different types of rocks that might be encountered during excavation and construction. Plus, in soil science, I do have some understanding the difference between topsoil, different layers of subsoil types and bedrock.
I may not be a geologist, nor soil scientist, but I still remember what I was taught in civil engineering. Which is lot more than what you would know. If you really want an expert, like a geologist, then you should ask any question to
@shunyadragon as he would know lot more about igneous and sedimentary rocks.
Lava are not sediments, YoursTrue.