so that you can age determination of sedimentary stones, we have to index fossil the fossil which major geographical circulation and low time period. Paleontologic information supports the index fossil of each and every set of paleo-organisms.
A lot of paleontology and stratigraphy records enable you to figure out the chronilogical age of sedimentary stones. I would suggest the USGS website website link which explain to you need for fossils and stratigraphy in your concern.
Igneous intrusions form whenever magma breaks via a layer of stone from beneath, or lava flows straight straight down from above. They are able to permeate levels of sedimentary stone. When igneous intrusion causes newer sedimentary levels to sink into older people, it is called subsidence. Once they break and engulf chunks of sedimentary stones, it really is called stoping.