What was carbon in the lithosphere initially a part of before the burning of fossil fuel?

Initially, carbon was a part of the lithosphere in the form of [coal, carbon dioxide, or diamond] and [carbon monoxide, petroleum, or graphite] before the burning of fossil fuel.

Initially, Carbon is found in the lithosphere in the form of carbonate rocks. These Carbonate rocks were formed from the deposits of ancient marine plankton at the bottom of the ocean when acted upon by heat and pressure and got converted into petroleum and coal.

Coal & petroleum when burnt will produce carbon dioxide. Thus it can be stated that initially the carbon existed in the form of carbonate rocks (diamond and graphite) in the lithosphere.