(A) Rock-Eval CO₂ signal (oxidation phase) of increasing weights of the same sample: the peak on the right-side signs for calcite decomposition, while the peaks on the left side are the signature of the combustion of the organic matter trapped into the rock. (B) Rock-Eval FID signal (pyrolysis phase) of increasing weights of the same sample: the peak area increases in the evenly distributed manner toward low and high temperature, but T _peak remain constant, which is an indication of order 1 decomposition of organic matter reaction.