if something is made of something / a material then that something contains that something / that material & if something is formed from a material then that something is made of that material ->  if something is formed from a material then that something contains that material  if something is formed from a material then that something contains that material & organic material is a kind of material ->  if something is formed from organic material then that something contains organic material  if something is formed from organic material then that something contains organic material & a sedimentary deposit formed from organic material ->  a sedimentary deposit formed from organic material contains organic material  an organism is a source of organic material & organisms are made of organic compounds ->  organic material is made of organic compounds  organic material is made of organic compounds & organic compounds mainly are made of carbon / hydrogen / oxygen / nitrogen ->  organic material is mainly made of carbon  organic material is mainly made of carbon & if something is mainly made of something else then that something contains high amounts of that something else ->  organic material contains high amounts of carbon  a sedimentary deposit formed from organic material contains organic material & organic material contains high amounts of carbon ->  a sedimentary deposit formed from organic material contains high amounts of carbon  a sedimentary deposit formed from organic material contains high amounts of carbon & to contain something means to include something -> a sedimentary deposit formed from organic material includes high amounts of carbon