Organic geochemistry is the study of the impacts and processes that organism

Organism

In biology, an organism is any contiguous living system . In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of homoeostasis as a stable whole.An organism may either be unicellular or, as in the case of humans, comprise...

s have had on the Earth

Earth

Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

. The study of organic geochemistry is usually traced to the work of Alfred E. Treibs

Alfred E. Treibs

Alfred E. Treibs was a German organic chemist who is credited with founding the area of organic geochemistry. He received his PhD under Hans Fischer at the Technical University of Munich. Fischer had received the Nobel Prize in Chemistry for elucidating the structures of porphyrins. In the...

, "the father of organic geochemistry." Treibs first isolated metalloporphyrin

Porphyrin

Porphyrins are a group of organic compounds, many naturally occurring. One of the best-known porphyrins is heme, the pigment in red blood cells; heme is a cofactor of the protein hemoglobin. Porphyrins are heterocyclic macrocycles composed of four modified pyrrole subunits interconnected at...

s from petroleum. This discovery established the biological origin of petroleum, which was previously poorly understood. Metalloorphyrins in general are highly stable organic compound

Organic compound

An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...

s, and the detailed structures of the extracted derivatives made clear that they originated from chlorophyll

Chlorophyll

Chlorophyll is a green pigment found in almost all plants, algae, and cyanobacteria. Its name is derived from the Greek words χλωρος, chloros and φύλλον, phyllon . Chlorophyll is an extremely important biomolecule, critical in photosynthesis, which allows plants to obtain energy from light...

.

The relationship between the occurrence of organic compounds in sedimentary deposits and petroleum deposits has long been of interest. Studies of ancient sediment

Sediment

Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....

s and rock provide insights into the origins and sources of oil

Oil

An oil is any substance that is liquid at ambient temperatures and does not mix with water but may mix with other oils and organic solvents. This general definition includes vegetable oils, volatile essential oils, petrochemical oils, and synthetic oils....

 petroleum geochemistry

Petroleum geochemistry

Petroleum geochemistry is the application of chemical principles to the study of the origin, migration, accumulation, and alteration of petroleum.... Petroleum is generally considered oil and natural gases having various compounds composed of primarily hydrogen and carbon. They are usually...

 and the biochemical antecedents of life.

Modern organic geochemistry includes studies of recent sediments to understand the carbon cycle

Carbon cycle

The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth...

, climate change

Climate change

Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions or the distribution of events around that average...

, and ocean

Ocean

An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...

processes.