Petrology

Definition

Petrology is the study of the macroscopic and microscopic mineralogical and chemical composition of rocks. In addition to assessing sedimentary, igneous, and metamorphic rocks that are accessible at the surface, experimental petrology aims to create high pressure and temperature conditions to investigate what rock types may exist in the Earth’s subsurface.

Latest Research and Reviews

  • Research | | open

    The lithospheric controls on giant gold deposits remain unclear. Here, the authors show evidence for native gold in the mantle from the Deseado Massif in Patagonia demonstrating that refertilisation of the lithospheric mantle is key in forming metallogenic provinces.

    • Santiago Tassara
    • , José M. González-Jiménez
    • , Martin Reich
    • , Manuel E. Schilling
    • , Diego Morata
    • , Graham Begg
    • , Edward Saunders
    • , William L. Griffin
    • , Suzanne Y. O’Reilly
    • , Michel Grégoire
    • , Fernando Barra
    •  & Alexandre Corgne
  • Research |

    A decrease in mafic continental crust coincides with the rise of O2 in the Earth’s surface environments about 3 billion years ago, according to an analysis of sediment chemistry. Reduced rates of serpentinization of mafic material, which produces chemicals that react with O2, could explain the link.

    • Matthijs A. Smit
    •  & Klaus Mezger
    Nature Geoscience 10, 788–792
  • Research | | open

    Dating of inclusions within diamonds is used to reconstruct Earth’s geodynamic history. Here, the authors report isotope data on individual garnet inclusions within diamonds from Venetia, South Africa, showing that two suites of diamonds define two isochrons, showing the importance of dating individual inclusions.

    • Janne M. Koornneef
    • , Michael U. Gress
    • , Ingrid L. Chinn
    • , Hielke A. Jelsma
    • , Jeff W. Harris
    •  & Gareth R. Davies
  • Research | | open

    Current estimates of dissolved CO2 in subduction-zone fluids based on thermodynamic models rely on a very sparse experimental data base. Here, the authors show that experimental graphite-saturated COH fluids interacting with silicates at 1–3 GPa and 800 °C display unpredictably high CO2 contents.

    • S. Tumiati
    • , C. Tiraboschi
    • , D. A. Sverjensky
    • , T. Pettke
    • , S. Recchia
    • , P. Ulmer
    • , F. Miozzi
    •  & S. Poli
  • Research |

    Super-eruptions are fed by large magma reservoirs. Geochemical analyses of volcanic rocks erupted in New Mexico suggest the magma was stored under cool conditions in the crust for 600,000 years, before late-stage heating triggered an eruption.

    • Dawid Szymanowski
    • , Jörn-Frederik Wotzlaw
    • , Ben S. Ellis
    • , Olivier Bachmann
    • , Marcel Guillong
    •  & Albrecht von Quadt
    Nature Geoscience 10, 777–782

News and Comment

  • News and Views |

    The long-term cooling of Earth's mantle is recorded in the declining temperature and volume of its volcanic outpourings over time. However, analyses of 89-million-year-old lavas from Costa Rica suggest that extremely hot mantle still lurks below.

    • Oliver Shorttle
  • News and Views |

    The composition of Earth's oldest crust is uncertain. Comparison of the most ancient mineral grains with more recent analogues suggests that formation of the earliest crust was heavily influenced by re-melting of igneous basement rocks.

    • Elizabeth Bell
    Nature Geoscience 10, 397–398
  • News and Views |

    The geological record preserves scant evidence for early plate tectonics. Analysis of eclogites — metamorphic rocks formed in subduction zones — in the Trans-Hudson mountain belt suggests modern-style subduction may have operated 1,800 million years ago.

    • Clare Warren
    Nature Geoscience 10, 245–246
  • News and Views |

    Mantle enrichment processes were thought to be limited to parts of oceanic plates influenced by plumes and to continental interiors. Analyses of mantle fragments of the Pacific Plate suggest that such enrichment processes may operate everywhere.

    • Jonathan E. Snow
    Nature Geoscience 9, 862–863
  • News and Views |

    The composition of Earth's crust depends on the style of plate tectonics and of the melting regimes in the mantle. Analyses of the oldest identified rocks suggest that these styles and the resulting crust have changed over Earth's history.

    • Alan Brandon
    Nature Geoscience 9, 731–732