The division of the Earth's crust into two distinct types has been long established:
Debate and research about how and when continental crust was formed and how it has changed over time is very active. The ability to make precise measurements of isotope ratios of individual minerals, or even layers within minerals has provided the raw data to revolutionise our understanding of the processes involved in crustal genesis.
- Oceanic crust: young, thin, basic composition, simple structure, primarily igneous
- Continental crust: old, thick, acidic composition, complext structure, igenous, metamorphic and sedimentary
This thread is opened as a place to discuss some of the current hypotheses and uncertainties in the field. I shall post some overviews in the next few day, but in the meantime if anyone has any specific questions I shall do my best to answer them.