Lecture: Granite Petrogenesis – where on Earth did that come from?
Speaker:
Entry Fee
Members: Free
Visitors: £5.00
Date and Time
19:30 -
Location
Bath Royal Literary and Scientific Institution, 16-18 Queen Square, Bath BA1 2HN
Lecture Description
People live on continents. We take them for granted, but we’d be a bit stuck and rather wet without them. To a first approximation, continents are made of granites and rocks derived from granite. Granites are wonderful things, defined by a disconcertingly simple mineralogy that disguises a bewildering array of genetic options. It is important to understand the relative importance of these so that, ultimately, we can understand our own home.
The discussion of granite petrogenesis has a long history, from the days of granitisation vs. magmatism, through the paradigm of S- (sedimentary) and I- (igneous) type granites, to an alphabet soup of SIAMese siblings and the recent acceptance that some (by no means all, but yes, some!) granites can be largely juvenile: directly mantle-derived.
This talk will explore the different mechanisms for the formation of the same thing and the different methods for finding this out. It will then highlight recent work on juvenile granites that may represent unrecognised long-term crustal growth, with attendant implications for the evolution of the planet (well, bits of it anyhow…).