Category Archives: Rocks & minerals

The Charlevoix impact crater

Tim Sherry

Special thanks to field trip leaders Alain Tremblay and Francine Robert Last month the Canadian Tectonics Group (CTG) held their annual meeting at Charlevoix, Quebec, the site of a Devonian [Lemiux et al. 2003] impact structure. The field trip portion of … Continue reading

Categories: planets, Rocks & minerals

Accretionary wedge #35 – Porphyroblast

Metageologist

I like long words (I might even say I was egregiously polysyllabic in my discourse) and when Accretionary Wedge #35 asked me for my favourite geological word I knew it had to be one of those compound names based on … Continue reading

Categories: Rocks & minerals

Chalk is weird

Metageologist

Sometimes you live with something and regard it as normal, dull, quotidian, jejune, blah or maybe just meh. Then one day you suddenly get a moment of clarity and realise that actually, it is really weird. Subtly weird perhaps, but … Continue reading

Categories: Rocks & minerals, Uncategorized

Impact and Geology: spherules rule

Metageologist

One of the most striking changes in Earth Science in the last 20 years has been the way meteorite and associated impacts (or bolides and astroblemes, if you prefer) are viewed by Geologists. In the dark days of the 1990s … Continue reading

Categories: planets, Rocks & minerals

Impacts and Geology: deep peace?

Metageologist

Metamorphic rocks typically come from deep in the earth and form slowly. Simple physics shows that transferring heat into large volumes of rock (a key driver of many types of metamorphism) takes millions of years. Rocks that form the deep … Continue reading

Categories: planets, Rocks & minerals

Cu – The Finale

Nina Fitzgerald

(NOTE:  I would like to thank Chris @ Highly Allochthonous for giving me this opportunity to cross-post a favorite sedimentary-stratigraphy class project (from 2007) on Earth Science Erratics.  All mistakes are mine and I welcome comments.  ESE is a great … Continue reading

Categories: Ore geology, Rocks & minerals

Still Wondering About Cu?

Nina Fitzgerald

(NOTE:  This is the second in a series of three posts on copper mineralization in skarn.) As a geology student several years ago, I had wondered why copper (chemical symbol Cu) shows up where it does.  I had wondered how … Continue reading

Categories: Ore geology, Rocks & minerals

What’s Up With Cu?

Nina Fitzgerald

Since returning two weeks ago from my four-day hiking extravaganza in southern Nevada and northwest Arizona, I have been doing a lot of thinking about mining and its long history in that part of the country.  In Arizona, in particular, … Continue reading

Categories: Ore geology, Rocks & minerals

Impacts and Geology: from lahar to suevite

Metageologist

As I’ve written before, the last 30 years has seen a big change in the way Geologists think about the Earth; this planet of ours does not sit in isolation in the Universe but is frequently hit and changed by meteorites … Continue reading

Categories: planets, Rocks & minerals