Tag Archives: geology

Accretionary wedge #35 – Porphyroblast


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


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


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?


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

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