Geological Sciences | Science Communication
Severity: 1st worst Cause: Eruption of Siberian Traps Climate: Cold to extremely warm; ocean acidification and anoxia, ozone destruction Aftermath: Permanent ecosystem reorganization; low O2 for >106 years There’s good reason why the End-Permian extinction is referred to as “The Great Dying”; 95% of all species, 53% of all marine families, 84% of marine genera,… Continue reading Mass Extinction Monday | END-PERMIAN (250 Ma) – “The Great Dying”
Severity: 3rd worst Cause: Still unclear, changes in sea level and ocean anoxia (?) Climate: Abrupt cooling Aftermath: Marine filter feeders diversify Rather similar to the End-Ordovician extinction, warm-water marine invertebrates were the hardest hit during the Late Devonian extinction. 22% of known marine families and 57% of marine genera were wiped out during a global cooling event. Gondwana glaciations were… Continue reading Mass Extinction Monday | LATE DEVONIAN (365 Ma)
I thought I’d share my final project from Introductory Geology! I made this back in fall of 2011 when I had no idea I’d be going on to study geology. I was just psyched to be able to use my graphic design skills, and this is still probably my favorite thing I’ve ever made.
Typically when you look at a geologic time scale, the Precambrian is all scrunched up, so even though it accounts for about 80% of Earth’s history, you forget how significant it is in the whole scheme of things. Putting the time scale into perspective like this just makes me marvel even more at human existence…… Continue reading ~4.55 BILLION YEARS – TO SCALE!
Images by author
Image by author
Specimen from Anselmo Mine, Butte, Montana Image by author
Rhyolite is an igneous, extrusive volcanic rock high in silica forming typically in continental arc settings. The flow-banding in this sample is caused by the friction of the viscous magma in contact with a solid rock surface or by compaction, causing flattening and welding of shards and pummice. [Be prepared for pictures of a bunch… Continue reading Flow-banded rhyolite
As a geologist, not only do you have to be good in math, chemistry, physics, history, and writing, but you also kind of need to be decent at art. These are thin sections of magmatic rocks with my accompanying petrographic sketches. For a relatively small little circle, these guys take a really long time to… Continue reading Art of Geology
Here’s a few highlights from the history of the Earth and life during the Cenozoic Era, the third of the Phanerozoic, which is the fourth Eon in Earth’s history. These events are mainly focused on North America, and the dates of Periods and Epochs are partially rounded. CENOZOIC (CZ) [65 Ma – on] PALEOGENE (PE)… Continue reading Highlights of the Phanerozoic: Part 3 – Cenozoic [65 Ma – on]
Emily Zawacki, Ph.D. 