Geological Sciences | Science Communication
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
Thin section of dunite under XPL. Dunite is a type of peridotite that contains over 90% olivine and may either be found in ophiolitic complexes or xenoliths in basalt lavas. Note the ‘bubble’ texture of the vibrant birefringent olivine grains at the top and bottom of the image, and the serpentine (gray and white) and… Continue reading Dunite
Thin sections of lunar basalt (3.15-3.35 Ga) viewed under plane polarized light and cross-polarized light. Sample contains olivine, clinopyroxene, and plagioclase. Images by author
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]
Here’s a few highlights from the history of the Earth and life during the Mesozoic Era, the second Era of the Phanerozoic, which is the fourth Eon in Earth’s history. These events are mainly focusing on North America, and the dates for Periods and Epochs have been partially rounded. MESOZOIC (MZ) [251 – 65 Ma]… Continue reading Highlights of the Phanerozoic: Part 2 – Mesozoic [251 – 65 Ma]
Here’s a few highlights from the history of the Earth and life during the Paleozoic Era, the first Era of the Phanerozoic, which is the fourth Eon in Earth’s history. These events are mainly focusing on North America, and the dates of Periods and Epochs are partially rounded. PALEOZOIC ERA [542 - 251 Ma] CAMBRIAN (Є)… Continue reading Highlights of the Phanerozoic: Part 1 – Paleozoic [542 – 251 Ma]
Aragonite (left) and calcite (right), both CaCO3; image by author Here in this photo, we clearly have two different minerals–one aragonite and the other calcite. However, they both have the same chemical formula of CaCO3. So how can it be that these two different minerals are both calcium carbonate? Aragonite and calcite are polymorphs of… Continue reading A tale of two CaCO3’s — Calcite and Aragonite
Crystal Cave diorama in Coors Mineral Hall at the Denver Museum of Nature & Science. Depicts a selenite and calcite grotte form the Naica Crystal Cavern in El Petosi, Mexico Image by author
Rhodochrosite - MnCO3 The Alma King, largest known rhodochrosite crystal; state mineral of Colorado. Specimen from Denver Museum of Nature and Science; photo by author
Emily Zawacki, Ph.D. 