Hole in the Rock (Arizona)

Papago Park, located just a few minutes north of downtown Phoenix, features gorgeous Miocene sandstone formations and buttes, one of which is Hole in the Rock. As its name connotes, Hole in the Rock is known for its series of erosional openings and windows. The formation itself is composed of conglomeritic sandstone (individual clasts can… Continue reading Hole in the Rock (Arizona)

arizona, sedimentary, Southwest

The Red Rocks of Sedona, Arizona

When compared to many igneous and metamorphic rocks, sedimentary rocks often aren’t the most visually stunning. However, you’ll be hard pressed to find more vibrant and beautiful rocks than the sedimentary rocks exposed at Sedona, Arizona. Rather than the standard hues of gray or beige, these sandstones, limestones and shales are breathtakingly vibrant shades of… Continue reading The Red Rocks of Sedona, Arizona

geology of disney

The geology behind Disney/Pixar’s “The Good Dinosaur”

The trailer for the new Disney/Pixar movie “The Good Dinosaur” begins by asking the simple question, “What if the asteroid that destroyed the dinosaurs missed?” As a geologist, my immediate answer to the question was, “Well, the dinosaurs still probably would have died out.” Most public knowledge of the End-Cretaceous mass extinction 65 million years ago involves… Continue reading The geology behind Disney/Pixar’s “The Good Dinosaur”

geochronology, isotopes

Introduction to Geochronology

Have you ever wondered, “How do geologists know how old a rock is?”  Geochronology is the science of determining how old rocks, sediments and fossils are. Whether they formed 4 billion years ago or within the historic record, geologists can employ geochronologic methods to determine either the relative or absolute ages of these materials. Radiometric dating–which measures… Continue reading Introduction to Geochronology

structure, tectonics

How do you make a green rock?

Typically when we think of rocks, we don’t often picture them as having vibrant hues. Minerals themselves often come in a spectacular array of colors, but rocks overall tend to have more muted tones and earthy colors. These rocks (pictured above) from the Buckskin Mountains in western Arizona stand out in stark contrast to the… Continue reading How do you make a green rock?


Tips for applying to graduate school programs in the geosciences

Even though it’s only October, it’s definitely prime-time for thinking about applying to graduate school programs if you haven’t already. As someone who went through the grad school application process last year (and is currently in a Ph.D. program), I thought I’d share a few application tips that might assuage any fears/make the process a… Continue reading Tips for applying to graduate school programs in the geosciences


The Many Shades of Fluorite

When you’re first learning mineral identification, it’s tempting to use color as the main distinguishing factor. It’s the first visual clue you perceive, and we gauge so many other things in our lives by color. However, as many know, color is hardly ever a good property for accurately identifying minerals. Take these fluorite (CaF2) samples… Continue reading The Many Shades of Fluorite

sedimentary, wisconsin

Can you spot the unconformity?

This photo displays a pretty spectacular unconformity—an erosional/non-depositional surface where rock units deposited during different intervals of time appear to be continuous. In the bottom half of the image, you can see Paleoproterozoic pink quartzite ~1.7 Ga in age, while in the top half of the image—directly overlying the quartzite—is Cambrian sandstone conglomerate ~540 Ma… Continue reading Can you spot the unconformity?

structure, tectonics, wisconsin

Van Hise Rock

If you’re a structural geologist or geology student in the midcontinent region, you’ve most likely made the pilgrimage to Van Hise Rock. Located near Rock Springs, Wis., in the Baraboo quartzite range, Van Hise Rock is among the best-known structural geology landmarks in the Midwest. Van Hise Rock provides spectacular exposure of the nearly vertical… Continue reading Van Hise Rock