Here’s a cool fact: 20 million years ago, Nevada was half as wide as it is now. Literally.
In a post earlier this week we showed a very small normal fault of the Basin and Range province in the western U.S. This satellite photo shows the Basin and Range at its true extreme. The state of Nevada, and several others, is crossed by a series of ranges that trend almost north-south, with valleys/basins in-between
The continent being pulled apart created this topography. As the continent is pulled apart, normal faults have grown, with the rocks dropping down to fill in the space required by extension. The ground dropped down by these faults has filled in with sediments shed from the higher-standing basins, creating mountain ranges, fairly flat basins filled with sediment, and sharp, sometimes spectacular boundaries between them.
When in candy cane form, it is easy to forget where the flavor came from. Peppermint (Mentha x piperita) is actually a hybrid between two other mint species, water mint (Mentha aquatica) and spearmint (Mentha spicata). It is commonly grown for food or medicinal herb in gardens. It is also well known to escape garden settings and spread aggressively. Like other mints, this species is in the plant family Lamiaceae, which includes many strongly scented kitchen herbs. Members of the mint family are well recognized by their unique flowers and characteristically square stems.
This peppermint specimen was collected on August 29, 1965 by Norman R. Farnsworth in an open field at Ranalli’s Drive-In, eight miles north of Etna off Route 8, outside of Pittsburgh, PA.
Farnsworth (1930-2011) received his PhD from the University of Pittsburgh, where he researched medicinal plants. He was an influential professor and researcher in the field of pharmacognosy (study of medicinal drugs derived from plants). He was a founding member of the American Society of Pharmacognosy.
The Carnegie Museum herbarium includes 1,108 specimens collected by Farnsworth. Each specimen is recognizable, with an envelope attached to each sheet that includes a typed description of the results of chemical screenings he did on the specimen.
Check back for more! Botanists at the Carnegie Museum of Natural History share digital specimens from the herbarium on dates they were collected. They have embarked on a three-year project to digitize nearly 190,000 plant specimens collected in the region, making images and other data publicly available online. This effort is part of the Mid-Atlantic Megalopolis Project (mamdigitization.org), a network of thirteen herbaria spanning the densely populated urban corridor from Washington, D.C. to New York City to achieve a greater understanding of our urban areas, including the unique industrial and environmental history of the greater Pittsburgh region. This project is made possible by the National Science Foundation under grant no. 1801022.
Almost 34 years to the day (December 27th, 1984), a meteorite named Allan Hills 84001 was discovered in Antarctica.
This particular meteorite is famous for all the media attention it received in the 90s. Johnson Space Center’s chief astrobiologist, Dr David McKay published a paper in the renowned journal, Science stating that ALH84001, of Martian origin, may contain evidence of life on Mars. This claim stemmed from results obtained using a scanning electron microscope. The results showed what was thought to be fossilized lifeforms referred to! as nanobacteria due to their size of the order of nanometers.
Volcanic rocks are born as lavas or layers of ash, and stack up eruption after eruption, sometimes thick enough to form islands such as Japan and Iceland (in the featured image) on the mid Atlantic ridge. Much of the rock in the latter is basaltic, but gets transformed after its birth into a variety of chewed up and brightly coloured rock remnants.
SOUND ON! This is a small sample clip of a 360 experience we built as part of my current cover story in @natgeo magazine (Nov). You are looking at a perfectly preserved Kiva in #BearsEarsNationalMonument, Utah, with storytelling by @marlon.magdalena
from Jemez Pueblo. You can find the link to the full interactive
version of this in the link in my header (first download the “YouTube”
app to view it and after clicking the link be sure to then click “open
app” at the top). While this looks like a video, the world you move
through is actually a virtual model that takes you into the various
rooms of the 800-1000 year old dwelling and ceremony room of this
Ancestral Pueblo site. (From the BLM: While this includes a digital
simulation of a fire inside the Kiva, building fires within cultural
resource sites on public lands is illegal and can damage the integrity
of the site). My partner in this project was @devlin_gandy and we were able to make this experience thanks to funding from @insidenatgeo and National Geographic magazine, and the video with the help of @max.salomon from @blackdotfilmsvr! LINK IN HEADER! Special thanks to our field producer and cultural advisor Kevin Madalena (@jemezscientist_occamschainsaw)! We couldn’t have done it without you! #photogrammetry
Working in the field is a wonderful experience. On the central Oregon Coast, the vast sequence of sedimentary rocks provides a wonderful training ground for geologists. Present on this one outcrop on the beach in North Cove at Cape Arago are many of the common sedimentary structures. Pictured top to bottom are: flame structures, flute casts, and convolute bedding.
Flame structures are a form of soft sediment deformation, which is disturbance in the nice flat beds of sandstone due to the compaction from the weight of overlying material. These sandstones were deposited in a shallow marine area, just offshore of the ancient Oregon coast, and contained a lot of water as a result. The weight of sand and mud deposited in the future caused these old sands to release their water, disturbing the neat layers and laminations of this rock. In the case of flame structures, small points of sediment are forced into overlying beds. These can indicate the ancient flow direction of whatever water deposited the sediment, which is useful for reconstructing the geologic history of a site.
Flute casts are not musical, and are related to the way streams move sediment. Shallow water moves sediment in interesting ways, but if you ever look into a shallow stream on a beach, you’ll see scooped-out holes in the bed of the stream. These result from scour and other sediment movement behaviors causing pits. Later sand was deposited on top of these flutes, filling them up and solidifying, preserving a cast of the ancient stream bed.
Convolute bedding is another form of sediment deformation. These are a type of fluid escape structure, which form in a similar way to flame structures. When water is forced out of the rock be overlying material, the water moves sand grains and sediment around, causing the beds to realign in these odd shapes.
All of these sediment structures go toward reconstructing the history of this part of Oregon, and the scenery that surrounds them adds to the mystique of the tales the rocks have to tell.
[Image description: Image shows five diagrams, each of a different profile and corresponding contoured Pi diagram of variously shaped folds. The first is a zigzag, with a pi diagram with two small dots. The second is a parabola, with a pi diagram containing two ovals surrounded by a line, outlining them both. The third is a line resembling that of a quartic function, with a pi diagram containing one black oval and one white oval, surrounded by a line outlining them both. One side of this outline is larger than the other. The fourth is a narrow parabola, with a pi diagram of two half ovals outlines by a line. The image appears stretched sideways. The fifth is a line resembling a tilted sine curve, with a pi diagram that has a black oval with a white oval on either side, all outlined by a line.]
Diatoms are a type of photosynthesising (although some are heterotrophic) algae which are found in almost every aquatic environment; from fresh and marine waters to soils. Diatoms are microscopic, most falling in the range of 20 to 200 microns (0.02-0.2 mm) in diameter or length. But don’t underestimate them. Diatoms play a fundamental role in aquatic ecosystems. In the ocean itself, the oxygen given off by diatoms (and plants) supports the majority of other marine life. Without this oxygen, the water would be uninhabitable and stagnant. Diatoms are also the basis of many food chains within aquatic environments and indirectly provide a food source for us terrestrial beings. These tiny algae also provide approximately 25% of the oxygen we breathe- the greatest gift of all!
They are also quite a diverse group, as you can see in this image. Their siliceous wall can be highly patterned with a variety of pores, ribs, minute spines, marginal ridges and elevations; all of which can be used to delineate genera and species. There are more than 200 genera of living diatoms, and it is estimated that there are approximately 100,000 extant species ranging in shape from circular, triangular, square, or elliptical.
This image shows a classic normal fault in fairly young (<20 million year old) sedimentary rocks outside of Harrison, Montana.
The fault plane is clear and it dips to the right in this image. If you look at both sides of the fault, layers on the right and left are nearly identical, just the layers on the right have moved down. The layers even have specific features; the more resistant layer sticks out, while the weaker layer has been used for homes by a bunch of birds, hence the holes.
It’s slightly out of frame so I can’t easily match up beds, but there’s potentially another normal fault on the left side of this image. A single block bounded by normal faultls on both sides is callled a Horst: this is a good candidate to be one.
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