Mineralogy Made Me Cry

Metamorphic petrology field trip to Minas Gerais countryside

Some pictures of the metamorphic petrology field to the region of Ponte Nova in the Minas Gerais countryside. We described lots of rocks theses days. We had to describe some really weathered rocks since here in Brazil weathered rocks are more common than fresh rocks and we'll probably work with rocks in that condition. But it was very fun at the end!

Hello! For this post, I’m going to be talking about a glacial period, known as Pulse-1a. This was a period in geologic history that occurred around 21,000-14,600 years ago. This time period was originally discovered through coral records back in 1989 on the island of Barbados in the Caribbean. 

This time period is so unique because in a very short frame of time, sea levels rose about 120 meters, about 4 meters per century, which is a very rare occurrence. Since then, many scientists have debated how global sea level could have risen to such lengths.

The main theory is that this meltwater came from retreating ice sheets. During this time, temperatures were rising. Prior to, a portion of the world had been covered by ice sheets, a well known ice sheet being the Laurentide ice sheet, which covered Canada completely and parts of America. Global temperatures were rising, particularly around 14,700 years ago, known as the Bolling-Allerod period, a time of abrupt warming. Not too long before, a Heinrick event occurred, 16,000-17,000 years ago, which also caused global temperatures to spike. This caused ice sheets to melt, particularly the Laurentide ice sheet, which is what caused such a great rise in sea levels.

However, there are some problems with this theory. The Bolling-Allerod period was more at the end of 1A, so it may not account for the time before when global sea levels were still rising. The same goes for the Heinrich event. There are a few other prominent theories, with some scientists believing that the source could have come from the Southern Hemisphere, instead of just the Northern Hemisphere, from the Laurentide ice sheet. Some also believe that the meltwater may have come from the Antarctic region, using glacial isostatic adjustment. However, there is still not enough evidence to fully prove any theory. Due to constraints with geologic time frames, no method currently has been enough to fully support these theories.

Various methods have been used to find the source of the meltwater. Geologists have derived mathematical equations to find relative sea levels to find the source. Many have also used geophysical modeling to reconstruct past sea levels of 1a. However, more research is needed to conclude what the true source is. However, there is still not enough evidence to fully prove any theory. Due to how limited the scientific methods are, there's still research being done on this event today, and many geologists are still trying to figure out the source of meltwater. Only time will tell what the true cause is.

The Waitomo Glowworm Caves

​The imagery from the Waitomo Caves in New Zealand is captivating, but the science behind this natural wonder is even more remarkable. This isn't just a beautiful cavern; it's a dynamic ecosystem shaped by millions of years of geology and inhabited by a unique species.

​The Bioluminescent Tenant: Arachnocampa luminosa

​The "stars" are actually the light produced by the larval stage of the fungus gnat, Arachnocampa luminosa, a species endemic to New Zealand.

This steady, blue-green glow is a result of bioluminescence, a cold-light chemical reaction involving the pigment luciferin and the enzyme luciferase. The light serves a vital function: it attracts small, flying insects.

Once attracted, the prey is caught in sticky, proteinaceous silk threads—or "fishing lines"—that the larva drops from the cave ceiling. The brightness and concentration of the glow are often a direct indicator of how hungry the colony is!

​The cave system itself is located within a Karst landscape, formed over approximately 30 million years.

​Formation: Water infiltration slowly dissolved the ancient marine limestone, creating underground streams, chambers, stalactites, and stalagmites.

​The Waitomo River is crucial, flowing through the caves and contributing to the humidity and environment necessary for the glowworms to thrive.

Lines of Pits in Protonilus Mensae

The objective of this observation is to examine lines of pits. Cracks (then maybe ridges and troughs) may start as lines of pits. It has been suggested that pits are caused by material collapsing into voids, after ground ice has sublimated. HiRISE will be able to see pits that are barely visible in CTX images. Studies of images like this will help us understand the evolution of surface features, the distribution of ground ice, and past climates.

ID: ESP_076405_2240 date: 13 November 2022  altitude: 301 km

Send Your Name Around the Moon

Your name goes here. The Artemis II mission is launching in early 2026. You can sign up now to have your name aboard the Orion spacecraft when it flies around the Moon. All of the names will be recorded onto a memory card that will be stowed inside of the capsule. You can submit as many names as you want — including your friends or pets!

Bright Spots on Desolate Plains

HiRISE has been observing widespread small bright patches on the plains around the Martian North Pole. These patches appear to be persistent water frost or ice, lasting well into the summer and in some cases all the way through it.

This demonstrates that the ice is perennial or nearly so, meaning that the environment is close to conditions where surface ice can accumulate and survive. This image was acquired to monitor some larger perennial deposits near the center as well as widespread, small bright spots throughout most of the observation. The image is after Martian northern summer solstice, the equivalent of early July for Earth. 

ID: ESP_088767_2550 date: 4 July 2025  altitude: 314 km

Gullies on the Wall of Ross Crater

The objective of this observation is to examine gullies on the south wall of Ross Crater. The gullies seem to be in light-toned material, and HiRISE will be able to see many more details than existing Context Camera data. Located in Aonia Terra, the impact crater is 82 kilometers (51 miles) in diameter.

ID: ESP_076385_1220 date: 12 November 2022 altitude: 248 km

Magmaclast from a vulcanoclastic kimberlite in thin section.

Magmaclasts are the “hallmark” of the KPK variety and don't occur in hypabyssal kimberlites.

More about Kimberlite petrology: Mitchell, R. H., Giuliani, A., & O'Brien, H. (2019, December). What is a Kimberlite? Petrology and Mineralogy of Hypabyssal Kimberlites. Elements, 15(6), 381–386. https://doi.org/10.2138/gselements.15.6.381

"What's Happening?" Like this is occurring right now in this very instant? okay...

Landing in Elysium

From HiWish: “The team at NASA ARC is working on a project called HiRISE Image Analysis, aimed at selecting potential future landing sites for a robotic mission. This area shows a thermal anomaly in THEMIS data, indicating a potential cave entrance or simply a depression with high thermal inertia. However, to distinguish between these two hypotheses, HiRISE images are necessary. The area of interest is located on young lava flows in the Elysium region.”

ID: ESP_088994_1975 date: 21 July 2025 altitude: 280 km