Wednesday, June 14, 2017

PALSAR - Hiccups Part II

I'm very excited to say that next week I have the pleasure of attending the Earth Observation Summit in Montreal!  The summit is a combination of three meetings: the 38th Canadian Symposium on Remote Sensing (CSRS), the 17th Congress of the Association Québécoise de Télédétection (AQT) and the 11th Advanced SAR (ASAR) Workshop.  My main purpose in attending is for the ASAR Workshop, but I am also very keen on learning all about the cutting edge remote sensing techniques and satellite technologies!

I have a presentation in one of the sessions on Advanced Polarimetric Methods. Mike and Hun will also be attending, and they have talks in the Geology session (wah! I'm geology, too! But my topic fits in either session :) )  Next post, I'll tell you all about the cool things I learned!

In preparation for my talk and our upcoming field season to Axel Heiberg Island, I was going through some of my data with a fine picked comb.  Remember those PALSAR Hiccups I was having before? It turns out things are a bit worse than I previously thought!  Not only are the images poorly registered (i.e. they don't line up with the other maps properly) but there is also some severe distortion to a process called 'layover', which is a common, unfortunate challenge with radar imaging. I wrote a little bit about layover in a previous post last year.  Usually terrain correction helps lessen the distortion.

Compare these HH-Intensity image pairs:

Figure 1 Two images of South Fiord Diapir. Above, RADARSAT-2, water is masked out. Below, PALSAR-1 with water included.  Note how the shape of the dome is distorted in the PALSAR image, with a thick white line on the eastern margin.


Figure 2: Above, RADARSAT-2, below PALSAR-1. Again, water is masked out in the RADARSAT but not the PALSAR image. Pink outlines delimit salt diapirs as identified in  other spectral datasets, including (west to east) Surprise Central Diapir, Bastion Ridge Central Diapir, and Glacier Fiord Diapir. Notice how the mountains are more defined and '"3D" looking in the top image, but appear almost sideways or overturned in the lower image. Additionally notice how combination of the layover distortion and poor image registration results in the pink outlines being offset from the actual features.

The cause for this distortion is the incidence angle. The incidence angle is the angle between the radar beam and the normal (perpendicular to) to the surface (Figure 3).  

Figure 3: Illustration of angle of incidence, from Wolfram

For the RADARSAT-2 images the incidence angle is ~40▫, where as the PALSAR-2 images have an incidence angle of 21.5▫.  For a flat surface, this wouldn't be much of a problem.  However, as shown in Figure 2, Axel Heiberg Island has a lot of hills, mountains, and diapirs!  The angle of repose for most materials is around 30▫, and that can be less for bigger blocks.  It is likely that a lot of the mountainous areas are sloping close to the incidence angle of the PALSAR-1 images. This means that the radar beams are inflicting the surface almost perpendicular to the mountains, making them look flat!  And oddly sideways!  To help me visualize this better, I made some sketches and set up a physical model using my bus pass, an external hard drive and a pen, but hopefully you won't need to do that. 

There are two main types of slope angle effects, forshortening and layover. Most radar images (unless you are looking at extremely flat terrain!) will experience these to some extent. The effects are exacerbated in mountainous areas, and with smaller incidence angles. Recall how radar works - we are sending a beam to a surface, and measuring the amount that bounces back.  The amount of time it takes for the beam to bounce back can affect its position in the image, so if a radar beam is taking different amounts of time to reflect off of different parts of an object, that can affect what the object looks like in the image.

Foreshortening occurs with a radar beam reaches the bottom of a slope feature before the top. In foreshortening, slope facing the radar beam will appear "shortened" in the resulting image. The lower image in Figure 1 shows foreshortened western flank of the diapir dome.  Layover is similar, but occurs when the radar beam hits the top of the slope before the base.  This makes it look like the sloped feature is tilting towards the radar position. The lower image of Figure 2 is a better example of layover, because it looks like those mountain ranges are tilted sideways towards the east (I think - that's what it looks like to me, but I'm still learning how to recognize these effects. :) )

Ultimately, these distortions have shown that not all of our PALSAR-1 data is reliable.  I noticed that a lot of the salt polygons were misplaced from the distortions.  However, I am happy to say I was able to perform a quick band-aid solution.  I went through each of the polygons and did a quick visual assessment to see if the radar looked reliable. I manually moved some of the polygons in ArcGIS so they would be overlying the right features even if the shapefiles aren't registered the same. This has given me enough patched-up data to still present some PALSAR-1 results at the conference next week, but it is a short term solution until we either re-register the data, or scrap it.

So, the 'new' results show that the salt diapirs more rough in PALSAR-1's L-Band than in C-Band.  In C-Band, the CPR average values are ~0.4, but in L-Band they are ~0.6! The non-diapiric salts have similar signatures.  In C-Band non-diapiric salt has CPR ~0.21, and in L-Band it is ~0.23.  Previously we thought there were some radar-rough areas of non-diapirc salt in L-Band, but I have confirmed those were registration issues.

This is still good, and we can work with this!

I'll let you know how the Earth Observation Summit goes!

For more information on radar slope effects, this page is awesome: 

RADARSAT-2 Data and Products (c) MacDonald, Dettwiler and Associates, Ltd. (2016) - All Rights Reserved. RADARSAT is an official trademark of the Canadian Space Agency.

Monday, May 29, 2017

Back to the Arctic: An anomalously radar-rough area

Hi, hi!

For this week's update, let's return up north to Axel Heiberg Island, NU.  Recently, I've been revisiting my radar and spectral images in preparation for our upcoming field season. In July, four of us will be visiting the island to ground-truth what we've been seeing in the satellite imagery, with a specific focus on the salt diapirs I've been studying. This will help us better understand the surface texture of the diapirs, how rough they are, and why they are producing the signatures we see in radar.

Part of the Canadian High Arctic, including Axel Heiberg Island, and most of Ellesmere Island. Boxed represents study area for Elise's research. Image credit at bottom right.

One area, not made of salt, is quite curious. There is nothing abnormal about it in the true-colour satellite imagery.

Overview of study area on Axel Heiberg Island. This "wall-and-basin structure" contains a high abundance of salt diapirs. Image credit same as above. Box outlines "weird" area.

But yet it appears very rough in C-Band radar.  More rough than the diapirs, even! Check it out:

RADARSAT-2 C-Band ciruclar polarization ratio (CPR) image over study area. The purple box surrounds anomalous radar rough area. The red circle outlines a large salt diapir for comparison.
That is super rough! How odd! But it definitely isn't salt, because the area doesn't show an anhydrite/gypsum signature in the spectral images:

Spectral (ASTER TIR) band composition of study site. Boxes are in same features as above image. Salt appears as dark maroon.  The mysterious radar-rough feature appears as dark blue.
Curiouser and curiouser! The rough area is appearing blue in the spectral image.  I'm not sure what that corresponds with in this band ratio - something to look up perhaps. However, we can definitely say it isn't salt.  Now, I know there are volcanic intrusions in the area, particularly in the Isachsen formation, so one of my ideas is that it could be made of lava. Lava is radar-rough.

I pulled up Harrison and Jackson's (2014) geological map of the site.  The area is mapped as Isachsen formation! At first I thought that confirmed my hypothesis that the area is lava, but then I looked at the detailed geological description of the units.  Whereas other Isachsen areas are mapped as basalt flows, or sedimentary units with localized volcanics, this area is just mapped as being limestone and siltstone.  No lava.  That is weird, because limestone shouldn't be producing a really rough signature. 

If we have time on one of our helicopter days in the field this July, I'd like to check it out!

RADARSAT-2 Data and Products (c) MacDonald, Dettwiler and Associates, Ltd. (2016) - All Rights Reserved. RADARSAT is an official trademark of the Canadian Space Agency.

Tuesday, May 16, 2017

Incised meanders - When uplift beats migration

Hello!

There has been a two-week hiatus in posts because I was at fieldschool! The Centre for Planetary Science and Exploration at Western hosts an annual/semi-annual planetary surface processes fieldschool in the southwest United States. As mentioned last post, we visited numerous sites in Arizona and Utah, where there are abundant geological and geomorphological features that shape the landscape. We tweeted extensively about the experience, and you can follow our updates and see many exciting pictures on the hashtag #PS9605.

One of my favourite sites that we visited might surprise you.  Even though we visited many famous sites like the Grand Canyon and Meteor Crater, I really appreciated Goosenecks State Park, Utah. I suppose my fluvial sedimentological side is showing!

To explain why I found this river channel so exciting, let's recall how meandering rivers form. There are four main types of river:
  1. Straight
  2. Anastamosing
  3. Braided
  4. Meandering
The shapes of these rivers are controlled by the slope gradient and types of materials being carried by the river. In general, the steeper the slope, the quicker the river moves and the larger sediments and grains it can carry. Meandering rivers are found in areas with the lowest slope gradient, and typically carry very fine grained sands and clays. 
Types of rivers (from University of Indiana course webpage)
Water flows turbulently in river channels, and the water undergoes what we call "helical flow", that is the water is being driven in a corkscrew-like motion as it travels downsteam. Imagine the forces acting upon water in a river: water at the bottom and at the sides of the channel are slowed down by drag forces against the channel walls. Water in the middle and top of the stream is free to move more quickly. We also know that an object in motion likes to stay in motion. This means that the water at the top of the river channel has more momentum when it collides with a bend in the river.  The water gets forced down the wall, and any sediments it is carrying will erode into what we call the "cutbank" on the meander loop. That water is then forced across the bottom of the channel, losing momentum from the drag forces, and slows enough to begin depositing sediments on the other side (the "point bar"). This cycle repeats, and we get meandering rivers as the cutbank is cut away and the point bars build up.  Meandering rivers migrate - if they keep cutting away and building point bars eventually the channels will move back and forth across the landscape. Sometimes rivers will even cut themselves off, trapping ponded water called "oxbow lakes". 
Depiction of helical flow in a meandering river, note how water is
being driven down the cutback, across the bottom of the channel
and then up the point bar (via The British Geographer, source unknown)
It isn't easy to visualize that process in words, so here is an animated gif to illustrate the evolution of meandering rivers:
Source: The skeptical geologist at this blog

Let's bring this back to Goosenecks State Park, where the San Juan River has incised into 300 m of limestone, siltstone, sandstone and shale cliffs.

Just look at this landscape.


180° panorama of Goosenecks State Park (Elise Harrington 2017)

At first glance, you go, "Wow, yup, that is a meandering river!" because it shows very dramatic sinuousity.

But once you start remembering how the meander process works, a sneaking suspicion will creep up on you... It didn't migrate. There is no floodplain, here! Look at the above gif - we know that these types rivers move around through time and cut themselves off. Here, the river somehow stayed in one place for long enough to eroded and incise downwards rather than laterally.

The reason?  The same as why the Grand Canyon is so deep! Within the past 6 million years, the Colorado Plateau has undergone significant tectonic uplift.  Uplift dramatically exacerbates erosion. Imagine pushing down on an object. Now imagine that as you are pushing down, it is pushing back up at you! You intuitively know that the force you feel is stronger, and this helps rivers cut down into canyons like the Goosenecks and the Grand Canyon far more quickly than they otherwise would be able. Because the river is incising so deeply, so quickly (on a geological time scale, of course) it is not able to migrate and meander, and becomes "locked" and only able to cut down vertically.

Standing at the edge of the cliffs was spectacular.  My brain had a difficult time processing the scale of the river, and how deep the canyons were.  I highly recommend checking it out if you are in southern Utah!





Tuesday, April 25, 2017

Planetary Surface Processes Fieldschool!

Hello everyone!

This week we are busy getting prepared for field school!  Western offers a Planetary Surface Processes Field School, which is a two-week tour around Arizona and Utah to get acquainted with the geomorphological processes affecting terrestrial bodies in our solar system.  What shapes the surface of planets?  Here are the main culprits:

1. Tectonics
2. Volcanism
3. Impact cratering
4. Erosion and weathering (Includes liquid, aeolian, glacial, and gravity driven processes!)

Not all planets and moons have been affected by all of these.  While we see river channels on Mars, we don't see them on Mercury.  Additionally, not all fluvial processes necessarily H2O water - there are many fluvial-like channels formed by hydrocarbons on Titan!

Tectonic processes also differ across planetary bodies. Earth is the only planet to show developed plate tectonics, although Venus shows mantle-plume tectonism forming volcanoes similar to Hawaii, and many planets and moons show compressional and extensional tectonic deformation.

All planets and moons in the solar system are affected by impact processes - meteorites don't discriminate!

With the exception of icy bodies, volcanism also appears pervasive across the solar system with most planets and moons showing evidence for past volcanism, or even modern volcanism in the case of Jupiter's moon Io.

Our planet is overall an excellent laboratory for studying the geology of other planets and moons. We expect to see most of these processes on our field trip!

For example, Arizona is located within the southwestern US basin and range province.  This is an area of tectonic extension causing regional thinning of the crust.  The pulling apart of the crust produced "horst and graben" topography which results in the steep sided valleys that we will see in Canyonlands National Park, Utah. Similar terrain can be seen in on many other planetary bodies, including Venus and Jupiter's moon Ganymede.

We will be visiting the Marysvale Volcanic Complex in Utah.  This field is characterized by pervasive many cinder cones and calderas.  The most recent volcanism is bi-modal, meaning there are both basaltic and rhyolitic lava flows.  Most volcanism in the solar system is basaltic, but there is increasing evidence for felsic volcanism on different planetary bodies, such the Moon. One region on the Moon, the Compton-Belkovich volcanic complex, contains a dozen steep-flanked domes interpreted to be from viscous lavas, like the rhyolitic volcanic domes found in the Marysvale Volcanic Field. The bimodal volcanism on the Moon and in Utah both likely formed via the same mechanism.

Some of the more famous sites we will be visiting include Meteor Crater (yup, that's its official name) and the Grand Canyon.  Meteor Crater is one of the best preserved simple craters in the world, and is a classic analogue for studying impact craters on other planetary bodies.  The Grand Canyon is world-class example of how fluvial activity coupled with tectonic uplift can deeply incise into rock. The largest known canyon in the solar system, Vallis Marineris, is found on Mars and is 5x longer and over 4x deeper than the Grand Canyon!

Overall, this will be a great trip, and I look forward to what I will be able to share with you!

You can follow our adventures on Twitter, using the hashtag #PS9605 (our course number at Western)


Best,
Elise





Wednesday, March 29, 2017

LPSC Summary and Microblogging

I had the pleasure of attending the 48th Lunar and Planetary Science Conference! I submitted two abstracts this year.  One on the B.Sc. thesis work I did at Simon Fraser University on Venusian canali, and the other was on my role on the GIS and Mapping team for the Canadian Mars Analogue Sample Return Mission.  I'm very proud of both abstracts, and was delighted to be able to share my work with the broader scientific community. Many people I spoke with were unfamiliar with the CanMars project, and were very intrigued when I explained the incentive behind it, that is, to test how well decision making from a rover mission control centre differs from an geological field team with regards to sample selection.  I also spoke with many members of the Venus scientific community, as well as a lava modeler from the FINESSE team (see Gavin's work for more information on FINESSE), who were very intrigued by the thermorheological flow modelling I'm performing for Venusian canali.  All of the Venus scientists were hoping that I had modeled carbonatite in the channels, but unfortunately carbonatite melt is beyond the scope of our work at this time.

Overall, I attended many fascinating talks and met a diverse group of talented people. I also had the opportunity reconnected with old friends and colleagues from my LPI internship, CPSX alumni, the CanMars mission, my Misasa internship, and people from my previous attendance at LPSC and other conferences.

I was one of the official "microbloggers" for the conference.  This means I was responsible for posting frequent Twitter updates throughout the event.  You can read my tweets here:  http://twitter.com/elusieum.  I found being a microblogger to be an engaging opportunity.  For one, I found myself needed to focus on how to summarize key points from talks in 140 characters or less. I frequently have difficulties paying attention and focusing during presentations (one of my undergraduate colleagues will attest that she watched over my shoulder as I read a list of "top 25 pies of all time" during a geochemistry lecture) but microblogging kept me concentrated and focused on what the speaker was saying. I also needed to write the summaries in accessible language - 140 characters doesn't give you much space to elaborate.  Finally, microblogging was very useful for networking.  Not only did I meet many of the other microbloggers, but I also had other people come up and introduce themselves to me because they recognized my name.  Overall it was a great experience, and would definitely sign up again, next time I attend LPSC!

Feel free to follow me on Twitter for more comments about the Lunar and Planetary Science Conference, or to see me post new updates in space and planetary exploration. 😊

Tuesday, March 14, 2017

SEDS Ascension

Hello hello~

Two weekends ago, I had the lovely opportunity to attend a mini-conference organized by the Students for the Exploration and Development of Space (SEDS).  SEDS is, as the name implies, an international student-run organization for all things space related.  SEDS-Canada is predominantly based in Toronto and places a strong emphasis on the engineering side of the industry, largely based on student membership from the University of Toronto and nearby universities' strong engineering programs.

SEDS Ascension was their annual big event, and they had invited over a dozen keynote speakers from across various facets of space exploration to speak, including CPSX's own Dr. Osinski, who spoke on "Getting the Maple Leaf Back to Mars" which included mention of the successful Mars Sample Return Analogue Mission that Gavin and I took part in last autumn.

From Dr. Osinski's talk. Many places on Earth can be used
as analogues for geomorphological features on Mars, including
terrain wedge polygons seen in the Canadian High Arctic.
Some of my favourite talks were regarding space policy and economics - that is, how do we rally public interest to support planetary science and exploration and work with government agencies to fund these initiatives? A speaker from Magellan Aerospace spoke about the entwining of space policy and business, and how we can leverage Canada's Innovation Agenda for in a push space sciences.

On a similar vein, a Canadian space economist from NASA HQ spoke about how the drive for space science needs to come from the people.  One of the points he made was that NASA has bases across the U.S.A, and JAXA has bases across Japan, but Canada only has offices in Montreal and Ottawa: engaging the people and researchers across the country would generate more local involvement in the Canadian space program.  I, for one, would strongly support a CSA office in Vancouver.  Not just because Vancouver is my home, but because of the co-existing presence of industrial partners like MDA and UrtheCast having headquarters in the Vancouver area.  Furthermore, the local institutions like the University of British Columbia and Simon Fraser University have strong engineering, computer science, and earth science programs - I'm sure that there is plenty of opportunity for collaborations with the CSA.

The speaker was pushing for the "Canadian Spacecraft Confederation from every province for the 150th" initiative, in which students across the country would work towards developing a cubesat, and for Canada's 150th anniversary one cubesat from each province would be selected to launch. He argued that national pride generates support for space exploration. The prospect of a satellite developed by young engineers in one's own province would drive local excitement and local support, both training the next generation of aerospace engineers as well as drive towards building a stronger space program nationally.  How can we support the cubesat initiative?  We can write to our local MPs to show our support for the program, and encourage our fellow engineering students to get involved.

I look forward to seeing what comes out of this.

CPSX squad. I took the picture, therefore I am not in it.

Myself, Zach, Derek, Matt, and Liam volunteered at the CPSX booth.  Together, we met a lot of interesting people from a variety of backgrounds.  Mostly the attendees were engineering students, but we also met a few prospective graduate students interested in the CPSX collaborative graduate program (!).

The current president of SEDS-Canada approached me at the end of the conference, and asked if I would be interested in running for board of directors.  I'm not sure if I made a good impression, they are interested in diversifying their board, or if they are just desperate for volunteers, but this seems like a good opportunity to get more involved with space administration in Canada. I've nominated myself as a candidate for vice-chair, and we'll see where it goes!

Cheers,
Elise

Tuesday, February 28, 2017

Enstatite Chondrites

Let's take a break from radar for a moment and talk about some of my past work.

In the summer of 2015, I had the opportunity to take part in the Misasa International Summer Internship Program in Misasa, Japan.  The program has two branches: Geochemistry and Geophysics.  I took part in the Geochemistry program, hosted by the Pheasant Memorial Laboratory. Six of us worked as a team to analyse the compositions of three meteorite samples, and interpret any relationships between mineral phases and degree of thermo-metamorphism. All three were enstatite chondrites, the rarest type of meteorite, constituting only 2% of discovered falls. Our samples are as follows:

Things are getting pretty hot right over here

"E" designates that they are enstatite chondrites. H/L refers to them containing relatively high iron or low iron.  The number refers to the degree of thermo-metamorphism, with 7 being the highest (totally melted). Eagle shows the highest degree of thermo-metamorphism of our samples, and Sahara has the least.  The differences between them are striking.  Sahara is completely heterogeneous with abundant condrules, whereas Eagle's minerals are equigranular. Sahara is so primative, that not only is there an abundance of perserved glass matrix, but we even found a Calcium-Aluminium Inclusion! (CAI)  For those unaware, CAIs are the oldest known particles in the solar system, so this is a pretty incredible find. In the middle, NWA-1222 is also heterogenous, but does not have any condrules.  What is most interesting about NWA-1222 is that it seems to show intermediate exsolution phases of Cr and Fe-S minerals as the sample was heated up, but not to the extent or duration of Eagle (whose phases have completely exsolved).

Our objectives are to determine:

- The mineralogical composition of the samples using in situ analysis
- The chemical composition of the samples using whole rock geochemistry
- How the distribution of elements changes between mineral phases as metamorphism increases
- Age date the samples

The Pheasant Memorial Laboratory has every beautiful piece of equipment you could ever want.

Using both the in-situ and whole rock geochemistry techniques together allows us to build a broader picture of how these samples evolved through time and space (pun intended). In summary, we looked at mineral shapes and probed their composition with the scanning electron microscope-electron microprobe fancy hybrid machine, as well as crush up and dissolve bits of the meteorites in acid to find out what the powder was made of.  My favourite part was using the ICP-MS, where I got to blast little holes in our meteorite samples for element analysis.

I'm pipetting something dangerous!

The resulting products were pie charts to show the distribution of elements in different mineral phases (not shown).  

Introductory analytical geochemistry in a nutshell.  I have not shared any elemental analysis pie charts in this post, but you know they exist and what they show.
What we found:

EH3 (Sahara)
- Intergrowths of kamacite (Fe0.9Ni0.1) and troilite (FeS), forming a granophyric-like texture.  These two minerals are fully separate phases in the EL5 and EL6 meteorite.
- CAI contains many complex mineral phases that are not found elsewhere in the sample
- An unknown interstitial "glass" phase contains ample amounts of alkali elements.
- RAMAN identified christobalite (>1470oC silica polymorph)

EL5 (NWA-1222) - Elise's favourite
- Mineral shapes are irregular
- Fantastic exsolution texture between a chromium-bearing phase (proto-daubreelite (FeCr2S4) and troilite (FeS). There is also exsolution of a Mn-rich mineral out of troilite.
-RAMAN identified tridymite (870oC - 1470oC silica polymorph)

I feel fuzzy, proud, and excited every time I look at this figure.  We were getting anomalously high chromium readings for the troilite minerals (2%).  Upon closer inspection, there are small minerals of daubreelite with high Cr (10%) exsolving out of the troilite.  Also the same is happening with manganese, but that is covered by the watermark and isn't discussed as much in this post.

EL6 (Eagle)
- Exsolution of daubreelite (FeCr2S4) and troilite (FeS) is near completion!
- Crystals are (sub) euhedral
- "Mystery" SiO2 phase -> used RAMAN spectroscopy to detect sinoite (Si2N2O), which previous literature explicitly states is not in Eagle.  It's always a good day when you prove someone wrong.



Big picture:

From the exsolution of Cr-phases between the EL5 and EL6, we can constrain the temperature of metamorphism.  The transition of Cr-Troilite to Troilite + Daubreelite occurs below 800oC. SO COOL! (because it's below 800oC? Get it?) I have a ternary diagram that illustrates this, but this post already has quite a few technical figures.  I was the ternary diagram-shishou (master) in my Misasa MISIP cohort. 

We can also constrain the temperature of metamorphism further to being between ~600-800oC by the relative abundances of magnesium sulphides and manganese sulphides.  I made a ternary diagram for that, too. It is nice when your minerals agree with one another.

There is a continuous depletion of sodium from the least to most metamorphosed.  This is evinced by feldspar composition.  K and Na depletion in feldspars may indicate loss of low melting point material with increasing temperature.  I will bless you with at least one of my ternary diagrams.



Age dating

Couldn't age date Sahara (EH3) because we only had a thin section and no bulk sample.
Both Eagle and NWA-1222 showed Sm/Nd isotopes dating close to the age of formation of the solar system, and Rb/Sr ages close to the late heavy bombardment.  It is possible that the Sm/Nd age pertains to the age of formation, while the Rb/Sr ratio dates the age of metamorphism.

In conclusion:

The exsolution of Fe/Mn/Cr phases consistently occur ~600-700oC.  The exsolution lamallae are indicative of slow cooling. This texture constrains peak metamorphism temperature, which likely occurred during the late heavy bombardment period.

We used RAMAN to identify different silica polymorphs.  These minerals likely formed prior to chondrite accretion, but this constrains our temperatures of formation, which was likely during the formation of the solar system. Further, we found sinoite in Eagle, which wasn't supposed to be there.

This post ended up way longer than I expected.  I admit that it is still a quick synopsis of this project, with a plethora of important details and measurements missing.  If you're interested, feel free to contact me and I'm happy to discuss our enstatite chondrite study with you!