Micro-Paleontology In Wyoming

[JoyH]

I have been interested in micro-fossils for a long time, but have not had the opportunity to collect them in anything but a random fashion before now. I now have easy access to Cody Shale, the Frontier Formation, and the Lance Formation. What is the best way to begin my journey into this fascinating world?

What formation am I most likely to be successful in?

Is it best to collect slabs of shale or containers of loose material?

If I collect slabs, how small should I break it before I begin to try to break it down chemically?

What questions am I not asking?

[JohnJ]

Just some thoughts...whatever the formation, collect a little of both, loose material and slabs. Use a magnifying visor and/or microscope to initially survey the slabs. You may find things associated on them that breaking them down would destroy. Take things a logical step at a time before the last step of breaking matrix down.

[ynot]

I agree with John and would add that it may be that one area in a formation has better results than others. So take samples from many areas within the formation, and keep track of what came from where.

Good luck with Your endeavor, and please keep Us updated on what results You get.

Tony

Edited September 22, 2015 by ynot

[MarcoSr]

Unless the shale is very weathered and soft it will be very difficult to break down in a home environment. There are methods that you can use in a lab environment that will work much better. Mechanically breaking the shale apart can damage a lot of the specimens but the smaller the pieces the better. Cycles of freezing the shale and then putting it in boiling water can break down some shale but it is a very slow process. Walmart 3% H2O2 (Hydrogen Peroxide) can help with some shale. If it is bubbling it is helping. However lab grade 30% H2O2 which you should only use in a lab environment works much better. Drying and hot water cycles will break down most sand and clay based formation. Sometimes kerosene will help with tough clay. Some folks use detergents on sand and clay. You can break down limestone and some conglomerates with vinegar. If it bubbles it is working. Vinegar can be a very slow process and can etch some teeth. Don't use stronger acids. They are dangerous and will destroy your fossils. Other materials require other methods. Every matrix is a little different. With experience you will learn what method to try first. If in doubt, start out with simple and cheaper methods like freeze/thawing or drying/hot water. Some materials just don't break down.

The suggestions to take samples from many areas are what you need to do. What you are looking for is a lag layer or micro lens where the micros concentrated. Otherwise, you can take a lot of formation material and not find much. I hate to disturb the poor ants too much, but ant hill material is always good to sample. They do all the work and concentrate small material for you.

I can answer very specific questions when you get them.

Marco Sr.

[jpc]

Hi JoyH-

I know nothing about micros in the Frontier or Cody Shale, but they are primarily marine shales. Marco Sr's advice for those is very good. The Lance, on the other hand has microvertebrates which are fairly common and bigger than the micros you will get from the marine units. Small teeth and bones are to be found. They occur in bone beds, so you have to walk around and find the bone bed first. Usually in sandstones or gray shales. Gar scales are very common and are one of the more obvious fossils to look for when doing the walking around. Many times these bone beds are in poorly consolidated sandstones and can be collected with a shovel and then screen washed. For this, you have to make some boxes... I use window screen and basically build a box of wood with an open top and the bottom is the window screen. Place a bit of sand in the box and let it sit in water for a while, thern pull it out to dry and then look for oyur little fossils in the stuff you have left over. I use a binocular microscope, but a Magnivisor or magnifying lamp works well also. If you do a search for some of my ealrler posts, you can see some pix of Lance things I have found and shared with these folks. But that was a long time agio, and I don't know how far back the archives actually go.

If you are anywhere near Casper, stop in at the Tate Museum and I can show you our operation there. We have thousands of little Lance Fm micros.

[Mediospirifer]

Hi, Joy!

One thing I'll recommend for a start is to collect some of the sediment that has weathered out of the shale formation. You won't know exactly where in the exposure your micros come from that way, but most mud or soft clay breaks down very easily. I've been putting small chunks of weathered matrix in a bucket of water for a few days, then sieving it, and am finding a lot! It's a fun way to introduce yourself to micros.

After all, isn't having fun an important aspect of the hunt? Enjoy!

[JoyH]

You have all encouraged and inspired me. My husband and I are heading to the Lance formation in the morning and will be at the Tate Museum before too long. We are really looking forward to putting the great information we learn here to use. Wish us luck.

Hi JoyH-

I know nothing about micros in the Frontier or Cody Shale, but they are primarily marine shales. Marco Sr's advice for those is very good. The Lance, on the other hand has microvertebrates which are fairly common and bigger than the micros you will get from the marine units. Small teeth and bones are to be found. They occur in bone beds, so you have to walk around and find the bone bed first. Usually in sandstones or gray shales. Gar scales are very common and are one of the more obvious fossils to look for when doing the walking around. Many times these bone beds are in poorly consolidated sandstones and can be collected with a shovel and then screen washed. For this, you have to make some boxes... I use window screen and basically build a box of wood with an open top and the bottom is the window screen. Place a bit of sand in the box and let it sit in water for a while, thern pull it out to dry and then look for oyur little fossils in the stuff you have left over. I use a binocular microscope, but a Magnivisor or magnifying lamp works well also. If you do a search for some of my ealrler posts, you can see some pix of Lance things I have found and shared with these folks. But that was a long time agio, and I don't know how far back the archives actually go.

If you are anywhere near Casper, stop in at the Tate Museum and I can show you our operation there. We have thousands of little Lance Fm micros.