Tuesday, August 29, 2017

A midsummer diversion, unedited

Still existing in the recovery zone
after an intense season digging in the river 
as well as a rock-star style travel schedule, I had one last trip on the itinerary for 2017: a visit to my dad in Kansas City, Missouri.  
I had been wanting to visit the area where the borders of Missouri, Illinois, and Iowa converge in order to hunt keokuk geodes.  The hunting grounds are a 4.5 hour drive from Kansas City but they also turned out to be a 4.5 hour drive from where my snowbird friend, Miss Vickie, spends her summers.  We arranged a little side trip for ourselves.  
The drive through rural Missouri
was very pretty and restful so the time passed quickly.

I met Vickie at a motel in tiny Keokuk, Iowa, and we got right to business.
By the way, the use of the adjective "tiny" is superfluous as ALL the cities in this area are tiny.
We weren't sure what our success rate would be on day 1
as we were just going to drive around and see if we could find access to creeks, 
so we had arranged to go to a geode "mine" in the area on day 2 where we would be guaranteed at least a couple of geodes for the effort.
We only scouted for about an hour before we came across a truck parked next to a path that accessed a nice, shallow creek.  We'd seen so many "No trespassing" signs that the lack of one on this path encouraged us.  We were just getting out of Vickie's van when the owner of the truck came up the path toting a bucket of little geodes.  He and his son were very helpful and informative although he told us the creek bank was steep and we would be better off going to an easier area "where all the kids hunt."  
He obviously doesn't know Vickie and me.
We grabbed our buckets and headed to the water.
The geodes are relatively easy to find and we ended up spending the whole day in that very short stretch of creek.
The completely unexpected side benefit
of the hunt was finding these nuggets of Devonian period lithostrotionella coral.
I've seen and admired photos of this coral and was thrilled to find my own samples.  The pieces in the photo still have some sand on them.  They cleaned up beautifully.
We could've filled Miss Vickie's van with geodes
but the heat and the chore of hauling buckets of rocks up the significant slope of the bank eventually wore me down.  I was determined to get all my rocks from the creek to the van because I'm stubborn that way but a very kind local man who was spending the day on the creek with his girlfriend helped Vickie with her buckets.  
This local became a story unto himself.  I never asked his name because I am cautious and suspicious by nature.  Vickie was much friendlier but I'm content to play the bad cop. 
The 4 of us shared real estate on the creek for hours and he ultimately asked if we would drive his "old lady" (I kid u not) to his house to grab their fishing poles and more beer.  Probably a good idea because he was noodling and not having much luck (my first time seeing someone noodle in the flesh).  Vickie was ok with driving the girl friend a short ways up the road and I opted to wait with my cell phone cued up to 911.  This short wait was when I learned this young man's story: 32 years old,  never owned a home, never finished school, no bank account, first child on the way with his girlfriend of 6 months who he admitted was a smoker and drinker "but her other 2 kids turned out ok".  Said he realized he needed to turn his life around. His dad had died in his early 40's of a heart attack after a long series of DUI'S in varying states.  
All this made me consider, as I often do,  how lucky I've been in so many ways but mostly in having 2 parents who,  while not perfect, were committed to parenting together and raising children that would have decent lives.  Thank you,  Mom and Dad.  
But back to the rocks...
Per the usual m.o., I had to seal my buckets and send them up to Wisconsin,
awaiting their eventually journey to Florida when Vickie and Jim return for the winter.  
I was concerned about sealing the buckets as the geodes were thickly coated with all manner of creek life, but Tom assured me over the phone that the best option was to secure and label my swag and soak everything in bleach when I finally got my hands on it again.
I did take a couple of geodes home
that were already broken and just laying in the creek.
They are beautiful and may contain up to 14 different minerals in addition to the ubiquitous quartz.  The quartz crystals may also be stained different tints by minerals in the matrix or water.
I was gung ho to put all mine on the slab saw but read that cutting them open might damage large interior crystals.  The best method is to use a soil pipe cutter.
Luckily, Tom can get his hands on one through his work contacts so when I get my geodes in the fall, I'll be ready!


Here's a little info about keokuk geodes from the geode gallery web page.  The site has wonderful photos and very detailed information about the minerals associated with these types of geodes.
Minerals in Keokuk Geodes (Primarily from the Warsaw Formation)
The following minerals have been positively identified as being in Keokuk geodes, as well as those previously published to exist or are currently under study.  The photos for each mineral are currently under construction, please check back from time-to-time to see new additions.
Quartz- Lines almost all geodes. Clear, smoky, sea-green, iron-stained (orange), and pink or cherry tinted geodes are found (see photos below).  Clear and iron-stained geodes are the most commonly seen type of quartz geode.  To date, research findings have not confirmed the presence of "citrine" geodes in the Keokuk, Iowa area.  All such samples have been identified as iron-stained geodes.  Citrine is considered by many geologists and gemologists to be rather uncommon or infrequent anywhere on Earth, and is considered by many in the gemological sector to be more uncommon than amethyst (Holden, 1999).  Many iron-stained Keokuk geodes can be cleaned with any iron-removing product or various acids.  In the samples where the orange/yellow coloring does not clean out, it was found that the samples had successive layers of quartz on top of existing iron-stained quartz, but due to the transparency of the quartz crystals, the orange color still showed through.  Many geode samples have also been identified with "rings" of pyrite in the geode rind, indicating successive growth stages of quartz, then pyrite, then quartz again, etc.  Research by Sinotte (1969) also labels all orange quartz geodes as iron-stained.  The iron-staining is caused by the weathering of various sulfide minerals, most notably pyrite but also marcasite, chalcopyrite, etc.   The term "citrine colored" quartz is appropriate when describing Keokuk geodes, but true "citrine geodes" do not occur in the Keokuk area.  The pink or cherry tinted geodes, if naturally occurring (recently, several so called "red quartz geodes" were made available but they were simply orange iron-stained geodes that had been baked in an oven to a certain temperature to turn the orange to a red color) are occasionally caused by a close association with the surrounding host rock or where the chalcedony lining contained excessive iron amounts and resulted in a more of a reddish tint in the geodes. These will also clean up unless having been under the process of weathering for an extended period of time or subsequent growths of quartz have overlaid the layers of red iron deposits. In other geodes, the faces of several quartz crystals are coated with a very weak pink to vivid red, and can be washed out easily, these are most likely associated with hematite (see hematite section below). At most locations where hematite is the reason for the reddish coloring, other geodes in the same exposure will have actual hematite crystals and geodes containing pink to red water have been collected at a few locations.
"Snowball" Geodes:  An interesting variety of mainly quartz geode that is well-known among Keokuk geode collectors is the "snowball" geode.  Sinotte (1969) apparently first coined the term, and while definitions vary as to the true definition of a "snowball" geode from collector to collector, the main requirement for a Keokuk geode to be labeled as a "snowball" geode is the presence (or at least former presence) of a silica concretion in the interior of the geode (Sinotte, 1969 - refer to pages 74-77) that was later coated over by quartz and sometimes additional minerals, forming an attached round ball of quartz to the interior of the geode cavity.  Objectively defined, if there is proof of a separate entity in the form of the silica concretion in the geode cavity, regardless of shape, separate from the lining of the geode to at least some degree, it is, by definition, a "snowball" geode.  Some samples are formed better than others and contain less connections to the quartz wall and a more pronounced "ball", but the basic definition is still present in the more poorly or better-developed specimens.  Several such samples have been collected that noticeably contain such "snowballs", but the interior silica/chalcedony (usually a white solid material that is commonly mislabeled as kaolinite due to its appearance) has since disappeared, leaving an open void except for the layer of quartz on the outside.   The author of this page has collected several samples and also studied several other samples where this has been observed.  Such a phenomena may indicate an instability in the former interior silica ball in relation to the surrounding quartz, and a dissolving of the silica may have occurred after the silica ball was coated with quartz.  Research is ongoing - if anyone else has samples that fit this description or a sound theory based on research studies related to this topic, please contact me with your observations/opinions or references to the process that may have occurred and if possible, pictures of the samples under study or in question.  Below are two geodes containing "snowballs" - the left geode shows a hollow snowball and the right is a regular, typical snowball. 






Sunday, August 20, 2017

When it's 150º outside...

Could it be any hotter?!
I'm sitting here sipping Fresca and Campari and fretting,
"Is every summer from here on out
 going to be a record breaker?"
Sheesh...

The 4th of July weekend found Tom and me back in northwest Georgia
where we were quick to hightail it to the old coal mine spoil piles.
We were better prepared this time with shovels and hammers, boxes and bubble wrap, but we forgot
INSECT REPELLANT.
Forgetting insect repellant in the south in the summer
 is tantamount to heading into the desert without water.
One of the friends that went with us immediately declared,
"This is not my idea of fun,"
and Tom and I were left to our own devices.
We stuck it out for a couple of hours,
and found some more nice plant fossils, 
but to be honest, my heart wasn't in it.  
I had just returned from my big trip out west and I was beat.
I've come up with a handy formula for how long it takes one to recover after digging fossils all day:  for every day digging fossils, you must add a full day of recovery
 equal to every year of your age over 50, 
hence, at the age of 52, I figure I've got almost 2 months of sleeping late and attending PT sessions before I'll be back to square one.
This was my best Pennsylvanian period fern that I found but sadly, I rinsed the rock GENTLY and all the contrasting color came off.
Dang!
It's still a great imprint but I have to hold it at just the right angle to see it.
I did score a big chunk of lepidodendron bark:
FINALLY, someone on The Fossil Forum pointed out that I was using an old New Zealand coin for scale.  He was, of course, from New Zealand.
The Maori totemic art is almost as cool as the fossil.

And here is the frightening effect of high heat and humidity
on naturally frizzy hair:
I was not, as one might imagine, happy to see this photo.
Ah well, I suppose I need to put in a little more effort if I'm going to maintain a glamorous look when in the field.

We ended our digging early as we were having a lot of storms rolling through.
I took this photo from the deck of our Air BnB:
Worrisome at times.

Before we abandoned the hillside, we came across a turkey nest,

and a hydrangea shrub gone wild.
My smile isn't only for the flowers.
It's also because we were headed back to AC, showers, and adult beverages.
Tom helped me out with a little PT of his own:
Seriously, if your back hurts, 
gentle traction feels good!
I'm trying to get right before the Peace River season starts back up.

Here's a little more info regarding lepidodendrons from the Britannica.com website.
Lepidodendronextinct genus of tree-sized lycopsid plants that lived during the Carboniferous Period (about 359 million to 299 million years ago). Lepidodendron and its relatives—LepidophloiosBothrodendron, and Paralycopodites—were related to modern club mosses. They grew up to 40 metres (130 feet) in height and 2 metres (about 7 feet) in diameter. During their juvenile stages, these plants grew as unbranched trunks with a shock of long, thin leaves that sprouted near the growing tip. They branched at later stages, either in even dichotomies at the growing tip or in lateral branches that were later shed. After branching, the leaves became shorter and awl-shaped. As the plant grew, it shed leaves from older parts of the stemthat left diamond-shaped leaf bases. Stems were characterized by a slender central strand of wood and a thick bark. Since Stigmaria—the underground parts of the plant—resembled stems, they are not considered true roots. The shape of leaf bases and the arrangement of their vascular strands distinguish the different genera within the group of arborescent lycopsids.
Lepidodendron and its relatives reproduced by spores, with megaspores giving rise to the female (egg-producing) gametophyte and microspores giving rise to the male (sperm-producing) gametophyte. Lepidophloios wrapped its megasporangium in a layer of tissue much like that of the seed plants. This feature, however, was independently derived in the lycopsid lineage. In some genera, spore-bearing cones were produced at the tips of branches, suggesting that the plants could reproduce only once in their lifetime. Lepidodendron and its relatives lived in the extensive peat-forming swamps of the Early and Middle Pennsylvanian epochs (about 318 million to 307 million years ago) and became extinct when these swamps disappeared.












Sunday, August 6, 2017

Baculite Gallery from My Favorite Stop

One of my favorite places on this trip
was in the northeast corner of Montana
near the very small town of Ft. Peck.
Vickie's daughter lives in the area and graciously agreed to meet us (for the first time!) and show us one of her favorite baculite spots.  
To say we would never have found in on our own is an understatement.
As usual, it was in the middle of nowhere.
I have no aspirations to live in wide open country.
I'm too fond of things like grocery stores and cell phone reception.
But being able to visit places like this in a world crawling with 7.5 billion human beings fills my chest with a lightness that in equal measures makes me want to laugh and cry.  
And so, with gladness in my heart, I lugged my trusty rock hammer to the top of the hill
 and got to work.
This rocky promontory seems to be composed entirely of ancient Cretaceous sea creatures.
And these are not your run-of-the-mill baculites.
Many of them are filled with druzy crystals ranging in color from clear to golden yellow.
As soon as I join a mineral club, I'll find out why many of the crystals are square in shape.

I also uncovered a couple of jewels:
A single well-formed golden crystal resting in a bed of druzy.
Wow!

Some of the other sea creatures include loads of little bivalves, this one half-filled
 with some kind of concretion.
Round ammonites.
We all found a few small complete ones but this was the best, found by Don.
And nautiluses!
Vickie's daughter found this amazing specimen and there is a matching nautilus on the reverse side.
I found this perfect little segment laying on the ground.  
Hard to believe it is over 65 million years old.

We were guarded in our endeavors by the coolest little dog ever, Chewie.
I want this dog!

The surface hunting around the hill
yielded a whole different world of treasures.
Baculite segments replaced by different colors of minerals with a translucent quality.
Lavender chalcedony!
Cola brown with an interesting orange peel texture.
Half brown, half limestone.
A surprise was this orange-hued crystal, AND...
...out here in the middle of nowhere, Don found this token entitling the holder to 3 cakes of Camay toilet soap for 15¢ instead of the usual price of 25¢.

In an entirely different kind of topography,
only a few miles away,
Pam scored this incredible baculite hidden inside a long nodule.
...jealous...

So that's that for the annual fossil trip out west.
Next year, we're thinking Blue Forest and Utah and...
I can't wait!

Here's some info on the structure of mother of pearl 
and how it survives the fossilization process.  We found this on several baculites and shells.
This excerpt was borrowed from The Fossil Forum and written by an advanced member.

Nacre consists of rounded or polygonal (normally hexagonal) tablets of aragonite, which is a form of calcium carbonate. The plate-like tablets are arranged in broadly continuous, regular, mutually parallel laminae which are separated by sheets of organic matrix. That matrix is composed of biopolymers such as chitin, lustrin and silk-like proteins. 
It’s that unique arrangement, coupled with the fact that the thickness of the aragonite tablets approximates to the wavelength of visible light, which creates the interference pattern of iridescence we call “mother of pearl”.
The other parts of mollusc shells are composed principally of aragonite, with some calcite. Although they’re both calcium carbonates, aragonite is geochemically unstable over long periods of time and readily converts to stable calcite in most shelly fossils by recrystallization during diagenesis and post-diagenetic alteration. Those processes also destroy the organic components of the nacre.
Although it’s possible for the tablet arrangement of the original nacreous structure to be preserved (it’s sometimes replaced as a pseudomorph by the phosphate mineral apatite), the iridescence doesn’t survive in those circumstances. Intact original nacreous structures with iridescence are only seen in two sets of circumstances. Young fossils, or those where something has prevented the recrystallization… and that “something” is most usually petroleum or one of its derivatives.
Famously, for example, the Buckhorn Lagerstätte of Oklahoma is rich in aragonitic shelly fossils preserved with their original iridescent nacre. In fact it’s the oldest deposit in the world which contains such material. It’s a late Middle Pennsylvanian palaeo-seafloor oil seep deposit which became impregnated with asphalt before the sediments lithified and that prevented the nacre from recrystallizing.