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07/20/07
Another Day With Rocks
Topic: geology et al

There is a very good site which has endlessly fascinating articles about dinosaurs, and other items of scientific interest.  If you are a rockhound you have probably accessed Bob's Rock Shop.  Don't neglect the article section. 

 Today I was reading about Gigantoraptor, a bird-like creature that stood sixteen feeet tall.  It looks like a bird but has thrown off the theory of shrinking descent from Archaeiopteryx to the modern sparrow.  It is primitive but big.  

 

And now back to the study of mineralogy.  The next group is called skutterudite, named for the town of Skutterud in Norway.  I will admit that I asm more curious about the town of Skutterud than this mineral group, which includes smaltite and chloanhite.  It is a source of cobalt and can be found in numerous locations around the globe.  I really should go back and explain the molecular structure of minerals.  That aspect of the subject is beginning to intrigue me very much.   

But each day has only 24 hours and I have much to do.

 

 


Posted by oh5/ojhoff at 10:28 AM CDT
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07/19/07
Resuming a consideration of mineralogy and dinosaurs
Topic: geology et al

I really shouild resume my reading in the book of mineralogy.  Some of this stuff doesnt't interest me much but I am determined to plow  through.  Sometimes a concept or two will strike a chord.  I wait for those moments

  I don't remember where I left off but I think it was with marcasite.  The next group is cobaltite.  It includes three minerals similar in appearance to pyrite.  They are cobaltite, gersdorffite, and ullmannite.  These are major ores of cobalt and nickel.  The composition is arsenic, antimony and sulfur.  

 

D inosaurs are more interesting I think.  I was just reading about a six inch coprolite found in Saskatchewan.  A coprolite is petrified feces from any species.  This one was supposed to come from a tyranosaurus and contained bone fragments which it was somehow surmised came from feeding on a juvenile herbivorous dinosaur about the size of a cow.  A picture accompanies the article.  And it looks about like you would expect it to look. 


Posted by oh5/ojhoff at 1:41 PM CDT
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07/18/07
RETURN OF THE BLOG
Topic: geology et al

It has been ages.  I finally got my rock shop cleaned up.  It was a real mess for a long time.  And I have quite a bit of the new stromatolite on hand. 

I was just reading about stromatolites.  They were more common during precambrian times, but they still exist today.  My grandfather used to say they were the earliest known life form, but really there is an ongoing discussion about whether or not they were a real life form or the forerunner thereof.  This is a question I am going to research.

I am going to add pics of kittykats to my photo page.  I got what I thought was two female cats last spring and one turned out to be a tom.  I grew up on a farm so it will be difficult to live this down.  The mother cat is Siamese and the dad cat is orange striped.  Am taking steps to see this never happens again.

As far as writing is concerned, I just now finished a story about my dad and the war and Okinawa.   I should have been working on something more publishable, but this is the story I felt I had to write.


Posted by oh5/ojhoff at 8:07 PM CDT
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11/30/06
COLD DAYS
Topic: geology et al
In spite of the fact that I was going to put mineralogy on the back burner, I find myself reading in this discipline again.

I got a letter from someone who saw my website and is looking for a piece of minnesotaite. Now I have lived in MN all my life and my family owned a rock shop since...probably before I was born...but this one was new to me. It is an iron rich talc found in Saint Louis County. There are over 4000 named minerals, the biggest percentage of which are rare or extremely rare.

Another one I was reading about today was either new to me or I hadn't thought about it in a while. Electrum is a natural alloy of gold and silver and was used by the ancients to make coins. Sometimes there are other metals such as copper in its composition. It is a good conductor of electricity, hence the name..

Posted by oh5/ojhoff at 10:55 AM CST
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08/28/06
picking up where I left off....
Mood:  vegas lucky
Topic: geology et al
It has been ages. I can only blame it on confusion in my life, including health issues.

Not sure where I left off. I think it was with the sphalerite group of sulfides. The copper sulfides include chalcopyrite, stannite, and bornite. As a collectible ore, bornite is popular because of its appearance. It is called peacock ore and has a purplish blue tarnish. The chalcopyrite is an important copper ore and it alters naturally to malachite, azurite and limonite. These are extremely popular sulfites. Personally I find their colors too strong and lacking in sublety. And these are soft stones.

Writing. I got nowhere on my endeavors to hold a writers workshop at church but since failing miserably, two women have offered to prepare a supper and try to entice the facilitator back.

Hoffs Rock Shop

Posted by oh5/ojhoff at 10:06 AM CDT
Updated: 11/02/06 12:00 AM CST
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08/07/06
time to order a new book
Mood:  hungry
Topic: geology et al
Geology texts aren't written in stone. That is to say, an old book is just that. It's valid to a point, but the study of the earth is ongoing. I like my books but sometimes I feel I am stuck in the past, and it's not the geological past.

I live in one of the counties that is not mentioned in the book I am reading. Although I feel it is quite significant that springs on this farm feed into the Bungashing, which in turn feeds into the Mississippi. Lake Itasca is recognized as the source of the Mississippi but who knows what the true source is?

Back to the minerals. Sphalerite is also a sulfide, and an ore of zinc. Sphalerite crystals are attractive but I have not heard of anyone using them for lapidary purposes. In this group are also metacinnabar (an unusual mineral that when heated in the laboratory changes to regular cinnabar), tiemannite, and the poisonous coloradoite. I think the old time rockhounds were less inclined to collect these minerals because they were not as useful for lapidary purposes, that is unless they had a special interest in mineralogy. My grandfather had quite a few as he was interested in geology. He had a geiger counter and a black light (not as easy to obtain as nowadays). I remember asking for a chemistry set for Christmas but it was not forthcoming. Instead, I got a microscope. I don't remember asking for a telescope. As of right now, I would llike all of these things and a spectroscope besides.

I'm working on my confession. The person who gave me the idea for this story didn't tell me enough to write a vivid story. I am making it up and telling it from a man's point of view, wondering all the while if it doesn't still sound like a woman wrote it.


Posted by oh5/ojhoff at 3:47 PM CDT
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08/03/06
flint again
Mood:  happy
Topic: geology et al
The archaeology guy showed up again. He owed me $2, He gave me some Knife River flint. Still confusion over terminology.

I'm reading in the Minnesota geology book again. One of the final chapters. It is about southeastern Minnesota. It is a rugged area with hills formed by stream erosion, glaciers, wind and the solvent work of groundwater. The gradient out of the Mississippi river from Fort Snelling down is much lower than the northern portion which received a huge volume of water from Lake Agassiz. This glacial meltwater that cut a steeper gradient.

The sulfides (and selenides and tellurides) of the argentite group are argentite, aguilarite, naumannite, hessite and petzite. These occur with copper and sulphur. The minerals of this group vary in cleavage, brilliance and color. Most are blackish or silver. I did sell a sample of argentiferous galena recently, from Montana but I couldn't locate a source for more.

Am writing a confession that MIGHT require a few words of bislama, the way I have conceived of it. It's a form of pidgin English but it's a legitimate language.

Posted by oh5/ojhoff at 11:16 PM CDT
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07/28/06
reading two books
Mood:  happy
Topic: geology et al
 
Hoffs Rock Shop

Posted by oh5/ojhoff at 5:47 PM CDT
Updated: 12/21/08 4:51 AM CST
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07/21/06
sulfides
Topic: geology et al
Sulfides are complex and valuable. Scientific understanding of their origins is incomplete. Sulfides are deposited in cracks in the earth's crust. Igneous rock (usually granite) forms the core of folded mountain ranges. It has been formed from crystallizing magma, the hot stuff that forms the earth's core. As the magma cools, its minerals form, starting with iron, magnesium, calcium silicates, and so on. The last one to form is quartz. As the granite formation cools, cracks form. Hot water left over from the process moves through the cracks and elements precipitate out, with metals and semi metals combining with sulfur and forming veins. As the less soluble elements crystallize at higher temperatures, those are found near the source and more soluble elements are found further away. These deposits are called hydrothermal veins. It is not so easy to understand the crystallization sequence.

Some of these sulfur compounds are realgar, orpiment, cinnabar and greenockite. To my knowledge I don't have any of these in my collection.

I am finishing up my confession story today. It's sort of funny...humorous type funny I mean. At least I hope it is.





Here's my rockshop siteHoffs Rock Shop

Posted by oh5/ojhoff at 1:36 PM CDT
Updated: 11/02/06 12:03 AM CST
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07/12/06
more geology
Mood:  down
Topic: geology et al
Now I'm reading about an area of Minnesota with which I have more affinity than the eastern part...northwestern Minnesota. The Red River Valley. It was once the bottom of Lake Agassiz. That must have been quite a lake. 600-700 feet deep in places. The Red River is quite young, having been formed soon after the last glacier retreated. Glacial activity has left several hundred feet of drift in places. Where it has been possible to drill down to bedrock, Cretaceous shale has been found on top of pre Cambrian granite, slate and schist. There are no outcroppings and I know that the area is very dry as far as rock hunting is concerned.

I had a customer at my real life rockshop today who purchased stones for healilng. This happens quite often. She bought a clear quartz crystal, two apache tears, and my last elestial.

The medication I take makes me drowzy so I didn't get my writing done yesterday.

Have to work at the church Friday I guess, and try to observe a writing class tomorrow if I am up to it.


Hoffs Rock Shop

Posted by oh5/ojhoff at 12:07 PM CDT
Updated: 11/02/06 12:06 AM CST
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07/11/06
The Minnesota Iron Range
Mood:  don't ask
Topic: geology et al
The iron range is of great social and cultural interest as well as geological, esp. for rock collectors, but that is not the focus of this blog. As someone whose grandfather was once known as "the binghamite king" and as someone who owns or has access to several ton of the algal material of the upper cherty division of the Biwabik formation, part of the Mesabi range, I am very interested in this.

These are mostly open pit mines rather than underground, because the deposits are just under the glacial drift. (An exception to this has been at Ely). The extraction of high grade ore is not as profitable as it once was. Taconite is another name for the lower grade iron bearing rocks.

A complex series of events over the eons resulted in deposits of the high grade ore that for the longest time made this area the greatest iron producing area in the world. Mining was begun in 1884. I am eager to see what a more recent books says about this subject.

I sell drill cores at my shop.

Hoffs Rock Shop


Posted by oh5/ojhoff at 12:33 PM CDT
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07/10/06
cloudy day....cat flatulence
Mood:  d'oh
Topic: geology et al
According to that Minnesota geology book I'm reading, Carlton County deserves special attention and is an entity in itself. To make a long story short, mud turned into shale and compacted into slate. Due to movement and pressure, the slate buckled and folded and molten rock forced its way into the folds. Streams have eroded the bedrock so all of this has been exposed and created a rugged, interesting terrain, esp. in the Jay Cooke state park, which I have not visited. Another must do. Have driven through this area so I'm vaguely familiar.

That kitten smells really bad sometimes. I still haven't named her.

I'm working on three stories. Wish I could spend the day reading, writing, and painting. Hoffs Rock Shop

Posted by oh5/ojhoff at 8:11 AM CDT
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06/22/06
back on the Gunflint
Mood:  chillin'
Topic: geology et al
Interesting geological aspects of the Gunflint Trail: the trail cuts across several belts of various rocks including lava flows where gabbro and red rock granite can be observed. There is a conspicuous boulder bed. The finer glacial drift has been washed away leaving the bigger rock. Granite, being resistant to erosion, is seen as outcroppings in the form of hills. One is 2230 feet above sea level, the highest point in the state. A lot of the lakes are longitudinal because that's the direction the glaciers gouged out depressions, from west to east. I suppose this is pretty boring to most people.Hoffs Rock Shop

Posted by oh5/ojhoff at 2:02 PM CDT
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06/20/06
I'm just not with it today
Mood:  cheeky
Topic: geology et al
Where were we? Discussing Minnesota geology, I believe.

Speaking of rocks, did you see that closeup that Japan's scientists have taken of the closest asteroid? It's the one that has the greatest chance of hitting the earth. Surprisingly, it looks quite a bit like a ....well, a rock. Wouldn't I love to snag a chunk for my collection!

I am a lifelong resident of Minnesota but I have never visited the North Shore nor the prairies of southwestern Minnesota. I am reading about the North Shore and it's geological peculiarities including magma flows along Lake Superior, massive outcroppings of feldspar (resistant to erosion) growing out of the darker diabase. Also the rugged terrain, gorges and valleys left over from pre-glacial times. I think I shall have to visit that area.

Also I've never attended the Moose Lake rock show, which is July 14-15 this year.

I wrote 700 words out of a targeted 3500 of a short story about the MGM Grande Hotel. Quite a struggle for someone who has never visited Las Vegas. Somehow, I am more interested in the Mojave Desert than the bright lights, although I love neon art objects.



Hoffs Rock Shop

Posted by oh5/ojhoff at 1:35 PM CDT
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06/09/06
rainy day
Mood:  celebratory
Topic: geology et al
I've been reading about the Duluth gabbro, a topic that has never entered my mind. As I read about Minnesota geology, most of this is vaguely familiar to me but some is new.

The Duluth gabbro is famous as far as igneous rock is concerned. It is very old and was formed in early geological times. Lava flows in what is now northeastern Minnesota had accumulated to a great thickness and it was difficult for molten magma to force its way out of the center of the volcano. A large mass did eventually make its way out and spread out into a dome, And then the center of the dome sank into a basin. Kind of exciting, isn't it?

I remember when I was a kid, my grandfather and uncle made a card with an explanation of igneous, metaphoric and sedimentary rocks and samples of each. Many were sold but then they had problems obtaining the samples. It couldn't be that difficult, could it?

Again, the celtic theology interests me because it is nature friendly. I do need to look into it.

I have finished 9 lines of my sonnet.

Hoffs Rock Shop

Posted by oh5/ojhoff at 11:51 AM CDT
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06/08/06
more geology, two customers, the rock business, geology
Mood:  caffeinated
Topic: geology et al
I had a friend/customer visit yesterday. She was mentioning how you can't pick up rocks along the shore of Lake Superior. It's illegal. I can see the rationale here. We don't want our natural heritage picked up and carried away.

Lake Superior is the largest body of fresh water in the world, and one of the deepest. It is a fine heritage. But how was it formed? Not sure I understand the process but I think the original trough was formed by a downfolding in the rocks of the pre-Cambrian age, which should have filled up by sediment by now, but instead the trough was reamed out by ice lobes. Then the ice melted and filled up the lake.

My desire to finish my sonnet and read it at the poetry event in my barn on June 16 is very strong.
I would also like to finish my paintings.

But there is rock work to do, my website in particular, and that takes precedence over what the world would term "hobbies".

Church work? As long as I have consented to take this job, I should do as good a job as I can while I am in the position, no matter how humble.

Hoffs Rock Shop

Posted by oh5/ojhoff at 10:49 AM CDT
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06/07/06
a sunny day
Mood:  bright
Topic: geology et al
If I go rock hunting this summer, it will be in northeastern Minnesota, which has some of the most complex geological formations in the world, also the most easily observed because of erosion and mining that has been done. I have been reading that the ely greenstone is the oldest of all rock formations in Minnesota, perhaps in the world, and it may have underlain the entire state at one time. Now it is visible in outcroppings.

CarolAnn is planning a poetry reading and potluck in the barn for June 16. It is the last day of a class she is teaching and the participants will read. Some will bring guitars. I am going to provide beverages. I hope i can get the barn cleaned up by then. Maybe I can finish my sonnet and read that.

I set the tomato plants out today, rather late, and stuck in a few summer squash seeds. The geraniums I had on the graves for Memorial Day are in pots in the front yard flower bed. I need to put a few plants in the outdoor planters, petunias, violas, marigolds. It should look nice.



Hoffs Rock Shop

Posted by oh5/ojhoff at 9:29 AM CDT
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06/06/06
interesting tidbits
Mood:  blue
Topic: geology et al
Mineral wealth in Minnesota includes iron ore, not as important as it used to be but still prominent, dimension stone for quarrying (granites and other igneous rocks...also sedimentary limestone), peat, marl, clay, and of course, water in abundance, for which we should be grateful.

I just read that one type of granite was marketed as "Reformatory Gray" because the reformatory near Saint Cloud was made of this stone and there were once several active quarries within the walls. What kid hasn't been warned to behave in the car when nearing this formidable structure with its high walls and lookout towers?

Did a whirlwind clean up job on the house yesterday and entertained family. Tonight I've been shanghaied into accepting an invitation to supper at the house of friends. I need, I crave time to myself. Too much socializing lately.

I bought myself another sherbert colored gauze shirt today (lime). They didn't have the orange in my size.

I'm still working on my sonnet and perhaps i've lost my touch.

Hoffs Rock Shop

Posted by oh5/ojhoff at 3:28 PM CDT
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06/04/06
more about nature and science
Mood:  accident prone
Topic: geology et al
According to the book I am reading, and contrary to my comment in an earlier post that Minnesota is not particularly well known for fossils, there have been quite a few finds from the Quaternary (Pleistocene) era, which is the most recent of geological ages and continues to this day. A lot of mammal remains have been found in the glacial drift. Apparently there were elephants (mastadons) in Minnesota (four kinds). This era began sixty million years ago and during this time, evidence of three glacial ages can be traced, rather than one single glacial age as was first believed. At one point the glaciers scraped the ground down to bare rock and redistributed it in southern Minnesota, resulting in the Canadian Shield all the way north to the arctic. Mention was made of celtic theology in church today. I got my garden planted today. Hoping for rain tonight as the soil was powdery and dry. I am still working on my sonnet. It's one of those no-no subjects. Unless I write that which is shocking and unacceptable, I am not really interested. For me that means ...well, never mind. Hoffs Rock Shop

Posted by oh5/ojhoff at 5:18 PM CDT
Updated: 12/21/08 4:34 AM CST
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06/03/06
dinosaurs etc.
Mood:  bright
Topic: geology et al
I was just reading that no dinosaur fossils from the Mesozoic era have ever been found in Minnesota with the possible exception of the gizzards but they are not sure. Maybe the big bones were removed by glacial abrasion. Some flowering plant fossils from this era have been found in sandstone, and some fossils fish teeth. Also mollusks and that sort of thing on the Mesabi range.

I have written the first eight lines of my sonnet. A couple of lines are awkward and could use work. The form I use is Petrarchan. ABBAABBA CDECDE Also I am using a few oblique rather than direct rhymes but am sticking to the iambic pentameter.

I hope to plant today, corn, greens, beets, carrots, peas, stringbeans, squash, herbs, flowers. I don't have a lot of any one thing but it's good to put in some kind of garden.




Posted by oh5/ojhoff at 9:22 AM CDT
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