Accretionary Wedge #57- Seeing Geology everywhere

Accretionary Wedge #57 - Seeing Geology Everywhere

Evelyn at Georneys has put out a call for post here accretionary-wedge-57-seeing-geology-everywhere/

I like to walk. No; that's not right - I love to walk.  If I don't do any other form of exercise for the day I always try to get a walk in.  Most of the time I like to walk a set course that is a little less than 3 miles.   I follow the sidewalks in my neighborhood.  And as I walk I like to meditate on things or just think about things in general.  Most of the time I brood about my family and the things that are going on within it.  But other times I like to clear my mind and just think about things in general.  One of my favorite general things to think about is geology.  I love it because I see it everywhere.  And as I walk I can see all sorts of geological things going on in the sidewalks that I walk on.

So now  Evelyn has put out this call and as I was walking I was trying to figure what I was going to write about.   I was getting thirsty on this walk.  Ta -da - something popped into my head - I know I can write about Slurpees and how when you suck on the straw too fast you break the capillary action and don't get anything out of it, but if you suck on it really slowly and steadily you can get so much more out of it.  I used to use this explanation all the time in discussing how to produce an oil field.  For awhile I was a developmental geologist and it was my job to help design how a discovered oil field could be produced to obtain its maximum production.  Most of the time when I would start talking about why drawing the oil out too fast wasn't good for the field, I would hit resistance - they wanted get as much out as fast as they could.  But if I got a slurpee and had them see how it draws down they could understand that.
    So that was what I was thinking about as I was walking.  And the more I was walking the more I was thinking about getting that slurpee when I was done.   Boy would it be good, especially since the weather was already in the nineties.
    But then gosh darn it wouldn't you know I would see something and the geology just popped out at me.  This is what I saw:

 Here Evelyn wanted cat stuff and in the side walk was these cat paw impressions, and also these molds being infilled with sandy material. 

All I could think about were those paleontology courses and how rare it is to get a land animal imprints and what would someone a million years from now think about this stuff if they discovered it while doing an excavation of the area.
    It also got me thinking about how when I see wet concrete there is just something in me that wants to leave an imprint. These people had the same impulse that I had and put their imprints for the rest of us to see for a long, long  time.  It also got me thing about years ago we did some remodeling and had to pour some concrete and we did something very similar.  When I got home I checked to see if I could still find it and I could get to a part of it but the rest was covered over. 

So I continued to walk and thought about the geology I was seeing.  And trying to decide what I should be writing about.  Then I came upon this weathered stain.

It reminded me so much of a field trip I was on where I saw something similar. If I recalled these red spots were from iron oxide weathering out from siderite.

Decisions, decisions- the more I thought about it I should just stick with the sidewalk stuff and see what I could come up with.
     It wasn't long before I came upon stuff like this to make up my mind.

When you first look at this you think oh- more iron oxide staining but then when I looked closer I realized there had been an magnolia petal that had deteriorated there.  This stain wouldn't last long but the other will stay for a long time.
Then there were other things like this which finally made up my mind for me and made me want to do sidewalk geology instead.

 Here was a vug where at one time there had been some organic matter that had gotten into the cement and had deteriorated leaving this hole.  Now its being filled in with other debris.

 I wondered if this hole had been created the same way? But when I looked at it more I decided it may have been an air pocket that collapsed when the cement hardened or else there could have been a pebble that was slightly higher and had popped out. 

Then I saw this crack that really showed the cement cracking out of it and creating holes that way.  It's so interesting to see how the cement cracks and weathers. 

Look at this radial cracking.  It looked like something may have impacted this sidewalk at one time.  Or Maybe a car drove on it.

Look at this crack.  To me it is a good example of normal faulting with the hanging wall to the top and the footwall to the bottom.   Here's another example of faulting with the tree roots being the cause for the uplift of the hanging wall.

 I then like to see the layering of sediments on top of the concrete.  And how in the lows the water has a tendency to accumulate the muds and such which then can harden.  I also like looking at how the redish sands are heavier and settle out then with the less heavy dark organic material on top.
    Some times you can see imprints in the mud/ graywacke material.

 Which reminded me also of these photo where there were dog prints in the sidewalk.  My dog was kind enough to provide a scale for those dog imprints. He's about 10 lbs.

Another imprint that I liked seeing was  these: 

I thought they were really neat to see.  I saw this section of concrete as it was being poured.  It started to rain really heavy as they were finishing up.  The striations across were done with the broom but the round circular marks are from the rain drops.
    On 6-18-13 which was after I did this post we got some very heavy rain.  As I walked after the rain I couldn't help but to notice the rain drop imprints on some sidewalks.   When the stuff is still damp that's when you really notice it.  
This 1st one isn't very in focus but you can get an idea as to how big the raindrops were - there is a dime for scale.
  This was almost all organic debris from the rain. 

Different side walk with more of a sandy underneath and less organic material.

raindrop imprints on a sidewalk

But I thought it was also interesting to see after it had dried in some places too and the matrix was more sandy than organic material (which also lead to its drying faster).  I always think of 'The present is the key to the past' and if you can see things in the present you know what you maybe seeing when you look at past rocks.  

raindrop imprints on a sidewalk

      Here's another interesting one. 

I like to think of this as an igneous dike cutting into the sidewalk and driveway.  It fun trying to figure out the sequence of events.  First there was the driveway to the NW corner.  Then came the sidewalk to the SE.  The there was fill in in the SE corner and the last was the W central driveway material added to make a circular driveway.

Some times the side walks act as conduits for water.  This to me looked like a natural spring but in reality it was a hose that had been left on to water a plant. 

 A channel is being formed.  There is so much that can be said about  water and water features that I'm going to skip them. 

 And sometimes you can see ripple marks in the street concrete. 

 And sometimes you can see graded bedding going on,  with the courser grains on the bottom and the finer ones near the top. 

I could go on and on about the rocks in the concrete but there isn't enough room to write about all of that.

One of the things I was not expecting to see but was just too cute not to take its picture was this baby blue jay.

baby blue jay on sidewalk

 I couldn't tell if its wing was damage or what but it sure did favor the wing over the other as it was hopping/ flying trying to get away. 

baby bluejay

I was just glad this bird wasn't at my house because here's what I have staying by my front door all the time.

And here's Evelyn's cat picture.
I always thought he was trying to do a good job demonstrating  stalagmites (rising from the cave floor) and stalactites (hanging from the cave's ceiling).

Now I wish I could have that Slurpee I was thinking about earlier.