Cedar in Rock

Cedars are amazing in their ability to grow in a wide range of conditions.  In rich soil, they quickly become towering giants.  In less then ideal conditions, they take a more leisurely path to grandeur.  Even in the most inhospitable situations, they manage to survive.  This cedar growing from a stone is one of my favorites.

The small tree emerges from a narrow fissure at one end of the stone.  The opening is no wider than a dozen sheets of paper, but the tree has managed to penetrate the gap with its roots and has survived here for at least several decades. 

When I first encountered the tree about 25 years ago, it was not much smaller than it is today.  It would be an interesting tree to have growing near the house.  It’s like a natural bonsai.  The stone couldn’t be moved though, because it’s really the end of a bedrock slab protruding above the soil.  I also imagine that the roots have penetrated to a point where they are able to access a reliable source of moisture.  The little tree manages to stay green all summer.

There seems to be a natural pruning cycle at work here that maintains the tree’s dainty appearance.  Instead of the inner needles dieing and falling away as you see in the large trees, it’s the outer needles on this little guy that do an annual die off.  New sprouts from farther down the branch grow out to replace what was lost.

I found a small earthen structure affixed to one of the stems.  The inside was chambered in a fashion similar to an ant gallery.  The structure crumbled quickly as I pried it open.  There were no occupants.

The structure or its former occupant seems to have had some affect on the branch it covered.  So, here’s another instance where I’ve found something new, but learned very little about it.  Each time my mind tucks away a new bit of information; it also stores a myriad of questions about the same subject.  My awareness of things that I don’t know always outpaces my acquisition of new facts.  I’m happy with the amount of knowledge I’ve gained over the years, but I sometimes think my greatest achievement lies in the great wealth of unknowledge I’ve amassed in my lifetime. 

Newly Exposed Rock

Heavy spring rains caused flood waters to tear through the creek channels at Blue Jay Barrens. This is a point in the creek where high water slams into a rock wall and makes an abrupt 90 degree turn to the right. Water doesn’t like to turn corners and it expends a lot of its energy by tearing apart the obstacle that makes it do so. I benefit by having freshly exposed rock layers available for my personal viewing.

It’s always fun to examine a new rock face. It’s sometimes hard to comprehend the fact that this material has been hidden below ground for hundreds of millions of years. I feel privileged to be the one to greet it when it is finally exposed to the light.

There’s not much left to the roof of this overhang. The roots that once grew between the rock layers are now hanging down from the ceiling. I’m not sure that the rock is very stable now. I’ll have to remember this spot when I’m walking topside. I don’t want to witness the collapse as part of the falling debris.

The thicker limestone layers are more durable and will last for much longer. The fractures and the tilt to the bedrock are evidence of the prehistoric meteor impact that occurred here roughly 350 million years ago. It makes for some interesting geological finds.

One of the things I find most interesting is the distortion of thin rock layers. When these layers were originally formed they should have been oriented horizontally in parallel bands. The layers I see are rarely like that. I see thin bands that are broken or twisted or stretched or compressed or otherwise reconfigured into a unique pattern. It’s amazing to think of a single event producing enough heat and energy to make the rock malleable enough to shape into a new pattern.

This is one of my new favorites. Looks like someone made up a batch of caramel swirl ice cream. I’m not very knowledgeable about geology, but my niece is a super geologist. I’ll have to get her down here to explain to me what I’m looking at.

Rock at Creek Curve - Part 2

This is the obstacle that forces the straight creek channel to form a curve. In the process, rock is moved and the bank falls away.

When rock at the base of the slope is moved away, the rock above slides down. This is a slow, continual process that changes the face of the bank and the landscape above. You would think that a rock wall would be able to stand against a bit of fast moving water. The bedrock at Blue Jay Barrens isn’t typical of what you’d find other places and that’s where things get interesting.

This is limestone, a type of sedimentary rock. Sedimentary rocks are formed when deposited materials are acted on by a combination of heat, pressure and time. The resulting rock is generally found as solid, horizontal layers. At Blue Jay Barrens the layers are neither solid nor horizontal. This phenomenon is the result of a meteor strike about 300 million years ago that produced what is called the Serpent Mound Disturbance.

The layers in this photo seem to be generally falling from the left to the right. There are also fractures that appear to fall in the opposite direction. The larger pieces of rock look solid, but most contain small fractures that make them easy to break into smaller bits. This is why the water has a fairly easy time of detaching the rock from the bank.

Trying to sort out the original rock layers from the maze of fractures can be confusing. Sometimes the fractures converge at vertices of finely crushed rock particles. Moisture enters the fractures and freezes during the winter. This action loosens the rock pieces and makes them more vulnerable to movement by flood water. You can see a lot of fine particles that have fallen atop the larger pieces. This will be easily moved when the water comes up again.

Looking beneath the overhang you can see large cedar roots that once grew on top of the rock layer. Small roots found their way into fractures in the rock and also helped to destabilize the bank.

Further around the curve the bank is still collapsing. The small point coming out on the right is blocking most of the water from this section of bank. Eventually that point will be lost and these large rocks will find their way into the creek channel.

Some of the large rock pieces are more durable than others. They become a more stable part of the stream bed and act as shelter for stream dwelling organisms. The Streamside Salamander is one that depends on immovable rock slabs for successful breeding. These rocks must be perfect for that salamander since this pool fills with their larva each year.