My World: Rock Bluff (Ozarks Geology)

Rock bluff along the route of a recent afternoon walk.

I usually say I live in the Ozark Mountains, but "mountain" is a generic term largely based upon appearance.  If you have hills and valleys, the combination of the two is called "mountains".  In geologic terms, it would be more correct to say I live on the Ozark Plateau because the Ozarks are actually a dissected plateau.  Most mountain ranges were formed when geologic events -- like the collision of tectonic plates -- caused the earth's crust to buckle and fold, uplifting mountains and leaving valleys between them. By contrast, the entire area known as the Ozarks (northern Arkansas, southern Missouri, a bit of eastern Oklahoma and a tiny corner of southeastern Kansas) was uplifted as a plateau with relatively little buckling and folding..  Over millions of years since the uplift, valleys eroded into the plateau leaving hills behind.  


Being a dissected plateau gives the Ozarks some unique features.  Our mountain tops tend to be flat.  The decent into valleys is rugged and steep.    The various strata of sedimentary rock deposited before the Ozark Plateau was uplifted remain in place just like they were laid down millions of years ago. There is little of the scrambling of strata that occurs when the earth's crust is folded and buckled.  Geologist can easily follow a particular rock stratum over a wide geographic area.

Overview of the Ozark Plateau and its four main regions.  (Wikipedia)

Side Note:  The origin of the name "Ozarks" is disputed.  Many think it is a linguistic corruption of  the French abbreviation aux Arks (short for aux Arkansas, or "of Arkansas" in English) which originally referred to the French trading post at Arkansas Post, but eventually came to refer to all Ozark Plateau drainage into the Arkansas and Missouri Rivers.  Other possible derivations include aux arcs meaning "of the arches" in reference to the dozens of natural bridges formed by erosion and collapsed caves in the Ozark region.  (Source:  Wikipedia)

Join the fun by posting photos of your world.  Please visit My World Tuesday to participate.

.

My World: Rock Bluff (Ozarks Geology)

My World In Black and White

An "X" in the snow marks the location of my world in recent days.  

How was the "X" formed?  Ice accumulated on the power lines above, forming an ice tube around the line.  When the sun came out, it melted the top off the tube and the remaining ice fell to the ground.  These two pieces just happened to land on the snow in the pattern of an "X'.  The rake-like tines on one side were caused by icicles hanging down from the tube's bottom side.

An additional couple of inches of heavy, wet snow fell overnight.  This photo was not converted to black and white.  My world IS black and white on Monday morning.

Please visit My World to participate and/or find links to other photos from around the world.

.

My World In Black and White

Nine-Banded Armadillo (Dasypus novemcinctus)

The claws on the front feet of this critter leave little doubt it is 

well adapted for digging.

Nine-banded Armadillos live in my world -- or do I live in their world?  Neither of us is native to the Ozarks, though armadillos have inhabited the Earth much longer than humans.

The Nine-banded Armadillo's ancestors lived quite comfortably in South America until around three million years ago when the formation of the Isthmus of Panama allowed them to start moving north.  They've been heading north ever since.  Armadillos were first recorded in south Texas in the early nineteenth century.  Many researchers thought the dillers' northward migration would be severely limited by cold weather.  Armadillos have a slow metobolic rate, little fat and lack the ability to regulate their body temperatures as well as most mammals.  However, Nine-banded Armadillos proved to be much more adaptable than early researchers thought.  By 1995 the species had become well-established in Texas, Oklahoma, Louisiana, Arkansas, Mississippi, Alabama, and Florida, and had been sighted as far afield as Kansas, Missouri, Tennessee, Georgia and South Carolina. A decade later, the armadillo had become established in all of those areas and continued its migration, being sighted as far north as southern Nebraska, southern Illinois, and southern Indiana.  (There is also ample evidence humans introduced armadillos into several southern states where they thrived.) (Source:  Wikipedia)

That I was able to take these photos during the middle of the afternoon, illustrates one of the  Nine-banded Armadillos' adaptations to colder temperatures.  They are normally nocturnal, but when the weather is cold, dillers remain in their underground burrows all night and come out to forage during the warmer parts of the day.

The bands on the Nine-banded Armadillo's carapace

are the basis for its common name, but it can actually have between

7 and 11 bands.  I only count eight bands on this individual.

Armadillos are primarily insectivores.  They dig up and eat a wide variety of bugs, larvae, grubs, etc.  However, stomach content analysis has show dillers will eat pretty much any small critter that doesn't get out of their way, including small reptiles, amphibians and birds.  Their digging behavior often makes armadillos unpopular among gardeners and those dedicated to having beautiful lawns.  I have no interest in maintaining a convention lawn, but do find it exasperating when a diller "tills" a well-mulched vegetable garden bed.

A previous post shows an armadillo litter out foraging.  (Armadillo litters are always identical quadruplets.)  Other sources of more information than you ever really wanted to know about these unique critters include Mammals of Texas, Biogeography of  the Nine-Banded Armadillo and Armadillo Fact File.

To participate in My World or find links to more posts from around the world, please click the logo above.

.

Nine-Banded Armadillo (Dasypus novemcinctus)

Woolly Bear Caterpillar Predicting the Weather in My World

Woolly Bear Caterpillar - Pyrrharctia isabella

(Photo:  Jo Smith on 11/14/09)

Folklore says: The longer the black ends on a Woolly Bear caterpillar, the longer and more severe the winter will be.

Entomologists say: The amount of black varies with the age of the caterpillar and the moisture levels in the area where it developed. Also, the length of the black ends can vary on caterpillars grown out together from the same group of eggs.

BugGuide makes a half-hearted defense of the Woolly Bear's powers of weather prediction by saying: The variability of the bands depends on many factors. As larvae mature, the reddish bands lengthen. Wetter weather lengthens the black bands. So while not a reliable measure, it makes some sense that onset of an early and thus longer winter will force younger and less red caterpillars into hibernation.

Woolly Bear caterpillars are the larval stage of Isabella Tiger Moths (Pyrrharctia isabella). They are common throughout almost all of North America. Larvae eat many plants and trees including grasses, asters, birches, clover, corn, elms, maples and sunflowers. There are usually two broods of P. isabella each summer. The first of two broods pupates in summer. The second brood overwinters as a caterpillar and pupates in spring. A photo of an adult Isabella Tiger Moth is here.

This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License.

.

Woolly Bear Caterpillar Predicting the Weather in My World

My World Is Foggy

Morning Fog by Jo.

(Photo:  Jo Smith on 11/11/09)

My World is foggy
-- sometimes.

I don't know if meteorologists make a distinction between fog and being enclosed by clouds. The effect is the same. Up here on a ridge in the Ozark Mountains were are sometimes up in the clouds. As you drive down into Bear Creek Valley, the fog/cloud dissipates. Driving along the valley floor you are free of fog with a low, overcast sky overhead.

This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License.

.

My World Is Foggy

My World: Frost Flowers

It's been cold in My World over the past few days.  We've experienced our lowest temperatures thus far this winter.  One of the most beautiful and delicate phenomena resulting from this cold are frost flowers, which are actually neither frost nor flower.

Frost flowers occur when the air temperature is below freezing but the ground remains unfrozen.  Here in the Ozarks, that is a fairly common wintertime event.  Our ground never freezes deeply and usually thaws between cold snaps. A frost flower forms when water inside a plant stem freezes, expands and is extruded through cracks in the stem forming thin ribbons of ice. Air bubbles trapped in the ice make it appear frothy white. The extruded ribbons of ice are often much more petal-like than the ones pictured above.

Not all plants form frost flowers.  Two of the more common ones that do are yellow ironweed (Verbesina alternifolia) and white crownbeard (Verbesina virginica). In fact, white crownbeard also is commonly called frostweed.

Links:
Wikipedia:  Frost Flowers
Missouri Conservationist Online

To participate in My World Tuesday, please click on the logo above.

.

My World: Frost Flowers