Mountain Effects on Climate

Rain Shadow - Part 2

In my educated opinion, the Rain Shadow Effect is the primary "cause" of the four North American Deserts, the Chihuahuan, Sonoran, Great Basin, and Mojave.  The Mid-Latitude High Pressure Zone (related to Hadley Cells) is secondary but still important.  

Rain Shadow Effect - Part 1

Not to over-dwell upon this subject (with this and the two following videos), but the Rain Shadow Effect is the primary "cause" of the four North American Temperate Deserts, the Mojave, the Great Basin, the Sonoran, and the largest, the Chihuahuan Desert.

The Rain Shadow Effect is the "2nd half" of the Orographic Effect.  The first "half" occurs when prevailing air currents bring moist air masses into contact with linear mountain ranges.  Over the long-term climate effects, due to our Jet Stream position, usually westerly wind currents bring moist air masses in from the Pacific Ocean.  As the moist air is uplifted, it chills, condenses, and brings precipitation to the Windward side of the mountain ranges.

Once the air currents "top" the mountain range(s), as it starts to fall in altitude (down the Leeward side of the mountain ranges), it expands, warms, and dries.  Due to the mountainous areas west of the Rockies Front Range and west of the eastern-most parts of the Basin and Range Province, that is the primary reason for the prevailing dryness of the "American West".

Update and Planned Index to Recent Posts

Due to a variety of reasons (procrastination being just one), I have been derelict in my desire to post regularly.

[I have some personal writing projects in progress,  about past cross-roads events in 1974 and 1977, e.g., moving to El Paso for grad school.  With these writings being interrupted by life events, I am also doing these daily writings to "stay in the mindset/habit" of getting something written down, every day, if at all possible.  And hoping to resurrect memories and find inspirations.]

As a quick review, I am not a world-traveling Geologist, though have I visited 42 U.S. states, 2 Canadian provinces, and 2 Mexican states, however briefly.  I haven't traveled through North America as well as I would have liked (and sometimes I was distracted and sometimes I didn't have a decent camera).  

When family responsibilities permit, my second wife enjoys History and Science and we manage a few multi-day excursions, so we still manage some nature photos, museum visits, and travel learning opportunities.  [To clarify, my first wife (1984-2015) passed away from a stroke and other health problems in the spring of 2015.]

I never claim to be an "expert" at anything, rather I am "learned student" with a constant desire to learn more, understand more, and recover some of what has been forgotten over the decades.  That being said, from my position of being a "wizened greybeard", I can use my diverse education, life lessons, numerous mistakes, and memories as "teachable moments", "educational resources", etc.  When you reach the vaunted (or self-delusional) status of "village elder", you will understand.

Anyway, an Index with links is planned to guide you through my posts.  [When I see errors and omissions in my posts, I will endeavor to edit and fix these problems.]  I enjoy being outside, as well as sharing those experiences, and I hope to inspire an enjoyment of learning, too. 

Thanks for your patience.

Super-Volcanoes, Part 1: Yellowstone

Happy Thanksgiving!

Gold Panning Video

Distance and circumstances have precluded gold panning lately.  But it is still on my mind.

Naked Science - Super Volcanoes

Carolina Bay Formation Part 3: The Impact!

Carolina Bay Formation Part 2: LiDAR...A Game Changer!

There seems to be some controversy about these videos.  I will keep them here until I come to an understanding in regard to their veracity and methods.

Carolina Bay Formation--A REALLY bad day! Part 1: What are Carolina Bays

I haven't had time to properly "digest" this info, but as this is pertinent to the area around Georgia Southern University (where I received my Bachelor of Science degree in Geology), and where I worked years later with the Georgia EPD (Environmental Protection Division, DNR), it caught my attention and I needed to capture it and its two following companions.

[After some squawking when I posted these videos on Facebook, I am not taking sides.  I am capable of finding something interesting, without being a "believer" of every shiny, new thing that comes along.]

Science works best when dissenting voices are allowed to state their case.

Identifying Metamorphic Rocks -- Earth Rocks!

Another Place Not Visited Enough ... Carrizozo Basalts, New Mexico

About 150 miles north of El Paso are some lava flows I should have visited more than once.  

Figure 1.

The area is variably known as the Malpais Carrizozo and the Valley of Fire State Park, in the Tularosa Basin, north of Alamogordo, NM.

It is noteworthy because the flows are estimated to be only 5,000 years old, the second youngest in the state behind the McCartys Basalts on I-40.  From its source, Little Black Peak (a little north of U.S. Hwy 380 and west of U.S. Hwy 54), the basalt flows eventually traveled by lava tubes some 50 miles south, making it one of the longest flows on Earth erupted in the last 10,000 years.

I stopped by there on the way back from Shattuck, OK, with some of my in-laws in 1985.  (We might have been returning from a family funeral.)  I should have made a return visit, but as I was married by then, I didn't have as much free time and had to concentrate on getting my Thesis Project underway in the Aden Basalts.  (I guess I could have emphasized how I needed to see these fresh flows and their source to better appreciate the Aden Flows.)

Figure 2.

I had a few minutes to walk a little way into the flows for photos, but I didn't have my boots or a hat with me.  [Please pardon the dust spots on these 35 mm slides.] 

Figure 3.

I am not sure if that is Little Black Peak in the right background or not.  It might be and if so, a little to the east are a couple of older Scoria Cones called "Broken Back Craters", according to this link.  They are very photogenic, too.

Figure 4.

Such pretty, fresh rocks.

References:
Anthony, E. Y., Hoffer, J., Williams, W.J., Poth, J. and Penn, B.  Geochemistry and Geochronology of Quaternary mafic volcanic rocks in the vicinity of Carrizozo, New Mexico: New Mexico Geological Society 49th Field Conference Guidebook, Las Cruces Country II, p. 117-122, 1998.

NM Museum of Natural History - Carrizozo

USGS Volcanoes, Carrizozo

Volcano Discovery

Volcano Live

Updates

Appealing to your patience ...  Since October 28th, I have been attempting to post at least once a day on both blogs, for at least a month.  This is to atone for the patchy, sporadic posts that have unfortunately been the case for too long.  (I am also attempting to waste less time on Facebook.)  

As the Itinerant Geologist posts are generally longer and usually with multiple photos, I have gotten behind on this one.  Attempts will be made to "balance out" things.

Posting other people's videos or cited photos, with no accompanying additional notes, is just an unintended stopgap measure.  So if you see just a posted video or photo, that is the "crude" version, with the edited "refined" version planned to arrive in stages (I have a life outside of blogging too, that must be addressed first.)  Responsibilities are what they are.

Geology: Relative Dating of Rocks

I haven't had time yet to watch every minute of this video, but the point of "Relative Age Dating" is to establish a sequence of events, even if the "precise" radiometric ages for each event are not known or otherwise available.

 Figure 1.

As this rock (above) is not in its original position, the estimate of which lithology is the older host rock vs. the younger intrusion is based upon a general assumption that the rock is from a local Georgia Piedmont quarry.  Also, in this case, the sharp, straight contact is assumed to be that of an intruded pegmatitic dike.

 Figure 2.

In the case of Figure 2, this outcrop is on eastbound Ronald Reagan Parkway, adjacent to the off-ramp to Lawrenceville Hwy. (I.S. Hwy. 29).

 Figure 3.

 Figure 4.

 Figure 5.

This laboratory specimen (above) is probably from Apache Junction, AZ.

 Figure 6.

Actually, Figure 6 is a combo.  The Xenolith is an "Inclusion" and the Fracture is a "Cross-Cutting Relationship".

Figure 7.

The Host Rock of Figure 7 is the Elberton Granite and the dark schistose rock is the older Xenolith.

 Figure 8.

 Figure 9.

Among the other features of Figure 9, the Joints and the Thrust Fault are Cross-Cutting Relationships.

 Figure 10.

 Figure 11.

Laurel Park, Lake Lanier, Hall County, Georgia.

Figure 12.

A small fault (Cross-Cutting Relationship) is present in the Inner Gorge, in the lower part of the photograph.

Figure 13.

In Figure 13, clasts within the boulder represent one "generation" of Inclusions, the boulder itself within the Ash Flow Tuff represents another, while the Pumice Fragments in the Tuff represents still another.

Figure 14.

The Tuff specimen is from the Valles Caldera eruption, near Los Alamos, NM.  The Conglomerate is from the Crater of Diamonds State Park, Murfreesboro, AR.

Naked Science - Landslides

 

Mass Wasting is the down-slope (down-gradient) mass movement of Earth Materials, e.g., rock, sediments, mud, soil (and its associated plants), due to gravity and various "Triggering Events".  It is part of the Natural Processes that reshape the land and includes characteristics of both Erosion and Deposition.  

Though it is a Natural Process, we humans often play a role in facilitating the conditions leading up to the Triggering Events.  Mass Wasting is one of those aspects of Earth Science that average people can learn for themselves, in an effort to avoid hazards and point them out to others, including authorities.  The idea is not to live in fear, but to be educated and aware of the subtle warnings that Mother Nature often gives us.  In other words, you don't have to be an Engineer to be aware.

 Figure 1.

Sometimes, we can use "construction materials" as ways to illustrate Earth Processes.  A couple of reasons are; 1) The setting is on a small scale and easily-observed; 2) There is no soil/vegetation cover; 3) In the cases of Figures 5 & 7 below, the piles are fresh, dry, and devoid of the Cohesion of clays.  In this case, the pile of sand is of a uniform size, better still for illustrating the "Angle of Repose".  

In regard to "Angle of Repose", different scientists will use somewhat different terms to define it, so you may need to read multiple sources before you completely understand the term.  [And take notes to help you remember.]  

The Angle of Repose is basically a natural angle of stability for earth materials.  Strahler and Strahler (1997) define it in their Glossary as: "natural surface inclination (dip) of a slope consisting of loose, coarse, well-sorted rock or mineral fragments ... ".  For loose, well-sorted, dry sand, the natural Angle of Repose is about 35 degrees.  The degree of Angularity can affect how the grains "lock" against each other to support the slope.  A pile of .5 mm diameter well-rounded beach sand will have a slightly lower Angle of Repose than a pile of .5 mm diameter angular river sand or quarry-crushed rock.  Larger angular (or rough) clasts can support steeper angles, e.g., Cinder Cone slopes, Talus Slopes, and Talus Cones.  (Figures 10 & 11 show Talus slopes and Talus Cones)

In the image of this construction sand pile (and Figure 6), you can see how the numerous, tiny landslides are "trying" to stabilize this "over-steepened", unnatural slope.  When humans cut into the "Toe" of a natural slope, it removes that natural support at the base and it "Oversteepens" the slope.

Figure 2.  

Figure 3.

Arid Climate Weathering is different from Humid Climate Weathering, partially because Chemical Weathering plays a bigger role in Humid Climates, whereas Physical Weathering plays a bigger role in Arid Climates.  Monument Valley is a good place to illustrate Arid Climate Weathering.  [Perhaps this video will help explain.]

In the arid climate of Monument Valley, the Organ Rock Shale forms a relatively-stable slope, easily seen from a distance.  In this and other arid climates, cliffs are usually either Sandstones or Limestones.  Unlike humid climates where rainfall and natural acids readily dissolve carbonate minerals, when it does rain, the dissolved carbonate in the water doesn't travel far, i.e., when water evaporates, fractures in the limestone are "repaired" as the dissolved-carbonate re-solidifies.

Using the Oklahoma example above:  Here is a naturally-eroded slope and cliff "combo".  The top of the Cliff could be referred to as the "Head", while the base could be referred to as the "Toe" (per the usage of some people).  In the case of Figure 2, the "Toe" of the slope rests upon the somewhat stable floodplain of the Cimarron River.  

If the Permian Flower Pot Shale was well-lithified, it would better "support" the gypsum cliffs of the overlying Blaine Formation.  But as the Flower Pot Shale appears to be not-well-lithified and because Oklahoma's rainfall is higher than that of Monument Valley, Rockfalls are going to be a persistent occurrence at this site.  Based upon the size and concentration of fallen clasts at the base of the cliff and/or slope, one could make a "snap judgment" of the frequency of rockfalls.  In other words, pitching a tent at the base of the slopes would be a bad idea, besides, the floodplain at that site is very narrow.

Figure 4.

In the "Book Cliffs" image above, there are three "sets" of cliffs, underlain by shales in the upper portions of the exposure.  Below is a long slope with the base obscured.  It might be difficult to estimate a frequency of rockfalls, but I have pointed out two evident future rockfalls.

Figure 5.

The scene above is fairly common in the "Four Corners area".  Similar to the Oklahoma image (Figure 2), just in a drier climate.

Figure 6.

Figure 7.

"Saprolite" literally means "rotten rock".  Making an unsupported vertical construction cut in Saprolite is a bad idea.  Others may differ, but because this mass didn't fall far enough to shatter, I call the Figure 7 Earth Movement a "Nontraditional Slump", i.e., it is still somewhat "coherent". 

Figure 8.

Figure 9.

Figure 10.

Figure 11.  Talus Cone, awaiting labeling for Educational Use.

Small Talus Cone, west side of Virgin River Valley, Zion National Park, UT.



[Editing currently in progress.  More images planned, too.]

Massive Landslides Caught on Camera 2

Suggestion: From this and other Mass Wasting videos, learn the conditions leading to Mass Wasting events.

Johnson Canyon Flash Flood, July 28th 2017

Getting to photograph and/or video a flash flood start is another "Bucket List" item.

(I have seen a New Mexico flash flood a few minutes after it began is the closest I have been.  Sadly, I didn't have my camera with me.)

Ice Age Lakes between Seattle and the Cascade Range

I hope to visit this area, some day.  (Bucket List thing.)

Lava Tube Shatter Ring Reference

Lava Tube Shatter Rings.

The subject of my 1990 UTEP Geology Master's Thesis.

Bulletin of Volcanology, April 2011

"Lava tube shatter rings and their correlation with lava flux increases at Kīlauea Volcano, Hawai‘i"  

By Tim T. Orr, USGS

Something I Wish I Could Still Do...

Add to the Bucket List/Geo-Bucket List, I wish I could go on a college-level Geology Field Trip again.  Largely for the sake of nostalgia, perhaps as the Visiting Curmudgeon.  And maybe to catch up on current interpretations.

A Few More 40th Anniversary Thoughts and Photos

Part 1 is here.

All in all, my 1979 summer job south of Farmington, NM was an enjoyable respite from the personal storms of the Spring and the unforeseen personal storms to come.  Basically, I was dealing with the chronologically drawn-out wreckage of my first serious love, that would continue after I returned to El Paso for the Fall Semester.  ["That's all I have to say about that."]

To reiterate, the purpose of the Fossil Recovery Project in the Bisti Badlands was to clear a designated area of all Cretaceous vertebrate fossils (dinosaurs, turtles, crocodiles) and obtain samples of all occurrences of "petrified" (Permineralized) wood and invertebrate fossils (freshwater clams).  The target formation was the Fruitland Formation.  Western Coal Co. furnished us with great topographic maps (1" = 100', 5-foot contour interval).  It made locating sites pretty easy.  Each site had to be located as accurately as possible and for the vertebrate sites, we had to pick up each and every fragment and place the fragments in cloth collecting bags.  Sometimes that meant 2 hours on your hands and knees in the sun.  But then I was a bit younger than I am now.  We covered 2 and 1/2 square miles in 6 weeks.  We might have done more, but it rained almost every day for the first two weeks.

These photos have been labeled (some need to be relabeled for better readability on projection screens) for educational purposes.

 Figure 1.

 Figure 2.

 Figure 3.  Bony "Scutes" from the back of a crocodile.

 Figure 4.

 Figure 5.

 Figure 6.

 Figure 7.

  Figure 8.

On the way into and out of our daily "base camp", Ron had pointed out a red "clinker zone", in which the clay had been baked by a long-ago coal-seam underground fire.  I stopped one day and picked up a couple of pieces with plant fossils (later gave one away).  [See comments in "Regrets".]

What I did on my days off.  

Both my field partner Ron and I had a pickup truck with a camper.  His a late-1960's Ford F-100 and my 1976 Jeep J-10 4x4.

Figure 9. 

As my field partner and I had different outlooks on life, while he chose to veg out in his motel room in Farmington, drink beer, and watch TV, I chose to camp out (in my truck) at a local campsite and shower there (to save money), then leave out the next morning, usually for photography, mineral collecting, and looking for old beer cans in the Durango and Silverton, CO areas.  And visiting some of the watering holes in Silverton and chatting with the locals.  We were there for 6 weeks, mid-May through June.  I did return to Moab, UT and Arches National Park (see results below).  I also did a return trip to the Black Canyon of the Gunnison, after visiting it in 1977 (no camera problems there, either time).

Noteworthy Glitches

Camera

My personal 35 mm camera at that time was a Miranda Senorex II.  It seemed pretty good for its time (the middle and late 1970s).  To save money, I usually shot Kodak Kodachrome 64 slides.  Or Ektachrome 100 when I was around more greenery.  

In El Paso, I was usually satisfied with K-Mart processing services.  there was usually about a 5-day turnaround.  Farmington being more remote, the K-Mart there had a 10-day turnaround, but there weren't other choices that I could find easily.

Not sure when the shutter jammed.  It had done the same during my 1977 Field Camp field trip.  Then it somehow unjammed itself.  It always sounded as if it was functioning.  I would only find out when my slide film was returned "all black", i.e., unexposed.  In 1977, it caused me to not get any photos at Arches National Park, yet I got photos before and after at Mesa Verde and Canyonlands National Parks.

After I got my first un-exposed rolls back, I had no other choices but to keep shooting, just in case.  But it didn't come back (unjam).  So a 2nd trip to Arches yielded no photos.

Paychecks

As Western Coal Co. was funding the project (by Federal Law, prior to opening a strip mine), I assumed I would get paid in Farmington.  Instead, the money was funneled through UTEP and UNM to pay the student workers.  Driving back 440+ miles to El Paso to pick up a check just didn't work.  One of our professors would visit once a week and I called the folks in El Paso and begged them to let my professor pick it up.  No dice.  

So, for 6 weeks, I had to borrow money from my professor and my family and live off ham sandwiches and potato chips. I did have a credit card for emergencies.  When I finally got paid when I went back to El Paso, the $2200 I got for 6 weeks was pretty good in 1979, even after paying back the loans. That paycheck glitch also prevented me from searching Farmington pawnshops for a backup camera. 

Weather

According to the Silverton "old-timers", the 1978/1979 Winter was the worst since 1950/1951.  I had wanted to try gold panning in the Silverton area, but the creeks and rivers were running too high.  And too many backcountry and mountain roads were snowed in until the 3rd week in June.

Truck Tire Issues

I somehow suffered a sidewall cut on one of my Jeep's tires.  The tire dealer (same one as El Paso) didn't have the same tread pattern, they didn't seem to want to order only 2, did I worry too much over different tread patterns?  Having been told "bad things" about mixing tread patterns, I wound up getting "street tires" for the front.  They lasted for 100 miles, before the rocks on the backcountry roads did them in.  I had to buy whatever I could get two of in Silverton and just deal with the results.  

Regrets

Not visiting Chaco Canyon.  Enough said.

Not having a back-up camera, even a "disposable" 35 mm camera.

Not synching my days-off with the normal Saturday/Sunday weekend.  I think Ron and I arrived on a Thursday and went to work the next day.  So our days off were Wednesday and Thursday.  Not really a problem, until I discovered the University of New Mexico Archeology base camp between Farmington and Aztec.  

After my days off in Silverton, I stopped by to chat and was invited to hang out for dinner and a beer, then go meet Ron the next morning and return to the field.  And I was invited back to their camp on weekends, just park my truck and blend in (I think there were perhaps two or three dozen students and grad students there).

After my painful springtime breakup, I was lonely and at that time, there were more female students in that Archeology base camp than I was used to seeing in Geology settings.  Ron seemed unwilling to mix with the UNM folks.  I should have put my foot down to nudge our days-off to a normal weekend schedule.  I regret not being more assertive.  So it goes.

Not filling a bucket with the "Clinker Zone" samples.

As the site was off the highway and we had permission to be there, I should have picked up more samples.  (As was planned, the area is now an open-pit coal mine.  So "saving some for other people" would have done no good.  I would probably have given away most of the specimens if I had gotten more.)

Saying Goodbye to the 40th Anniversary of the "Best Summer Job" (Ever)

As 2019 is drawing to a close, it is time to revisit the best summer job I ever had and then say "Bye" to its 40th anniversary (unless I am inspired to write about it some more).

I have reminisced about my 1979 summer job as part of a Fossil Recovery Project south of Farmington, New Mexico, numerous times.  And numerous times I have entertained kids with the story of "How I Got Paid to Find Dinosaur Bones, as a Summer Job". 

The area is called the Bisti Badlands.  One of the major drainages (normally dry) is called De-Na-Zin Wash.  As a Western Coal company coal mine was slated to open, by Federal Law, after Archeological surveys and Recoveries were done, then along came the Fossil Recovery.  It included two of us from UT El Paso and an unknown number later from the University of New Mexico.  The Recovery included all recoverable Vertebrate fossils and samples of Invertebrate fossils and Permineralized wood.  

(There was supposed to be a 1980 repeat, but apparently, they couldn't get all of the permits for the Federal and Tribal lands.  We covered about 2 and 1/2 square miles in 6 weeks.  (And that was after it rained almost every day for the first two weeks.)

My field partner Ron and I each had our own pickup truck with a camper.  On our days off, he preferred to "veg out", watch TV, and drink beer in the motel room.  I preferred to roam around the mountains of SW Colorado, camp out, and drink beer there.  As I think we started work (after driving 440 miles from El Paso the day before) on a Thursday, so our "weekends" were Tuesday and Wednesday.  (I wish we had adjusted to a normal weekend, for reasons I may describe in a future post.)

Aside from some painful life experiences (in regards to getting my heart broken), the summer of 1979 was a pretty cool summer and driving back through those areas (Farmington, NM and Durango, CO) during 2015 and 2016 provided memories, enjoyment, and adventures.

Here are a few scanned slides from 1979 (complete with a few dust spots).  They are of the exposures of the Cretaceous Fruitland Formation.  As I was generally unfamiliar with the area, I am uncertain about the direction in which most of these were taken (and there weren't many nearby landmarks).

 Figure 1.  Mountains in the background are uncertain.

 Figure 2.  A freshwater clam.

 Figure 3.

 Figure 4.  Thin surficial coal seams.

 Figure 5.  A nice stump cross-section.

Figure 6.  A side view of this nice Permineralized stump.  (I hope it wound up in a museum.)

 Figure 7.  An Erosion Pedestal (right) and a dinosaur bone (center).

 Figure 8.  Same dinosaur bone.  I think most of the dino bones were from Hadrosaurs.

 Figure 9.

Figure 10.  As you can see, it ain't suitable for plant growth = "badlands".

Figure 11.  Erosion Pedestals. 

 Figure 12.  Hillside littered with Permineralized Wood.

 Figure 13.  We had to Recover every bone fragment associated with an exposed dinosaur bone.

Figure 14.  Another set of Erosion Pedestals. 

 Figure 15.

Figure 16.  A rather nice Permineralized log, complete with knots.

Well, that's enough for now.  May do a follow-up with more photos.