BajaNomad - I keep scratching my head???

I keep scratching my head???

Iflyfish - 1-20-2013 at 10:58 AM

With Catavina and the unique geology and paleontology of Baja on my mind I started to do some research on the Peninsula. The literature is full of geological jargon and difficult for me to wade through. The scope of it's history is vast and complicated.

I found this overview useful in getting a big picture:
http://www.sci.sdsu.edu/salton/The%20Gulf%20of%20California....

I still can't get my head around why the unique formations of Catavina?

There are so many different kinds of rocks on the beaches here in El Visciano Biosphere Reserve. One also finds amazing sea fossils very close to the surface and what look like basalt, quartz, jasper and green colored rocks. There are mounds of sand that clearly appear to be ancient sea bottom and deposits that look like sea shore. There are basalt outcroppings that are clearly volcanic. It looks like the land has been covered in volcanic flows, sea bed sedimentation, tectonic plate upwelling, twisting formations perhaps from the shifting of the plates. It's all fascinating.

I would appreciate your sharing what you know about how the amazing rocks of Catavina got there. How can we understand the geological diversity of Visciano Biosphere Reserve?

Thanks,
Iflyfishinaweandwonder

Udo - 1-20-2013 at 11:09 AM

I recall reading in my geology class @ UCLA that the Cataviña rocks were originally shlepped by the receding glaciers from the northern area on South America.
I am a little fuzzy about the details, Rick, but at that time Antarctica had a higher ice shelf than the Arctic and therefore the ice retreated noth-bound first, bringing with the glaciers the South American boulders we now see in Cataviña.
Some of those same boulders are found in areas of the Rockies, and Cascades.
I do not profess to know geology :biggrin:

, and my college days were 40 years ago.

Hook - 1-20-2013 at 11:11 AM

I always assumed that material "weathered" away around the granite, leaving them exposed. Same with El Pedregoso. It just doesnt seem like it could be moraine remnants that far south, but I dont know. Just speculating.

DENNIS - 1-20-2013 at 11:24 AM

"I keep scratching my head???"
========================

This stuff is guaranteed to work, Rick. :biggrin:

[jes funnin' wicha]

http://www.medshopexpress.com/838952.html

bajaguy - 1-20-2013 at 11:55 AM

Similar types of rocks on Hwy 3 between Ensenada and Ojos Negros

Skipjack Joe - 1-20-2013 at 12:02 PM

This could be a fascinating thread, depending on where and how far nomads will take. One of the best qualities of any baja journey is to look at the country around you and try to speculate how it got that way.

For example. There are many buttes along the way: mountains sheered perfectly horizontal at the top. Clearly the forces from pounding waves must have accomplished. And yet they're so high above ground that the only way to explain is that the landmass rose, lifting what was at sea level to new heights. The one near the turnoff to Pt Abreojos comes to mind.

It's an enormous puzzle. The land is shaped and reshaped and then you show up at a point in time and try to make sense of how it all happened by what's out there at a point in time.

Regarding the boulders. I'm not a geologist but it seems to me that all such boulders have probably been created in similar ways. Therefore perhaps the explanation that park rangers provide at Joshua Tree State Park may apply to the Catavina boulder field as well.

There's also a peak on the west side of hwy 1 that we call "The Tata". It's perfectly cone shaped except for the "nipple", which is vertical. My guess is that this "nipple" is of a harder substrate that's more resistant to erosion.

Then there's the biological questions. There's an entire hillside of red barrel cactus. Why there and nowhere else? And can you predict where an ocotillo stand will grow by looking at the landscape?

inselberg

Skipjack Joe - 1-20-2013 at 12:11 PM

This is an interesting explanation that has relevance to the Catavina boulders:

http://www.desertusa.com/magdec97/rock/rockpile.html

From this:

To this:

[Edited on 1-20-2013 by Skipjack Joe]

Osprey - 1-20-2013 at 01:00 PM

Igor is so right. There's a huge diorama of the formation of the structures at Monument Valley in Arizona that teaches you patience ---- after the 15th change, from seabed to mesa, to upheaval, then glaciation, back to seabed, it will have your head spinning. Heads made similarly itch when caused to spin. I have several theories on that. You may want to U2U me for a zip of the exhibits. You see it's all about the basal........

Aliens

bajaguy - 1-20-2013 at 01:03 PM

Think Roswell........

woody with a view - 1-20-2013 at 01:34 PM

re: Pedregoso. first time my son saw the stack i wondered out loud how they all got there since there was nothing like it anywhere around. he said they stacked them while grading the new road!!!! :lol:

DENNIS - 1-20-2013 at 01:49 PM

Quote:

Originally posted by bajaguy
Think Roswell........

Think God..........hey.......it's Sunday. :biggrin:

vgabndo - 1-20-2013 at 02:30 PM

I think it is Dawkins who uses the illustration of imagining that the span of one's arms, fingertip-to-fingeretip, represented the total time that LIFE had existed on the planet. He goes on to express that if we then shaved off a fingernail, we would then have removed all evidence of any animal that looked anything like human. That's just for life. Geologic time....

13 billion years is a long time.

Minch and Leslie, in their The Baja Highway have a bit on Spheroidal Weathering. To me the physics is so pure I can "get it".
A fractured block of granite has three surfaces to erode at a corner, and only two at an edge. Given enough time; roundness.

Iflyfish - 1-20-2013 at 05:52 PM

This is making more sense to me.

Igor's post on the inselberg shows how rocks like Catavina could well be formed. I, like Udo, had postulated a terminal moraine, where glaciation deposited rocks rounded by the pressure of moving glaciers, then receding and leaving behind round rocks created under the mass of ice. I can clearly see from Igor's post how these round rocks could be the result of upwelling and erosion, fascinating.

I appreciate Perry's graphic example of the time involved in the formation of these various geological phenomenon. It is clear from my reading that earth faults and plate tectonics moved massive geological materials apart, up and around under volcanic materials deposited on what was at one time the surface. It is also clear that rising and falling sea levels played a part in creating these amazing areas where one can find Paleolithic Fossils on the surface and see sheer cliffs topped with thick layers of clam shells more modern clam shells. There are places here where it appears that there are visible both sea bed and sea shore. There are areas where one can clearly see bedrock basalts of various kinds, clearly the work of volcanoes. I would be most interested in seeing a link on this from you Osprey, others may also share my interest.

I had a bit of an awakening before coming down to Baja this time from Oregon where we have the Columbia Gorge with massive basalt cliffs standing hundred of feet above the river with waterfalls cascading down. This is a spectacular sight if you have never driven the Gorge. A friend told me before I left that the huge Missoula Floods, about 8 of them, caused by southern flowing glaciers breaking of an enormous ice dam that formed and broke in Montana released enormous amounts of flow the consistency of wet cement that carried materials, including glacier chunks to a height of 400 feet ABOVE the existing tops of the Gorge. It is hard to get ones head around such massive geological events and I am starting to see how some of these fascinating geological features could have come into being.

I appreciate the thoughtful and humorous posts on this topic and hope I can learn more from fellow Nomads about this amazing peninsula.

Iflyfishconminomadamigos

BajaBlanca - 1-20-2013 at 06:08 PM

great thread as those huge boulders are just incredible to ponder on.

I adore the book THE BAJA HIGHWAY, I have read it over and over as we travel up or down.

shari - 1-20-2013 at 07:06 PM

today I roamed through ancient oyster beds...up an arroyo...mind boggling indeed!

DENNIS - 1-20-2013 at 07:12 PM

Quote:

Originally posted by shari
today I roamed through ancient oyster beds...up an arroyo...mind boggling indeed!

Same here. There are baby Abalone shells and others in the hillsides up above my place.

vandenberg - 1-20-2013 at 07:39 PM

Quote:

Originally posted by vgabndo
I think it is Dawkins who uses the illustration of imagining that the span of one's arms, fingertip-to-fingeretip, represented the total time that LIFE had existed on the planet. He goes on to express that if we then shaved off a fingernail, we would then have removed all evidence of any animal that looked anything like human.

Don't bite your nails or we're doomed. :biggrin:

Osprey - 1-20-2013 at 07:40 PM

Flyguy, I'm very busy trying to get my head to accept the peninsula separating from Mexico. (They ) say it took 4.5 million years. How come the Sierras of California didn't shove off the same way? Same kind of tectonics involved way back then. How come Mexico couldn't hold on to this place given the weight of the Sierra Madres?

Ateo - 1-20-2013 at 07:49 PM

The Earth is only 6000 years old silly Nomads. That is my lame trolling comment. =)

Now I'll go back and read this whole thread (looks muy interesante) from the beginning instead of scanning quickly and posting out of my own narcissistic tendencies. =)

Iflyfish - 1-20-2013 at 08:30 PM

If you go to the original posting in this thread there is a very interesting description of how the shifting of plates affected the mountain ranges, moving one from its N/S axis to E/W, or close proximity thereof. We are talking movement on monumental scale.

Iflyfish

AmoPescar - 1-20-2013 at 08:53 PM

YEAH...I WAS THINKING MAYBE FLEAS OR SOMETHING! Funny what first pops into your mind sometimes when you read something!!

Quote:

Originally posted by DENNIS
"I keep scratching my head???"
========================

This stuff is guaranteed to work, Rick. :biggrin:

[jes funnin' wicha]

http://www.medshopexpress.com/838952.html

But looking forward to reading all the explanations of why it's that way. The rocks and rock formations on CA Hwy 8 as you head East and down into the Imperial Valley, Calexico and AZ are also very interesting!

Miguelamo :yes:

Iflyfish - 1-21-2013 at 08:24 AM

Quote:

Originally posted by AmoPescar
YEAH...I WAS THINKING MAYBE FLEAS OR SOMETHING! Funny what first pops into your mind sometimes when you read something!!

Quote:

Originally posted by DENNIS
"I keep scratching my head???"
========================

This stuff is guaranteed to work, Rick. :biggrin:

[jes funnin' wicha]

http://www.medshopexpress.com/838952.html

Good one!

Good thing I didn't start this thread with "I was just standing around scratching my burro and wondering about these rocks"! Goddess only knows what that might have generated!

Iflyfish

Iflyfish - 1-21-2013 at 08:28 AM

Quote:

Originally posted by Ateo
The Earth is only 6000 years old silly Nomads. That is my lame trolling comment. =)

Now I'll go back and read this whole thread (looks muy interesante) from the beginning instead of scanning quickly and posting out of my own narcissistic tendencies. =)

You might have something there according to Louisiana and Tennessee Legislators. Watch them take on this kid take the issue on. The videos are jaw dropping.

Iflyfish

Iflyfish - 1-21-2013 at 08:43 AM

I understand that an ancient camel fossil has been found in upper Baja and that there is a petrified forest in Baja.
http://www.bajabound.com/bajatravel/petrified_forest_of_el_r...
This just gets more curiouser and curiouser.

Iflyfish

David K - 1-21-2013 at 09:42 AM

What I recall from my geology class days...

The granite is the older rock, weathering/ quakes turns it into boulders. The lava flows and volcanoes are newer and have covered much of the granite rock... You see this as you go from Cataviña to Laguna Chapala. El Pedregoso (the boulder mountain) was once the highest mountain in that region, then the volcanoes rose higher, and lava flows filled the area.

The peninsula and the west side of the San Andreas Fault in (Alta) California is on the Pacific Plate part that is moving north and forming the Gulf of California. The Sierra Nevada range is on the seperate North American Plate... Cabo San Lucas started near Puerto Vallarta before the plates separated.