Posts Tagged ‘volcanoes’

The Riddle of Red and Black

September 22, 2019

Guy Noir, the Prairie Home detective, spent many years trying to puzzle out answers to “life’s persistent questions.”

Some of those life questions are very important, such as how will I make a living?; what career should I  choose; is there life after death? 

Others are not so important as that, but nevertheless persistent, which is to say. . . they keep coming back again.

This morning I find myself researching, in order to answer a question that has perplexed me for a long time, ever since Pat and I started visiting the Hawaiian Islands about a dozen years ago.

The question is: What’s up with these red rocks and black rocks that seem to constitute the entirety of this Hawaiian island archipelago?

Spoiler alert: I haven’t completely figured it out yet. I will be describing herein my path of wonder, not necessarily giving you an informed report on the subject of red rocks/black rocks in Hawaii.

While I have not yet fully discovered why some Hawaiian rocks are red and others are black, I have managed to gather some learning along the way.

In many ways, I am person who is driven by an appreciation for lifelong learning.

The ancient dynamics and pyrotechnics through which these islands were formed is described in noteworthy detail here:

    https://en.wikipedia.org/wiki/Evolution_of_Hawaiian_volcanoes

You can learn far more about this subject by following the above link. 

But getting back to my little take on it . . . In our ten visits to Hawaii, the photo that I snapped which best shows what lava looks like is:

Formless

This dark gray/black solidified lava flow is called pāhoehoe. You see it throughout all the islands, but mostly on the big island, Hawaii, because it is the newest island, and the one that still displays an observable continuance of recent and still-active volcano activity. It’s fascinating stuff, especially for a curious person like me who took a geology course a long time ago.

We enjoy traveling these islands, year after year. In noticing the vast array of different volcanic rock formations, this question about the red rocks keeps popping up, as “one of life’s persistent questions.’ This never fails to fascinate me. 

Here’s a pic, taken a few years ago on Maui, that shows two layers of black rock with a layer of red rock between them.

RockStory

So we can see that there is some kind of “story” told in these rocks, some sort of history.

Geologic history, Earth history. Hawaiian Islands are perhaps the best location on the planet to identify features by which Earth reveals itself, by telling, in the rock, its own story.

SO, what about that strip of red rock in the middle? you may ask? I’m glad you asked.

I don’t know, but I did ask a Hawaiian about it.

As she began driving our tour bus up into Waimea canyon, I asked Jana about the red rocks, and she said the difference was:

“Rust.” The red rocks have rusted. And, she said, they are older.

I greatly appreciated her immediate answer. It has helped me a lot. It does seem, however, a little too simple for my over-active mind to accept completely. Nevertheless, her concise explanation was confirmed a few days later when I found online a Galapagos report from Cornell U:

     http://www.geo.cornell.edu/geology/GalapagosWWW/LavaTypes.html

Herein I found an authoritative source confirming that the difference in color, in some cases, is “a reflection of age. The older ʻaʻā . . . has weathered and the iron in it has oxided somewhat, giving it a reddish appearance.”

And that’s good enough for me to understand a little bit about what is going on in these vast, ancient islands, which represents processes that have built up our vast, ancient earth.

Meanwhile, back at the beach, I found, two evenings ago, a different working out of the red/black interface.

KaRoksRedBlk

In this scenario, I surmise that, somewhere along the ancient timeline, red rocks were weathered down to red sand and grit, then deposited at low places. During that time, the volcano or the weather must have torn black boulders loose. The black rocks tumbled down into red sands as what you see here. It appears to be black lava rocks trapped in red sandstone, nowadays being gradually dissembled by the thrashing Pacific Ocean.

Or something like that. That’s my answer for the riddle of red and black, one of life’s persistent questions.

  Glass Chimera

Wai’ale’ale

September 14, 2019

KauWaialeale1

Kauai

Hawaii

where long

ago hot lava

spewed up skyward

into prehistoric atmosphere

and falling back down to earth

deposited Wai’ale’ale the mother of

all Hawaiian volcanoes dormant volcanoes

now

stands

as cloud

catcher

mist

collector

waterfall

dropper

streams

trickle

KauWaialeale2

down

ancient

crater

plummet

KauWaialeale5

and then

flow

Wailua

River

to Pacific

KauWaialeale6

from

magma

mountain

Wai’ale’ale

Mahalo

Selah

Glass half-Full

Speculating on a Stratified Story

June 25, 2012

Wandering on a rocky Hawaiian shore we discovered this layer of red rock stratified between two layers of black rock. I was wondering, how did this happen?

I am no geologist, but I have done a little reading about the earth and the rocks within it, and some exploration, as you can see here. That’s my hand in the pic.

In offering a layman’s analysis of this geological puzzle, I must begin with a basic fact: TheHawaiian islands are all exposed parts of one very big volcano, situated on the Pacific Ocean floor three miles below the surface, but extending high enough to protrude into air.

In this particular case, the red strata, formerly hidden within massive black/gray lava fields on the edge of Maui island, has been exposed by the erosive action of nearby ocean waves that have been perpetually crashing upon these rocks for a long time.

What I do now about the black layers is that they are igneous rocks formed by volcanic lava, which had flowed from the erupting earth fissures many years ago.

I’m not so sure about the red streak. My investigating touch (shown above in the pic), indicated that the texture of the red rock is granular, sandy, which is different from the feel of the black layers below and above it. This apparently sandy composition may indicate that the red layer is sedimentary rock. If that is correct, we could say that the red, iron-bearing deposit was laid by weathering wind/water forces, and laid upon the black basalt lava rock below it.

Presuming that my sedimentary assessment contains, perhaps, a grain of truth, we could infer that the red streak may indicate a more recent epoch of time when the volcanic lava flow had ceased, enabling earth processes to leave something different for awhile–say, a few thousand years? I don’t know.

A geologist could tell you. On the other hand, he may blow my whole theory to smithereens, just like the volcano, Puukukui, blew all that black rock into the location you see here.

Whatever that red layer is, obviously it was later covered by a another black volcanic lava flow, and thus was covered for many an eon until the Pacific Ocean knocked the shoreline around and taught it, and us human inquisitors, a thing or two. If you can help me interpret this stratified story, please do. Rock on.

Glass half-Full 

Planetary birth pangs

June 22, 2012

Out in the middle of the Pacific Ocean, about three or four miles down below the water surface, our planetary home gave birth to Hawaii.

As Father in Heaven had sewn within Mother Earth’s deep crevices the seeds of creative planetary development, she cried out from the Deep in her anguish when the aweful time of delivery had come.  With wailings of hot magma and rumblings of steamy contraction,  Mama pushed out those volcanic islands-to-be. Spewing forth from her ocean floor, striving upward from her tectonic fissures,  the nascent super-hot lava tumbled and rolled skyward from beneath its tectonic birthplace, into cold Pacific waters.  Then,  after a few million years of childlike submersion under watery tutelage, these pubescent islands stuck their stony little heads out into air and proclaimed to the birds and the stars that they had at last arrived, ready to be transformed as the land of the living.

Yesterday, we were walking on some of those rocky island shoulders. We watched with fascination as vehement Pacific waves pounded her dark lava extremities with ceaseless planetary fury, casting high cascades of spray into the blue sky with airy veils of aquamarine and silver-white brilliance. The basaltic wasteland whereon we trod was sculpted with moonish alacrity, revealing with otherworldly starkness layers of black, grey, reddish brown– solid rock punctuated with massive boulders, cracky protrusions, some rounded by the rushing of the water and wind, others still sharp with the newness of elemental violence.

Then, there is was. A small carpet of vivid green something living, splayed upon the barren rock, growing as merrily as you please in the sunshine, with little orange-tipped teardrop succulent leaves spreading across the lithic void.

“That,” said the traveler to his nephews and nieces, is the beginning of dirty old life.

CR, with new novel, Smoke, in progress