Sunday, April 16, 2017

Landslide in Alaska's Taan Fjord

Ground view of the landslide scar in Taan Fjord.
In October, 2015, the land gave way in a remote Alaskan fjord letting loose 200 million tons of rock. When the rock entered the sea, it sent a wave 600 feet high up onto the other side. No one saw it, except those monitoring a seismograph at Columbia University in New York. You can read an article about the event here.

Note the landslide scar at the head or the fjord to the left of the glacier.

Thursday, April 13, 2017

Giant Paleoburrows in South America Thought to be Dug by Ground Sloths

Discover Magazine is reporting on giant paleoburrows that have been identified in the Amazon Basin in South America. The burrows are thought to have been excavated by Ice Age megafauna.

The morphology of the caves as well as the youthful nature of the material they are found in, suggests that they were dug perhaps by giant ground sloths or giant armadillos. The full article in Discover Magazine can be read here. (The images I have included in this post are from the article).

Researchers note that these paleoburrows have been also identified from the southern Brazilian states of Santa Catarina and Rio Grande do Sul, but not across the border in Uruguay. They also have not been identified north of the Amazon. Now some are beginning to wonder if they simply have not been recognized, although a lack of suitable rock type or the distribution of species could also explain their absence elsewhere.

Monday, April 03, 2017

Rocky Mountain Association of Geologists Honors "Carving Grand Canyon" with the 2016 Geosciences in the Media Award


I was honored this past November to receive the Geosciences in the Media Award from the Rocky Mountain Association of Geologists for my book, "Carving Grand Canyon." I am honored to have this book recognized. First published in 2005 by the Grand Canyon Association, it was re-released in a 2nd edition in 2012. The book highlights the history of thought on how and when the Grand Canyon may have formed and details all of the current theories. You can read reviews on Amazon of the book here.

All of the past awardees for this honor can be found at this link. In 2014 another one of my books co-authored with Dr. Ron Blakey won the same award - "Ancient Landscapes of the Colorado Plateau."  Reviews on Amazon.com can be seen here.

Thanks to everyone who reads and shares my books. Geology rocks!

Wednesday, March 29, 2017

Trackway Paradise in Australia's Kimberley Region

A new trackway in the Kimberley region of northwest Australia was recently announced. Here are two photos and the story is here.



And thanks to reader and friend Joan L., here is another story about the find. To see more fantastic rock photos of the Kimberley, see here. And finally, a map and description sent to me from Joan L.

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Geology and Geomorphology of the Kimberley 

The rocks of the Kimberley region contain a geological record that spans the last 1900 million years of the Earth's history. The oldest rocks in the Kimberley form the Lennard Hills in the west Kimberley and the Bow River Hills and the Halls Creek ridges in the east Kimberley. These comprise metamorphosed sediments,volcanics and granites.


Geological Map of the Kimberley Region 

The main part of the Kimberley, known as the Kimberley Plateau comprises of generally flat lying sedimentary rocks. These sandstones and quartzites were deposited about 1800 million years ago by major river systems that flowed from north to south across the whole region. These rocks also contain considerable volumes of concordant basalt lava flows that are a characteristic of the Mitchell Plateau. Subsequent to around 1790 million years ago the region has seen several periods of geological activity that has resulted in deposition of further sedimentary sequences, largely around the margins of the Kimberley Plateau, and there is evidence for periods of major glaciations.

The current landscape of the Kimberley has been evolving over a period of at least 250 million years. Periods of uplift resulted in peneplanation of the land surface and deeply incised rivers. A lengthy period of tropical conditions 70-50 million years ago resulted in the development of a lateritic cap, particularly over the volcanic rocks which are more susceptible to weathering. This is a characteristic feature of the Mitchell Plateau.

As sea levels rose from approximately 120m below current levels following the end of the last glacial maxima 18 000 years ago, the Kimberley coast line became drowned with the sea filling what were once river valleys. This phenomena gives the coastline its distinctive irregular outline.

Reference: Geology and Landforms of the Kimberley. I Tyler. Department of Conservation and Land Management. 2000

Sunday, March 12, 2017

Funky Valparaíso Chile

There's no other way to describe Valparaíso. Starting as an important port in the southern Spanish Empire, it then became the center of the Chilean Navy. In 1990 the National Congress of Chile was moved here from Santiago. However, the main purpose of our visit was to see the Historic Quarter of the city, which is a UNESCO World Heritage Site. The colorful street art is not to be missed. No words can describe it  - so I won't. Enjoy the color and textures of Valparaiso.













Saturday, March 11, 2017

The Ever-Incredible Torres del Paine National Park

Another trip to Torres del Paine National Park.

There were clouds but very high clouds such that the highest peak in Patagonia was visible for perhaps the first time to me. Monte Balmaceda (elev. 6,677 ft.) is the squarish knob in the background. Both the Balmaceda and Serrano glaciers flow off of the peak - one of them is visible here.

Crossing the Pingo River - only six folks allowed on this swinging bridge at a time.

It leads into the southern Beech forest.

A walk on a long gravel beach to the mirador...

...where we got a great view of the Grey glacier. This is usually clouded over and impossible to see but the clouds were quite high today.

A nighttime shot with the half moon.

And sunrise the next day from our hotel. Can't wait to bring Helen here!

Later in the same morning.

I had never seen such calm weather here - not a hint of wind! Look at the reflection on the Pehue River.

The Perhue Lodge at the foot of the Cuernos de Paine.

Driftwood on the shores of Lago Nordenskjöld.

Lago Nordenskjöld.

Seeing the guanacos on the west side of the park.

Great views of flamingos on Lago Amarga.

Flamingos on Lago Amarga.

Guanacos in the Rio Paine.

The granite is a mere 12 million years old and was likely intruded at a depth of no more than two miles. The intrusion is technically a laccolith with the confining black shale clearly visible as eroded remnants on top of the granite.

A visit to Chile is never complete without a typical asado, this time with lamb.

The chef carved off pieces of the juicy flesh for all to taste. Thanks for reading. This has been a great trip with wonderful weather and a fantastic group.

Sunday, March 05, 2017

Rounding Cape Horn and Other Sights in Tierra del Fuego

Our expedition cruise to Cape Horn and Tierra del Fuego was unusual. The high pressure system that was blistering Buenos Aires in 90 degree heat had a pronounced effect in the latitudes of the 50s such that the weather systems moved from east to west. For this reason we approached the island of Cape Horn on its western side, normally the side that feels the brunt of Pacific storms. As we rounded the Horn from west to east, items flew off of my table in my cabin as the ship rocked and rolled. I knew it was an unusual event - we never feel rough seas when facing the east here.

Cape Horn! The southernmost point of land in the Americas. The rock type is diorite and is part of the South American batholith.

Looking northwest from the cape toward the snow-capped peaks of Hoste Island.

Waves batter the rocks. This was taken with my telephoto lens (300 mm) and so the distance is deceiving. Those waves are likely rising up 25 feet on the rocks.

I was standing on the 2nd deck here shooting right out into the waves, which rose up higher than I was.

An even bigger swell. To stand next to something this large and powerful is a humbling feeling. I was extra cautious standing out here on the open deck as any fall would certainly be a trip into the drink. Nearly 2,500 sailors are known to have lost their lives rounding the Horn, most of them in the winter when real A-1, first class storms rock the region. Staring into the waves was an eery feeling.

Later in the day we visited Beautiful Bay, called Wulaia in native Yagan tongue. My 2nd lecture was about the native people that once lived in these islands, a canoe-going group that wore no clothes in this harsh environment (clothing got damp and held disease). The Yagan were the ones who greeted the Beagle and Charles Darwin in the 1830s voyage through the Beagle Channel.

Low tide exposed these glacially rounded boulders covered in bright orange lichen.

This landscape is part of the Brecknock Peninsula. Note the light-colored granite set within a darker igneous rock.

A long glacier exiting from the Darwin Range Ice Sheet.

I have only seen Mt. Sarmiento (elevation 7,369 ft.) twice in all my years sailing down here and this was a fantastic view from the Agostini Sound.

Agostini fjord.

In Agostini National Park, we visited the Aguila Glacier, here seeming to plow through a grove of southern Beech trees of the genus Nothofagus.

Close-up of the Aguila Glacier. We walked through the forest to its base. Next stop is Torres del Paine National Park.