The Southern Coast of Brazil

Rio de Janeiro 

RDJ - it seems to me now -  is a place that I used to know. Back in the 1990s, I came here a lot and stayed a month or two at a time. That seems like a different life and I am a certainly a different person now. But the memories of this unique combination of a giant megapolis situated within and upon a stunning landscape still holds enchantment for me. That is, if you can ignore the sweetish-smell of rotting fruit permeating the air or the polluted water in the very restricted and closed basin that is Guanabara Bay (one of the original Seven Natural Wonders). Rio is essentially a mix between a city on a bay - like San Francisco - and a world-class landscape - like Yosemite Valley. What a place!

The magnificent landscape surrounding Guanabara Bay is perhaps most easily recognized near its entrance (upper left), where the Paõ de Açucar (Sugarloaf) monolith seems to rise up from beneath the sea. The rocks are between about 714 and 644  million years old (Ma), being emplaced during the Panafrican-Brasiliano orogeny (younger ages have been reported across the bay in Niteroi of 564 and 533 Ma, meaning that a precise age is elusive so far). This mountain building event is related to the amalgamation of the Gondwana supercontinent, that formed after the breakup of its predecessor, Rodinia. Crustal collisions caused metamorphism within the crust as well as the production of liquid magma. This occurred as various South American cratons came together - see the diagram below for a visual. (Cratons are the ancient cores of the continents and today's South America is made up of four, formerly disparate cratons). 

Another view to the south and east reveals more of this stunning landscape! The peak in the distance is Pedra da Gávea, rising some 2,769 feet (842 m) above the sea. Some say it is the highest coastal monolith in the world. Note it's relatively flat top that is a different and younger granite in contact with the metamorphic rocks below. While these monoliths appear to be original shapes of plutons, they are not. The shapes are the result of tropical weathering.

This is a close-up of the most widely used building stone in Rio de Janeiro. It is technically an augen-gneiss. Its abundance, durability, and textural beauty enhances its use throughout many of Rio's buildings and rock-lined walls. When it is polished, it is one of the most beautiful rocks I've ever seen and I fell in love with it while walking the promenades of a quiet neighborhood called Urca, located at the base of the Sugarloaf in photo 1.

The majority of the rocks in Rio's landscape formed as a result of continental convergence. Cratons shown in purple and light blue were microcontinents that collided to form larger land masses. Rio de Janeiro is located where the numeral 4 is depicted, in a collisional terrain called the Ribeira Belt, shown in light brown. Other mobile belts of a similar age are darker brown with the numbers representing different mobile belts; yellow stars are locations of ophiolite, slivers of ocean crust that was caught and crushed between two cratons. 

Note how some cratons overlap both Africa and South America (Amazonian with West Africa and Congo with Saõ Francisco (SFC). The two modern-day continents would not attain their present outlines until the opening of the Atlantic much further into the future in the Cretaceous (120 Ma). 

The diagram is from Figure 5 in: S. Oriolo, P. Oyhantçabal, K. Wemmer, S. Siegesmund; 2017, Contemporaneous assembly of Western Gondwana and final Rodinia break-up: Implications for the supercontinent cycle; in Geoscience Frontiers, Vol. 8, # 6, pp. 1431-1445, ISSN 1674-9871. https://doi.org/10.1016/j.gsf.2017.01.009.

(https://www.sciencedirect.com/science/article/pii/S1674987117300294).  

I could on and on about Rio. But I have to catch a ship - we're sailing south to other locations in Brazil! As we left the dock in Rio, the futuristic Museu do Amanhã (Museum of Tomorrow) was visible. This was constructed in advance of the 2016 Summer Olympics in Rio. 

Ilha Grande

Ilha Gande (Big Island in Portuguese) was a green surprise! With the summertime temperature already in the high 80s at 10AM, the proximity to the water in the village of Abraão was welcoming.

Map of Ilha Grande. The island is a little less than 8 miles long and 4 miles wide. The location relative to the mainland can be seen in the upper left. Ferries to the mainland take only 1.5 hours. Brazil is slightly smaller than the continental USA. Image from Wikipedia by Rosso Robot. 

Approaching Abraão by the ship's tender, it did not look like much. About 4,000 people live in the village however.

This is not the main beach-fronting street but more of a look inland into the non-tourist area. The commercial center has palapa-like restaurants and curio shops. I was surprised that a medium-sized cruise ship like Splendor came to a place like this but it was well worth it.

A street mural.

A very calm day in the harbor. The temperature was hot and it was steamy.

Splendor at repose at Ilha Grande.

We walked a half a mile toward the ruins of the penitentiary...

...and there were some beautiful glimpses along the way of the tide zone, that included smooth, rounded boulders of the same granite and gneiss seen further north in Rio de Janeiro. The rounded shapes form by spheroidal weathering. See a description of this process in the next photo.

A small rockfall in 2023 had exposed a relatively fresh look into how the rounded granite boulders are formed. Note that the entire body of rock is massive to begin with. But as fractures and cracks develop within the granitic mass, water seeps into the cracks and begins to chemically weather the granite. The feldspars in the rock do not like humid conditions and turn to "mush" through time. Eventually a hard, unweathered core of rock remains surrounded by the crumbly weathered fracture zone. Voilà! Spheroidal weathering and the rounded boulders fall out and are washed to the shoreline..

On one of the rounded boulders, metate marks were seen. Human habitation has been here at least for 7,000 years.

There are many fresh-water springs that emanate from the landscape, providing domestic water and a cool swim.

We hiked up the hill to see an aqueduct that fed water to the penitentiary. Impressive!

Beach scene from the heart of Abraão. One of our local guides told me that he came here from Rio to surf when he was 16 years old. He fell in love with the island and its laid back way of life. He vowed to return. It took him a few more years but he has now lived on the island for 25 years. When he moved here, his mother was aghast - as a former penitentiary island, she was worried for his safety.

Santos and Brazilian (and Italian) Coffee Culture

São Paulo is the fourth largest city in the world with nearly 22 million people. About 50 miles from the coast its port is a city called Santos. This has been a major port in Brazil for centuries and when the coffee crop was introduced in the 1600s, this was a major export location.

The mains treat from the old port is being refurbished on the "Brazilian schedule". It's been underway for years.

The morning stop was Museu do Café - the Coffee Museum. This used to be where the buying and selling of the crop crop took place so it is an ideal location to learn about the long history of Brazilian coffee.

This is a view of the balsa or trading floor. It operated just like the New York Stock Exchange with buyers and sellers screaming prices from the chairs beneath the ornate stand glass above. A detail is below.

Detail of the stained glass on the ceiling of Bolsa do Café. To learn more about the buildings history, see this.

A special exhibit was in place concerning the making of espresso, something Brazilians learned to love beginning at the start of the 20th century. It arrived to these shores from Italy. See a description of this exhibit here.

Santos is also the home of the Pele Museum, since he began his career playing for Santos!

Everything Pele can be found here, from his humble rural upbringing, to the lessons in life and futebol from his father, to his signing a contract at the age of 15 with Santos and his illustrious career. I really enjoyed this museum. 

A Day at Sea Towards Uruguay 

As we left Brazilian waters we had a gloriously calm day at sea sailing toward Montevideo Uruguay. The weather was superb and seas calm as glass. Streaming to the south out of the north were the wispy tendrils of beautiful cirrus clouds. They were present in the sky for most of the afternoon. I love cirrus clouds! Awesome!