Geobulletin alpha

Source info:

Author:	Wayne Ranney
Date:	2014-01-30 14:02:00
Blog:	Earthly Musings
URL:	http://earthly-musings.blogspot.com/2014/01/iguazu-falls-brazil.html

Summary:

It was a short flight from Buenos Aires to Iguazu and this would be our only one night stay. But we packed a lot into the short time we were here.Flying into the Brazilian side of the falls Into the jungle for a boat ride on the Iguazu River.The falls pour over Cretaceous-age basalt, erupted about 121 Ma and known as the Parana volcanics. These lavas are related to the rifting that occurred when the South Atlantic Ocean opened between Africa and South America. The polygons here are weathering features as water invades the fractures and begins to chemically dissolve the rock along these lines of weakness.Our craft as we head up the rive towards the fallsThe power of the falls is astounding and flow levels were high enough that we dare not travel father up to the main fallsIt was a wet and enjoyable rideTime to view the falls from the topLooking into the Devil's Throat on the Brazilian side. This was one of the highest levels of flow I have ever seen here and record flows were recorded last June. The power and sound of the falls is impressive.The average discharge of the Iguazu River is between 600,000 and 1,500,000 cubic feet per second!It was hot and steamy during our visit, about 92 degrees with about 95% humidity. I was soaked.Iguazu FallsThese is a catwalk constructed right above the lip of the falls. This photo looks downstream over the lip. In June the water ran over this catwalk.At the end of the catwalk looking upstreamSunset at the fallsAt the end of the trail where the Devil's Throat is located. The falls are an impressive knickpoint on the River that is slowly migrating upstream. As rocks are plucked off the edge of the falls, the falls gradually retreat in the upstream direction.The Itaipu Dam on the Parana River is one of the largest hydroelectric plants in the world. Only the Three Gorges Dam is larger. When this dam was completed in the 1980's, it drowned out the Seven Falls on the Parana, the location of a knickpoint on that river. My next post will be about the fantastic flight from Brazil to Nicaragua.

Content analysis:

Stratigraphic context:

Recognized stratigraphic terms [n]:	Cretaceous [1]
Agenames chronostratigraphy [rating]:	Cretaceous [0.1] Mesozoic [0.1] Phanerozoic [0.1]

Geographic context:

Location	Country	Latitude	Longitude
Africa		2.07079	15.8005
Atlantic Ocean		4.07229	-32.0542
Brazil	BR	-14.2429	-54.3878
Buenos Aires Province	AR	-37.1482	-60.0297
Iguazu	AR	-25.6122	-54.5747
Nicaragua	NI	12.8667	-85.424
On The River	AU	-26.6487	153.088
Parana	BR	-24.616	-51.3146
Seven Falls	US	38.7849	-104.874
South America		-23.0301	-67.9037

Keywords:

Africa, average discharge, boat ride, Brazil, Buenos Aires, catwalk, catwalk.At, Cretaceous-age basalt, cubic feet, Devil, downstream, end, enjoyable rideTime, fallsThe power, fantastic flight, features, flow levels, fractures, Gorges Dam, highest levels, humidity, Iguazu Falls, Iguazu River, Iguazu River.The, impressive knickpoint, Itaipu Dam, jungle, largest hydroelectric plants, lavas, lines, lip, main fallsIt, Nicaragua, night stay, Parana River, Parana volcanics, photo, polygons, record flows, rifting, rock, short flight, short time, soaked.Iguazu FallsThese, sound, South America, South Atlantic Ocean, Throat, water, weakness.Our craft