Breizh!: time to explore the physical geography of Carnac and its surrounding region, Bretagne!

(Here is a little local music to get us in the mood!)

( Bretagne has the temperament of crotchety, old, Irishman with its rocky hills and long winter nights. However, the land has been twisted and pulled for billions of years, giving us river valleys and beautiful granite rock formations.)

 i. Why does Bretagne have wonderful long summer days, and long dark winter nights?

ii.Why is Bretagne, and consequently, Carnac where they are today?

iii. Why are there little mountains in central Bretagne?

iv. What main types of rock are found in the region?

v. Hmm, that's an interesting looking river valley just north-east of Carnac... I wonder why it's there...?  

Photo by Itzel-Marine G. 2008

The earth’s tilt allows the poles to alternatively receive the full sunlight during their summers. Bretagne, is at a higher latitude than Nova Scotia in Canada at: 47˚34’41”N 3˚05’12”W  By being so far North, Carnac is affected by long summer days and long winter nights. But, what shifted Bretagne into its current place? First, as Dr. Allen mentioned in class that our "best guess is that convection runs throughout the mantle," to move the tectonic plates; which in turn, crack, melt, and pull to create the geography we see today. Through the tectonic process ancient mountains from the Paleozoic age, called the Monts d'Arrée, formed hogback mountains as the land folded together and eroded; and, simultaneously, rivers formed in the anticlinal valleys washing away the sedimentary rock and leaving behind granite and gneiss that had been formed by the extreme heat and pressure.

The rough, stony land; the high latitude; and windy coastal location have made living in this region difficult. Crops are hard to grow as the sandy, granite stridden earth is far from ideal. However, the rivers spread across the land have allowed these tough people to survive the tough conditions of this northern coastal area. 

( Left: The image depicts that Bretagne is nowhere near a major fault line nowadays. This, however, does not mean that France has not been shoved around just as much as some other countries in the world, as shown below by the video) 


(Please pause the music above for the full effect of the video!)

(Above: The hogback mountains of the Mont D'Arrhée)

(Above: The numerous rivers and folded aspect of the land can be observed.)

Photo by Itzel-Marine G. 2009

(The Menhir are made from the local felsic, intrusive rock known as granite. The purpose of the upright stones has not yet been discovered, but it is assumed they are for religious purposes.)

Photo by Itzel-Marine G. 2009

(Left: The sand-bridge built by my cousin and me, is nestled between two granite boulders at the beach.)

Fin!

Citations:
http://fast.ucdenver.edu/case/1202/Battle/Build/PlateTectonics/platesUSGS.gif
http://www.ogre3d.org/tikiwiki/img/wiki_up/Latitude_PSF.png
http://www.fond-ecran-image.com/galerie-membre,france-bretagne,sortie-en-mer-le-8-mars-2007-082jpg.php
http://upload.wikimedia.org/wikipedia/commons/e/e9/Bretagne_region_relief_location_map.jpg