Rasac (possibly Quechua for toad) is a

mountain A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher t ...

in the Huayhuash mountain range in west central

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

, part of the

Andes The Andes ( ), Andes Mountains or Andean Mountain Range (; ) are the List of longest mountain chains on Earth, longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range ...

. It has a summit elevation of , although other sources cite a height of . Rasac is a long, relatively squat mountain on the western edge of the Huayhuash range, across the glacier from the tallest peak in the range,

Yerupajá Yerupajá is a mountain of the Huayhuash mountain range in west central Peru, part of the Andes. It is located at Áncash, Bolognesi Province, Lauricocha Province. At (other sources: ) it is the second-highest in Peru and the highest in the ...

. Although it is a 6,000 metre mountain, Rasac's broad profile is dwarfed by Yerupajá.

Geology

As the rest of the Huayhuash, Rasac is made mainly of

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

, interbedded with

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

and

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of Clay mineral, clay minerals (hydrous aluminium phyllosilicates, e.g., Kaolinite, kaolin, aluminium, Al2Silicon, Si2Oxygen, O5(hydroxide, OH)4) and tiny f ...

. These sediments were originally laid down on the ocean floor and have been pushed up and folded due to the convergence started about 90 million years ago when the Nazca oceanic plate started to slide under the South American continental plate. The limestone has a coarse, sharp texture and is light to dark grey in colour (although sometimes a slight bluish tint can occur). Marine fossils (

bivalves Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed by a calcified exoskeleton consis ...

and

ammonites Ammonoids are extinct, (typically) coiled-shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living octopuses, squid, and cuttlefish (which comprise the clade Coleoidea) than they are to nautiluses (family N ...

) may be found within some of the limestone beds. Some volcanic activity has also influenced the geology of the Huayhuash.

Climbing

Rasac is considered to be the easiest 6,000-metre peak in the Huayhuash range, but it is still a challenging climb. The long, snowy West Face is divided by a series of buttresses, most of which have routes in the D range according to the International French Adjectival System. The Right Buttress is still unclimbed. The East Face is almost all rock, most of which seems in the condition not to be climbed. There is allegedly a snow route of moderate difficulty (considered to be the normal route and rated around AD) up a gulley on this face that looked in the summer of 2007 to be totally out of condition. Even if Rasac is overall the most climbed peak of the Huayhuash range, it remains a mountain climbed very rarely (less than a climb per year). The mountain lies in a remote and wild setting. Expeditions willing to climb in this area have to be fully self-sufficient in case of an accident or emergency. A traverse of the mountain begins with five pitches of rock up the east face to gain the south ridge, a long airy corniced snow and ice ridge to the summit followed by descending the north ridge and down NE face of mixed snow, rock and ice. V 5.8 AI 3–4 James Garrett, Paul Gonzales spring of 1996.

External links

Rasac on Summitpost

References

{{reflist Six-thousanders of the Andes Mountains of the Department of Ancash Mountains of the Department of Lima