8/17/2019 Ppt Seg Conference

1/1

egmatite-Hosted Mineralization at Casma, Perurank Aliaga Livia  –  frank.aliaga.livia@gmail.comniversidad Nacional Mayor de San Marcos, Lima, Peru

eographic and Geological Location

enesis of the DepositThe convergence tectonic setting produced the

mplacement of the Coastal Batholith of 

Cretaceous age.

Pegmatites are associated to granitic rocks.

he depth formation is around 8 km.

Structural features trapped and formed the

egmatite bodies as veins and lens.

Uplift caused by the continuous subduction

llowed the outcrop of the complex pegmatite.

Additionally, there are a thin supergene blanket of 

opper secondary minerals.

neralogy of the pegmatiteconsists of quartz, K Feldspar, allanite, smoky

artz, plagioclase and micas, different textures are

served in the hand samples.

Does Peru has geological potential to host

economic REE deposits?Huajoto Project - Alturas Minerals (2010)

Capacsaya Project  – RioSol (January, 2015)

U.S.-based rare earth explorers RioSol announced

last month (January) a significant rare earth

element and poly-metallic claim discovery.

The company believes that having a supply source in

the Americas for commodities used today and in the

future will be important for geographic diversity and

commercial competition

Granite-Quartz-AllaniteQuartz crystals and micas

Quartz with allanite (UV Light at right)

he Coastal Batholith of Peru is located in the west

the country, there is a central segment called

anta Rosa Superunity that hosts a complex

egmatite in the location of Casma in the Ancash

egion, these rocks present petrographical

ariations from tonalites to granites.

ew of the supergene blanket

overprinting the pegmatite

 At the top of the main body

there are rounded xenoliths

Classification of the depositThe pegmatite of the Adan mine is in the NYF type,

the rare earth element class is subdivided according

to the mineralogical / geochemical characteristics. In

this case, the pegmatite is an allanite-monazite

subtype and the geochemical signature is composed

of LREE, U and Th. If we consider the classification

of NYF-type pegmatites (Mike Wise, 1999) the

deposit is an allanite subtype from the metaluminous

group.

Granite around the

pegmatitic bodies

 Allanite between quartz and K-

feldspar, sample from a dyke

About allanite

(Ca, Ce, La)2(Al,Fe+2,Fe+3)3Si3O12(OH)

Sorosilicate, from the group of epidote. It is found,

commonly, as accessory mineral of granitic rocks

and pegmatites. Rare in schists, gneiss, limestone

and skarn. The associated minerals depends on the

geological environment, quartz, K-Feldspar, epidote,

muscovite, fluorite and cassiterite are some

associated minerals.

Prismatic and elongated crystals, brown color to

black, vitreous to submetallic brightness.

View of the work in the Adan Mine

 According to a geological report finished earlier this

month, the 10-kilometer Capacscaya and adjacent

claims, contain significant quantities of high-range of 

Neodymium, Scandium, Lathanum, Cerium,

Europium and Yttrium, as well as other LREEs and

HREEs and their related oxides. Radionuclides,

however, were found to be extremely low.

View of the Capacsaya Project

Average Chemical Content

SiO2   32.97% Al2O3   17%

FeO 11.24% Fe2O3   2.66%

TiO2   0 .2% CaO 15.33%

Ce2O3 8.9% La2O3 4.76%

 Y2O3 0.21% Nb2O3 0.03%

Nd2O3 2.23% Sm 0.35%

ThO2   0 .67% UO2   0.04%

OH 3.16%