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8/17/2019 Ppt Seg Conference
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egmatite-Hosted Mineralization at Casma, Perurank Aliaga Livia – [email protected] 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%