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{{Short description|Emerald mine in Boyacá, Colombia}}
{{Infobox mining
{{Infobox mine
⚫
| name = La Pita Mine
| image = La_Pita_Portal_2.jpg
| name = La Pita Mine
| width =
| image = La Pita Portal 2.jpg
| caption = Las Pita Mine Maripi, Boyaca, Colombia
| width =
| caption = Entrance to the mine
| subdivision_type =
| state/province = Boyaca
| pushpin_map = Colombia
| country = Colombia
| pushpin_mapsize =
| pushpin_map_alt =
| authority = Ejercito Colombia
| pushpin_map_caption=
| official website = https://www.ejercito.mil.co
| commodity = EMERALDS
| pushpin_image =
⚫
| pushpin_label =
| production = Colombia produced 1.782.058 Carats in 2015 up 15% from 2014
| pushpin_label_position =
⚫
| value =
| coordinates = {{coord|05|34|N|74|04|W|display=inline,title}}
⚫
| employees = 100
| year = 2016
| place = [[Maripí]], [[Muzo]]
| subdivision_type = [[Departments of Colombia|Department]]
| state/province = [[Boyacá Department|Boyacá]]
| country = {{COL}}
| official website = {{URL|http://www.lapitaemeralds.com/Spanish/index.html|Website La Pita}}
| products = [[Colombian emeralds|Emeralds]]
| amount = <!--include units-->
| financial year =
⚫
| type =
| greatest depth =
| opening year = {{Start date|2016}}
| active years =
| closing year = <!-- {{End date|YYYY}} -->
| owner = Zuliana De Esmeraldas Ltda
| acquisition year = 2015
⚫
| module =
}}
}}
'''La Pita''' is an [[Colombian emeralds|emerald]] mine located in the western belt of the [[Colombia]]n emerald mining area. It is owned and operated by the Colombian company, Zuliana De Esmeraldas Ltda.


⚫
== History ==
⚫
{{Location map+ | Colombia
⚫
[[File:La Pita Mine Mtn View.jpg|250px|thumb|right|La Pita mountain view]]
| AlternativeMap = Colombia relief location map.jpg
⚫
La Pita is one of Colombia's largest emerald mines in Colombia, tantamount to its competitor, previously called Puerto Arturo, at present known as the [[Muzo Mine]]. La Pita has been one of the biggest contributors to Colombia's emerald production at times producing more than 80% of the total output of emeralds in Colombia. La Pita was discovered when an access road was being built, the workers and owners of the land descended towards [[Río Minero]] and noticed a yellowish patch of earth accompanied by the black carbonate altered [[shale]]s of the Muzo Formation. This area is known as ''Amariallal'' and marked the establishment of La Pita Mine. The entrance of the mine was first opened in a ravine at the bottom of the mountain near Río Minero and extends approximately {{convert|500|m|ft}} until the tunnel makes contact with the principle fault line running through the length of the La Pita property.
| width = 260
| caption = La Pita, Boyaca, Colombia
| places =
{{Location map~ | Colombia
| lat_deg = 4.6
| lon_deg = -74.08
| label = <sub>Bogotá</sub>
}}
{{Location map~ | Colombia
| lat_deg = 5.3
| lon_deg = -74.8
| label = ‘''<sup><big>La Pita</big></sup>'''
}}
}}


⚫
La Pita is north of neighboring mine Cunas. Previously, a dispute between the two mines existed and both groups founded a mining agreement, that is defunct today. The agreement proposed that mining {{convert|35|m|ft}} north and south of the border between the mining districts was allowed by both parties. Today, the building structures and campsite are located on the property of Cunas.
The '''La Pita''' an [[emerald]] mine located in a [[Colombia]]n emerald mining area that is neighboring some of Colombia's largest emerald mines, [[Cunas]], [[Totomas]], [[Polveros]] and [[Espanoles]]. It is located 200&nbsp;km (124.27&nbsp;mi) north-west of [[Bogota]], Colombia in the western emerald belt , and about 235&nbsp;km (146.02&nbsp;mi) west of the [[Chivor]] which is in the eastern emerald belt. It is 100% owned and operated by Colombian company, [[Zuliana De Esmeraldas Ltda]].


⚫
Recently, La Pita had entered into an agreement with a publicly traded company, FURA Emeralds Inc.<ref>{{cite news |last1=Market Wire |title=Fura Emeralds Inc. |url=http://www.marketwired.com/press-release/fura-signs-letter-of-intent-to-operate-la-pita-mine-tsx-venture-fur-2105962.htm |accessdate=15 March 2016}}</ref> This has since been terminated.<ref>{{cite news |last1=Market Wire |title=Fura Emeralds Inc |url=http://www.marketwired.com/press-release/fura-announces-termination-of-letter-of-intent-to-operate-la-pita-mine-tsx-venture-fur-2115474.htm |accessdate=15 April 2016}}</ref>
⚫
==History==
⚫
La Pita is one of Colombia's largest emerald mines in Colombia, tantamount to its competitor [[Puerto Artuto]] (Now, Muzo - it is owned and operated by [[Mineria Texas Colombia]] - MTC) La Pita has been one of the biggest contributors to Colombia's emerald production at times producing more than 80% of the total output of emeralds in Colombia. La Pita was discovered when an access road was being built, the workers and owners of the land rounded a corner on a decent towards [[Rio Minero]] (Miners River) and noticed a yellowish patch of earth followed by the famous black carbonate altered [[shale]], Muzo formation. This area is known as "Amariallal" and led to the birth of La Pita. The entrance of the mine was first opened in a ravine "Quebrada" at the bottom of the mountain near Rio Minero and extends some 500 meters until the tunnel makes contact with the principle fault line running through the length of the La Pita property.


⚫
Following that, a Canadian company entered into a non-binding agreement and was unable to successfully close on the contract. In 2016, a third company was entering into agreements for full operation at La Pita Mine and to acquire a stake in Zuliana De Esmeraldas Ltda.
⚫
La Pita is north of neighboring mine Cunas, however in earlier times there had been a dispute between the border between the two mines and both groups founded the mine Consorcio which is now defunct. The agreement was that Consorcio was able to mine 35 meters north and south of the actual title border. Today the building structures and campsite are legally on the property of Cunas. Both company's respect their neighbors and are actively mining each respective legal title.
⚫
[[File:La Pita Mine Mtn View.jpg|250px|thumb|left|La Pita Mtn View]]


⚫
== Geology ==
⚫
Recently, La Pita had entered into an LOI agreement with a publicly traded company, FURA Emeralds Inc. "(TSX VENTURE:FUR) announces that it, through a wholly owned subsidiary, has entered into a binding letter of intent (the "LOI") with Zuliana De Esmeraldas Ltda. ("Zuliana") to become the operator of the La Pita Emerald Mine in Boyacá, Colombia..."<ref>{{cite news|last1=Market Wire|title=Fura Emeralds Inc.|url=http://www.marketwired.com/press-release/fura-signs-letter-of-intent-to-operate-la-pita-mine-tsx-venture-fur-2105962.htm|accessdate=15 March 2016}}</ref> This has since been terminated <ref>{{cite news|last1=Market Wire|title=Fura Emeralds Inc|url=http://www.marketwired.com/press-release/fura-announces-termination-of-letter-of-intent-to-operate-la-pita-mine-tsx-venture-fur-2115474.htm|accessdate=15 April 2016}}</ref>
⚫
La Pita mine is mining emeralds from the Muzo Formation, operations are currently focused wholly in the [[footwall]] of the Río Minero Fault. The property lies on a productive portion of the fault, with ~1&nbsp;km of the NNE, moderate to steeply dipping fault (~025/75(?)) running along the long-axis of the property. The Rio Minero fault is characterized by an ~80m wide, very irregular, but sharp contact [[breccia]] zone. This breccia is a carbonate altered, with minor content [[kaolinite]] altered clasts, localized [[fluorite]] matrix, polymicitic carbonate altered shale and carbonate vein clasts, laminated to massive euhedral to [[anhedral (petrology)|anhedral]] carbonate matrix, chaotic order, clast-supported to matrix-support, fine to very coarse unsorted sharp clast contacts, sub-angular to angular. At present the mine is focused only on the footwall of the fault, exploiting oblique fractures in the Muzo Formation shales of the western flank of the fault. There appears to be a periodicity to the occurrence of variable thickness ({{convert|1|to|30|cm|in}}) calcite veins (observed between 070/35 and 320/65 orientations), that are the primary target for emerald production. The intersections of vein sets are a fertile setting and may represent an upgrading feature. Where these secondary fractures intersect with the primary vein orientation, anecdotally it has been observed that there appears to be an improvement in both quality (colour and clarity) as well as, sometimes, quantity/size. These oblique vein sets (which may simply be conjugate fractures as a product of how the faulting influenced the host Muzo Formation (rheology during formation)) represent the primary source of emeralds in the current operations at La Pita. These vein sets are productive up to several meters away from the fault itself.


⚫
=== Muzo Formation ===
⚫
Following that, a second Canadian company entered into a non-binding MOU agreement and was unable to successfully close on the contract. In 2016, a third company is entering into agreements for 100% of the operations at La Pita and to acquire a stake in the Zuliana De Esmeraldas Ltda.
⚫
Muzo Formation (K1m - Hauterivian-Barremian age), outcropping in the sector of Las Pavas, Peñas Blancas, Coscuez, also appears in [[Vélez, Santander|Vélez]], [[Chiquinquirá]] and La Palma. It is part of the flanks of La Chapa-Borbur Anticlinal, also observed in the syncline of [[Otanche]], in the sector of [[Coscuez Mine|Coscuez]]. In the region of Muzo and Calcetero, the formation is also part of the syncline of El Almendro and forms the nucleus of the Pauna Anticlinal.


⚫
This unit houses most of the emerald-producing mines in the region such as Coscuez. The Muzo Formation is a generally calcareous sequence, while to the north of the Ibacapí Fault it is observed to be weathered and its calcareous composition is not recognized. To the north of Pauna the formation has a [[siliceous]] character. In general it is composed of dark gray calcareous claystones with lenses and limestone concretions. Additionally, it is common to find [[pyrite]] and calcite veins. These claystones are interspersed with sandy [[siltstone]]s and quartz sandstones. Towards the middle of the segment arise shales and [[albitized]] limestone, somewhat calcareous. At this level appear a brecciated and mineralized zone with veins of calcite and sheets of oxidized sulphides. The upper part of the segment is interspersed with layers of gray claystones with layers of siltstones containing fauna depicted in [[ammonite]] molds. At the bottom of this unit is the La Marina Mine and to the south the emerald mines of La Pita, Consorcio, Totumos, Polveros and others. The first calcareous package becomes thicker towards the south, it has a thickness of {{convert|2|m|ft}}, and in the sector of Totumos and Polveros reaches {{convert|45|m|ft}}, and is composed of intercalations of limestone ([[micrite]]), loam and sandy [[siltstone]]s. The zone of hydrothermal breccias that is immediately above the calcareous rocks, in the La Pita Mine has a thickness of approximately {{convert|30|m|ft}}, and at the Totumos Mine can reach to {{convert|50|m|ft}}. This unit in the area of Coscuez and Muzo presents emeralds; its characteristic remains limestone in layers of calcareous siltstones interspersed with calcareous claystones. To the south of the area, this unit presents similar characteristics. A stratigraphic column along the La Palma-Yacopí road, shows that this unit is composed of a black [[marl]] with a solid appearance with black calcareous claystone intercalations.<ref>Acosta and Ulloa, 2001</ref> In the upper part, intercalations of black shale with [[gypsum]] flakes and abundant pyritic micritical concretions appear, some with ammonites.<ref>Reyes et al., 2006</ref><ref>Ortega Medina, 2007, p.22</ref>
⚫
==Geology ==


== Mining licence ==
⚫
La Pita mine is located in the Muzo Formation, operations are currently focused wholly in the [[footwall]] of the Rio Minero fault. The property lies on a productive portion of the fault, with ~1&nbsp;km of the NNE, moderate to steeply dipping fault (~025/75(?)) running along the long-axis of the property. The Rio Minero fault is characterized by an ~80m wide, very irregular, but sharp contact [[breccia]] zone. This breccia is a Carbonate altered, with minor content [[kaolinite]] altered clasts, localized [[fluorite]] matrix, polymicitic carbonate altered shale and carbonate vein clasts, laminated to massive euhedral to [[anhedral]] carbonate matrix, chaotic order, clast-supported to matrix-support, fine to very coarse unsorted sharp clast contacts, sub-angular to angular. At present the mine is focused only on the footwall of the fault, exploiting oblique fractures in the Muzo Formation shales of the western flank of the fault. There appears to be a periodicity to the occurrence of variable thickness (1 to >30&nbsp;cm) calcite veins (observed between 070/35 and 320/65) that are the primary target for emerald production. The intersections of vein sets are a fertile setting and may represent an upgrading feature. Where these secondary fractures intersect with the primary vein orientation, anecdotally it has been observed that there appears to be an improvement in both quality (colour and clarity) as well as, sometimes, quantity/size. These oblique vein-sets (which may simply be conjugate fractures as a product of how the faulting influenced the host Muzo formation (rheology during formation)) represent the primary source of emeralds in the current operations at La Pita. These vein-sets are productive up to several meters away from the fault itself.
⚫
The La Pita concession agreement is active and registered with the National Mining Agency of Colombia. The title holders of Las Pita have a 30-year exploration/exploitation license, this title granted the exclusive right to extract the corresponding minerals and to conduct the necessary efforts to explore, exploit, process, transport and ship the relevant minerals.


== Mine safety and security ==
⚫
===Muzo Formation===
⚫
Site security currently has several weak points, from the working face to processing of potential ore. The mine is not currently managed with consideration for who is in the mine when it is open and material is not properly processed before being dumped and accessed by the general public. Improvement in security would be relatively simple both from a capital expenditure and implementation perspective. There are 4 points of access, which can be controlled by guards, cameras and doors/walls. The ore would need to be handled differently than it currently is, as there is a substantial amount of material being moved out of the mine and into public area, with only the identified mineralization isolated, but emeralds being present in the other material after. Although effort is made to capture emeralds coming off the face, it has been demonstrated that there are emeralds winding up in the tailings with regularity, of variable quality. The two primary security issues are, access to the mine site when the workings are open and ore processing. Porto Gringo access to the north may represent the greatest weakness to securing the site right now, because of the agreement to allow access to the neighbouring operation.
⚫
Muzo formation (K1m - Hauterivian-Barremian age) This unit, outcropping in the sector of Las Pavas, Peñas Blancas, Coscuez, also appears in Vélez, Chiquinquirá, La Palma, is part of the flanks of La Chapa-Borbur Anticlinal, also observed in the syncline of Otanche, in the sector of Coscuez, in the region of Muzo and Calcetero, also part of the syncline of El Almendro and form The nucleus of the Pauna Anticlinal.


⚫
The mining region, despite its poor reputation is actually safe and community orientated, the violence is now a faint memory of the past.{{citation needed|date=December 2016}} Security in the mine is a collaboration between private security, [[National Police of Colombia]] and the National Armed Forces of Colombia. This presence provides for a very secure work place and community support, where the police and military often participate in community social projects ranging from building homes, aqueducts and road maintenance.
⚫
This unit houses most of the emerald-producing mines in the region such as the Coscuez area; Although it also has non-producing mines, so it is of great interest for exploration. The Muzo Formation is a generally calcareous sequence, however to the north of the Ibacapí Fault, it is observed to be weathered and its calcareous composition is not recognized and to the north of Pauna it has a [[siliceous]] character. In general it is composed of dark gray calcareous lodolites with lens interpositions and limestone concretions, in addition it is common to find pyrite and calcite veins. These lodolites are interspersed with sandy [[siltstone]]s and quartz sandstones. Towards the middle of the segment arise [[lodolite]]s and [[albitized]] limestone, somewhat calcareous, at this level appear a breciated and mineralized zone with veins of calcite and sheets of oxidized sulphides. The upper part of the segment is interspersed with layers of gray lodolites with layers of siltstones containing fauna depicted in [[ammonite]] molds. At the bottom of this unit is the La Marina mine and you can continue to the south the emerald mines of La Pita, Consorcio, Totumos, Polveros and others. The First calcareous package becomes thicker towards the south, it is as well as in the La 22 mine La Pita, has a thickness of 2 meters and in the sector of Totumos and Polveros reaches 45 meters and is made up of intercalations of limestone (micrita), loam and sandy [[limolite]]s. The zone of hydrothermal breccias that is immediately above the calcareous rocks, in the Mine the Pita has a thickness of approximately 30 meters and being this one sector of the mines Totumos can reach to have 50 meters. This unit in the area of Coscuez and Muzo presents minerals of emerald, here its characteristic remains limestone in layers of calcareous limolites interspersed with calcareous lodolites. To the south of the area, this unit presents similar characteristics; Acosta and Ulloa (2001), show a stratigraphic column along the La Palma-Yacopí road, where they conclude that this unit is composed of a black terrígena micrograin (marl) with a solid appearance with black calcareous lodolite intercalations towards the In the upper part, intercalations of clayey black shale with gypsum flakes and abundant pyritic micritical concretions appear, some with ammonites (Reyes et al., 2006).<ref>TIPOLOGÍA Y CONDICIONES DE FORMACIÓN DE LAS MANIFESTACIONES HIDROTERMALES DEL SECTOR ESMERALDIFERO “PEÑA COSCUEZ” (MUNICIPIO SAN PABLO DE BORBUR, BOYACA), LAURA MILENA ORTEGA MEDINA Proyecto de grado presentado como requisito para optar el título de Geóloga Director: Ph. D. LUIS CARLOS MANTILLA FIGUEROA, Codirector: M. Sc. OSCAR MAURICIO CASTELLANOS ALARCÓN, pp. 22</ref>


==Mining licence ==
== References ==
⚫
{{reflist|30em}}
The La Pita concession agreement is active and registered with the NMA (ANM) [https://www.anm.gov.co National Mining Agency] of Colombia. www.cmc.gov.co:8080<ref>National Mining Agency mining title and solicitation website repository - www.cmc.gov.co:8080</ref>


⚫
=== Bibliography ===
⚫
The title holders of Las Pavas have a 30 year exploration/exploitation license, this title granted the titleholder the exclusive right to extract the corresponding minerals and to conduct the necessary efforts to explore, exploit, process, transport and ship the relevant minerals. These titles have a 30-year term.
⚫
* {{citation |last=Ortega Medina |first=Laura Milena |year=2007 |title=Tipología y condiciones de formación de las manifestaciones del sector esmeraldífero "Peña Coscuez" (municipio San Pablo de Borbur, Boyacá) (MSc.) |url=http://repositorio.uis.edu.co/jspui/bitstream/123456789/1261/2/124138.pdf |publisher=[[Industrial University of Santander|Universidad Industrial de Santander]] |pages=1–121 |accessdate=2017-01-05}}
==Mine Safety & Security==
⚫
Site security currently has several weak points, from the working face to processing of potential ore. The mine is not currently managed with consideration for who is in the mine when it is open and material isn’t properly processed before being dumped and accessed by the general public. Improvement in security would be relatively simple both from a capital expenditure and implementation perspective. There are 4 points of access, which can be controlled by guards, cameras and doors/walls. The ore would need to be handled differently than it currently is, as there is a substantial amount of material being moved out of the mine and into public area, with only the identified mineralization isolated, but emeralds being present in the other material after. Although effort is made to capture emeralds coming off the face, it has been demonstrated that there are emeralds winding up in the tailings with regularity, of variable quality. The two primary security issues are, access to the mine site when the workings are open and ore processing. Porto Gringo access to the north may represent the greatest weakness to securing the site right now, because of the agreement to allow access to the neighbouring operation.


== Further reading ==
⚫
The mining region, despite its poor reputation is actually safe and community orientated, the violence is now a faint memory of the past.{{citation needed|date=December 2016}} Security in the mine is a collaboration between private security, [[National Police of Colombia]] and the [[Ejército Nacional de Colombia]]. This presence provides for a very secure work place and community support, where by the Police and Military often participate in community social projects ranging from building homes, aqueducts and road maintenance.
⚫
* {{citation |last1=Branquet |first1=Yannick |last2=Laumonier |first2=Bernard |last3=Cheilletz |first3=Alain |last4=Giuliani |first4=Gaston |year=1999 |title=Emeralds in the Eastern Cordillera of Colombia: Two tectonic settings for one mineralization |url=http://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_7/b_fdi_51-52/010019064.pdf |journal=[[Geology (journal)|Geology]] |volume=27 |issue=7 |pages=597–600 |doi=10.1130/0091-7613(1999)027<0597:EITECO>2.3.CO;2 |bibcode=1999Geo....27..597B |accessdate=2017-01-05}}
⚫
* {{citation |last1=Giuliani |first1=Gaston |last2=Cheilletz |first2=Alain |last3=Arboleda |first3=Carlos |last4=Carrillo |first4=Victor |last5=Rueda |first5=Félix |last6=Baker |first6=James H. |year=1995 |title=An evaporitic origin of the parent brines of Colombian emeralds: fluid inclusion and sulphur isotope evidence |url=http://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_6/b_fdi_35-36/42470.pdf |journal=European Journal of Mineralogy |volume=7 |pages=151–165 |doi=10.1127/ejm/7/1/0151 |bibcode=1995EJMin...7..151G |accessdate=2017-01-05}}
⚫
* {{citation |last1=Pignatelli |first1=Isabella |last2=Giuliani |first2=Gaston |last3=Ohnenstetter |first3=Daniel |last4=Agrosì |first4=Giovanna |last5=Mathieu |first5= Sandrine |last6=Morlot |first6=Christophe |last7=Branquet |first7=Yannick |year=2015 |title=Colombian Trapiche Emeralds: Recent Advances in Understanding Their Formation |journal=Gems & Gemology |volume=LI |pages=222–259|doi=10.5741/GEMS.51.3.222 }}


== References ==
== External links ==
{{commons category|La Pita Mine}}
⚫
{{reflist|30em}}
* [http://www.lapitaemeralds.com/About_lapita_mine.html Information about La Pita Mine]


⚫
{{Mining in Colombia}}
⚫
== Bibliography ==
{{Colombian emeralds|state=expanded}}
⚫
* {{cite LSA |last=Branquet |first=Yannick |last2=Laumonier |first2=Bernard |last3=Cheilletz |first3=Alain |last4=Giuliani |first4=Gaston |year=1999 |title=Emeralds in the Eastern Cordillera of Colombia: Two tectonic settings for one mineralization |url=http://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_7/b_fdi_51-52/010019064.pdf |journal=[[Geology (journal)|Geology]] |volume=27 |pages=597-600 |accessdate=2017-01-05}}
⚫
* {{cite LSA |last=Giuliani |first=Gaston |last2=Cheilletz |first2=Alain |last3=Arboleda |first3=Carlos |last4=Carrillo |first4=Victor |last5=Rueda |first5=Félix |last6=Baker |first6=James H. |year=1995 |title=An evaporitic origin of the parent brines of Colombian emeralds: fluid inclusion and sulphur isotope evidence |url=http://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_6/b_fdi_35-36/42470.pdf |journal=European Journal of Mineralogy |volume=7 |pages=151-165 |accessdate=2017-01-05}}
⚫
* {{cite LSA |last=Ortega Medina |first=Laura Milena |year=2007 |title=Tipología y condiciones de formaciónde las manifestaciones del sector esmeraldífero "Peña Coscuez" (municipio San Pablo de Borbur, Boyacá) (MSc.) |url=http://repositorio.uis.edu.co/jspui/bitstream/123456789/1261/2/124138.pdf |publisher=[[Industrial University of Santander|Universidad Industrial de Santander]] |pages=1-121 |accessdate=2017-01-05}}
⚫
* {{cite LSA |last=Pignatelli |first=Isabella |last2=Giuliani |first2=Gaston |last3=Ohnenstetter |first3=Daniel |last4=Agrosì |first4=Giovanna |last5=Mathieu |first5= Sandrine |last6=Morlot |first6=Christophe |last7=Branquet |first7=Yannick |year=2015 |title=Colombian Trapiche Emeralds: Recent Advances in Understanding Their Formation |journal=Gems & Gemology |volume=LI |pages=222-259}}


{{DEFAULTSORT:Pita, La}}
{{DEFAULTSORT:Pita, La}}
[[Category:Mines in Colombia]]
[[Category:Emerald mines in Colombia]]
[[Category:Buildings and structures in Boyacá Department]]
[[Category:Buildings and structures in Boyacá Department]]
[[Category:Colombian emeralds]]
[[Category:Colombian emeralds]]

Latest revision as of 10:08, 19 July 2024

La Pita Mine
Entrance to the mine
Location
La Pita Mine is located in Colombia
La Pita Mine
La Pita Mine
LocationMaripí, Muzo
DepartmentBoyacá
Country Colombia
Coordinates05°34′N 74°04′W / 5.567°N 74.067°W / 5.567; -74.067
Production
ProductsEmeralds
History
Opened2016 (2016)
Owner
CompanyZuliana De Esmeraldas Ltda
WebsiteWebsite La Pita
Year of acquisition2015

La Pita is an emerald mine located in the western belt of the Colombian emerald mining area. It is owned and operated by the Colombian company, Zuliana De Esmeraldas Ltda.

History

[edit]
La Pita mountain view

La Pita is one of Colombia's largest emerald mines in Colombia, tantamount to its competitor, previously called Puerto Arturo, at present known as the Muzo Mine. La Pita has been one of the biggest contributors to Colombia's emerald production at times producing more than 80% of the total output of emeralds in Colombia. La Pita was discovered when an access road was being built, the workers and owners of the land descended towards Río Minero and noticed a yellowish patch of earth accompanied by the black carbonate altered shales of the Muzo Formation. This area is known as Amariallal and marked the establishment of La Pita Mine. The entrance of the mine was first opened in a ravine at the bottom of the mountain near Río Minero and extends approximately 500 metres (1,600 ft) until the tunnel makes contact with the principle fault line running through the length of the La Pita property.

La Pita is north of neighboring mine Cunas. Previously, a dispute between the two mines existed and both groups founded a mining agreement, that is defunct today. The agreement proposed that mining 35 metres (115 ft) north and south of the border between the mining districts was allowed by both parties. Today, the building structures and campsite are located on the property of Cunas.

Recently, La Pita had entered into an agreement with a publicly traded company, FURA Emeralds Inc.[1] This has since been terminated.[2]

Following that, a Canadian company entered into a non-binding agreement and was unable to successfully close on the contract. In 2016, a third company was entering into agreements for full operation at La Pita Mine and to acquire a stake in Zuliana De Esmeraldas Ltda.

Geology

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La Pita mine is mining emeralds from the Muzo Formation, operations are currently focused wholly in the footwall of the Río Minero Fault. The property lies on a productive portion of the fault, with ~1 km of the NNE, moderate to steeply dipping fault (~025/75(?)) running along the long-axis of the property. The Rio Minero fault is characterized by an ~80m wide, very irregular, but sharp contact breccia zone. This breccia is a carbonate altered, with minor content kaolinite altered clasts, localized fluorite matrix, polymicitic carbonate altered shale and carbonate vein clasts, laminated to massive euhedral to anhedral carbonate matrix, chaotic order, clast-supported to matrix-support, fine to very coarse unsorted sharp clast contacts, sub-angular to angular. At present the mine is focused only on the footwall of the fault, exploiting oblique fractures in the Muzo Formation shales of the western flank of the fault. There appears to be a periodicity to the occurrence of variable thickness (1 to 30 centimetres (0.39 to 11.81 in)) calcite veins (observed between 070/35 and 320/65 orientations), that are the primary target for emerald production. The intersections of vein sets are a fertile setting and may represent an upgrading feature. Where these secondary fractures intersect with the primary vein orientation, anecdotally it has been observed that there appears to be an improvement in both quality (colour and clarity) as well as, sometimes, quantity/size. These oblique vein sets (which may simply be conjugate fractures as a product of how the faulting influenced the host Muzo Formation (rheology during formation)) represent the primary source of emeralds in the current operations at La Pita. These vein sets are productive up to several meters away from the fault itself.

Muzo Formation

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Muzo Formation (K1m - Hauterivian-Barremian age), outcropping in the sector of Las Pavas, Peñas Blancas, Coscuez, also appears in Vélez, Chiquinquirá and La Palma. It is part of the flanks of La Chapa-Borbur Anticlinal, also observed in the syncline of Otanche, in the sector of Coscuez. In the region of Muzo and Calcetero, the formation is also part of the syncline of El Almendro and forms the nucleus of the Pauna Anticlinal.

This unit houses most of the emerald-producing mines in the region such as Coscuez. The Muzo Formation is a generally calcareous sequence, while to the north of the Ibacapí Fault it is observed to be weathered and its calcareous composition is not recognized. To the north of Pauna the formation has a siliceous character. In general it is composed of dark gray calcareous claystones with lenses and limestone concretions. Additionally, it is common to find pyrite and calcite veins. These claystones are interspersed with sandy siltstones and quartz sandstones. Towards the middle of the segment arise shales and albitized limestone, somewhat calcareous. At this level appear a brecciated and mineralized zone with veins of calcite and sheets of oxidized sulphides. The upper part of the segment is interspersed with layers of gray claystones with layers of siltstones containing fauna depicted in ammonite molds. At the bottom of this unit is the La Marina Mine and to the south the emerald mines of La Pita, Consorcio, Totumos, Polveros and others. The first calcareous package becomes thicker towards the south, it has a thickness of 2 metres (6.6 ft), and in the sector of Totumos and Polveros reaches 45 metres (148 ft), and is composed of intercalations of limestone (micrite), loam and sandy siltstones. The zone of hydrothermal breccias that is immediately above the calcareous rocks, in the La Pita Mine has a thickness of approximately 30 metres (98 ft), and at the Totumos Mine can reach to 50 metres (160 ft). This unit in the area of Coscuez and Muzo presents emeralds; its characteristic remains limestone in layers of calcareous siltstones interspersed with calcareous claystones. To the south of the area, this unit presents similar characteristics. A stratigraphic column along the La Palma-Yacopí road, shows that this unit is composed of a black marl with a solid appearance with black calcareous claystone intercalations.[3] In the upper part, intercalations of black shale with gypsum flakes and abundant pyritic micritical concretions appear, some with ammonites.[4][5]

Mining licence

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The La Pita concession agreement is active and registered with the National Mining Agency of Colombia. The title holders of Las Pita have a 30-year exploration/exploitation license, this title granted the exclusive right to extract the corresponding minerals and to conduct the necessary efforts to explore, exploit, process, transport and ship the relevant minerals.

Mine safety and security

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Site security currently has several weak points, from the working face to processing of potential ore. The mine is not currently managed with consideration for who is in the mine when it is open and material is not properly processed before being dumped and accessed by the general public. Improvement in security would be relatively simple both from a capital expenditure and implementation perspective. There are 4 points of access, which can be controlled by guards, cameras and doors/walls. The ore would need to be handled differently than it currently is, as there is a substantial amount of material being moved out of the mine and into public area, with only the identified mineralization isolated, but emeralds being present in the other material after. Although effort is made to capture emeralds coming off the face, it has been demonstrated that there are emeralds winding up in the tailings with regularity, of variable quality. The two primary security issues are, access to the mine site when the workings are open and ore processing. Porto Gringo access to the north may represent the greatest weakness to securing the site right now, because of the agreement to allow access to the neighbouring operation.

The mining region, despite its poor reputation is actually safe and community orientated, the violence is now a faint memory of the past.[citation needed] Security in the mine is a collaboration between private security, National Police of Colombia and the National Armed Forces of Colombia. This presence provides for a very secure work place and community support, where the police and military often participate in community social projects ranging from building homes, aqueducts and road maintenance.

References

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  1. ^ Market Wire. "Fura Emeralds Inc". Retrieved 15 March 2016.
  2. ^ Market Wire. "Fura Emeralds Inc". Retrieved 15 April 2016.
  3. ^ Acosta and Ulloa, 2001
  4. ^ Reyes et al., 2006
  5. ^ Ortega Medina, 2007, p.22

Bibliography

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Further reading

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