1 MINISTRY OF EDUCATION AND TRAINING HA NOI UNIVERSITY OF MINING AND GEOLOGY DUONG NGOC TINH THE LITHIUM MINERALIZATION CHARACTERITICS IN DUC PHO - SA HUYNH MAJOR: GEOLOGICAL ENGINEERING CODE: 9520501 PHD DISSERTATION SUMMARY Ha Noi - 2019 The thesis is executed at Department of Prospecting and Exploration, Faculty of Geology, Ha Noi University of Mining and Geology ADVISOR AND CO-ADVISORS: Asc.Prof PhD Nguyen Quang Luat, Ha Noi University of Mining and Geology PhD Do Van Nhuan Ha Noi University of Mining and Geology Referee 1: Asc.Prof PhD Dang Xuan Phong, Vietnam Union of Geological Sciences Referee 2: PhD Tran Ngoc Thai Vietnam Institute of Geosciences and Mineral Resources Referee 3: PhD Nguyen Van Nguyen General Department of Geology and Minerals of Vietnam This PhD thesis will be examined by University’s PhD Committee at Hanoi University of Mining and Geology, Duc Thang Ward, Bac Tu Liem District, Hanoi Schedule time: The full version is available at National Library and Ha Noi University of Mining and Geology’s Library INTRODUCTION Overview Lithium (Li) is one of the strategic metals, having particularly important applications in the fields of science, technology, energy and environmental protection The demand for lithium has been increasing while the resources and reserves in the world are limited The prospecting discovery and evaluation of lithium deposits become necessary The lithium mineralization zone in Duc Pho - Sa Huynh region was discovered in 2002 during mineral geological survey mapping at the scale of 1: 50,000, Ba To sheet group and evaluated from 2004-2009 This is similar type of mineralization to Na-Li granite pegmatite type, which are the industrial valuable deposits, the major lithium supply as well as another rare and precious minerals: Sn, Ta, Nb, Be, Rb It can be said that this is the first lithium deposit in Viet Nam, which was evaluated in detail, is the basic for lithium exploration and exploitation in the next time However, many problems must to be kept studying for further clarification: To clarify characteristics of material composition; to determine the geological conditions of ore formation, the relationship between magmatic, metamorphic formations and physic-chemical conditions of ore formation; to define the ore controlling elements: magma, tectonic structure, lithology - stratigraphy, metasomatism activities; to establish the deposit types, classify the ore forms The thesis "The lithium mineralization characteristics in Duc Pho - Sa Huynh region” is completely necessary and derived from the urgent requirements in science and life Objective The thesis aims to clarify the characteristics of material compositions, origin and conditions of lithium ore formation in the area of study, creating a scientific basis for determining the deposit types for exploration prospecting Research accountability - Studying on the characteristics of material composition: Mineral components, the assemblages of paragenesis minerals, forming, ore structure; lithium chemical components and the assemblages of useful minor ones - Studying on the formation conditions: The geological conditions, physic-chemical conditions of lithium formation - To study the lithium ore controlling elements - To establish the deposit types, classify the ore forms - To define the prospecting-forcasting premises and signs Research subject and scope The thesis focuses on lithium ore and the related geological subjects in Duc Pho - Sa Huynh region Academic and practical denotation a Academic denotation The establishment of lithium deposit types in the study area is the scientific and practical basic supplementing theories for deposit-ore geosciences b Practical denotation The research results will contribute to orienting the survey and discovery of similar mineral deposits for the basic geological survey plan on mineral resources Proposes The lithium ore in La Vi area, Duc Pho - Sa Huynh region belongs to Na-Li – type pegmatite granite, pegmatite lepidolite subtype, formed during metasomatism of pegmatite bodies and gresenization with overlaping tin mineralization The factors controlling lithium ore in La Vi area, Duc Pho - Sa Huynh include of: The intrusive magma factors are granitoid formations, sa Huynh Complex (P3-T1 sh); tectonic - structural factors are the northwestern southeastern fault system; lithological - stratigraphic factors are crystalline schists combination of Kan Nack complex surrounding the ore Original contribution The topic studying results has clarified the geological, formation physic-chemical conditions, the isotope age of lithium ore and the age of the intrusive magma formation, Sa Huynh Complex The analysed results shows that the litium ore and granitoid rocks of Sa Huynh Complex have formation ages of Late Permi to Early Trias (P3-T1) The research results of stable isotope (δO18 & δD), petrography, mineralography, inclusion have have determined that the origin of ore forming solution derives from intrusive magma and the metamorphic processes related to Lithium in the area The lithium industrial deposit types in Sa Huynh – Duc Pho have established as Na-Li - type pegmatite granite, pegmatite lepidolite subtype, which formed during metasomatism of pegmatite bodies and gresenization with overlaping tin mineralization The factors controlling lithium ore in La Vi area, Duc Pho - Sa Huynh region have been defined: Magma factors (Sa Huynh Complex granitoid); tectonic - structural factors (the northwestern - southeastern fault system and sub-resulting structures); lithological - stratigraphic factors (crystalline schists combination of Kan Nack complex) Data The thesis is completed basing on own PhD candidate data when he had carried out the Science and Technology project of TNMT.03.52 “Studying on the distribution rules of rare lithium metallization in Kontum zone, orienting to the investigation, discovery of rare metal ores”, the analyzed results (ore ages, magma ages) and had referenced the projects such as: Assessment of tin ore and rare metal potential (Ta, Li, Be) in La Vi, Quang Ngai province (Pham Van Thong, 2009); Geological mapping and mineral investigation of Ba To sheets, scale 1: 50,000 (Duong Van Cau, 2004) During carrying out the thesis as well as taking part in the other projects, PhD candidate had the field excursions, studied some detailed sections of Duc Pho - Sa Huynh area Collected and analyzed different kind of samples: 139 thinsection lithological samples, 85 polished samples, 30 microsond, 15 roentgen, 20 chemical silicate, 38 panning samples, 206 36-element ICP samples, 380 atomic absorption samples, 269 Sn chemical samples, 20 ICP-MS samples, 20 rare earth 15-element ICP samples, 33 inclusion samples; sets of samples to determine the age of lithium ore isotopes by Rb/Sr method; sets the isotope age of granitoid rocks, Sa Huynh Complex by U-Pb isotope method in zircon and 06 δO18 & δD isotope samples in pegmatite quartz containing lepidolite The structure In addition to the introduction, conclusion and references, the thesis consists of chapters with 132 pages, 18 tables and 57 figures, images 10 Place of thesis implementation The thesis has been carried out and completed at Department of Prospecting and Exploration, Faculty of Geology, Ha Noi University of Mining and Geology under scientific advisory of Asc.Prof PhD Nguyen Quang Luat and PhD Do Van Nhuan During the thesis, PhD candidate has received the attention and assistance from the Board of Directors of the University of Mining - Geology and the units: Department of Minerals, Department of Prospecting and Exploration, Faculty of Geology, Postgraduate Department; the attention and assistance of Mid-Central Geological Division, General Department of Geology and Minerals of Vietnam, Ministry of Natural Resources and Environment PhD candidate also expresses his thanks to scientists, lecturers and colleagues for the valuable and constructive comments to increase the quality of this thesis RESEARCH CONTENT Chapter GEOLOGICAL STRUCTURAL CHARACTERISTICS IN DUC PHO - SA HUYNH 1.1 Location of the study area The study area belongs to Duc Pho - Sa Huynh geological map, the scale of 1:50,000, with the area of 590km2, limited by geographical coordinates: Longitude: 108º44’55” - 109º4’55”; Latitude: 4º40’2,6” - 15º50’2,6” Detailed study area covers an area of 40km2 On the regional structural diagram, the study area is located in the eastern margin of Kon Tum terrane, the structure of ancient basement 1.2 Studying history of geology and Li minerals 1.2.1 Studying history of regional geology Pre-1975 period: occured mainly French geologists' study works at small and outlined scales Post-1975 period: The study area has been mapped at scales of 1:500.000, 1:200.000, 1:50.000; metallogenic mapped and mineral forecasted in Kon Tum terrane at scale of 1:200.000 The work of geological and minerals mapping, Ba To sheet group (Duong Van Cau, 2004) [3] had found the mineralization zone containing tin, lithium rare metal in La Vi and had detailed investigation, forcasted the mineral prospect 1.1.2 Overview on lithium studies in Viet Nam The study projects on litium minerals in Viet Nam: Prospecting the uranium and other minerals such as beryl, fluorite, lithium in Cao Son, Cao Lan, Cao Bang (Nguyen Dac Dong, 1990); The study on pegmatite and related minerals in Hong river basin (Hoang Sao, 1995); the study on pegmatite containing gemstone in Luc Yen (Nguyen Thi Minh Thuyet, Nguy Tuyet Nhung, 2016); Geological and mineral mapping at scale of 50.000, Ba To sheet (Duong Van Cau, 2004); Evaluating tin minerals and rare metals (Ta, Li, Be) in La Vi, Quang Ngai (Pham Van Thong, 2009); The study on sorting and processing technology of lithium ore in La Vi, Quang Ngai (Dao Duy Anh, 2014); Studying on the distribution rules of rare lithium metallization in Kontum zone, orienting to the investigation, discovery of rare metal ores (Duong Ngoc Tinh, 2017) In general, the study of lithium ore is still new and sketchy in Viet Nam In the area of study have basically been detemined material composition charactertistics, in which Li and Sn have particularly industrial value, and the other rare valuable minerals such as Ta-Nb, Be, Rb, have not been studied yet The researching results have showed that the structure of ore bodies is very complex, the mineralization characteristics, the rule of ore distribution is not clear, the level of study is still not high and must to be kept studying the material composition characteristics, geological conditions, phisical chemical formation, the factors of ore controlling as well as establishing types of origin deposits 1.3 Duc Pho-Sa Huynh geological structure 1.3.1 Stratigraphic overview In the study area, the stratigraphy consists of: the eruption formation of Late Miocen bazan, Dai Nga Formation, N2-Q11 bazan eruption - sediments, they are distributed into the higher buttes on terrain surface; the unconsolidated sediments of Quaternary are distributed in the lower part of the terrain 1.3.2 Intrusive magma overview In the area, the intrusive magma occupies as granitoid of Sa Huynh Complex (γP3-T1 sh), moreover, there are some another ones: Ben Giang (δ-γδ PZ3 bg), Phu Loc (υT1-2 pl), Hoang Lan (σT2hl), Son Dung (γδ-γξ T2 sd), and some dykes which have not been defined their age - Ben Giang Complex: consists of the dykes distributed in the eastern margin of the study area, an area of 2km2 The components comprise Phase (fine-grained quartz diorite), Phase (medium-grained biotite-hornblende granodiorite) This complex’s granitoid belongs to I-S type, lime-alkaline, aluminum saturation, formed in the environment of active continental margin There is a high concentration of Co, Ni, Sn, Cu, Ag elements (2-3 times higher than clark), especially Mo is 250 times higher than clark - Phu Loc complex: consists of small intrusions in the isometric forms of 0.2-0.3 km2 area The petrographic composition comprises gabbro, pyroxene gabro, websterite and a little pyroxenite The rock has fine-grained, mediumgrained, little coarse-grained; massive structure The rocks of this complex are tholeite, high iron and magnesium serries - Sa Huynh Complex In the area, Sa Huynh complex consists of Dong Ram lagre block, with an outcrop area of over 150km2 The compositions consist of: Phase (medium to coarse-grained biotite granite, two-mica granite), Phase (fine-grained biotite granite, two-mica granite), Phase of ore stone comprises pegmatite, aplite The granitoid formations of Sa Huynh complex have similar geochemical characteristics to tin-containing granite and rare metals S-granite type, aluminum saturation, formed in the environment of synkinematic collision The elements have higher content than clark value as Sn, Li, Ta, Th, Rb, Hf, B, W, Mo, Zn, Pb The contents of Sn, Li, Be, and Ta elements have strongly increased from Phase to ore stone Phase and the clack, albitization, greisenization altered rocks The clark contents of Sn in Phase is 0,21, in Phase is 1,38, in ore stone Phase (aplite, pegmatite) is 9,95, in greisenization altered rocks is 48,19 The clark contents of lithium in the corresponding phases as 1,04, 7,34, 10, 14, 9,02, of Be as 0,08, 0,96, 2,29, 4,37; of Ta: 0,95, 1,23 - Hoang Lan Complex: comprises the dark lamproit phlogopite and lamprophyr dykes The rocks of this complex have a high increase from 3.1 to 47.6 times in the light rare earth elements (La, Ce, Pr, Nd, Sm, Eu, Gd) and a high increase (over 10 times) of elements: Ba, Ta, Hf, Th - Son Dung Complex: In the region occured small monzogabromonzodiorite blocks of Phase distributed in the west and severals kersantite dykes The rocks of this complex belongs to the series of alkaline-lime, aluminum saturatio, the samples of Phase are mainly I-granite field On the maps according to Sattran, 1977, Son Dung Complex has Au-Mo mineralization potential 1.3.3 Metallogenic metamorphic complexes - Kan Nack Complex Kan Nack Complex is divided into rock assemblages as follows: Granulite mafic (gr/A-PPkn); Gabroamphibolite (Gba/A-PPkn); Gneis pyroxen (gpx/Appkn); Gneis biotite mixed marble; crystallined schist mixed marble, quarzite (fh/A-PPkn); aluminum saturatio crystalline schist (nf/A-PPkn) In Dong Ram, La Vi discovered the pegmatoid dykes interpenetrating the assemblages of crystallined schist (f-h/A-PPkn) The attitude and country rocks of most these pegmatite veins were consistent, some rock-cut veins Besides, there were microvein, vein rays which injected into rocks - Song Re Complex: Consists of 02 small areas distributing in the north-west The major petrographic compositions comprise biotite gneis, biotite plagiogneis, biotite schist interbeding a few thin layers of amphibol gneis 1.3.4 Structural and tectonic characteristics 1.3.4.1 Petrotectonic assemblages (PTAS) - Tectonic setting unknown PTAS of Arkei- Paleoproterozoi age: Consist of the metamorphic rocks of Kan Nack complex The rocks were metamorphosed to granulite facies and superimposed amphibolite facies - Tectonic setting unknown PTAS of Paleoproterozoi age: Comprise biotite gneis of Song Re complex The obvious characteristic is that they are rather homogeneously metamorphosed in amphibolite facies - The pluton volcanic arc PTAS belonging to active continental margin of Late Paleozoi age: Consist of the assemblages of intrusive horblend granodiorite, biotitehornblend granodiorite (Ben Giang complex) - The plate collision PTAS of Late Permi - Early Trias age: consist of two main rock assemblages: the mafic intrusive rocks of Phu Loc complex and felsic intrusive ones of Sa Huynh complex which is typical for the plate collision regime re-melting crust - The thermal renovation due to extension after plate collision PTAS of Middle Trias age: comprise differentiated intrusive rock assemblages from monzogabro to granite of Son Dung Complex, I-granite type - The boulder uplift PTAS with basalt eruption appended (N13-Q1): consist of two main rock assemblages: basalt eruptions and unconsolidated sediments 1.3.4.2 Folding The study area is the northern wing of An Lao fold The folds shown on the current structural plan are the structures of 2, and higher level They play a role complicating the structure plan of the study area 1.3.4.3 Joints The study area is located in the southeast of the Ba To - Gia Vuc faults, the strong fractured rocks create many cracks The mineralization vein systems containing Li-Sn are the northwest - southeast, a few centimeters-meters wide separated structures, mainly strikes to the southwest with the common dip of 50o They are extension fractures created of Ba Trang - Nui Chua fault system 1.3.4.4 Faults In the study area, the faults are developed according to principal axis systems: northeast - southwest, northwest - southeast, meridian - submeridian, parallel - subparallel In which, the northeast - southwest, northwest - southeast and meridian fault system is the most strongly developed, the parallel fault system is weaker developed The northwest-southeast fault system plays a role in localizing the pegmatoid bodies containing Li, Sn Chapter RATIONALE AND METHODOLOGIES 2.1 Geochemical and mineralogical characteristics of lithium (Li) Lithium of group I is an alkali metal, of the litophil group, and in terms of minerals, Li is classified into rare metals Silvery white to gray Atomic weight: 6.94 Density (g/cm3): 0.534 Melting temperature: 453.69oK (180.54oC) Boiling temperature: 1615oK (1342oC) The average content in the earth's crust is 0.006%, increasing according to the rule: in gabro 0.0003%, in bazan 0.003%, in granite 0.03% The highest depositional level of lithium is in the formations after granite magma and mainly in the late phases of the pegmatit process, herein it is most closely associated with Na The lithium largest industrial deposits are known to be in granite pegmatite (Na-Li type) At lower level, lithium accumulates in gas formations to become hydrothermal, the typical type is the assemblages between Li and F to form a sequence of Li containing F In endogenous deposits, lithium minerals often combine with Be and B minerals Lithium is a reactive metal, which gives priority to link more with silicate than with sulfide or metal During the magmatism Li + replaced Mg2+ and Fe2+ in pyroxene, tourmaline and amphibol It can also replace Mg and Al in mica, such as lepidolite and chlorite, but its small charge and ion radius limit its competitiveness for network cell locations, so it still exists in late differentiation phase Under exogenous conditions, lithium is easily adsorbed by clay minerals Lithium is a cation of I valence, in terms of its properties, it is closest to Na but due to the size of Li+ ions is small in comparision with the size of Na+ ions, lithium can be limited substitute for sodium in crystals The replacement of ions can occur between Li+ and Al3+, Fe2+ and especially Mg2+ because of the radius similarity of these ions regardless of their chemical nature This replacement takes place in the late magmatic crystallization stage and affects to the composition of some minerals such as clinopyroxen and mica Lithium is found in more than 150 minerals, but the true minerals of Li are only about 30, of which, the most common are spodumene, lepidolite, petalite, amblygonite and zinwaldite 2.2 Uses of lithium Lithium has been currently widely used in many different areas: electrical industry, energy battery electronics, aerospace engineering, environmental technology, nuclear materials, metallurgy, chemicals, ceramics - glass, polymer technology, refrigerants, fireworks and medical Currently, the demand for using Li as is very large and increases rapidly including cost 2.3 Types of lithium deposits - Granite-pegmatite deposits of Na-Li type The granite-pegmatite Na-Li deposit type is classified into the following sub-types: spodumene pegmatite, spodumene-lepidolite pegmatite, petalitepegmatite, lepidolite pegmatite The basic lithium minerals have industrial value (spodumene, lepidolite and pentalite and little ambligonite, in a complex with other useful minerals such as beryl, columbite, tantalite, puluxite, microlite, cassiterite, feldspar, ) "The formation of lithium minerals is related to the metamorphic processes in pegmatite Moreover, it is characterized by the replacement of K metamorphic metasomatism by Na metamorphic metasomatism, and then Li by metamorphic metasomatism This deposit type supplies about 95% of the world's lithium mining production" (Tatarinov and Kariakin, 1975) 11 northwest The geological structure comprise mainly crystalline schist of Kan Nack Complex, a small granite area of Sa Huynh Complex These formations are covered by Neogen - Pleistocene basalt In the ore field, 20 ore bodies and 15 mineralized bodies were identified, including Li ore bodies, Li-Sn ore bodies, Sn bodies, 14 Li mineralized bodies and a Sn mineralization These ore bodies are concentrated in three subzones: Dong Ram, La Vi river and A Kham, 300 - 500m from each other Dong Ram sub-area Dong Ram sub-area is located in the center of the ore field, consisting of 18 ore bodies, mineralized bodies The distribution area has a extended form in the northwest - southeast about 2km, the width of 500-600m The ore bodies are from tens meters to 600 meters long; mainly from 240m to 480m; the thickness of 0.4m to 2.3m, average from 0.9m to 1.5m Stretching in the northwest southeast direction They mainly strike to the southwest with a dip of 400 to 750, either vertical or inverted The morphology of ore bodies is mainly vein, flying veins and lens series This is the most prospective area in the region, with a total forcasting resource of 5,100 Li2O tons, 2,700 Sn tons and 1,000 Rb tons, in additon The content of Li2O from 0.3-1.49%, Sn from 0.1-5.77% La Vi river sub-area La Vi river sub-area is located in the southeast of the ore field, consisting of ore bodies distributed into a stretching band to subparallel of 1,2km long, the width of 250m Ore bodies are from 200 to 600m long; the thickness of 0.9m to 1.5m Extending according to subparallel They strike mainly in the southwestern west with a dip of 400 to 750 The morphology of ore bodies is thin and stretching veins This is the second prospective area in the region, with a total resource of 4,400 Li2 O tons, 970 Rb tons The content of Li2O from 0,3-1,56%, Sn from 0,1-0,92% A Kham sub-area A Kham sub-area is located in the southwest of the ore field, including a collection of ore bodies, mineralized small-scale bodies, with the length from 200 to 300m, thickness of 0.6m to 1.9m The same stretching direction of the ore bodies is mainly northwest-southeast They strike into the south and southwest with a dip of 500 -750 The morphology of ore bodies is mainly thin veins This is the small-scaled detailed evaluated area, with a total forcasting resource of 440 Li2O tons, 495 Sn tons and 90 Rb tons The content of Li2O from 0,3-1,41%, Sn from 0,1-2,06% 12 3.1.2 Nuoc Giap ore field Nuoc Giap tin mineralization is located in the southwest corner in La Vi with an area of 2.0km2 The geological structure consists mainly of metamorphic rocks, Kan Nack complex, phase granite of Sa Huynh complex; The joint systems are mainly in the northwest - southeast Here, mineralized bodies that greisenization altered have been identified containing tin with the low content 20% In aditional, biotite, turmaline, zircon The typical MPAS: quartz + muscovite + casiterite 4.1.4 The mineral characteristics Lepidolite: Often in the form like the petal of rose or the fan, a lower refractive and double refraction index than muscovite Under microscope lepidolite 15 is almost colourless, lepidolite is light purple, pinkish after careful observation Interference colors is low, bright grey, light yellow at level Based on the associated relationship between lepidolite and quartz, albite can identify two generations: lepidolite in a combination with quartz, a large size albite characterized for pegmatite origin; lepidolite in a combination with quartz, small xenomorphic albite in greisenization alteration rocks According to the microsond (SEM) and ICP-MS analysing results lepidolite components are as follows: Li2O 4.65-4.96%, SiO2 47.15-57.62%; Al2O3 25.12-32.07%; Na2O 0.27-4.1%; K2O 6.45-9.28%; MgO 0.04-0.07%; F 0.901-8,705% Notably, rubidium content is quite high Rb2O 0.598-2.415%, Cs2O content is 0.036-0.357% (these are very valuable and recoverable metals during processing process of lithium ore) Mineral formula K1.8 (Li2.6Al2.9) (Si6.7Al1.3) O20 (OH, F)4 [24] Topaz- Al2(SiO4) (F, OH2): usually in xenomorphic form, 0.1-1.8 mm in size Colorless, high buoyancy, full cut, stand off, yellowish interference, level Casiterit - SnO2: usually exists in the form of xenomorphic particles, elongated particles with size of 0.2-5 mm, sometimes larger They are disseminated distributed unevenly on the rock platform which is greisenization, usually see the typical elbow-shaped twinning form The content of casiterite minerals (microsond analysis) is as follows: Sn2O 97.58-99.32%, MnO 0.1-1.19%, Fe2O¬3 0.25-1.25%, Ta2O5 0.59%, Nb2O5 trace Tantalite-columbite (Fe, Mn) Ta2O6 - (Fe, Mn) Nb2O6: usually exists in idiomorphic-granular forms, thin sheets, and twin plates Dark gray, low reflectivity, weak anisotropy The microsond tantalite - mineral analysis results showed that the content of components is as follows: Ta2O5 33.44-63.88%; Nb2O5 50.86-20.68%; MnO 11.3-17.24%; FeO 15-3.44% 4.2 The chemical composition characteristics 4.2.1 Li ore In Li ore bodies, Li is main element, the other minor ones comprise: Sn, Ta, Nb, Be The content of Li2O in the samples from 0,10% to 1,72%, the average of 0,82%, high The very valuable minor element is Rb with the oscillation content about 798-4320ppm, the average of 2638ppm (ICP-MS) In this ore type Li has correlated quite clearly with Rb, Be, Nb, Ta, characterizing rare metal pegmatite ore type 4.2.2 Li-Sn ore In Li-Sn ore bodies, Li, Sn are main minerals, the other minor ones comprise: Rb, Ta, Nb, Be The content of Li2O in the samples varies from 0,08% to 2,04%, the average of 0,69% The variation coefficient of Li content (VLi) is 64%; Sn content in samples alters unevenly from 0,04% to 4,93%, the average of 16 0,52% Tantalum and Niobium (Ta, Nb): are relatively common elements in this ore type, many samples reach Ta content> 100ppm and Nb> 100ppm, in particular > 400ppm Ta Li has an inverse correlation with Sn, Be, Nb, Ta; whereas, Sn has a close correlation with Ta, Nb and Be 4.2.3 Sn ore In Sn ore bodies, the main mineral is Sn, the other minor ones comprise: Li, Ta, Nb, Be The content of Sn oscillated from 0,06% đến 5,77%, the average of 0,62% In this ore type Sn has a close correlation with Nb and the correlation with Ta, Be 4.3 The physic-chemical conditions of lithium mineralization 4.3.1 The genesic of mineralization fluid The samples for O-D isotope of quartz minerals were directly collected from lithium and tin -containing pegmatoid veins in La Vi area, Duc Pho - Sa Huynh were analyzed at China University of Geoscience - Beijing, China and were displayed on the δO18-δD diagram (Sheppard, 1986) to identify the origin of the water in mineralization solution The results showed that the composition of δO18 is rather stable at about 6,5÷7,3‰, δD strongly oscillated from 70 ÷ -116‰ The correlation chart indicated that one sample in the magmatic water field and the others in the intermediate water field Combined with the results of other studies, especially the study results of regional metasomatism can suggest that the mineralization solution has primary magmatic origins; however, the mineralization solution has been mixed with other sources due to tectonic and metasomatism activities which had strongly occurred in the study area 4.3.2 Temperature conditions, formation pressure and evolution of postmagma solution Summary of inclusion analysis results can show temperature ranges as follows: From 520-617oC; from 360-445oC; from 195-320oC In the study of metasomatism (Pollard 1983) has indicated that, albitisation strongly occurs in the range of temperatures of between 400 and 800oC and at pressures of kbar or less; the greisenization was occured at the depth of 1,5 – km, temperatures range of 350-450oC The greisenization occurred at the time when the acidity of the post-magma solution associated with granitoid increased at the maximum level In the study area, related to the process of Li mineralization, there are stages: The first if microclinization (the orthoclas was replaced by microcline), It is subsequently albitization, K-felspat was replaced by albite These rocks was subsequently altered by greisenization to make complicated structure According to the acid and temperature evolutional diagram of postmagmatic solution, albitization and greisenization alterations in the region 17 are in the period 2-4 and a range of temperatures of between 400 and 600oC are also very suitable for study results 4.4 The mineralization process The study results showed that Li mineralization process in the region had undergone many phases, quite complicated, as follows: Pegmatite period This period has a phase (Phase I) The formation of pegmatite veins containing lithium with the main simple components comprise: felspar quartz, large-sized mica The typical structure is coarse-grained, micro pegmatite The typical MPAS is quartz + orthoclas + muscovite The formation temperature is over 600oC Metasomatism period This period can be devided into Phases (II, III, IV) Phase II: Alkali metasomatism (Microclinization) The microcline replaced the large - sized orthoclas and was subsequently replaced by albite Banded, pocket forms; the typical structure is xenomorphic idiomorphic-granular, instead corrosion The typical MPAS is quartz + orthoclas + muscovite The formation temperature is 617-520oC Phase III: Na-Li metasomatism This Phase is characterized by two Na (albitisation) and Li (lepidolitation) metasomatism processes These metasomatism processes strongly occurred in the pegmatite dykes containing lithium Albite always accompanies lepidolite in Li, Li-Sn ore bodies, they often create different colored bands, pockets and lenses Here, albite replaced orthoclas even albite in the previous phase Lepidolite replaced biotite and muscovite minerals by replacing isomorphous method There is Li+ abundance in the residual liquids, ionic substitution can occur between Li+ and Al3+, Fe2+ and especially Mg2+ due to the similarity in the ionic radius The typical forms are banded, pocket and lens; the structure is xenomorphic allotriomorphic-granular, instead corrosion The typical MPAS is quartz + albite + lepidolite + topaz The formation temperature is 617-520oC Phase IV: Greisenization This phase occurred when the acidity increased at the maximum level The typical alteration was greisenization closely related to Sn mineralization; with them, albitization (albite of generation 2), has altered the formations in Phase I and has recombined the albite and mica minerals containing lithium of smaller size The typical MPAS for greisen in pegmatite veins containing lithium is quartz + albite (generation 2) + lepidolite (generation 2) + topaz + casiterite For the veins, greisen vein rays penetrating through the shale, the typical MPAS is quartz + muscovite + 18 casiterite The typical ore forms: banded, pocket, lens, disseminated; structure: hypautomorphic - allotriomorphic, lepidoblastic and granular Hydrothermal period Phase V: Forming the polymetallic sulfur-quarzt veins Table 12: The forming order and the lithium mineralogy paragenesis assemblages in Duc Pho - Sa Huynh Period Phase MPAS Mineral name Pegmatite I Pegmatit thực II KMetasomatism Metasomatism III Na-Li Metasomatism Qu+Or +Mus Qu+Mi +Mus Qu+Ab+ Lp+Tp pocket, mass pocket, band, mass Coarsegrained, micro pegmatite xenomorphic idiomorphicgranular, instead corrosion xenomorphic idiomorphicgranular, lepidoblastic, instead corrosion hypautomorphic allotriomorphic, lepidoblastic and granular hypautomorphic allotriomorphic granular microclinization Albitization Lepidolitation greisenization Sericitization, chloritization 450-360o 320-195o IV Hydrothermal VI Greisenization Q+Mus+Cs; Qu+Ab+ Lp+Tp Qu+Py+ Chp+Gal +Spl pocket, band, veins, lens disseminated veins, infected Quartz Plagioclas Orthoclas Biotite Muscovite Microcline Albite Turmalin Beryl Topaz Lepidolite Montebrasite Amblygonite TantaliteColumbite Cassiterite Pyrite Chalcopyrite Galena Sphalerite Hematite Structural features Typical structure Typical altered phenomenon Formation temperature >600o 617-520o Notes: Major minerals: ; minor: ; rare: ; Abbreviations: Qu- quarzt, Or- Orthoclas, Mi- Microcline, Mus- muscovite, Ab- albite, Lp- lepidolite, Tp- topaz, Cs- casiterrite, Py- pyrite, Chp- chalcopyrite, Gal- galena, Spl- sphalerite 19 4.5 The age of lithium mineralization and granitoid, Sa Huynh Complex The mineralization age of lithium rare metal in Duc Pho - Sa Huynh Lithium mineralization age in Duc Pho - Sa Huynh is analyzed by Rb/Sr total-rock method Samples were analyzed at the Department of Geology and Physics, Ryukyu University, Okinawa, Japan, using Neptune Plus MC-ICP-MS Multisystem Mass spectrometry machine Results processing with Isoplot v.4.1 (Ludwig, 2014), the correlation chart 87Rb / 86Sr and 87Sr / 86Sr give the age results of the lithium ore sample set of 264 ± 3.6 MA The 87Sr/86Sr isotope ratio of the lithium ore group is very high (0.8025) compared to 0.703 to 0.707 mantle-derived material, indicating that the acid rock group has the origin of re-molting (S-type granite) Figure 4.15: Isotime line identifying lithium ore isotope age The granitoid isotope age of Sa Huynh complex The granitoid isotope age of Sa Huynh complex was analyzed by UPb isotope method in zircon Samples were processed and analyzed at the State Key Laboratory- China University of Geosciences (Beijing), analysis of sets of samples The results of analysis and calculation for age values are 259.4 ± 7.9 million years (SH3 sample) and 251.6 ± million years (SH4 sample) corresponding to the Late Permian to the Early Triassic (P3-T1) The results showed that lithium and granitoid rocks of Sa Huynh complex had the same formation age in the Late Permian to the Early Triassic (P3-T1) Figure 4.16: Concordia curve representing the value of granite isotope age, Sa Huynh complex 20 4.6 Establishing the type of Li deposits and ore in Duc Pho - Sa Huynh 4.6.1 Establishing the type of lithium deposits in Duc Pho - Sa Huynh Based on geological conditions, distribution characteristics, structural morphology, the relationship with granitoid magma in the region; Material composition characteristics, physic - chemical formation conditions In comparison with the industrial deposit types which mentioned in Chapter 2, it is possible to classify the lithium mineralization in Duc Pho - Sa Huynh into the type of industrial origin deposits which is Na-Li granite pegmatite type, lepidolite pegmatite sub-type: the main lithium mineral is lepidolite, the useful minor minerals are casiterite, columbite, tantalite, 4.6.2 Classification of ore types in Duc Pho - Sa Huynh area Based on their useful composition characteristisc and their industrial values, the ore types can be classified as: Li, Li - Sn and Sn 4.6.2.1 Li ore: Consitsts of pegmatite ore bodies containing lithium, major alteration is albitization The typical MPAS is albite + quartz + lepidolite + topaz Major mineral is Li, attached minor minerals are Rb, Sn, Ta, Nb, Be 4.6.2.2 Li-Sn ore: Comprises pegmatoid ore bodies containing lithium, major alteration is albitization and greisenization The typical MPAS is albite + quartz + lepidolite + topaz + casiterite Major minerals are Li and Sn, attached minor minerals are Rb, Ta, Nb, Be 4.6.2.3 Sn ore bodies: Consists of veins, vein system, greisen lens The typical MPAS is quartz + muscovite + casiterite Major minerals are Sn, attached minor minerals are Ta, Nb Chapter FACTORS CONTROLLING LITHIUM ORE AND LI PROSPECTING PREMISES - SIGNS IN DUC PHO - SA HUYNH 5.1 Factors controlling Li ore 5.1.1 Magmatic factors - Sa Huynh complex The magmatic factors controlling lithium ore in La Vi area, Duc Pho - Sa Huynh region have been defined: Space relationship: Lithium ore bodies were distributed in the contacting zone between the granitoid formation of Sa Huynh complex (γP3-T1 sh) and metamorphic rocks of Kan Nack complex (A-PP kn), here albitization and greisenization altered zones have strongly developed Formation time: The stydied results showed that lithium ore and granitoid rocks of Sa Huynh complex have same formation age from Late Permi to Early Trias (P3-T1) Origin relationship: represents in the following relation 21 - The typical minor mineral compositions of rocks and ore are similar: ilmenite, granat, monazite, tantalite-columbite, casiterite - Lithogeochemical characteristics: The granitoid formations of Sa Huynh complex have similar geochemical characteristics to granite bearing tin and rare metals S-granite type, aluminum saturated, formed in the synkinematic setting, the evolutionary level strongly occurred to fractionated The elements have a higher content than clark value are Sn, Li, Ta, Th, Rb, Hf, B, W, Mo, Zn, Pb - On the variation chart of standard trace elements with Chondrit has showed that rare earth elements in variable lithium ore are similar to the granite samples of phase of Sa Huynh complex - Metallogenic potential: geochemical characteristics, from phase to the vein-stone phase and greisenization altered rocks, the clark content of Sn, Li, Be, Ta strongly increased The clark content of Sn in Phase is 0,21, phase is 1,38, vein-stone phase (aplite, pegmatite): 9,95, in greisenization altered rocks: 48,19 The clark content of Li in the corresponding phases as 1,04, 7,34, 10,14, 9,02, of Be: 0,08, 0,96, 2,29, 4,37; of Ta: 0,95, 1,23 - Metallogenic specialization: On the correlation diagrams of K+ - Na+, Mg2+ K+ and Mg2+ -Na+ classifying metallogenic specialization of granite magmatic rocks the samples mainly fall into Mo-Sn field - The results of stable isotope analysis δ18O & δD showed that the mineralization solution has primary magmatic origin but was mixed due to the tectonic and metamorphic activities which had strongly occurred in the study area 5.1.2.Tectonic structural factors Tectonic structural factors have played a role as a waterway and place of setting the ore forming materials, to decide the ore concentration and distribution - Fault: The northwest - southeast fault system plays a dominant role and controls Li, Sn mineralization veins - Joint: The mineralization vein systems containing tin are separated structures of northwest - southeast, they are several centimeter-meter wide, strike mainly to the southwest with a common dip of 50-700 They are the attached joint systems (strike in the opposite direction to the main fault system) of the Ba TrangNui Chua fault system - Folding: plays a role to make complicated structure of the study area 5.1.3 Lithological stratigraphy factors In the region the lithium-containing pegmatoid dykes mainly encountered in the crystallised schist intercalated marble, quartzite (f-h/A-PPkn) mixed with gabroamphibolite assemblages distributing in the contact zone with granitoid magmatic rocks of Sa Huynh complex 22 5.2 Premise, prospecting and forcasting signs 5.2.1 Prospecting premise 5.2.1.1- Intrusive magmatic premise The granitoid formations of Sa Huynh complex have a close relationship with lithium ore in the region They are S-granite type, aluminum saturation; formed in the tectonic collision setting, the evolutionary level strongly occurred to fractionated Metallogenic potential is Li, Sn, Be, Ta, Mo 5.2.1.2- Tectonic structural premise The geological structures such as magmatic dome positions, to contact to metamorphic rocks, to develop folded, laminated, jointed structures to create the convenient space for ore forming 5.2.1.3 - Lithological stratigraphy premise In Duc Pho-Sa Huynh, the lithium - containing pegmatite dykes intruded into the metamorphic rocks of Kan Nack complex Most the lithium - containing pegmatites intruded into the metamorphic rocks, typically low-pressure amphibolite facies to greenschist facies, eruptive sedimentary rocks or unmodified rocks (Ĉerný, 1992), this is the survey orientation, not condition 5.2.2 Prospecting and forcasting signs Pegmatite fields: Lithium-containing pegmatites in the study area have been in pegmatite field stretching to the northwest - southeast and controlled by the same fault system Boulder zone: The Li-Sn containing boulder zones are directly related signs to the original ore Altered rock zones: altered rocks by albitization, microclinization which often distributed in the dome part of granitoid intrusive mass, in the margin of pegmatite veins and in the hydrothermal veins Placer dispersion haloes: The Placer dispersion haloes assemblages of casiterite, tantalite, elbait, spesartin, monazite minerals Secondary geochemical dispersion haloes: The dispersion haloes assemblages of As Be, Sn elements can form a distance of 10-20km; of Nb-Ta is 1-5km; while of Li, Rb, Cs tend to highly flexible and can be found in clayriched line sediments 23 CONCLUSION AND RECOMENDATION Conclusion On the basis for clarifying the geological and physic chemical conditions of the ore formation and the relationship with magmatic and metamorphic formations, it is possible to classify the lithium mineralization in Duc Pho - Sa Huynh into the type of industrial origin deposits which is Na-Li granite pegmatite type, lepidolite pegmatite sub-type: the main lithium mineral is lepidolite, the useful minor minerals are casiterite, columbite, tantalite, There are types of ore: Li, Li-SN and Sn Lithium mineralization in the study area was formed during metasomatism of pegmatite bodies and gresenization with overlaping tin mineralization Lithium mineralization in Duc Pho – Sa Huynh has been controled by the geological factors: Magmatic factors: the intrusive magma of Sa Huynh complex; Tectonic structural factors: Northwest-southeast fault system and attached structure are both waterway and storage areas, localizing ore bodies in the region; Lithological factors: metamorphic rocks of Kan Nack complex The study area has undergone many magmatic activity, tectonic and metallogenic stages, so the geological formations have been metamorphosed strongly and complexly with many stages which overlapped in the same ore controlling structure The study results showed that the Li-bearing metasomatism occurred in Phases: K metasomatism (microclinization), Na-Li metasomatism (albitization), metasomatism (lepidolitation) Thereto, there were also greisenization hydrothermal altered processes with related Sn ore The isotope age analyzing results showed that lithium ore and granitoid rocks of Sa Huynh complex had the same formation age in the Late Permian to the Early Triassic (P3-T1) According to U/Pb isotope analysis results in zircon, the granite isotope age, Sa Huynh complex had the age values of 259.4 ± 7.9 million years (SH3 sample) and 251.6 ± million years (SH4 sample) corresponding to the Late Permian to the Early Triassic (P3-T1) The mineralization age of lithium rare metal in Duc Pho – Sa Huynh region was analysed by total-stone Rb/Sr method for the age isotope result of 264±3,6 million years The 87Sr/86Sr isotope ratio of the lithium ore group is very high (0.8025) compared to 0.703 to 0.707 mantle-derived material, indicating that the acid rock group has the origin of re-molting (S-type granite) The results of stable isotope analysis δ18O & δD showed that the mineralization solution had primary magmatic origin but was mixed due to the tectonic, metasomatism and hydrothermal activities which had strongly occurred in the study area 24 Lithium prospecting premisses: S-type granite intrusive magma; geological structures such as magma domed positions; ancient metamorphic rocks The prospecting signs: pegmatite ore fields; albitization, microclinization altered zones; Placer dispersion haloes of casiterite, tantalite, elbaite ; geochemical dispersion haloes of Be, Sn, Nb-Ta, Rb, Cs, Li Recomendation Na-Li-type pegmatite granite deposits in the study area are very valuable not only for Li but also for many other rare and strategic metal minerals In Vietnam in general and in Kon Tum in particular, many areas have the premises and signs related to this type of industrial origin deposits which need to be investigated and evaluated, especially the areas having favorable geological structures for ore forming must be invested in mineral prospect and evaluation, some areas are: Luc Yen, Yen Bai; Pia Oac, Cao Bang; Phu Hoat, Nghe An; Ba To, Kan Nack, Nam Chu Sing, Kon Tum 25 PUBLICATION A B Articles Duong Ngoc Tinh, Nguyen Manh Hai, Nguyen Huong, Tran Hoang Vu, Nguyen Thi Mo (2015) Mineralization characteristics of lithium rare metal in La Vi area, Quang Ngai province Journal of Geology, Series A, No 349, 1-2/2015, p 61-69 Tran Hoang Vu, Tran My Dung, Duong Ngoc Tinh (2015) The U - Pb isotopic age in zircon of Ngoc Tu granitic massif, Dak To District, Kon Tum Province Viet Nam Resources and Geology, The collection of scientific reports in National Scientific Conference celebrating 70 years of development, Vietnam Academy of Science and Technology, p 246-252 Duong Ngoc Tinh, Do Van Nhuan (2016) The metasomatism related to lithium mineralization in Duc Pho - Sa Huynh area Session: Geology and Geo-resources (GAG), Proceeding of the ESASGD 2016, Ha Noi, November 14, 2016, page 19-25 Duong Ngoc Tinh, Nguyen Quang Luat, Do Van Nhuan (2018) Factors controlling lithium ore in La Vi area, Duc Pho - Sa Huynh region Earth Sciences and Natural Resources for Substainable Development (ERSD 2018) Research projects Duong Ngoc Tinh (2017) Project: Studying on the distribution rules of rare lithium metallization in Kontum zone, orienting to the investigation, discovery of rare metal ores Nguyen Manh Hai, Duong Ngoc Tinh et al (2018) Forecasting the deep blinding Sn-W ore potential in Lam Dong - Khanh Hoa basing on study of the structural characteristics of some ore fields which have been evaluated, explored and exploited ... 206 36-element ICP samples, 380 atomic absorption samples, 269 Sn chemical samples, 20 ICP-MS samples, 20 rare earth 15-element ICP samples, 33 inclusion samples; sets of samples to determine... Pho - Sa Huynh area Collected and analyzed different kind of samples: 139 thinsection lithological samples, 85 polished samples, 30 microsond, 15 roentgen, 20 chemical silicate, 38 panning samples,... severals kersantite dykes The rocks of this complex belongs to the series of alkaline-lime, aluminum saturatio, the samples of Phase are mainly I-granite field On the maps according to Sattran, 1977,