TANBREEZ. Hans Kristian Schoenwandt

Transcription

1 TANBREEZ Hans Kristian Schoenwandt

2 Geological Setting The Ilimaussaq Intrusion belongs to the Meso-Proterozoic Gardar Province. The Province is related to continental rifting between 135 and 114 Ma.

3 Geological Setting The Province consist of continental sandstones and different volcanic and Plutonic rocks of which several are alkaline to peralkaline intrusive complexes. The Ilimaussaq (17 x 8) has been dated at 116 Ma and consist of alkaline to peralkaline rocks of which most are agpatic, for which eudialyte is an index mineral.

4 Ilimaussaq Intrusion has THREE successive intrusive phases. 1. Ring Dyke (augite syenite) 2. Roof cover (alkali granite & quartz syenite) 3. Agpaitic nephenline syenits of the complex GEOLOGY Agpaitic nephenline syenits The agpaitic rock suite can be divided into a: a) floor sequence, solidifying upwards. The floor sequence consists of a rhythmically layered rock type called kakortokite b) roof sequence, solidifying downwards c) Intermediate series sandwiched between roof and floor series (different types of lujavites) The kakortokite is the ore body of the TANBREEZ deposit.

5 TANBREEZ Ore Body The kakortokite are exposed over an area of 5 X 2.5 km on the south side of the fjord Kangerluarsuk. The exposed sequence goes to about 4 m asl. The exposed area comprises of 95% Kakortokite and 5% related rocks.

6 TANBREEZ Ore Body The Kakortokite are exposed over an area of 5 X 2.5 km on the south side of the fjord Kangerluarsuk. The exposed sequence goes to about 4 m asl. The exposed area comprises of 95% Kakortokite and 5% related rocks.

7 TANBREEZ Ore Body Kakortokite has been subdivided into three parts. From bottom to top: i. Lower layered Kakortokite ( app 2 m thick) ii. Slightly layered Kakortokite (app 35 m thick) iii. Transitional layered Kakortokite (app 4 m thick). Upper boundary of the ore deposit. The transitional layered Kakortokite grades into the overlaying green Laujavrite. The contact is gradual and concordant.

8 TANBREEZ Ore Body Lower boundary of the ore deposit. The lower layered Kakortokite rest upon a Black Unit which has been intersected just below sea level in 7 drill holes. General impression is that the Black Unit roughly has the same dip as the layered Kakortokite. The Black Unit (preliminary called the Black Madonna) is a nepheline-sodalite- Syenitic rock. The Black Madonna has primarily been subdivided into three textural types. Reaching from a dense, fine grained rock to a Kakortokite like rock. The contact between the Black Madonna and the layered Kakortokite is well defined without being sharp. Inclusions of Black Madonna occur regularly in the layered Kakortokite however clearly decreasing in number away from the contact.

9 TANBREEZ Ore Body Outer boundary of the ore deposit. The Kakortokite grades into a Border Zone of massive, equigranular agpaitic nepheline syenite of Kakortokitic composition. The Border Zone has also been called either Marginal Pegmatite or Basal pegmatite. The Border Zone is about 15 m wide at sea level decreasing to about 25 m at 4 m asl. The Border Zone, which is part of the ore body, has a well defined to sharp contact to the outer Augite Syenite whereas the boundary to the Kakortokite is gradual.

10 Structure of the Deposit The lower layered Kakortokite is a classic locality for layering in peralkaline rocks. The spectacular rhythmic layering is composed of a black, red and a white layer. The color of the layers reflects enriched content of arfvedsonite, eudialyte and alkali-feldspar nepheline respectively. Conventionally each colored horizon (black, red, white) is termed a layer. A unit is composed of a black, red and white layer in ascending order.

11 Structure of the Deposit The layered Kakortokite consists of 29 units labeled +1 to +17 and -1 to -11 above and below respectively of the datum unit. The layering stands out clearly from the distance however it is not always so obvious at close distance. Some layers are faint others much more strongly marked because of difference in enrichment of the cumulus minerals. There is pronounced thickness variations between layers as well as in texture and grain size. On average a unit is about 8 m ( 3.5 to 12.5 m) thick however not always fully developed in some cases black/red layers are very faint or missing.

12 A Conservative estimate of tonnage is more than one billion tones of ore Estimated grade will be around ZrO % Nb 2 O 5.18 % REO.41 % Y 2 O 3.8 % Ta 2 O 5.1% The Uranium content of the Kakortokite is approximately 2 ppm. The Thorium content is approximately 5 ppm. This is equivalent to background values of the country rock. Grade and Tonnage

13 Eudialyte The commodities of the TANBREEZ deposit are all contained in the mineral eudialyte. Eudialyte together with the other Rockforming minerals appear as Cumulus phases in Kakortokite. In General the eudialyte content of the black and white layers are fairly similar, being a little less than 1 vol %. Eudialyte content of the red layers are round 3-4 vol %. Several investigations has concluded that no cryptic variation occur in the cumulus minerals of the Kakortokite. Consequently surprisingly little change in Eudialyte composition should be expected in the Kakortokite.

14 Eudialyte Eudialyte is a Na-rich zirconosilicate with varying amount of elements including REE. Chemical formula of eudialyte is: Na15Ca6Fe3Zr3Si(Si25O75)(O,OH,H2O) 3(Cl,OH)3 Eudialyte is by far the most common Zr-bearing mineral in the Kakortokite and of the cumulus minerals the only REE-Bearing mineral. A linear correlation between ZrO2 and REE would be expected.

15 Nb2O5 (ppm) Ta2O5 (ppm) Eudialyte Two thousand samples, covering the border zone and the lower part of the Kakortokite clearly shows a linear correlation between ZrO 2, Niobium, Yttrium as well as with heavy and light REE. ZrO 2 vs Nb 2 O 5 ZrO 2 vs Ta 2 O Nb2O Ta2O ZrO 2 %

16 CeO2 (ppm) Eu2O3 (ppm) Sm2O3 (ppm) La2O3 (ppm) Nd2O3 (ppm) Hole 1- Light REE ZrO 2 vs La 2 O 3 ZrO 2 vs Nd 2 O La2O Nd2O3 ZrO 2 vs Pr 6 O 11 ZrO 2 vs Sm 2 O 3 Pr6O11 (ppm) Pr6O Sm2O3 ZrO 2 vs CeO 2 ZrO 2 vs Eu 2 O CeO Eu2O3

17 Ho2O3 (ppm) Er2O3 (ppm) Gd2O3 (ppm) Tb4O7 (ppm) Hole 1- Heavy REE ZrO 2 vs Gd 2 O 3 ZrO 2 vs Tb 4 O Gd2O3 3 2 Tb4O ZrO 2 vs Ho 2 O 3 ZrO 2 vs Er 2 O Ho2O Er2O3

18 Lu2O3 (ppm) Dy2O3 (ppm) Tm2O3 (ppm) Yb2O3 (ppm) Hole 1- Heavy REE ZrO 2 vs Tm 2 O 3 ZrO 2 vs Yb 2 O Tm2O Yb2O3 ZrO 2 vs Lu 2 O 3 ZrO 2 vs Dy 2 O Lu2O Dy2O3

19 Total of REE The pie diagram shows the distribution of the Total REE in the Kakortokite drilled and is also the likely distribution of REE in the whole of the Tanbreez deposit. Total of Light and Heavy REE HEAVY 12 % % 2.62 %.5 % 2.86 % 3.32% % %.34 % 2.12 %.29 %.28% % LIGHT HEAVY CeO % La2O % Pr6O % Nd2O % Sm2O % Eu2O3.28 % Gd2O % Tb4O7.5% Dy2O3 3.32% Ho2O3.72% Er2O3 2.19% Tm2O3.34% Yb2O3 2.12% Lu2O3.29% 4.38 % LIGHT 88 % %

20 TANBREEZ: Heavy Rare Earth REE Oxide Nechalacho Canada (1, tpa) Mt Weld Australia (11, tpa) Mountain Pass USA (2, tpa) Nolans (Australia) (2,) TANBREEZ (Greenland) (1, tpa) Europium (EU) Gadolinium (GD) Terbium (Tb) Dysprosium (Dy) Holmium (Ho) Erbium (Er) Thulium (Tm) Ytterbium (Yb) Yttrium (Y) Lutetium (Lu) Total Heavies % 31.1% Lanthanum (LA) Cerium (Ce) Praseodymium (Pr) Neodymium (Nd) Samarium (Sm) Total Lights 77.8% 98.33% 99.44% %

21 Feasibility study started