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Dalgaranga Critical Metals Project: October 2021

By 07/10/2021October 8th, 2021No Comments

During the period of 2016 to mid-2017, KTA initiated Ta-Li-Sn-Rb focussed, near-mine exploration work. A total of 64 rock-chips (16D001 to 038, AD001 to AD007, and 17D001 to 023) were collected over three field campaigns from pegmatites in the pit, mine dumps and from outcropping pegmatites south and southesat of the mine. Many samples were anomalous in the elements of interest, these are summarised in Table 1. Thirty-one samples returned >1000ppm Rb to a maximum of 7676.8ppm, 6 samples over 1000ppm Li to a maximum of 4289.4ppm Li, 11 samples over 100ppm Ta to a max. of 1518.58ppm. Two samples from the undrilled Southern Pegmatite swarm; AD004 returned >5000ppm Rb, 250ppm Sn and 348ppm Li.

Table 1: KTA anomalous rock-chip sample assays

Sample Li Nb Rb Sn Ta2O5
ID ppm ppm ppm ppm ppm
16D001 614 62 4014 140 37
16D003 220 338 1232 39 328
16D004 322 43 1262 45 767
16D005 511 618 2459 74 418
16D012 2398 87 1324 219 75
16D013 94 289 283 10 181
16D014 554 100 2834 98 70
16D015 148 253 381 16 111
16D016 485 130 1696 52 1853
16D017 116 11 313 18 1202
16D030 4289 20 5842 136 9
16D032 2346 245 7677 209 226
16D037 1509 417 1553 101 77
17D018 527 64 2134 59 613
17D022 470 233 3464 136 90
17D023 1399 68 2441 90 15
AD001 1940 85 3820 300 43
AD004 348 180 5000 250 153

 

Based on promising rock-chip results an 11 vertical hole, RC program (DRC001 to 011) totalling 1,066 metres was completed in September 2017. The drilling was designed to:

  1. assess grade along strike of the mineralisation in the open pit where pegmatites are known to thicken;
  2. test areas where zinnwaldite and lepidolite were noted with anomalous Li, Rb, Nb and/or Ta geochemistry; and
  3. determine the distribution and tenor of rare-metal mineralisation within the pegmatites.

The holes were drilled as three lines and targeted the flat-dipping pegmatites immediately east and northeast of the open pit. The target areas were tested with three lines of holes. The southern line drilled shallow, flat-lying pegmatites adjacent to the southeast corner of the pit and tested for deeper underlying mineralisation. The central line of three holes targeted the line of mineralisation immediately north of the pit and a deeper, approximately 30-metre-thick pegmatite. The northern line tested the further strike extension to mineralisation and an eastward extension of a previously drilled thick pegmatite, along with some thinner ones. These holes were the deepest holes drilled so far at the project.

The drill program intersected more extensive pegmatite intersections and widely distributed multi-element rare metal mineralisation than was anticipated; highlighted by the discovery of a rubidium, tin and tantalum enriched 71 metre interval. The assays revealed evidence of Rubidium (Rb) enrichment in addition to confirming the existence of Tin (Sn), Tantalum (Ta), Lithium (Li), Cesium (Cs), and Niobium (Nb). One hundred and ninety-seven (56%) of the samples returned Rb values exceeding 1000ppm, with a peak value of 4943.3ppm (0.49%). Pegmatite samples were enriched in Lithium, but not to the same extent as Rubidium. Better Rb intersections are summarised in Table 2.

 

Table 2: summary of rubidium (Rb) RC drill intersections

Hole ID From (m) To (m) Width Rb (ppm)
DRC001 92 105 13 1322
DRC002 93 111 18 1997.3
DRC003 66 137 71 1567.3
inc 66 83 17 1702
inc 87 98 11 2251.4
DRC005 22 34 12 1859.7
DRC008 57 90 33 1300.6
inc 60 77 17 1545.3
DRC009 38 46 8 1658
DRC010 29 45 16 1994
DRC011 46 68 23 2093.3
  92 108 16 1417.4

Figures: Drill sections with Rb geochemistry

ASX ANNOUNCEMENTS

  • 16 June 2017 (Rock Chips)
  • 14 August 2017 (Rock Chips)
  • 31 October 2017 (Drill Results)