Company: SQM
Filing Date: 2025-04-24
Form Type: 20-F
Source: 0000909037-25-000020
Chunk: 126

Company: CHEMICAL & MINING CO OF CHILE INC
Filing Date: 2025-04-24
Form: 20-F
Item: Item 4A
Chunk 126
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 resource in the Earl Grey pegmatite group, which consists of a main tabular pegmatite body, flanked by numerous minor dykes at both its top and bottom. The pegmatite field covers an area of up to 1 x 2 square kilometers and has a thickness of up to 100 meters. The pegmatites become progressively narrower and branched to the south and east of the main pegmatite until the main body divides into several narrower dykes. Isolated host rock enclaves are sporadically found within the pegmatite body.
The pegmatites have an approximate strike of 210° to 220° and dip of 5° to 15° to the northwest. At their western margin, the pegmatites appear to be affected by gentle folding. The dip of the pegmatites is variable, with the pegmatite steepening from sub-horizontal in the south to 10° to 15° to the northwest north of the Earl Grey gold pit.
Lithium mineralization within the fresh pegmatite is zoned, and primarily controlled by the dominant mineralogy; spodumene and petalite dominated assemblages are more lithium-rich than altered (cookeite) and Li-absent assemblages. Lithium mineralization is depleted in weathered pegmatite.
Extensive exploration supports the characterization of the Earl Grey pegmatite and the Resource and Reserve estimation, comprising surface mapping and extensive exploration drilling. Early exploration and resource definition was predominantly carried out by Kidman Resources, beginning in 2016. Since 2020, Covalent has conducted additional diamond drilling for metallurgical sampling, grade control drilling campaigns and improvement definition of the orebody geometry in the proposed starter pit area.
Most of the exploration drill holes completed at Earl Grey have been drilled using standard reverse circulation ("RC") drilling techniques. Diamond drilling comprises boreholes with diameters of 47.6mm, 50.5mm, 63.5mm and 85mm, which are drilled for geological, metallurgical and geotechnical purposes. Drilling recoveries for RC drilling range from 70-90% in this geological/geomorphological setting. The recoveries for diamond drilling are in the order of 95-100%. Recoveries diminish where shear zones or other structural disturbances have been crossed. The orientation of the boreholes is at relatively sharp angles (less than 90º) and, therefore, the intersected length is not considered as a representation of