Malargüe Silica Deposits

Malargüe, the southernmost department of Mendoza province, wedged between the Andes and the Río Colorado, sits at the geographic edge of the productive Vaca Muerta completions zone. The department has hosted hydrocarbons and potassium mining for decades. What makes it relevant to Argentine frac sand economics in 2026 is a combination of three facts: tested silica deposits, 35 km proximity to the Vaca Muerta wellhead, and the Río Colorado corridor as the truck route into Neuquén's North Zone.

Regional geology

Malargüe sits on sedimentary basins shaped by Andean uplift and Pleistocene fluvial systems. Silica-rich deposits appear as Quaternary fluvial terraces and older Tertiary sandstones that have been uplifted and re-worked. The grains are silica-rich with relatively high sphericity. Mineralogically the raw material is broadly compatible with API 19C / ISO 13503-2 certification subject to the usual wash and classification steps. See the Malargüe Department overview for regional context.

Deposit scale

Access and logistics

The site sits on the Río Colorado corridor. Access is by paved provincial road from Malargüe southeast toward Ranquil Norte, with a crossing of the Río Colorado near Rincón de los Sauces. Hydraulic studies have been performed for the river crossing at three load ratings (34.5 T, 60 T, 90 T). The existing single crossing has been an access bottleneck for heavier truck configurations; resolving the rating is a capex line item in the ramp plan.

Provincial context

Mendoza province has historically been cautious on extractive mining (the Ley 7722 constraints on metalliferous mining), but silica extraction for industrial use sits in a separate regulatory framework. Malargüe Department specifically has promoted a pro-mining stance since 2023, including the AMPF (Agencia Mendocina de Promoción de Fondos) incentive framework and Mendoza's opening to RIGI-qualifying projects. Operators considering the region should verify current provincial permits directly.

Test history

The Malargüe deposit used by In-Basin Sand has been validated by SGS Minerals (Chile) on attrition and granulometry for hydraulic fracturing service. The material is API 19C and ISO 13503-2 tested for crush resistance, sphericity, roundness and turbidity, and meets the spec for 85%+ of Vaca Muerta land operations. It does not pass the strict HCl-HF acid-solubility fraction; full lab reports are in the data room under NDA. A 2023 take-or-pay proposal circulated with a Tier 1 operator referenced these test results. See API 19C testing for the full test panel.

Why Malargüe specifically

• Proximity. 35 km to the Vaca Muerta wellhead, inside the productive North Zone.
• Scale. A 3.2M ton cubicated block plus 60M+ tons of inferred upside supports multi-decade production.
• Testing. SGS-validated on the laboratory panel that matters to operators.
• Road-only logistics. Single-mode truck movement, no rail dependency, no river-level variability.
• Plant fit. A 50 t/hr wash plant (about 15,000 t/month at the Phase 1 run rate) matches deposit extraction rates and buyer consumption patterns; 200 t/hr is the Phase 2 expansion option.

Comparison to other Argentine deposits