The Ordovician–Devonian Sierra Grande Formation, Río Negro Province, Argentina contains three quarzitic members with two iron horizons. Its South Deposit includes both iron horizons. However, the East Deposit is relatively unknown, lacking information about geometry, depth and reserves. To answer these questions, we apply geophysical methods for the rapid evaluation of the East Deposit, using gravity and magnetic measures. The processing of these data allows the suggestion of two 2D models for calculating thicknesses, angles and depth of the iron horizons. The adjustments between the calculated and the observed curve are less than 6%. One model proposes the existence of the Alfaro iron horizon, and the other one proposes the presence of the Rosales iron horizon at depth. The Bouguer anomaly gravimetric maps allow us to calculate the mineral mass, resulting in 125 million iron tons. Thus, this study allowed us to calculate the thicknesses, angles and depth of both iron horizons, and to adjust and evaluate the mineral reserves with the maximum reliability that potential methods allow when applied to mineral prospecting. These results provide new and valuable information for future mining prospects.

中文翻译：

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阿根廷里奥内格罗省 Sierra Grande 地区铁矿床的重力和磁力勘探

阿根廷里奥内格罗省奥陶纪-泥盆纪 Sierra Grande 组包含三个石英岩成分和两个铁层。其南部矿床包括两个铁层。然而，东矿床相对未知，缺乏有关几何形状、深度和储量的信息。为了回答这些问题，我们应用地球物理方法，利用重力和磁力测量来快速评估东部矿床。这些数据的处理允许建议两个二维模型来计算铁层的厚度、角度和深度。计算曲线与观测曲线之间的调整小于 6%。一种模型提出了阿尔法罗铁层的存在，另一种模型提出了深部罗萨莱斯铁层的存在。布格异常重力图使我们能够计算矿物质量，得出 1.25 亿铁吨。因此，这项研究使我们能够计算两个铁层的厚度、角度和深度，并在应用于矿产勘探时以潜在方法允许的最大可靠性调整和评估矿产储量。这些结果为未来的采矿前景提供了新的、有价值的信息。