Revisiting a suspected impact structure in the Venezuelan Guiana Shield: implications for planetary remote sensing

Circular landforms are commonly interpreted as impact structures in planetary science, yet morphology alone can lead to ambiguous or incorrect classifications. We revisit a circular geomorphological feature in the Venezuelan Guiana Shield that was originally proposed as a possible impact crater based on aerial observations and radar imagery acquired in the 1980s.

Using modern digital elevation models from the Shuttle Radar Topography Mission (SRTM) and TanDEM-X datasets, we perform a detailed morphological analysis of the structure. The topography reveals an elevated annular plateau with discontinuous ridges surrounding a relatively flat interior, lacking diagnostic features of impact craters such as a continuous raised rim, central uplift, or ejecta distribution. Instead, the morphology is consistent with a known intrusive igneous structure, the Nuria ring dike, as supported by regional geological mapping and lithological context.

This case highlights how limited-resolution data and planform geometry can bias interpretations toward impact origin. Similar misclassifications have historically occurred in planetary exploration, where volcanic or tectonic features were initially identified as impact craters prior to higher-resolution observations.

As a terrestrial analogue, this study underscores the importance of integrating geomorphology, geological context, and multi-resolution topography when interpreting circular features on planetary surfaces. The results provide methodological insights relevant to current and future planetary missions, where data resolution and contextual information remain critical constraints.