60-23 From Vent to Horizon: Investigating the Long-Range Basaltic Carrizozo Lava Flow

Session: 2YC and 4YCU Geoscience Student Research Poster Showcase

Presenting Author:

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Abstract:

The Carrizozo lava flow in southern New Mexico is one of the longest known continental basaltic flows, extending approximately 75 kilometers. This ~5,000-year-old monogenetic eruption originated at Little Black Peak, a small cinder cone rising to just 1,730 meters. Lava was emplaced predominantly through an extensive lava tube system. Its exceptional preservation offers a rare opportunity to investigate the structure and dynamics of long-range, tube-fed pāhoehoe flows.

This study aims to (1) evaluate the mechanisms enabling long-range transport from a low-elevation vent, (2) refine estimates of effusion rate and eruption duration, and (3) develop rheological models for hazard forecasting. We are also examining lava behavior at lower temperatures, focusing on the effects of varying crystal and bubble contents to better constrain late-stage emplacement.

To characterize Carrizozo’s physical properties, we conducted high-temperature viscosity measurements using a rotating spindle viscometer. Measured viscosities increased from 2 Pa·s at 1600 °C to 103 Pa·s at 1200 °C, just above likely eruption temperatures. These values align with previous estimates for tube-fed basaltic flows (e.g., Keszthelyi and Pieri, 1993, JVGR 59: 59–75). Crystallization was observed in the rheometer at 1150 °C, and partial melting was achieved at 1200 °C under a heating rate of 30 °C/min.

Textural analysis reveals high vesicularity (40–74%) near the vent, decreasing to 16–40% eight kilometers downflow—consistent with progressive degassing during transport. Surface features such as ropey textures, lava tubes, and inflated pressure ridges highlight the complexity of emplacement dynamics. These observations underscore Carrizozo’s value as a terrestrial analog for lunar and Martian lava flows and contribute to hazard assessments in monogenetic volcanic regions such as Flagstaff, AZ, and Mexico City.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-11198

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