The Physical Properties of Volcanic and Impact Melt Rocks
Impact melt rocks form from instantaneous shock-induced total melting of rocks during exogenic hypervelocity impacts. Volcanic rocks, such as lava flows, form from partial melting of progenitor lithologies by endogenic heating processes. Comparably, impact melts and lava flows share petrographic and morphological features but are profoundly different in terms of their origin. Melt properties of lava flows have been extensively studied to understand their emplacement processes and magmatic origin. Due to the rarity of impact melt rocks on Earth, their melt properties and emplacement processes on planetary surfaces are not well understood. Terrestrial impact melt rock surfaces are heavily eroded or obstructed by vegetation. However, lunar impact melt flows are well-preserved, and their surface morphologies are analogous to some terrestrial lava flows. The surface morphologies of lava flows reflect their melt properties and emplacement processes. Since ground-truth information on lunar impact melt flows is non-existent, we must use centimetre‒decimetre scale remote sensing data (radar, LiDAR, optical, etc) to study and quantify the surface morphology and roughness of analogous lava flows. Although some terrestrial lava flows exhibit analogous surface roughness to lunar impact melt flows, only comparing terrestrial lava flows to lunar impact melt flows is not ideal since both melt products form under different conditions and processes. Therefore, it is critical to introduce a terrestrial impact crater that shares analogous features with impact craters on the Moon. The Mistastin Lake impact structure is an ideal terrestrial analogue site. The Mistastin impact melt rocks are the best terrestrial samples to study in an attempt to understand the distribution and emplacement of lunar impact melt flows as they formed in anorthositic-type target rocks similar to the anorthositic lunar crust. In this research, I aim to answer the following questions: 1) what are the physical properties of impact melt rocks? 2) what can we learn about lava flow surface morphology using different remote sensing datasets? 3) how analogous are terrestrial lava flows to lunar impact melt flows
Conference Presentations & Abstracts
Tolometti G. D., Neish C. D., Osinski G. R., Zanetti M., Maj R., Hughes S. S., and Nawotniak S. E. Kobs. (2017) Basaltic lava flow field analog at Craters of the Moon National Monument and Preserve [abstract #82]. Geological Association of Canada - Mineralogical Association of Canada. Kingston, Ontario, May 2017.
Tolometti G. D., Neish C. D., Osinski G. R., Zanetti M., Maj R., Hughes S. S., and Nawotniak S. E. Kobs. (2017) Variation in Petrography of Basaltic Lava Flows with Similar Surface Roughness [abstract #1643]. 48th Lunar and Planetary Science Conference. The Woodlands, Texas, March 2017.
University of St Andrews, UK, June 2016
- Leverhulme Study Abroad Studentship, 2017–2018