By JENNIFER MORRISSEY
What a year that was, and how ready we are to move forward! There’s light at the end of the tunnel, and it’s getting brighter every day.
We at the Mission Trails Regional Park (MTRP) Foundation thank you, our neighbors, for your continued support of the park through your gifts to the MTRP Foundation. We experienced an outpouring of support in December, and these contributions will help us fund initiatives to preserve and protect the park and provide educational opportunities.
On the subject of education programs, we’re excited to announce that San Carlos resident Dr. Patrick L. Abbott, Professor Emeritus of Geology at SDSU, will continue our OnTopic online lecture series with three presentations about the geology of Mission Trails. Dr. Abbott’s doctoral work at The University of Texas at Austin emphasized reading Earth history recorded in sedimentary rocks and fossils. He is the author of “Geology: Mission Trails Regional Park,” is featured in “Rise and Fall of the Mountains at Mission Trails Regional Park” on the MTRP Foundation’s YouTube channel.
Participation in the geology presentations is free of charge, but registration is required through our website, mtrp.org. The series is made possible by SDG&E and donors to the Mission Trails Regional Park Foundation. For a preview of what’s to come, we encourage you to watch “Rise and Fall of the Mountains at Mission Trails Regional Park” and consider purchasing “Geology: Mission Trails Regional Park” at www.mtrpstore.org.
How was Mission Trails Regional Park built? The science of geology can explain it. Take some basic building blocks of elements and minerals, and then use them to build rocks. These rocks are subjected to Earth’s active processes; some build new rocks, some transform existing rocks, and some destroy rocks. The rocks of Mission Trails Regional Park record the history of this area during the past 126 million years. We will ‘build’ the modern park in these three presentations:
“Rocks: The Building Blocks of the Park”
Thursday, Feb. 18, 6 p.m.
Take eight common elements. Arrange them into different structures thus making eight common minerals. Subject these minerals to different temperatures and pressures, and form three major groups of rocks: Igneous, Sedimentary, and Metamorphic. Igneous rocks form when magma cools at the surface as volcanic rocks or below ground as plutonic rocks. Weathering decomposes and disintegrates surface rocks, then the resulting debris is moved and deposited to form sedimentary rocks. Bury rocks deeply and the elevated temperatures and pressures cause transformation into metamorphic rocks.
“Earth Processes: Past and Present”
Thursday, March 4, 6 p.m.
The Earth is 4.57 billion years old. The same cycles have operated for billions of years. In the tectonic cycle, the outer shell of the Earth consists of pieces or plates which are formed and destroyed. In the hydrologic cycle, solar energy elevates water into the atmosphere; it falls as rain or snow, then flows back to the ocean under the pull of gravity. In the rock cycle, igneous, sedimentary, and metamorphic rocks transform into and from one another.
“Mission Trails Regional Park Forms in Four Phases”
Thursday, March 18, 6 p.m.
The site stays the same, but the rocks and processes change during the past 126 million years. In phase 1 (126 to ~90 million years ago), volcanism and plutonism build mountains. In phase 2 (~90 to 56 mya), the pull of gravity and erosion by running water reduce the mountains to hills. In phase 3 (56 to ~34 mya), the region was buried beneath a huge alluvial fan built of gravels and sands brought by a river from modern-day Sonora, Mexico. In phase 4 (~34 mya and ongoing), erosion again dominates and carves out Cowles and Fortuna Mountains, Mission Gorge, and the modern topography of Mission Trails Regional Park.
Register for these online presentations at www.mtrp.org.
— Jennifer Morrissey is executive director of the Mission Trails Regional Park Foundation.