Full title: FT26CD01. Transition from Subduction to Rifting and Marine Incursion in the San Ignacio-Santa Rosalía-Isla San Marcos Region, Central Baja California Peninsula, México
Leader(s): Scott Bennett, Michael Darin, Rebecca Dorsey, Valente Salgado Munoz, Kevin Gardner
Endorser(s): GSA Structural Geology and Tectonics Division, Sociedad Geológica Mexicana, A.C. (SGM), Unión Geofísica Mexicana (UGM), GSA Sedimentary Geology Division, GSA Mineralogy, Geochemistry, Petrology, and Volcanology Division
CEUs: 3.2
Date(s): Sat–Tue, 18–21 Apr.
Location: La Misión Hotel, Loreto, Baja California Sur, Mexico
Start Time: 8 a.m.(first day)
End Time: 5 p.m.(last day)
Description: This field trip will visit key localities along the central Baja California peninsula north of Loreto that provide insights into the late Cenozoic volcanic, tectonic, and stratigraphic evolution of northwest Mexico. Field trip participants will visit exposures that record the transition from Farallon-North America subduction to the Gulf of California transform rift and marine incursion of the Gulf of California seaway. Day 1, participants will visit the crest of the Baja California peninsula to view the Miocene Comondú Group that records subduction-related volcanism. The first night will be spent near the mission and plaza of the quaint town of San Ignacio. Day 2, we will visit post-subduction volcanic rocks that record chemical changes related to the transition to rifting conditions and a variety of terrestrial and marine sedimentary rocks that record the evolving Pacific and Gulf of California shorelines since Miocene time. Day 3 will be spent in the Santa Rosalía basin, visiting strata that record the ~6.3 Ma marine flooding of the Gulf of California and discussing the distribution and age of sedimentary facies related to evolving marine conditions within the Pacific-North America plate boundary. The last two nights will be spent in the historic mining town of Santa Rosalía, overlooking the Gulf of California. Day 4, weather permitting, we will take pangas (boats) to visit coastal cliffs of Isla San Marcos that expose volcanic and marine sedimentary rocks related to early Gulf of California rifting. Return to Loreto for the meeting’s evening Icebreaker.
Considerations: This trip will involve getting in and out of vehicles several times each day to visit key geologic sites. The trip will start (Day 1) and end (Day 4) with a ~3-hour drive, which will include a bathroom break. In between field trip stops, most drives are 15–45 minutes. Driving will be a mix of paved highways, smooth gravel roads, and bumpy dirt roads. At most field trip stops, hikes will be very short (< meters) on a variety of terrain, including flat gravel roads and short distances uphill and/or on uneven ground, following well-traveled routes. One stop includes a 1.6-kilometer (1 mile) hike in a flat sandy wash, before returning the same distance to the vehicles; an alternative outcrop can be arranged to avoid this longer hike, if requested. Several hours of the final day will be spent in a panga (small fiberglass boat) visiting key coastal outcrops. During the panga trip, participants will need to climb in and out of the boat several times, possibly experience bumpy, wavy, and/or windy ocean conditions, and bathroom breaks might be limited to 1 or 2 beach landings with only primitive (outdoor) bathroom options. The Sonoran Desert contains abundant plants (e.g. cactus, cholla, etc.) with sharp spines. Participants should be prepared for a variety of weather conditions in April, including clouds, sun, light rain, wind, cold to hot temperatures, etc. The vehicles and pangas will have snacks and drinks.
By purchasing this item, you are buying a seat for an in-person geological field trip
Field Trips offer Continuing Education Units (CEUs). One CEU equals 10 hours of participation in an organized continuing education experience under responsible sponsorship, capable direction, and qualified instruction.
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Product Code: FT26CD01
Product Category: FTRIP