Paper No. 207-13
Presentation Time: 4:55 PM
ON THE TECTONIC STABILITY OF THE YUCATAN BLOCK
The Yucatán Block (YB) is a 450,000 km2 continental microplate, covering southeast Mexico, northern Guatemala, and Belize, and has been a structural entity since at least 230 Ma. The Yucatán Peninsula is the subaerial portion of a carbonate platform deposited over the YB unit, and it has been understood to be broadly tectonically stable. We use geodetic derived data products from the UNAVCO Data Archive Interface v2.0 (DAI v2) for GPS stations within the greater area, including PBO, COCONet, and TLALOCnet networks to explore the present day Yucatan Block motion and evaluate tectonic behavior. Visualizations were created employing two reference frame datasets, NAM08 assuming the interior eastern North America functions as a 'stable' rigid plate, and IGS08 representing the motions with respect to the Earth's core. Present day NW motion of the YB is revealed, along with down-dip in the north-east corner. The 10+ years of data indicate vertical rates on the order of 1 mm/year, which is of significance in interpretations of the hydrogeology, speleogenesis, paleoclimate records, and adaptation to climate change driven sea level rise. Coastal geomorphology, ecology, and archeological observations further indicate persistence of the measured vertical motions at least to the mid-Holocene. In the strict sense, the YB is tectonically stable without apparent deformation or rifting, however the rotation and tilt of the block merits further determination.