Quaternary geology of the south-central New Mexico border region

TitleQuaternary geology of the south-central New Mexico border region
Publication TypeConference Proceedings
Year of Publication1969
AuthorsHawley JW, Kottlowski FE
Conference NameBorder Stratigraphy Symposium
VolumeCircular 104
Date Published1969
PublisherNew Mexico Bureau of Mines and Mineral Resources
Call Number00106
Keywordsabstract, abstracts, conference, conference proceedings, conferences, geomorphology, Quaternary geology, proceeding, proceedings
AbstractIn early to mid-Quaternary time, the intermontane basins of the south-central New Mexico border region were still internally drained. Environments of deposition ranged from alluvial-fan piedmont slopes to broad basin floors that were often sites of lacustrine sedimentation. In later stages of basin filling, local upland sediment sources were supplemented by the ancestral upper Rio Grande, which extended into the region by early Kansan time. Studies of vertebrate and invertebrate faunas and correlation of volcanic ash lenses indicate that basin filling in extensive areas adjacent to the Rio Grande Valley culminated in late Kansan to early Illinoian time. The complex of late Cenozoic basin fills predating Rio Grande Valley entrenchment comprises the Santa Fe Group. The Jornada and La Mesa geomorphic surfaces cap the Santa Fe sequence. Cyclic entrenchment of the Rio Grande was initiated after mid-Pleistocene integration of the lower and upper segments of the ancestral Rio Grande. Subsequently, four major, climatically controlled cycles of valley cutting have taken place. Aggradation of basin surfaces has continued in broad areas still not integrated with Rio Grande drainage. Parts of basin floors were occupied by large lakes during late Pleistocene pluvials. Significant structural deformation of basin- and valley-fill deposits and extrusion of basalts and maare formation in Mesilla bolson represent continuation of deep-seated disturbances in Quaternary time.
Custom 1Socorro, New Mexico