Detrital zircon geochronology of the Grenville/Llano foreland and basal Sauk Sequence in west Texas, USA

C.J. Spencer, A.R. Prave, P.A. Cawood, N.M.W. Roberts

Research output: Contribution to journalArticlepeer-review

43 Citations (Scopus)


U-Pb detrital zircon ages from Mesoprotero zoic and Cambrian siliciclastic units in west Texas (USA) constrain the depositional setting, provenance, and tectonic history of the region within a late Mesoproterozoic Grenville foreland basin and the early Paleozoic Sauk transgressive sequence. Two key units, the Hazel and Lanoria Formations, have detrital zircon age spectra dominated by detritus derived from the Grenville orogen (the Llano uplift and eroded equivalents), the ca. 1.4 Ga Granite Rhyolite, and the ca. 1.7-1.6 Ga Yavapai/ Mazatzal provinces. These data, combined with sedimentological data, permit interpreting those formations as the proximal and distal deposits, respectively, of a molasse shed into the Grenvillian foreland basin. Detrital zircons as young as ca. 520 Ma show that the Van Horn Formation, previously considered to be Precambrian in age, is no older than middle Cambrian. Further, the overall detrital zircon age spectrum of the Van Horn Formation is similar to that of the overlying Cambro-Ordovician Bliss Formation: both indicate derivation from sources that included the Colorado- Oklahoma aulacogen, Grenville, Granite- Rhyolite, and Yavapai/Mazatzal provinces. The similarities between the depositional history of the Van Horn and Bliss Formations lead us to conclude that the base of the Sauk Sequence in west Texas occurs at the base of the Van Horn Formation. Base-level rise associated with the Sauk transgression affected drainage patterns and sediment deposition along southwestern Laurentia some 20 m.y. earlier than previously assumed.
Original languageEnglish
Pages (from-to)1117-1128
Number of pages12
JournalGeological Society of America Bulletin
Issue number7-8
Early online date18 Apr 2014
Publication statusPublished - 1 Jul 2014


Dive into the research topics of 'Detrital zircon geochronology of the Grenville/Llano foreland and basal Sauk Sequence in west Texas, USA'. Together they form a unique fingerprint.

Cite this