U-Pb ages of granitoid clasts in upper Mesozoic arc-derived strata of the Vizcaino Peninsula, Baja California, Mexico

Journal Article · Thu Jan 01 04:00:00 EST 1987 · Geology; (United States)

DOI:https://doi.org/10.1130/0091-7613(1987)15<26:UAOGCI>2.0.CO;2· OSTI ID:5334521

Kimbrough, D L; Hickey, J J; Tosdal, R M

Minor but widespread granitoid clasts occur in Late Jurassic to Early Cretaceous age volcanogenic strata of the Eugenia and Perforada Formations on the Vizcaino Peninsula of Baja California. Most are of two common types: coarse-grained garnet-bearing biotite granite and xenolith-rich hornblende tonalite. Concordia modeling of U-Pb zircon data from a biotite granite clast indicates crystallization at 150 +/- 3 Ma and a strong inherited component of Precambrian radiogenic Pb of 1.34 +/- 0.08 Ga. Data from a hornblende tonalite clast indicate a slightly younger crystallization age and a small component of inherited radiogenic Pb. These clasts occur in association with quartzose sediments that contain abundant biotite probably derived from the same source as the biotite granite. This nonvolcanic component occurs in significant amounts throughout most of the Tithonian-Valanginian Eugenia Formation and in the overlying Aptian-Albian Perforada Formation. The apparent absence of a nearby suitable plutonic source for the granitic detritus, either from the Baja California Peninsula or from Sonora, Mexico, may reflect translation of the Vizcaino Peninsula relative to the North American craton since Aptian-Albian time and prior to the opening of the Gulf of California at 5 Ma.

• Research Organization: Univ. of California, Santa Barbara (USA)
• OSTI ID: 5334521
• Journal Information: Geology; (United States), Journal Name: Geology; (United States) Vol. 15:1; ISSN GLGYB
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580100* -- Geology &amp; Hydrology-- (-1989)
ACTINIDES
AGE ESTIMATION
AMPHIBOLE
BIOTITE
CRYSTALLIZATION
DEVELOPING COUNTRIES
ELEMENTS
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC HISTORY
GRANITES
HORNBLENDE
IGNEOUS ROCKS
ISOTOPE DATING
LATIN AMERICA
LEAD
MESOZOIC ERA
METALS
MEXICO
MICA
MINERALS
NORTH AMERICA
PHASE TRANSFORMATIONS
PLUTONIC ROCKS
ROCKS
SILICATE MINERALS
URANIUM
VOLCANIC ROCKS