The Summer Coon intrusive center is located seven miles
north of Del Norte, Colorado, on the eastern edge of the San Juan
Mountains. The intrusive center is the core of a dissected calcalkaline
composite volcano of middle Oligocene age. The Summer
Coon rocks belong to the Conejos Formation which is...
The El Salvador porphyry copper deposit in the Indio Muerto district of northern Chile has been geologically investigated for more than 60 years and provides one of the best bases for understanding similar environments of ore formation elsewhere in the world. Fourteen new zircon U/Pb isotopic ages obtained via in...
The Cretaceous was a period of extreme climatic conditions accompanied
by major perturbations in ocean-atmosphere biogeochemical cycles. One of the
most intriguing features is the sporadic interruption of normal marine pelagic
sediment deposition by organic rich sediments deposited during oxygen-deficient
conditions (ocean anoxic events OAEs). A current model for the...