On the age of the Laschamp geomagnetic excursion
- H. Guillou, B. Singer, C. Laj, C. Kissel, S. Scaillet, B. Jicha
- Environmental Science, Geography
- 15 November 2004
Magmatic history and evolution of the Central American Land Bridge in Panama since Cretaceous times
Chemical compositions for 310 igneous rocks from the Cordillera de Panama and the Sona and Azuero peninsulas were supplemented by 40 Ar/ 39 Ar dating and Sr-, Nd-, Pb-, and O-isotope analysis to…
The Role of Water in Generating the Calc-alkaline Trend: New Volatile Data for Aleutian Magmas and a New Tholeiitic Index
The origin of tholeiitic (TH) versus calc-alkaline (CA) magmatic trends has long been debated. Part of the problem stems from the lack of a quantitative measure for the way in which a magma evolves.…
Reducing Error Bars through the Intercalibration of Radioisotopic and Astrochronologic Time Scales for the Cenomanian/Turonian Boundary Interval, Western Interior Basin, USA
- S. Meyers, S. Siewert, D. Sawyer
- Environmental Science
- 1 December 2010
We develop an intercalibrated astrochronologic and radioisotopic time scale for the Cenomanian-Turonian boundary (CTB) interval near the Global Stratotype Section and Point in Colorado, USA, where…
40Ar/39Ar chronostratigraphy of Altiplano-Puna volcanic complex ignimbrites reveals the development of a major magmatic province
- M. Salisbury, B. Jicha, S. Silva, B. Singer, N. Jiménez, M. Ort
- Geology
- 1 May 2011
The Lipez region of southwest Bolivia is the locus of a major Neogene ignimbrite flare-up, and yet it is the least studied portion of the Altiplano-Puna volcanic complex of the Central Andes. Recent…
Eruptive history, geochronology, and magmatic evolution of the Puyehue-Cordón Caulle volcanic complex, Chile
Forty-three 40 Ar/ 39 Ar age determinations of lava flows, domes, ignimbrites, and dikes, plus 14 C dates from seven distal tephra layers, combined with stratigraphy, geochemistry, and Sr and Th…
40Ar/39Ar, K–Ar and 230Th–238U dating of the Laschamp excursion: A radioisotopic tie-point for ice core and climate chronologies
- B. Singer, H. Guillou, C. Johnson
- Environmental Science
- 30 August 2009
Revised age of Aleutian Island Arc formation implies high rate of magma production
- B. Jicha, D. Scholl, B. Singer, G. Yogodzinski, S. Kay
- Geology
- 1 August 2006
Radioisotopic dating of subaerial and submarine volcanic and plutonic rocks from the Aleutian Island Arc provides insight into the timing of arc formation in the middle Eocene. Twenty-eight 40 Ar/ 39…
Integrating 40Ar/39Ar, U-Pb, and astronomical clocks in the Cretaceous Niobrara Formation, Western Interior Basin, USA
- B. Sageman, B. Singer, D. Sawyer
- Geology, Environmental Science
- 1 July 2014
This study revises and improves the chronostratigraphic framework for late Turonian through early Campanian time based on work in the Western Interior U.S. and introduces new methods to better…
Testing the astronomical time scale for oceanic anoxic event 2, and its extension into Cenomanian strata of the Western Interior Basin (USA)
- Chao Ma, S. Meyers, B. Sageman, B. Singer, B. Jicha
- Environmental Science
- 1 July 2014
The development of integrated astronomical and radioisotopic time scales from rhythmic strata of the Western Interior Basin (WIB) has played a fundamental role in the refi nement of Late Cretaceous…
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