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Fenton, Cassandra R., Binnie, Steven A., Dunai, Tibor and Niedermann, Samuel (2022). The SPICE project: Calibrated cosmogenic Al-26 production rates and cross-calibrated Al-26 /Be-10, Al-26/C-14, and 26Al/21Ne ratios in quartz from the SP basalt flow, AZ, USA. Quat. Geochronol., 67. OXFORD: ELSEVIER SCI LTD. ISSN 1878-0350

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Abstract

The formally named SP lava flow is a quartz-, olivine- and pyroxene-bearing basalt flow that is preserved in the desert climate of northern Arizona, USA. The flow is independently dated with an 40Ar/39Ar age of 72 +/- 4 ka (20) and has undergone negligible erosion and/or burial, making its surface an ideal site for direct calibration of cosmogenic nuclide production rates. Production rates for cosmogenic 26Al have been determined from SP flow quartz in this study and are combined with production rates for 10Be, 14C, and 21Ne (Fenton et al., 2019) to yield a suite of production rate ratios. The error-weighted mean, sea-level, high latitude (SLHL) total reference production rate of 26Al is 25.8 +/- 2.5 at/g/yr (25x; standard error) using time-independent Lal (1991)/Stone (2000) (St) scaling factors. The St scaled spallogenic 26Al rate is 25.0 +/- 2.4 at/g/yr integrated over the past 72 ka. This rate overlaps within 20 uncertainty with other St-scaled production rates in the literature. SLHL spallogenic 26Al production rates in SPICE quartz (SP Flow Production-Rate Inter-Calibration Site for Cosmogenic-Nuclide Evaluations) are nominally lower if time-dependent Sf, Sa, and Lm scaling factors are used, yielding values of 22.9 +/- 2.2 at/g/yr, 22.6 +/- 2.2 at/g/yr, and 24.1 +/- 2.2 at/g/yr (25x), respectively. All 26Al production rates in SP flow quartz overlap within 20 uncertainty, regardless of time independent or time dependent scaling. Production rate ratios for cosmogenic 26Al/10Be, 26Al/14C, and 26Al/21Ne are based on the total, local production rates of each cosmogenic nuclide, independent of scaling models, and have error-weighted means (+/- 25x; standard error) of 6.7 +/- 0.6, 2.23 +/- 0.20, and 1.51 +/- 0.13, respectively. This study suggests that, similar to cosmogenic 21Ne and 10Be production rates in SP flow quartz, production rates of cosmogenic 26Al in quartz do not significantly increase when integrated over 72 ka, a time span which includes the period of decreased magnetic strength from 20 to 50 ka.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Fenton, Cassandra R. UNSPECIFIED UNSPECIFIED UNSPECIFIED Binnie, Steven A. UNSPECIFIED UNSPECIFIED UNSPECIFIED Dunai, Tibor UNSPECIFIED UNSPECIFIED UNSPECIFIED Niedermann, Samuel UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-580060
DOI:	10.1016/j.quageo.2021.101218
Journal or Publication Title:	Quat. Geochronol.
Volume:	67
Date:	2022
Publisher:	ELSEVIER SCI LTD
Place of Publication:	OXFORD
ISSN:	1878-0350
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language ACCELERATOR MASS-SPECTROMETRY; QUANTIFYING DENUDATION RATES; FRANCISCO VOLCANIC FIELD; NUCLIDE PRODUCTION-RATES; SURFACE EXPOSURE AGES; TRANSANTARCTIC-MOUNTAINS; FLUVIAL TERRACES; NORTHERN CHILE; EROSION RATES; VICTORIA LAND Multiple languages Geography, Physical; Geosciences, Multidisciplinary Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/58006