40Ar/39Ar dating of hydrothermal activity, biota and gold mineralization in the Rhynie hot-spring system, Aberdeenshire, Scotland

Mantled fungal reproductive units in land plant tissue from the Lower Devonian Rhynie chert

“…The cherts have been dated as Pragian-?earliest Emsian based on spore assemblages (Wellman 2006. High-precision age constraints on the Rhynie Lagerstätte indicate absolute ages of 407.1 ± 2.2 Ma (Mark et al 2011) and 411.5 ± 1.3 Ma (Parry et al 2011).…”

A high-precision 40Ar/39Ar age for the Young Toba Tuff and dating of ultra-distal tephra: Forcing of Quaternary climate and implications for hominin occupation of India

“…Detailed methodology for preparation of the proximal samples can be found in Mark et al (2011a) and we present a brief summary. An in-depth discussion of the methodology utilised for the preparation of the distal samples is presented below.…”

New high-precision measurements of the isotopic composition of atmospheric argon

“…Previous measurements have shown that over the range of Ar abundances in the NPL and SUERC reservoirs, the mass spectrometer sensitivity and mass discrimination do not vary with source pressure (Mark et al, 2009). Measurement and data reduction protocols are discussed elsewhere (e.g., Mark et al, 2011). Note that isobaric interferences (e.g., 12 C 3 + and 1 H 35 Cl + and 1 H 37 Cl + ) were not problematic owing to the large Ar signals swamping system backgrounds (also supported by data reproducibility, see Section 4).…”