Detrital zircon dating taboo dating service

Geologic processes and landscape evolution of the overriding plate were affected by these variations in subduction mode and are recorded in the forearc basin strata.

We investigate the Cenozoic to modern sediment of the forearc Cook Inlet basin in south-central Alaska.

Detrital zircon dating

What we want to ask, now that this paper has shown a significant “unknown” in geological sample collection and testing, is what other unknowns are still out there? Do any of them really know how old their samples are?

Subduction along the southern margin of Alaska, USA, has been ongoing since at least the Jurassic.

However, the character of the subducting slab has changed through time and has included subduction of normal oceanic crust, a spreading ridge, and an oceanic plateau.

The latter two resulted in a change of subduction mode by inducing a shallow subduction angle.

Geologists might assume they have a good sample, and conclude that biases are negligible, but be unaware of other sources of bias.

The authors seek to point out one source of bias and teach their colleagues that “statistically significant” is not necessarily the same as “geologically significant.” Here are some warnings about bias and interpretation in the paper: The experiments shown here pose the uncomfortable problem: If the questions we formulate in such a simple experiment from an active fluvial system fail to be accurately answered using current data evaluation tools, what confidence do we have in our quantitative detrital zircon provenance interpretations from the ancient geological record?

Although larger values of are evidently fundamental for improving representativity and statistical accuracy (Pullen et al., 2014; Zhang et al., 2016; Nie et al., 2018), Thus, in order to improve the quantitative use and application of geochronologic-based detrital mineral provenance approaches, we must better our understanding of how zircon crystals pass through, and fractionate from, sedimentary systems (Hietpas et al., 2011), and use that understanding to inform our statistical treatments accordingly.

This is particularly critical as the number of publications including a component of detrital zircon provenance continues to grow, because this is inevitably driving the community toward a “big data” approach that will (by necessity) continue to increase its reliance on robust statistical treatments. How long have geologists been publishing papers about formations dated with detrital zircons?

The story often told is that radiometric dating produces dates that are super-reliable, because lab rates of radioactive decay don’t lie.

The part of the story not told, though, is that many sources of bias can creep in. How many samples must be collected to converge on a reliable date? What should the geologist do with anomalous samples?

Does statistical convergence necessarily translate into geological convergence? In a new paper in , six geologists tested a widely-used technique of gathering detrital zircons: crystals of zirconium that often contain uranium (U) and its daughter product lead (Pb), found in debris piles below a slope.

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