I would like to know what phrasing is the correct geological technical term for a lode or ore vein that grows narrower and narrower till it narrows down to nothing - is it pinch out or peter out?

(besides, does it have to be geological technical term or geologically technical term or just geological term?)

Related: The lead has pinched right out

Yet again, you're being distracted by an outdated usage. There's merit in learning idiomatic peter out, because that's used metaphorically in a wide variety of contexts today. But not pinch out, which today only really exists in the sense of removing dead / unwanted parts of plants, and more recently the thumb+finger gesture used on touch screens to zoom the display. This really isn't relevant to "learning English". – FumbleFingers

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    You'd probably be better asking a geologist rather than an English language learner - maybe on earthscience.stackexchange.com
    – Stuart F
    Nov 7, 2023 at 15:40
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    Things peter out; they do not pinch out. So, FF is right. And it's not just geological either. Anything that extends over a distance can peter out. A road or path, for instance. In fact, pinch out is not at all common.
    – Lambie
    Nov 7, 2023 at 16:08
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    What is pinch out in geology? 1. n. [Geology] A type of stratigraphic trap. The termination by thinning or tapering out ("pinching out") of a reservoir against a nonporous sealing rock creates a favorable geometry to trap hydrocarbons, particularly if the adjacent sealing rock is a source rock such as a shale. Google linked to The Energy Glossary Nov 7, 2023 at 16:38
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    I think this question is just pointlessly trying to marshal support for disagreeing with my assertion as reproduced above. My comment specifically included this usage chart showing that vein pinched out was twice as common as vein petered out a century ago, but the latter is twice as common as the former today. And obviously the word vein means they're all for the mining / geological context. Usage has changed over time! Nov 7, 2023 at 17:16
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    I’m voting to close this question because this is about a technical use of a term, and not about learning English.
    – James K
    Nov 7, 2023 at 21:43

1 Answer 1


The correct geological term of art is pinch out.

Here's some text from some geology modeling software called Seequent:

Improved pinch-out behaviour – Previously, if a drillhole did not contain valid logging it was ignored for pinch-out creation, meaning vein models passed straight through drillhole traces. An additional control is provided to the user to choose whether the vein should pinch out on an empty trace (a hole where no lithology has been logged) or continue through it.

Export/Import of Bulk Vein Edits – it is common that manual editing of vein components is required to produce the vein model you want. Until now, vein edits were only accessible from within the vein model, which made it difficult to recreate a vein from scratch, or even keep a record of edits that had been made. It is now possible to export all user-made vein edits to file, using the Export Vein Edits option on the vein object. This dumps all user made vein edits for segments, midpoints and pinch-outs to a text file.

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