Talk:Isograd

This article is rated Stub-class on Wikipedia's content assessment scale.
It is of interest to the following WikiProjects:

Geology Low‑importance

	Geology portal Talk:Isograd is part of WikiProject Geology, an attempt at creating a standardized, informative, comprehensive and easy-to-use geology resource. If you would like to participate, you can choose to edit this article, or visit the project page for more information.GeologyWikipedia:WikiProject GeologyTemplate:WikiProject GeologyGeology articles
Low	This article has been rated as Low-importance on the project's importance scale.
	This article has been automatically rated by a bot or other tool as Stub-class because it uses a stub template. Please ensure the assessment is correct before removing the `\|auto=` parameter.

Plane of . . .

I'm not a geologist, but in the opening definition "surface" seems more likely than "plane". Normally in scientific usage a plane is flat. Musiconeologist (talk) 17:31, 25 August 2021 (UTC)[reply]

Update: The OED definition uses surface as do all its examples, so I've now changed it.Musiconeologist (talk) 18:16, 25 August 2021 (UTC)[reply]

References in introduction

I've made the first paragraph more explanatory using information from the articles for the various technical terms it uses. But I had to keep its three references together at the end, as I don't have access to the books. I think it would be sensible to check whether they can now be moved to the specific points where they're relevant. Musiconeologist (talk) 22:32, 25 August 2021 (UTC)[reply]

Lines on maps of metamorphic terranes

There are several issues with the second paragraph of the article as it stands. Safely fixing them requires more knowledge of geology than I have.

Metamorphic terranes: This needs a link, but the Terrane article appears to be about a different usage of the term so either is not the appropriate place, or needs clarifying so that it is.
(or landscapes underlain by metamorphic rocks): unclear whether this is an explanation (that is, . . .) or an alternative (or of . . .)
An isograd has just been defined as a surface, but now refers to a line.
the first occurrence of garnet is confusing. First in what respect? Presumably as one moves across the map into a region containing garnet, and then other index minerals, but on first reading I imagined moving vertically into the rock until one finds garnet, then somehow relating this to a line on the map. I think something like the garnet isograd represents the boundary between areas which do and do not contain garnet would be better.

I'd like to add a sentence immediately after the existing definition similar to one of the following, but worded so as to accurately represent the usage within geology:

The line where this surface and the upper surface of the bedrock intersect is also commonly referred to as an isograd.
The line where this surface intersects a horizontal section through the rock is also commonly called an isograd.

Alternatively I could just trust the OED definition and change surface to surface or line in the first paragraph, though this would be slightly less specific about what the line on a map represents.

Musiconeologist (talk) 18:01, 26 August 2021 (UTC)[reply]