Talk:Duluth Complex

Needs Rewrite

Most of the article sounds copied from somewhere. There are several terms which sound archaic or are undefined, as if the average reader already knows what they mean. Tmangray (talk) 20:23, 20 April 2008 (UTC)

This article is not copied from anywhere. Terms used are those used in the cited sources. Some of those sources used date back several decades. If anyone wishes to further define the terms or update the articles with more recent information, and source those changes, they are of course welcome to do so. The article does use some technical terms, as do other geology articles. Its readability scores are available here. Kablammo (talk) 21:09, 20 April 2008 (UTC)

quick suggestions

The section that actually talks about the complex is a bit confusing and might be better split into a few sections. one on genesis of the formation, one on petrologic discriptions of the materials that make it up, one on broad structures with in the formation and region (the alluded to syncline under the great lake nearby, etc).

The lead paragraph might also include something on the general age of the complex.

Also, something more on the geography/geomorphology of the current state of the region.

Otherwise, what is there is very good. --Rocksanddirt (talk) 21:19, 20 November 2008 (UTC)

Thanks for the suggestions; I'll get to these when I can get some more sources. Kablammo (talk) 01:40, 21 November 2008 (UTC)

Canada?

Is the Duluth Complex also located in Ontario? The mineralogy involved with large igneous provinces on the Natural Resources Canada site here mentions the Duluth Complex as if it's in Canada. Yet the article says it only lies in the United States. Black Tusk (talk) 06:34, 20 January 2009 (UTC)

I don't read the sources that way, but would be happy to be corrected. Instead they appear to acknowledge the relationship between the Keweenawan (rift-related) rocks and structures that exists on both sides of both the international and state borders.

I have often wondered if the Complex extended into Canada, as it is remarkable that it so closely approximates the border, which follows a river course that has nothing to do with the bedrock. But a close examination of several maps appears to show that the rocks of the complex are almost entirely contained within Minnesota, with the likely exception of some fingers of intrusive rock extending east along the lakeshore from Pigeon Point into the Thunder Bay District.[1] [dead link; archive link here, but image is not reproduced. Kablammo (talk) 15:39, 19 September 2016 (UTC)] Nevertheless, the highly-detailed map (archived here) referenced in the article shows older structures between the border and the Duluth complex at its northern margin, and, I believe, sedimentary rocks between them along the Pigeon River, interrupted by the fingers of rift rocks.

If anyone has better information feel free to add it or discuss it here. Kablammo (talk) 16:17, 20 January 2009 (UTC)

OK. Just wanted to know because I'm doing a rewrite for Volcanism in Canada and mineralogy is going to be one of the sections. When I seen the Duluth Complex mentioned on the NRC website I was somewhat confused. It made me think the Gunflint Range was a northern extension the Duluth Complex because they seem connected according to the article map. Black Tusk (talk) 22:56, 20 January 2009 (UTC)

The Gunflint and Mesabi were mid-Precambrian and were intruded and "separated" by the arcuate gabbroic late Precambrian Duluth. The Mesabi-Gunflint were NE striking and probably continuous across the border. The Late PC intrusive complex forms an arc shape with the northern boundary parallel to and just south of the border w/ Canada. (See Minnesota's Geology by Richard W. Ojakangas, Charles L. Matsch, 2001, pp 35ff ISBN 0-8166-0953-5) Vsmith (talk) 01:11, 21 January 2009 (UTC)