Fault with fault breccia in interbedded metagraywacke-slate (Lake Vermilion Formation, Neoarchean, 2.695-2.722 Ga; Pike River Bridge outcrop, just north of Peyla, Minnesota, USA) 13

            Faulted turbidites (interbedded metagraywacke and slate) in the Precambrian of Minnesota, USA.

Whitish-gray layers = metagraywacke
Dark gray layers = slate

The Lake Vermilion Formation is a Precambrian stratigraphic unit in northeastern Minnesota, USA.  It consists of low-grade metamorphosed volcaniclastic sedimentary rocks that were deposited in a moderately deep water marine environment.

The outcrop shown above is a Pleistocene-glaciated knob of Lake Vermilion Formation turbidites, which consist of interbedded graywackes ("dirty sandstones") and shales - these have since been metamorphosed to metagraywackes and slates.  Turbidites are deposits laid down by turbidity currents - underwater sediment slides.  Such slides commonly occur in continental slope settings.  Turbidity current deposits typically accumulate in the continental rise, at the base of the slope.  Turbidites consist principally of interbedded coarse-grained and fine-grained siliciclastic sedimentary rocks that show graded bedding, climbing ripple cross-stratification, flame structures, flute casts, and soft-sediment deformation.

The feature in the center of the photo is a fault zone, which has noticeably offset the layers.  This fault contains broken and pulverized and sheared fragments of the host rocks, resulting in a thin zone of fault breccia.

Stratigraphy: Lake Vermilion Formation, Neoarchean, 2.695-2.722 Ga

Locality: Pike River Bridge Outcrop - glaciated low outcrop on the western side of County Road 77, immediately north of bridge over the Pike River, just north of the town of Peyla, north-central St. Louis County, Minnesota, USA (47° 47’ 30.89” North, 92° 22’ 07.68” West)

Some rights reserved

Taken on: June 10, 2015

Tags:

Lake

Vermilion

Precambrian

Archean

Neoarchean

turbidites

graywacke

metagraywacke

shale

slate

Tower

Peyla

Minnesota

fault

faults

breccia

shear

zone « less

Sets appears in: • Minnesota Rocks & Minerals • Archean Rocks & Fossils more » • Lake Vermilion Formation (Neoarchean, 2.695-2.722 Ga; Tower-Peyla area, Minnesota, USA) • Faults « less

Groups appears in: • Earth Science Teaching Resource • in explore

Stats: 17,560 views / 7 comments

go back

close tools panel

Badge creator

Use Flickriver Badge Creator to create a badge linking to your photos, your group or any other Flickriver view.

You can place your badge on your Flickr profile, Blog or Website.

Add to your iGoogle or Netvibes page

Flickriver widget for iGoogle or Netvibes can display almost any Flickriver view - most interesting today, by user, by group, by tag etc. Once added to your personalized homepage, just edit widget settings to select your desired view.

Clickr on one of the buttons below to install:

Embed on your Web site

To embed this view, Copy and Paste the following HTML code:

Black background (preview):

White background (preview):

Firefox and Chrome addons

Adds a 'Flickriver' button to your browser. While viewing any Flickr photos page, click on this button to open the same view on Flickriver.

Install in Firefox
Install in Chrome

Search plugin

Add 'Search on Flickriver' to your browser's search box. Works with Firefox and Internet Explorer. Install search plugin

"View on Flickriver" Greasemonkey script

A Greasemonkey script that adds Flickriver links to various Flickr photo pages - user photos, favorites, pools etc, allowing to quickly open the corresponding Flickriver view.

Also, allows quickly viewing any Flickr photo on black background in large size.

Install "View on Flickriver" script

Bookmarklet

While viewing any Flickr photos page, click on the bookmarklet to open the same view on Flickriver.

To install: drag and drop the following link to your Bookmarks toolbar.
IE users - add the link to your Favorites under the Links folder