Author: Michael Smith

Pennsylvanian Morgan Formation, Yampa River Canyon, Dinosaur National Monument, CO

by Michael Smith, posted in Sedimentary Geology

morgan_yampa_canyon

reduced file size version (more functional for some computers): morgan_yampa_canyon_reduced

morgan_yampa_canyon2

reduced file size version (more functional for some computers): morgan_yampa_canyon2_reduced

Cyclothems of the Pennsylvanian Morgan Formation exposed in the canyon of the Yampa River, Dinosaur National Monument, Colorado. Alternating intervals of blue-gray limestone and orange cross-stratified sandstone record repeated glacio-eustatic sea level fluctuations. Photosets acquired from raft.

Pennsylvanian Hermosa Group, Highway 550, San Juan Mountains, Colorado

by Michael Smith, posted in Sedimentary Geology

hermosa_hw550

reduced file size version (more functional for some computers): hermosa_hw550_reduced

Roadcut of Pennsylvanian Hermosa Group strata exposed between Molas Pass and Engineer Pass along US 550, San Juan Mountains, Colorado. Amalgamated cross-bedded, lenticular arkosic sandstone bodies and fine-grained mudstone partings with complex bedding relationships.

 

Upper Cambrian Jordan Sandstone and Ordovician Oneota Dolomite, Weaver, MN

by Michael Smith, posted in Sedimentary Geology

weaver_jordan_oneota

reduced file size version (more functional for some computers): weaver_jordan_oneota_reduced

Roadcut of Late Cambrian Jordan Sandstone and overlying Ordovician Oneota Dolomite along Wabasha County 26, near Weaver, MN, illustrating large-scale crossbeds and unconformable formation boundary.

Upper Cambrian Franconia Formation, La Crosse, WI

by Michael Smith, posted in Sedimentary Geology

franconia_lacrosse

franconia_lacrosse_closeup

reduced file size version (more functional for some computers): franconia_lacrosse_reduced

Cross-bedded glauconitic sandstone of the Franconia Formation (Tunnel City Group in local lore) exposed on Grandad Bluff, La Crosse, WI.

 

 

Ordovician Platteville Formation, Saint Paul, MN

by Michael Smith, posted in Sedimentary Geology

platteville_st_paul

platteville_st_paul_closeup

reduced file size version (more functional for some computers): platteville_st_paul_reduced

Finely bedded Ordovician carbonates and marls of the Platteville Formation, Mississippi River bluffs, Saint Paul, MN. Close up of coarse shell lag within the bed that crops out halfway up the section on the right side of the image below.

 

Late Cambrian Jordan Sandstone, HW14 roadcut near Lewiston, MN

by Michael Smith, posted in Sedimentary Geology

lewiston_jordan

reduced file size version (more functional for some computers): lewiston_jordan_reduced

Large roadcut of Late Cambrian Jordan Sandstone and overlying Ordovician Oneota Dolomite between Stockton and Lewiston, MN, illustrating low-angle bedding, intraclasts, and several scales of cross-stratification.

Cross-stratified Late Cambrian Jordan Sandstone, Homer, MN

by Michael Smith, posted in Sedimentary Geology

homer_jordan_1

homer_jordan_2

homer_jordan_3

reduced file size versions (more functional for some computers):

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homer_jordan_2_reduced

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very reduced size versions

homer_jordan_1_smol

homer_jordan_2_smol

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Cross-stratified Late Cambrian Jordan Sandstone, Homer, MN.

Richards Mountain, SW Wyoming: Paleogene alluvial fan deposits

by Michael Smith, posted in Sedimentary Geology

richards_mountain_wy_paleogene_conglomerates

reduced file size version (more functional for some computers): richards_mountain_wy_reduced

Late Paleocene-Early Eocene conglomeratic alluvial fan deposits exposed on the upturned south face of Richards Mountain, on the north edge of the Uinta Mountains. Cliffs typically correspond to boulder conglomerate deposits. The Powell expeditions and subsequent workers discovered that its lowermost deposits contain predominantly Cretaceous clasts, while clasts at the top of the deposit contain Precambrian metasediments of the Uinta Mountain group, in total recording unroofing of the nearby Uinta Uplift. Images taken from small aircraft.

Lacustrine hot spring deposit, Miocene Lovell Wash Member, Horse Springs Formation, NV

by Michael Smith, posted in Sedimentary Geology

Lovell Wash Mb. Horse Spring Fm. (Miocene) fossil hot spring

Tilted carbonate lacustrine strata of the Miocene Lovell Wash Member of the Horse Springs Formation are host to 3-dimensional exposure of a paleo-hot spring capped by travertine pools. The brecciated region beneath the pools is silicified and likely transmitted hot fluids upwards towards a saline, alkaline lake. 

 

Oligocene Vaqueros Formation, Santa Lucia Range, CA

by Michael Smith, posted in Sedimentary Geology, Structural Geology

vaqueros_S1_oligocene_ca

reduced file size version (more functional for some computers): vaqueros_S1_oligocene_reduced

Marine sandstone of the Oligocene Vaqueros Formation containing macroscopic soft-sedimentary deformation and meter-scale bedforms.

 

 

3D GLG

Featured by Michael Smith, posted in Instructions

This collection of 3D models of geologic strata, structures, and hand samples was created using structure from motion (SfM) photogrammetry from multiple still images in the Northern Arizona University Sedimentary Geology laboratory using Agisoft Metashape. Credit to NSF for funding this effort. See https://en.wikipedia.org/wiki/Structure_from_Motion for more information on how SfM works. These models are offered for free for all for non-commercial purposes. To view these models in 3D, use the free Adobe Acrobat Reader. First, right click on the link and save the PDF file to your computer. Second, open the file with Acrobat Reader, then under options, select ‘trust this document’. Finally, left click once on the screen to make the model appear. Use the shift and control keys to navigate. By right clicking on the screen, you can activate the ‘3D measurement tool’ from the tool toolbar to measure distances, fault separations, stratal thicknesses, etc…