You are browsing the archive for 2011 June.
29 June 2011
This year, for the first time ever, I took students to map at Block Mountain, a classic field camp mapping site near Dillon, Montana. Here’s a quick look (enlarge it by a gazillion-fold by clicking through) of some columnar jointing in the Eocene Block Mountain basalt flow, a paleo-drainage turned mountain through the miracle of topographic inversion… This is where it outcrops along the Burma Road… not bad at all.
27 June 2011
Our field class visited the Museum of the Rockies yesterday. Here’s the full team!
West of Shell, Wyoming, on route 14, there is a lovely exposure showing the tilted stratigraphic contact between the lower Tensleep Formation (purple; Pennsylvanian period) underneath Goose Egg Formation (orange/tan; Permian to Triassic in age). The contact dips to the west because it has been deformed during Laramide mountain-building (uplift of the Bighorn block, and downdropping of the Bighorn basin). Here’s a gigapan to show the contact:
26 June 2011
Can you tell me why I am very excited to be holding this rock in my hand? (iPhone photos; apologies for the low quality. But the rock… is anything but low.)
25 June 2011
Visiting Butch Dooley and crew on a dinosaur dig in the Jurassic Morrison Formation on Wednesday morning, I did a lot of wandering around the area, dubbed the Two Sisters site. I noticed something in the sandstone at the top of one hillock, and thought it looked like a sauropod footprint: (The depression is filled in with modern mud.) I took a photo, and thought, I need to ask Butch …
24 June 2011
A boulder outside the door of the Geological Museum in Laramie, Wyoming. Purty, parasitic, passive folds… Happy Friday. My field course starts tomorrow here in Bozeman. I’ll soon have a lot less time for blogging. Brace yourself.
23 June 2011
These are the geobloggers that I was privileged enough to hang out with this last week, in chronological order: Steve Gough of Riparian Rap: Ed Adams of Geology Happens: Evelyn Mervine of Georneys: Alton Dooley of Updates From the Vertebrate Paleontology Lab: Garry Hayes of Geotripper: Geobloggers are good people. They blog because they like to share their enthusiasm for the geosciences, and this also makes them fun people to …
Another thing I saw last week in the Rockfish Conglomerate were several nice examples of “bookshelfing,” which is when a rock or mineral fractures into pieces, and the pieces slide down relative to their neighbors, like a set of encyclopedias slumping outward on a bookshelf. This has the effect of shortening the grain/clast in one direction, and elongating it in another direction: Ever seen anything like that? If so, where? …
22 June 2011
Callan presents a gazillion photos from a field trip to examine the Rockfish Conglomerate, a potential Snowball Earth glacial outwash facies from the Neoproterozoic of the Virginia Blue Ridge province.