More From the Road: Tilted Every Which Way?

I stopped while driving through the Virgin River Gorge in northwest Arizona to take this picture of some of the dipping sed rocks that are common through the greater Colorado Plateau area. (This area, lying barely within the Basin-and-Range province, is just outside the Colorado Plateau proper, but the rocks here are correlative to those throughout the plateau region, and they have been subjected to some of the same tectonic forces.)

It looks like the sedimentary layers are dipping every which way!

This second photo zooms in just a bit, focusing on the far hill, which shows a slight bend in some of the layers.

I've drawn in a few of the beds, as before, and point out a dip slope formed on the top of the reddish layer.

This Google Earth image of the area shows the photo location in purple.

I decided to see whether the beds were really dipping every which way. I used beds I could identify in Google Earth, picked out two points along the beds that were at the same elevations, and drew strike and dip symbols from these two points (method described here). The dip slope labeled above is the small lens-shaped hill beneath the central strike-dip symbol. It became apparent from looking at Google Earth that the primary reason the dips in the photos look cattywampus is because the rocks in the foreground are dipping toward the photographer (to the WNW), and most of the other beds are dipping in a more northerly direction (NW, N, or NE).

The same Google Earth image with some hypothetical strike-dip symbols.

So, how did I do on the strikes and dips? And is there anything else going on in the area? Well, okay (ish) and yes.

Map I-2165 (Bohannon et al, 1991) courtesy USGS, overlain on Google Earth.

The Cedar Wash high-angle reverse fault cuts right through the area, separating the strata dipping toward the west (the foreground strata in our photos) from strata dipping in a northerly direction. You can see, by clicking on the several images and going back and forth between them, that I did well on the strikes on the west and east, and not so well (in general) on the strikes in the center. Either that, or the strikes of beds in the center varies more than shown on the map (I'm pretty sure I did pretty well on the labeled dip slope, but I will never climb that hill to check it out!)

Read a little about the Cedar Wash fault and the general geology of the region here.

Across the West and Back Day 2: Are We Lost Yet?

We left this meandering trip report almost two weeks ago, after MOH and I had taken our short hike into the limestone at the Grassy Mountain Rest Stop. From there to Salt Lake City, we cruised while admiring the shorelines of ancient Lake Bonneville.

Lake Bonneville shorelines in the southern Lakeside Mountains, looking northeasterly from I-80 about five miles northwest of Delle, UT.

And then: Salt Lake City.

Driving into SLC can make me somewhat apprehensive unless I'm going directly to the airport, and I had already started wondering if I was getting a migraine — possibly from normal trip concerns, possibly from driving, maybe from poor sleep the night before, possibly from some other, unknown cause.

I had looked at our route on Google Maps and had looked at the interchanges and major turns in Street View. Examining the route online is not the same as having a physical map in hand while driving (or in the navigator's hand, as the case may be) — at least not for me, or at least not unless I have some ingrained or recent familiarity with the particular roads in question. The last time I'd driven (or been driven) east through SLC without turning onto I-15 to go either north or south was in 1957 when I-80 didn't exist — and the 1957 trip definitely didn't count as recent, maybe more like Ordovician, or even late Precambrian.

I knew I was looking for the turnoff from I-80 to U.S. 40 — not that far past SLC, I thought — but I don't think I'd written down the miles to the exit, and I know I hadn't written down the exit number. And for some mysterious reason I was thinking that Park City (which I've never been to, except possibly on that long ago 1957 trip) was a lot closer to SLC than it really is.

Consequently, when the interstate turned a bit to the northeast and headed upward into the fairly tight canyon of Parleys Creek, I instantly freaked and thought it was the even narrower Echo Canyon, which I remembered from coming west out of Wyoming on I-80 on a 2006 trip. I was sure I didn't want to be heading into Wyoming on I-80, so I thought I must have missed the desired exit up somewhere near Park City (!).

I turned around at the first opportunity amidst a rash of roadwork, blocked exits, and narrowed lanes.

I knew I needed a map, so we got off at what turned out to be Exit 4 on 215. We pulled into a gas station and got some gas and a relatively small scale map of Utah. It was at this point that I was sure I had a migraine — and migraines do this funny thing to your overall thinking and analysis skills.

After examining the map while experiencing fairly moderate noise, light, and motion sensitivity that caused me to have problems looking at the map and then looking anywhere else, like at the road, I decided we were on an "outer" loop around SLC that I was previously unaware of. (This "outer loop" actually consisted of I-84 from Ogden, east and southeast to I-80 at the beginning of Echo Canyon, and south and then back west into SLC on I-80, but that part of I-80 wasn't marked, neither was 215 marked, and the insert for SLC was surprisingly small and lacking in detail.) We were actually at a gas station along the 215 partial ring road, and I probably knew that fact when I had turned on to it after turning around in Parleys Canyon.

I figured all we'd have to do was get back onto this previously unheard of "outer loop" and head east or south to our desired exit onto U.S. 40 near Park City. Wrong.

The map in question.

By this time, MOH had wisely taken over the driving while I endeavored to determine our exact location. With a blur of freeway lanes, cars and trucks, and exits coming too fast to comprehend (this should have given me a clue), what I was seeing on the map (how could Alta and Snowbird already be north of us?) wasn't matching the route I'd incorrectly figured was the one we were on, and it wasn't matching my still intact knowledge of where we really were along the Wasatch.

Suddenly, the "outer" ring road turned due west, and I knew something was very wrong. I realized where we had to be (on the "inner loop" road, i.e. 215) just in time to navigate properly and direct us onto the exit for I-15 south. Whew!

At this point, we thought it would probably be just as easy to take the next road south over the Wasatch than to turn around and go back for I-80, Park City, and U.S. 40. As for this thought: not exactly correct.

View Our Crazy Route through SLC in a larger map

Because we went (unexpectedly, for sure) south on I-15, I was able to get a pretty decent, albeit somewhat grainy, shot of the Bingham Canyon copper mine.

View of the Bingham Canyon copper mine, looking west from I-15.

It has been quite a while since I've been to Bingham Canyon — and I've never had a tour into the pit itself — but I strongly recommend going to the overlook and Visitors Center (the latter of which I've never seen) when they are reopened. The overlook area has been closed since the April 10th landslide (see a pre-landslide panorama of the pit here, view Kennecott's photos of the slide here, and read about the slide on several blog posts by Dave Petley).

Looking east toward American Fork Canyon.

And so, with our most recent trip decision finally behind us, we proceeded down I-15 to the Utah S.R. 92 exit, onto 92, and into the Wasatch via the easy, wide-looking American Fork Canyon.

View Day 2: Elko, NV to Vernal, UT in a larger map

The embedded map above shows the location of the three photos in this post (and also the rest of the Day 2 photos already posted, if you move around inside the map or view it in an enlarged version).

Related Posts:
Across the West and Back Day 2: A Hike along a Limestone Ridge
Across the West and Back Day 2: Across the Salt Lake Desert
Across the West and Back Day 2: A Side Trip in West Wendover
Across the West and Back Day 2: Pequop Summit to West Wendover
Across the West and Back Day 2: Looking for an Old Roadcut
Across the West and Back: The First Day
Intro to Recent Western Loop Trip