Archive for August, 2014

Mountain roads

23 August 2014

Walking up Mountain Boulevard in the Laundry Canyon area takes you through one of Oakland’s old mining and timber districts. (Laundry Canyon proper is under the Warren Freeway.) First there’s the pyrite mine that I mentioned in the previous post. Then, looking up Bermuda Avenue toward the hills, you’ll spot a tempting area of exposed rock.

mtnroads1

That’s actually a switchback in the road that once served the Hotel Mine, at least that’s what’s shown in the Laundry Canyon historical map hosted on Oaklandwiki. The road meets Mountain Boulevard a little north of here.

mtnroads2

If this doesn’t tempt you, you have no blood in your veins. The land is within the city’s Leona Heights Park.

Knowing this historical background, it’s a safe guess that the flat Bermuda/Belfast Avenue neighborhood, with its sidewalks and homes dating from the late 1920s, is a former staging area for the various quarries and mines that once existed here.

Farther north on Mountain is the entrance to Horseshoe Canyon, the main attraction of Leona Heights Park. This path (technically, it’s Oakleaf Street) runs below the Leona Lodge and will take you all the way up to the former rock quarry by Merritt College.

mtn-leonacyn

A couple years ago, Dennis Evanosky led a walk through this neighborhood for the Oakland Urban Paths group.

Mine creek at Twitter Court

17 August 2014

I’ve shown you the ugly orange streambed just below the old McDonell pyrite mine. Farther downstream, the creek (which I’ll name Mine creek) emerges from private backyards next to Mountain Boulevard at Twitter Court.

mine-creek-at-twitter

It’s still pretty orange here, from extremely small (colloidal) particles of iron oxide minerals that form as the acid drainage from the mine is neutralized. The creek enters a culvert here and disappears. Somewhere under the Warren Freeway, it joins Lion Creek on its way to the bay. Lion Creek appears next as Lake Aliso on the Mills College campus, and unless the lakebed is all orange too, the pollution has been fully neutralized by that point. As I’ve said before, the pollution looks awful, but without chemical tests we can’t tell if it’s poisonous. Iron oxides by themselves are not a great hazard.

Local boulders in the Calaveras triangle

8 August 2014

Where the Warren Freeway ends in its merge into I-580, most people drive south onto 580 east. The handful of locals or lost drivers who instead take the last exit to get onto 580 west will go through perhaps 580’s most deserted interchange. That’s where the highway builders installed this humble triangle, splitting the freeway exit for the even smaller handful of drivers going east on Calaveras Avenue to Mountain Boulevard and those going west, briefly, on Calaveras and onto the upramp to 580 west. The triangle is paved with river cobbles and populated with natives.

13-to-580triangle

The oak trees are easy enough to see in this view from across Calaveras. But what’s that in their shade? Why it’s one of several large local boulders.

13-to-580trianglerock

I didn’t take notes, but I think these are Leona volcanics, the same stuff that was quarried nearby for decades at the Leona Quarry. Pay them a visit next time you’re walking or biking through that godforsaken area. Sit on them in the shade; they like that.

More local serpentine

1 August 2014

Every now and then I come across a wall or a garden boulder that’s so beautiful I have to take a picture. Such was the case with this serpentinite specimen on or around Huntington Street.

huntington-serp

This is near Oakland’s great serpentine patch, and it likely came from there.


Follow

Get every new post delivered to your Inbox.

Join 4,052 other followers