Archive for June, 2013

Fruit Vale

27 June 2013

The valley of Sausal Creek below Dimond Canyon made a natural site for orchards: a nice flat floodplain with decent soil and a permanent stream off on the western side. Also, the valley is straight to a degree that strikes me as unusual, which is handy for laying out blocks of land. It may or may not have been filled with oaks—I have a copy of an old print titled “Oaks of Oakland” that purports to be from this area. In any case it has a classic shape with a flat floor and steep sides formed by the Oakland alluvial fan (the Fan). I’ve shown the high, landslide-prone western side before; here’s the eastern side. This is the view from the Fruitvale freeway exit looking up Harold Street, where the valley wall is pretty dramatic.

fruit-vale-harold

Farther down, the valley wall fades away well before you get to Foothill Boulevard, which everywhere marks the edge of the Fan. Here at Fruitvale Boulevard and Bona Street, the valley wall is already lower and more subdued.

fruit-vale-bona

It looks like I’ll name this lobe of the Fan the Patten lobe. The valley of Peralta Creek is just over the hill. It’s interesting to speculate why the Peraltas put their rancho buildings there rather than here.

Thermal Hill and the Broadway lobe

15 June 2013

This is my own neighborhood so I don’t always think of documenting it: the western edge of the Pleistocene-age alluvial fan, labeled Qpaf (for “Quaternary Pleistocene alluvial fan”) on the geologic map below.

broadwaylobe-geomap

The Broadway lobe consists of two separate hills of this old sediment: Pill Hill on the south and Thermal Hill (as labeled on the 1912 map) on the north. (In a post five years ago I called it Montgomery ridge, after the street running up its crest.) Broadway Creek runs west of Thermal Hill and crosses the gap in the lobe to join Glen Echo Creek. The only spot it isn’t culverted is in the backyards of Brook Street, down near its mouth. It runs right under Tech High and Mosswood Park. Its valley is in the foreground of this photo, looking up 42nd Street past Opal, Manila and Emerald streets toward Broadway. Click the photo for a big version.

42dSt-big

The tall trees and associated homes are on the ridge. Behind them is the top of Mountain View Cemetery’s property and its continuation south, and the high hills where Skyline meets Pinehurst. Thermal Hill is modest in comparison, but walk over it, or keep an eye on it as you ride along Broadway, and you’ll know it’s there.

Farther south, 40th Street runs straight over the ridge. You really notice because the rest of 40 Street, all the way to Emeryville, is flat as can be.

40St-hill

Once upon a time the streetcar line punched right through it (the 40th Street cut), and today the original 40th Street, the lefthand one in this view, is named 40th Street Way while the former cut, filled in again, is named 40th Street.


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