Beale's Cut, Newhall, Southern California

Beale's Cut is a narrow, man-made gap through a ridge near the town of Newhall, in northern Los Angeles County, southern California. This gap (or pass) dates back to 1854, when Phineas Banning dug out a 30-foot gash, in order to allow horse-drawn wagons and stagecoaches to travel through a narrow canyon whose head was blocked by solid rock. The gap occurs in an area that has had a succession of names: Fremont Pass, San Fernando Pass, and more, recently, Newhall Pass.

On the approach to Beale's Cut in April, 1985.
(the view is to the northeast)

Beale's Cut, April, 1985, with a partial silhouette of a person
 and a chain-link fence, for scale.

Beale's Cut, April, 1985.

 Google Earth (2018) image showing a

 bird's eye (vertical) view of Beale's Cut.

In 1861, Edward Fitzgerald Beale deepened the gap to 90 feet in height, thus allowing even better passage to places like Fort Tejon, to the north. At that time, the gap in the canyon became known as Beale's Cut. It was used for vehicles until 1910. It was also used for many silent westerns and was where the American actor Tom Mix and his horse allegedly "jumped the gap," in the movie "Three Jumps Ahead."

Beale's Cut is still in existence, but it suffered during the Northridge Earthquake in 1994. Today, it is only 30-feet deep again because of infilling by rock falls. 

It is located just off of Sierra Highway, which is west of Interstate 14. Spotting if from the road level is difficult. Along the side of Sierra Highway there is a small monument/plaque, but the entire area is fenced off now in order to reduce vandalism and trash dumping. There is no place to turn off the road to park your car. 

The gap occurs in the Saugus Formation, a Pleistocene fluvial (ancient river) sandstone deposit associated with the erosion of the adjacent San Gabriel Mountains.

Miocene spring-deposited tufa in southern California Pt 2

Part 1 concerned an occurrence of Miocene spring-deposited tufa in the Barstow Formation, Calico Mountains, southern California. Part 2 is about another Miocene occurrence of spring-deposited tufa, 118 miles to the southeast of the Barstow locality, in the Diligencia Formation in the Orocopia Mountains, northeast of Salton Sea, Riverside County, California.

Google Earth (2018) image,

The Diligencia Formation spring-tufa deposits resemble fossil "logs," as shown above. These "logs" occur mainly as branching-horizontal tubes, in contrast to the mostly vertical buildups of the Barstow Formation spring-tufa deposits. The Diligencia tufa deposits are confined to a single thin bed that crops out for a least 6 km. This bed represents a lake-shoreline environment, which interfingers with basalt flows and river-delta deposits. The hammer, which is the same one shown in all the subsequent images, is 27 cm in length.

The Diligencia tufa tubes, are commonly parallel to bedding, can be up to 65 cm in length and 25 cm in diameter.  Hammer is 27 cm length.

This is a horizontal tube, which has been extensively weathered.

In some places, the Diligencia tufa deposits are transported accumulations of closely packed tubules concentrated into a thin bed of limestone.

In other places, the Diligencia tufa deposits occur as scattered, weathered remains.

All the Diligencia tufa deposits consist predominantly of wavy microcrystalline calcite laminations surrounding by small core that is filled with darker sediment and/or partly with coarser grained calcite. The "dime" coin is 18 mm in diameter.

Miocene spring-deposited tufa in southern California Pt 1

In 1981-1982, while doing field work on rocks of middle Miocene age in southern California, I and my students came across some interesting tubular and bulbous-shaped geologic features which are sedimentary rock structures, called spring-tufa deposits, made by waters seaping onto the floors of alkaline lakes. Tufa is composed of calcium carbonate (calcite). 

One of the locales is in the Barstow Formation in the Calico Mountains, west of the “ghost town” of Calico, near the town of Barstow, San Bernardino County, Mojave Desert, California.

Google Earth (2018) image

The tufa deposits at the Calico Mtns. locale occur in at least two beds (8 m apart vertically) in a fluvial-deltaic facies. The tufa deposits are laterally persistent but not continuous. About every 15 to 20 m along strike, there are in situ tubes (columns). In between, the tubes are busted apart because of weathering. All the tufa deposits are within the same general area. 

Outcrop of the Barstow Formation, with tufa deposits indicated by the red arrows. There is horizontal development of tubes in the lower right-hand side of photo, scattered horizontal accumulation of tubes on left-side of photo, and a small cluster of fan-shaped tubes on the middle right-hand side of photo. Jacob's staff is 50 cm length; rock hammer is 32 cm length (12.5 in.).

Close-up of same small cluster of fan-shaped tubes shown in the previous photo (hammer is 32 cm length, 12.5 in). Notice the horizontal orientation of the tubes at the base of the cluster, whereas they bend upward with growth. Also, the tube diameter increases upward.

Close-up of some tubes showing corrugated or fluted surfaces. Coin (USA quarter) is 2.5 cm width.

Close-up of some tubes showing their cross section structure (white part of Jacob's staff is 10 cm length). Some of the tubes are hollow, some one-half filled, and others are filled. Tubes vary in diameter, from pencil size to about 10 cm.

Largest cluster, approximately 1.3 m high.

Cross-section of one of the tubes, which shows wavy growth bands. Ruler is in cm (total of 15) on its left side and inches (total of 6) on its right side. The growth bands might have been influenced by microbial and/or algal processes.

Part 2 concerns another Miocene Formation with similar spring-fed tufa deposits. This formation crops out in the Orocopia Mountains, southern California.