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Old Salt Lake | Virtual Museum

The Oldest Mystery in the Land


You can't restore or preserve something until you understand how it works. Bertha Fuller, an early advocate for nature preservation in Los Angeles and the state, was certainly thinking about how the salt lake worked when she wrote the following two paragraphs excerpted from her Old Salt Lake landmark application to the state in 1940:

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"As the attached photos show the lake is quite dry during the summer months and as it is the natural drainage basin for a small acreage to the eastward in winter the water may be several feet deep. It is the wintering place of shorebirds but otherwise lies desolate and unvisited except by those who have made paths for shortcuts across and around it."

"One very interesting thing about the lake is that the fresh water vegetation is on the ocean side while the salt grass and atriplex grows on the land side. Where that great deposit of salt came from can hardly be definitely told. Had the lake been formed as most salt lakes are: either from limitless numbers of years of deposits from the sea with the arm finally shut off by delta like deposits from a stream, or from being a pool without outlet, its presence would seem even more unusual. There does not seem to be a sufficiently large drainage basin for any stream ever to have carried a large quantity of saline products into an outlet-less basin---and also while the sea might form a lagoon there by the currents carrying the sands into the mouth of the river thus shutting off the pond the vast quantity of salt present in the old days would have taken so many eons of years that this does not seem possible for even this energetic sand depositing sea to do."
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How the Old Salt Lake worked ... or, what was the source of the salt - was the oldest mystery in the land when research began on this waterfront. People have been marveling about what the source of the salt is ... for a long time. Documentation from the early American period shows interest in the fact the place was also a source for fresh water. The old mystery about the source of the salt may have been solved. Expert advice was obtained from an "informal international association of salt lake researchers from a variety of disciplines" the International Society of Salt Lake Research (ISSLR). They were kind enough to refer me to an expert on the subject and she was kind enough to provide analysis of a key 1890 document I found in the state geological library. In 1890, E. B. Preston, a state geologist, visited the site and wrote a four paragraph report on "Lake Salinas" as the place was called then. This 1890 Preston Report is interesting.

Preston, you will see, was thinking about what was the source of the salt. Now fast forward, and Preston didn't know this, but the source of the salt was a saline aquifer - oil field brine.

But first, here is the 1890 Preston Report transcribed:
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1890, "Lake Salinas, Los Angeles County", by E. B. Preston, Assistant in the Field, California State Mining Bureau, Report X, (p. 281), California Geological Survey Library:

[ Transcription ]


Lake Salinas

Within the town site of Redondo Beach is a small salt-water lake, about three hundred yards from the ocean, and about five feet above the high-water mark, that does not receive its water supply from the ocean, having an entirely different combination of salts, and has about it and its immediate surrounding features that make it of interest to the geologist and chemist.

The lake is about a half a mile long, and from four to six feet deep. At the south end is a large shallow basin connected by movable gates with the main lake, which is used for evaporating the water by the heat of the sun. The banks are low, gradually sloping up; a sand dune intervenes between the ocean and the lake; the bottom of the lake is a bed of clay. Around this lake on both sides, about thirty wells have been bored to an average depth of twelve feet into the clay that forms the bottom of the lake, and these all yield a good, soft drinking water. Between these sweet water wells next to the ocean, and the ocean itself, near the top of the dune a well has been sunk to a depth of twenty-six feet, which has passed through the clay for a distance of ten feet. The water obtained in this well is claimed as having medicinal qualities; it certainly tastes bad, if that is an criterion of its medicinal value.

The lake water is a much stronger solution of salts than the water from the open ocean, containing a very much greater proportion of chloride of magnesia; but the statement as made by the parties on the spot to the writer, that the water was ten times as saturated as the sea water, is evidently erroneous, as such a solution would pass the point of saturation. How to account for the presence of these different qualities of water in their relative positions, is not plainly to be seen. The salt water could be accounted for in several ways, as there are beds of saliferous shales and sandstones in the neighborhood; also, there are magnesian rocks on the flanks of the mountains surrounding the plain; but the fresh water in the wells surrounding the lake interferes, from the fact that these wells, terminating in the clay, compel the assumption that the water in them is drainage water from the near vicinity. To solve the question satisfactorily would require a closer investigation into the position of the different strata than the limited time at disposal afforded.

South of the town of Redondo Beach about three miles, the bluffs facing the ocean are composed largely of sandstones and shales, with a large bed of diatomaceous earth resting thereon; underlying these and running out to sea are beds of bituminous sandstones, showing natural bitumen in places. These continue in a southwesterly course out to sea as a reef for a distance of two and one half miles, at which point oil is seen coming to the top of the water in considerable quantities.

[ / Transcription ]
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Here is expert advice by Barbara Javor:

2010, Analysis of 1890 Preston report on Lake Salinas, by Barbara Javor, Ph.D., Consultant to the solar salt industry, Author: Javor, B. 1989. Hypersaline Environments. Microbiology and Biogeochemistry. Springer-Verlag, New York, 328 p.

Dr. Javor is commenting on the 1890 report "Lake Salinas, Los Angeles County", by E. B. Preston:

"My take on the document is that the clay layer is an impervious zone that prevents the upper freshwater from mixing with the deeper saline water. Somewhere under the lake, the clay zone is likely breached, allowing the lake to fill with brine. Hence, a salt spring would never be visible to someone standing by the lake. It may not be a single point source either, but rather dispersed on the lake bottom as a large set of smaller percolation pores. Because the southern California coastal region has many petroleum zones on land (e.g., the oil fields in nearby Long Beach), it is not strange to find a buried saline aquifer bearing relict seawater from earlier geological times (i.e., possibly from the time of deposition of the marine organic matter that transformed into petroleum). The relationship between salt domes and petroleum deposits in Louisiana is a well documented case of this phenomenon. Check out reports of oil drilling on land and you'll come across references to brines (google "oilfield brine" -- you'll get a lot of hits)."