AquariusRadar Eldorado
California's Ancient River
Of Gold
California's El Dorado -Secrets of Geology and finding gold treasure!
Hydrology Concept
Gold Home
This Google Earth screenshot shows barren limestone rock protruding from the bedrock Ancient Eldorado.. This area is just north and above the quiet town of Murphys. Quiet now but in 1851 a roaring wild gold camp located on the Bedrock of Ancient Eldorado The satellite image shows the striated channels of the river bottom cut into the Calaveras limestone just outside the town proper at an elevation of 2190'. The old river deposited gold over hundreds of thousands of years at this location . These striations were packed with the pay dirt that made Murphys one of the richest placer deposits of the Gold Rush 1849. Near the center of the gold treasure were many more bedrock exposures near the town center covered now by the tailings of the hydraulic mining of the upper extent of gold deposits and later built over by modern homes. As at Columbia, the river was held in place by a geologic basin for hundreds of thousands of years. The miners removed the pay dirt from every crack and crevice, to reveal the river bottom. The elevation here is 2170+/- near the town center and heart of the bonanza.




Angels Creek drained directly through the oxbows of Ancient Eldorado around the Murphys township and coursed downhill a short distance to the flat plain surrounding Angels Camp. Here the gold accumulated along the creek. Two very different elevations, but the gold at Angels camp was eroded from Eldorado at Murphys. A similar thing happened at Douglas Flat as Coyote Creek eroded the course of Eldorado along the flanks of Pennslyvania Gulch and deposited that gold in the level terrain of Douglas Flat. Mokelumne Hill and Chili Gulch are very similar as the Mokelumne river cut down through the earth between Pioneer and Glencoe, the new river uncovered, washed, and then deposited the Eldorado gold some 300 feet down in elevation and 4 miles downstream at Mokelumne Hill and Chili Gulch.

The Murphy brothers searched upstream from Angels Camp along Angels creek knowing the gold deposited in the creek flats was coming from a greater source. They found the bonanza in the gravels wedged among the limestone blocks of the ancient Eldorado river bottom. These multiple oxbows of the Ancient Eldorado were confined to a geologic bowl and deposited gold for hundreds of thousands of years. The oxbows (in yellow) are shown on both the inner and outer courses of the main path of the old river. The river path exited from under the overburden of soft volcanics north of the current township and after meandering through the township oxbows moves southwest and is covered periodically by eroded volcanics along Pennsylvania Gulch then completely slips under the hundreds of feet of volcanics near the junction of Peppermint and Coyote creek. Most of the gold here was further eroded and washed downstream to Douglas Flat. But some areas were still covered and as late as 1863, well after the golden pile centered on the township was depleted, the miners sunk shafts straight down to depths of a hundred feet to more to reach the gold river bottom. None other than Mark Twain describes the mining activity along Pennsylvania Gulch in his Roughing It chronicle.
Sonora
Gold
Old Stanislaus, sometimes called the Cataract or Inter volcanic channel (Table Mountain) cut down through the hundreds of feet of softer volcanics (ash and muds) that buried Ancient Eldorado and sometimes followed the general course of the older river valley. In geologic terms it was short lived; a few tens of millions of years. But growing stronger as the new Sierras rose up, the Old Stanislaus abandon all efforts to follow the meander of the older river and cut straight through on a linear path. But in its wake, the clear looping meander of the ancient Eldorado was left to mark the ancient rivers path. These oxbows and Yahzoo streams were sometimes capped with the harder volcanic lavas that the new mountain chain belched out as it emerged from the depths of the mantle. The Old Stanislaus was clogged by a final fiery explosion of lava that stoppered it completely and forcing the new drainage of the current Stanislaus. The new Stanislaus has cut a great canyon several thousand feet deep below the lava capped Old Stanislaus and remnant meanders of Eldorado. This results in the very confusing array of volcanic overburden that conceals Ancient Eldorado.
Fiddletown
Gold


Modern tools- the metal detector is useful in finding the occasional nugget. However, the most useful tool is the soil/rock sample and the the post hole digger used to extract the sample from the site. The post hole digger did not come into popular use until the advent of wire fencing, well after the rush of '49. If the explorer finds a likely spot for sample, the post hole digger allows the sample to be taken from depth. Remembering that gold seeks the lowest depth available before striking hard rock, the modern miner has a distinct advantage over the miners of yore. The sample should be taken from the bottom or as close to the hard rock boundary as the digger length will allow. That's not to say that the surface sample can't be useful. Either way, always look for mussel and clam shell fossils in the sample, using the jewelers lope or low power microscope. The presence of clay in any sample should be closely inspected for signs of fresh water mollusks. Future drift mining will use the population density of fresh water clams and mussels in order to follow the thin thread of gold that defines the Ancient Eldorado river bottom.
A break in the exploration is taken to discuss the question about lode versus placer gold production; which is more productive-profitable?

Lode mining has produced more gold in the Mother Lode than placer mining. But because of the much higher capitalization of hard rock mining, placer mining results in more profit for the individual miner. Being that lode mining generally consists of many men working the hard rock and placer mining working mainly watery gravels by individuals or just a few miners. The heyday of placer mining by individuals in the Mother Lode was 1848-1854. After 1855, lode mining soon surpassed the production of the placers as gold in the river riffles soon panned out and miners sought out the sources of gold imbedded in the quartz. Undoubtedly, the initial years of placer mining made spectacular wealth for more individuals while the later lode production made only a few hard rock mine owners wealthy but provided many more mining jobs. There is of course that in-between type of mining- part placer-part hard rock- called drift mining. The source of the treasure is a gold bearing gravel that sometimes is cemented to a near hard rock consistency. All the engineering techniques of the quartz mines are purposed to follow the bed of a gold laden channel of welded gravel and clay. Much of the gold of the Mother Lode was found in drift mines. And that is all that is left of the opportunity of gold mining in a profitable way in California. The margins will be small, as in hard rock quartz mining, but many mining jobs will be provided. Home Gold Page or continue on to more Southern Mines Sonora Gold Page
Columbia The Spanish expeditions that sought out the fabled Golden Cities of Cibola misinterpreted the information given by the very earliest of the Spanish explorations. Only a handful of men from this first exploration survived after a decade in the wilderness. The stories the survivors told of golden cities "north" of New Spain (Mexico) were referenced to the position of the surviving party when they finally returned to the Spanish frontier. At that point in the wanderings of the survivors, they were nearly upon the shores of the Gulf of California in extreme western Sonora province. "North" to the survivors meant an undiscovered land north of Sonora. The undiscovered land North of Sonora was of course present day California. But the Spanish explorers who came later seeking the golden cities used Mexico City as the reference for "New Spain" and sent the expeditions to areas of present day eastern Arizona, New Mexico, and west Texas as far north as Kansas.
It would be another two hundred years before the Spanish would return to find and mine for gold in the Mother Lode of California; the Americans and miners from around the world arrived a hundred years later in 1848. So Eldorado of old (todays Mountain Ranch) and many more riches of the Mother Lode was the source for the Golden Cities of Cibola.

The area between Murphys and Columbia has already been studied on the Gold Home page. But from what is known of the ancient rivers path, there must be many more geologic basins buried under the volcanics of the new Sierra Nevada. Each of these geologic basins or bowls consist of meanders and oxbows that were filled with gold just as Columbia and Murphys have shown. Keeping the linear nature of the main course within the old rivers meandering path in mind, what areas could provide a look at the horizon of the old river bed in this section of the Mother Lode?

O'neils Creek, San Domingo Creek San Antonio Creek or any of the numerous creeks that cut through the track of Ancient Eldorado between Murphys and Mountain Ranch and lie at 2150' or slightly above or below 2150' would be prime areas to sample. The terrain map above, with elevation in meters, is marked with the 2150' elevation (660 meters). These miles and miles of difficult terrain are the areas to search. While gold was found in these creeks- almost all streams in the Mother Lodes had some gold in 1848- none of these streams held a bonanza. The oxbows that holds the gold must remain buried under the volcanic debris of mountain growth. Where to look:
road cuts through 2150' should be checked with the metal detector and samples as well.
any drainage dry stream large or small. Remember that any gold found at 2150' could be the remnant of a thin thread of the river straightaway or the start of an oxbow loop with the bonanza treasure.

What gold hordes lie North of Murphys as the course of the ancient river is followed? How many basins similar to Columbia or Murphys lie buried at 2150 feet elevation along the path of the ancient river. The area near Mountain ranch shows many characteristics of lava caps over looping twists of terrain. Are these the telltale signs of Eldorado?

The path of Ancient Eldorado is not clear in the Mountain Ranch area. The Calaveras limestone bedrock observed at Murphys and Columbia is not visible here. The volcanic mudstone erosion of a later period appears mixed with the weathered limestone bedrock. The river bottom must have been exposed to the slightly acidic rainfall for a very extended period that created the caliche type surface containing the gold within. The occasional nugget was found here for many decades beyond the great gold rush.

Moving the exploration North away from Murphys, the above image shows the area around Murrays Creek, Whiskey Slide, and current township location of Mountain Ranch. Mountain Ranch started as the gold camp Eldorado on the banks of Murrays creek. The Spanish pioneers in California had been placer mining for several decades in this bowl of the Sierra foothills well before the 1848 discovery at Coloma. Hence the Spanish Eldorado name. Sometime after the placers were depleted by the rush of '49, the township was re-located a mile southwest to the current location and renamed Mountain Ranch due to a postal address conflict with another larger more politically strong township in California. The point being that the original Eldorado camp sat on the banks of Murrays Creek at an elevation of 2150+/-. The areas surrounding Eldorado camp and trending towards Whiskey Slide, were termed Chee Chee Flat. The miners worked and reworked the Chee Chee flat for several decades. Most of it is treeless as the soil was removed revealing a heavily weathered surface. The