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California's Ancient River
Of Gold
Home California's El Dorado -Secrets of Geology and finding gold treasure!
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This 1945 map details places to look- having secret knowledge of gold geology- you can find a treasure!

California's river of Gold. Ancient Eldorado, continues south to Sonora and beyond, of course. Just as Murphys and Columbia were geologic features that restricted Eldorado's meander to a small area, allowing gold to be deposited over a very long time, the Sonora bonanza was similar. Perhaps softer basement rock surrounded the Sonora area. Just south of Columbia, the Shaw's Flat, Brown's Flat, and other rich placers just north of Sonora were rather shallow gravels that in some initial cases allowed panning the roots of grass pulled from the soil. The ancient river had free reign to wander over the wide area of the flats, leaving a thin but rich load of gold. Just a short distance further, at Sonora, the river dug down once again, creating deep channels that locked Eldorado's path in place and into a repeating deposition of gold laden clay and gravel. Large nuggets were found at Sonora within big blocks of weathered limestone.The limestone was pocked with the whirlpool scouring effect of flowing water. Like Volcano far to the north, Sonora is surrounded by terrain at 2150'. The Sonora area is famous for big nuggets of gold. The most famous of which is the Holden Gardens nugget that weighed a little over 28 pounds. The nugget was described as smooth and solid with 20% quartz attached, indicating that the gold had not been tumbled and pounded in the river wash for a very long time. The Woods creek placers at Jamestown produced large nuggets as well. Woods creek runs parallel and closely upon the Ancient Eldorado as both new and old streams pass through the Sonora township. Most likely, the gold in Woods creek below Sonora are eroded from the bedrock of Eldorado.
Lode gold mines set above and below Sonora in what are termed the East belt and West belt of the Mother Lode are famous for producing beautiful "specimen" gold in quartz. Yet the majority were (are) milling gold producers; the gold laden quartz had to be crushed to a fine powder to separate the tiny gold particles of gold; invisible to the unaided eye. Most of the lode gold was produced this way. Pocket mines produced larger nuggets, wire, and fines that are visible to the eye and would be recovered using the placer methods. Placer mining lost a lot of extremely fine or "flour" gold. Once the flour gold enters a stream, it is quickly swept away.
Hail Suppression Hey -wait a minute. On the Home Gold page the elevation of Sonora is listed as 1880'-not 2150! What's up with that?
There is an easy explanation: the streams passing through the Sonora pass have eroded the terrain at a much greater rate that elsewhere. The Sonora cachement basin is an oblong lake or series of oxbows. Higher ground of 2200' stand on either side. Woods Creek, Sonora Creek, and possibly a defunct tributary of Sullivan creek cut directly through and have eroded the old placers of Eldorado. This is substantiated by the enormous amount of gold found in Woods Creek and Sullivan creek. There aren't enough pocket mines in the area to account for the volume of gold in the region's streams. The current rate of fall of modern streams would have swept away the gold provided by slowly eroding pocket ledges. The gold comes from the greater source- the erosion of Eldorado. Columbia Gold Page
The region below Sonora has plenty of 2150' terrain to investigate. Sullivan Creek of course yielded big gold nuggets. Curtis Creek and surrounding area streams start near the 2150'. Both of the larger streams were rich enough that in the elevation flats below 2150', dredging operations were conducted. The course of the ancient river lies below the high ground and is outlined on the terrain map by connecting the headwaters of streams and springs. The BLM surface management map ( 1993 Oakdale planimetric map) conveniently marks these features. On the approach to Turnback Creek, where streams begin to drain to the east and north as well as west and south the width of the old riverbed is reveled. The stream so named because no gold was found in the streams and terrain beyond Turnback Creek. The gravels of the ancient riverbed, aged to clay, absorb and retain rainwater and act as the source for springs and stream starting points. Because of the absorptive feature of the gravels and clay bottom, less runoff and reduced erosion over the river path results in higher ground directly over the riverbed of gravel. Google Earth is handy to find green grassy areas among the desert brown of the volcanic tuff of the Mehrten andesitic mudflow flats between Ward's Ferry and Curtis Creek.
The path of the Eldorado continues south until it reaches the Toulumne River about 1 mile beyond Blanket Creek. At this point, after crossing the river the elevation of the old river bed makes a leap up in elevation. The course of the new Sierra rivers follows the fault block lines of the rising plutons. Conversly, Ancient Eldorado flowed across (perpendicular) to the new rivers. With the mighty Yosimite plutons looming ahead, the pressure was too intense, the earth's crust was sheared it snapped upward, lifting Ancient Eldorado to a new elevation. The path of the old river can still be charted with the stream headwaters and springs as it moves south until it emerges at Big Oak Flat, Groveland and Second Garrote townships. Elevations in this area is some 600 feet higher, nearly 2800'. All these gold camps yielded a bonanza of placer gold. The old river continues south down Jackass Ridge above Coulterville and beyond. While 600 feet higher than regions north of the Tolumne river, the ancient river bottom is flat through the Big Oak Flat /Second Garrotte area. As the map shows, the Second Garrote basin is a cutoff meander or oxbow lake of the ancient river.

Here the course of Eldorado is marked by the gold line and this line is at a depth below the terrain surface; elevation=2800'. Note that the bottom of the river(gold color) is missing immediately south of the Tolumne River crossing. The gold lines show where to look for extreme meanders in this area. The ancient gravels and overburden have been washed away by the strong new river Tolumne and only reappears at the Big Oak Flat after passing under the Tip Top peak. The erosion of the ancient river gravels and clays here was the source of the gold for the big placer strikes at Big Oak Flat, Garrote, and Second Garrote. Further south, streams and creeks join at Coulterville after eroding Jackass Ridge and the ancient gravels that underly the ridge. The starting elevation of these gold streams is 2800' (860 meters on the terrain map.

Conventional geology relates the concept of the ancient river gravels that Lindgren studied and the rivers that created them flowed into the open and westward Pacific ocean. This study relates that an ancient river Eldorado was the body into which these ancient rivers flowed. Large deposits of gold was collected by this river system as it eroded and drained a larger and older Sierra mountain chain that extended into Nevada. The older mountain chain was eroded to a low flat plain of softly rolling hills by the ancient river system. It is noted that the ancient river gravel deposits, in large part, are on higher ridges that end just above the course of Ancient Eldorado and are submerged under the Mehrten formation. The nearly liquid volcanic andesitic mudflows buried not only the streams and tributaries but the main channel Eldorado as well. Where the remaining mudflows still exist, having escaped erosion of the modern streams, they are always very flat and often treeless as the andesite is porous and rainwater quickly drains away. These deposits of andesitic conglomerate can be several hundred feet thick. Under these deposits are the gravel and mud and gold of Ancient Eldorado. The outline of the deposits can be quite small or large as is the case of the huge looping meaner of the Ancient Eldorado when surrounding soil and softer rock has been eroded away.

South of Big Oak Flat, the area around Coulterville offers further evidence that the Ancient Eldorado river bottom, while at a higher elevation 2800' or 863 meters, remains flat. The various creeks that gathered at Coulterville have headwaters that are at or pass through 2800' (860 meters) and these streams eroded the Eldorado to form the placers worked by the earliest miners and later by dredges just below the Coulterville township. Note the dredge tailings shown on the map near the Dogtown branch of Maxwell's Creek is just below the 2800' elevation. This area has many mines marked on the map near 2800'. Several roads in the area cut directly through at 2800' and these would be likely locations to start the exploratory hike and sampling on the 2800' terrain line.