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 Nuggets of News Blog 

Saturday, November 19 2022

If you’re used to water mining, having success in the desert might seem challenging— that is until you start thinking of desert ground as a massive sluice box. Many of the principles you’re used to when prospecting and mining in waterways, will translate into desert mining. The most important thing to remember is that water is crucial to gold movement. Unlike a running river or creek with highs and lows, desert placers are much different in that gold is moved quickly during a flash flood, leaving gold stranded as opposed to being moved further by continual water flow in a creek.

During a river high-water event in a non-arid area, gold is moved over a larger area by massive water flows that continue until the water slows as the source dissipates its energy. Spring snow runoff is a good example. Rivers rise and sometimes flood based on the upstream water source. When the snow has melted, the river will slowly get back to  normal. In the desert, gold is moved in the exact same way with the exception that water powerful enough to move gold does so and then just simply stops. In a flash flood, gold is moved very violently and often a very short distance, sometimes percolating into valuable pockets. Here’s where the difference between water and desert mining principles comes into play generally flood gold will concentrate in areas that do not meet the standard thought of inside bends and where the water flow becomes lower.

For the most part, desert mining experts recommend staying out of the washes, gulches and dry river beds— that is unless you clearly see exposed bedrock. Gold will settle fairly quickly when it is trapped behind jagged bedrock and small fault lifts that have not been worn down over time by constant water flow. It IS true you can find areas of concentrated gold-bearing material in the washes, however, the amount of time and energy to get through feet of overburden is usually just not worth it, especially when there are higher values to be found outside of the wash.

Follow the leads out of the wash to where the gold lives in higher concentration. Test and sample areas you see with a great deal of runoff from a tributary coming into the main wash. Here you are only digging through the current flood layer and testing for flood gold. Make your way out of the wash carefully looking at the bottom of the tributary and the areas where the water flowed into the tributary. Look closely for jagged bedrock and slight lifts in the ground and then prospect. Continue to test each of those spots. What started as a few specks of flood gold in the main wash can lead to larger and larger deposits on the flats or in slight inclines across the desert floor. Keep in mind that when a flash flood is dissipating, there is not enough energy to move a lot of rock, but the sand will continue to flow a bit, creating great clues.

In general, cool season precipitation (October through April) is the most extensive source of rain in the desert regions. Rainfall is more widespread and of relatively long duration during the cool season. On the other hand, warm season precipitation (May through September) results largely from short monsoon-type thunderstorms.

If you’re ready to head to a sunnier climate this winter, keep these tips in mind and you just might find enough similarities between water and desert mining to make you return every year.  Good luck!

Posted by: Denise AT 08:51 am   |  Permalink   |  Email
Friday, September 30 2022
In an area either rumored or known to hold gold, where should you look first? The creek, the surrounding hills, washouts, or just where? The characteristics of the gold in that area will help you to know where to start. If the gold is flat and pounded, that indicates it’s been in the water a long time. If the gold is coarse and chunky, you know you’re getting closer to the source. When gold is smoother, stop and go back to the coarsest gold and start working upwards until you find the source.

Keep in mind that gold is gold, so there isn’t necessarily a better type of gold. Some is just easier to recover. There are only two typesgold nugget of gold deposits. The first type is “lode” which is simply everything that is still in the matrix and in the ground, and the other is “placer” —or everything else.

Lode deposits refer to gold that is still locked within its original solid rock formation. This formation of gold generally starts as a vein in rock and is formed over millions of years. Since the gold is locked up in rock, and can be mixed with quartz, calcite, pyrite, and other minerals, lode gold  usually requires specialized mining techniques to extract. Lode mining takes a lot more equipment and generally a lot more expense and is usually undertaken by large commercial operations instead of the average prospector. Placer gold is the gold that most prospectors are more familiar with. Placer gold isn’t really any different than lode gold. It is simply a concentration of that same gold that has eroded and traveled away from the vein.

Since gold is very dense, it will move downhill much slower than the surrounding sediment. It tends to become concentrated on or near the surface of the lode, forming a “residual placer” close to the original bedrock exposure. Gold found downhill from the immediate outcrop above the nearest watercourse is called an “eluvial placer.” Once it reaches the nearest waterway and is transported by flowing water, the gold now is known as “alluvial placer.”  The origin of the dust, flakes and nuggets found by panning and sluicing is usually from a vein up on a nearby mountain.

Bench placers were originally stream placers. Benches are simply where the water used to be, maybe even millions of years ago. They are formed by erosion or geological events such as uplifts, earthquakes or plate drops that changed the stream flow. Some of the most profitable mining is performed on benches. Many benches are highly concentrated by the alluvial deposits that still feed them.

Stream deposits are the last resting place for gold. Once the gold has been released from the lode, gravity and nature does the rest. And unless gold gets stranded on a bench, it will find its way to the water someday. It may take a million years, but it will get there.

When deciding where to begin prospecting, most of the time you’ll want to start panning in a water way, or a wash in the desert where water once flowed. Then let the gold tell you where to go from there. When the gold gets coarse and ragged, start to move up, looking in reverse of how it got to the spot where you found it. In addition to panning and sluicing you may wish to upgrade your mining efforts with a highbanker or power sluice, dredge or trommel. Moving soft soil or river gravel is obviously much easier than breaking rock, but for small scale miners, a rock crusher can pulverize 2 or 3 inch sized rocks into powder in no time. Move more material faster— get more gold! 
Posted by: Denise AT 01:00 am   |  Permalink   |  Email
Saturday, March 26 2022

Gold is gold, so there isn’t necessarily a better type of gold, however, mining for lode gold has many more challenges than mining for  placer gold. The formation of gold generally starts as a vein in rock. This is referred to as “lode gold” and is formed when molten rock in the earth’s crust heats groundwater under great pressure. In fractured bedrock with appropriate rock chemistry, super-heated water (hydrothermal) at approximately 400-700 degrees Fahrenheit dissolves certain elements alode goldnd molecules from cubic miles of crust and transports them in a circulation loop. When this hydrothermal solution cools or chemically reacts with local rocks, the elements and molecules will come out of the solution and solidify (precipitate), forming ore deposits. The hydrothermal solution will begin precipitating on the sides of the opening and slowly fill the entire crack over time. This is how gold veins can form.  These geologic processes take place over millions of years, and can happen many times over many years in the same location.  Since the gold is locked up in rock, it is usually pretty hard to get to— usually requiring specialized mining techniques to mine and extract. Lode mining takes a lot more equipment and generally a lot more expense and is usually undertaken by large commercial operations instead of the average prospector.

Placer gold is the gold that most prospectors are more familiar with.  Placer gold isn’t really any different than lode gold. It is simply a concentration of gold that is created over time as it erodes from hard rock veins.  When exposed at the surface, a mineralized deposit will break down and erode due to reactions with oxygen, water and wind, coupled with temperature fluctuations. Since gold is very dense, it will move downhill much slower than the surrounding sediment. It tends to become concentrated on or near the surface of the lode, forming a “residual placer” close to the original bedrock exposure. Gold found downhill from the immediate outcrop above the nearest watercourse is called an “eluvial placer.” Once it reaches the nearest waterway and is transported by flowing water, the gold now forms an “alluvial placer.”  The origin of the dust, flakes and nuggets found by panning and sluicing is usually from a vein up on a nearby mountain.

An ore body is a mineral deposit that can be mined, processed and sold at a profit. All ore bodies are deposits. Few deposits are actual ore bodies. Valuable gold deposits in placers are referred to as “pay streaks” instead of ore bodies. Over time, eluvial and alluvial placers can become covered with sediment. When buried long enough and deep enough, these deposits will turn into “fossil placers.”  Sometimes the fossil placers are re-cemented into sandstone or conglomerate rock and then must be mined using hard rock techniques.

Hard rock ores have mostly fine to micro-fine gold in solid rock; placers contain fine to coarse gold particles in a softer bulk material or matrix. That makes placers much easier to mine and process. Moving soft soil or river gravel is obviously much easier than breaking rock. For small scale miners, though, a rock crusher can pulverize 2 or 3 inch sized rocks into powder in no time!  But for the average prospector, panning and sluicing will be more fun and more profitable, and as time goes on, you may wish to upgrade your mining efforts with a highbanker or power sluice, dredge or trommel. Good luck!

Posted by: Denise AT 08:13 pm   |  Permalink   |  Email
Saturday, November 27 2021

If you’re ready to head to a sunnier climate this winter to do some desert prospecting, understanding the weather and topography can add to your success. Before loading up and heading to the Southwest, only to be disappointed by bad weather, first check out the weather patterns for the last 60 days and the predicted weather for the next 30-60 days. Why is that important?  Well, it mostly comes down to rainfall— how much and how fast. For example, if there will be a lot of rainfall over an extended time, soils will be loosened and gravity will do its job and cause deeper, and sometimes more concentrated, pay streaks. In general, cool season precipitation (October through April) is the most extensive source of rain in the desert regions. Rainfall is more widespread and of relatively long duration during the cool season. On the other hand, warm season precipitation (May through September) results largely from convective precipitation in the form of short monsoon-type thunderstorms. 

There are three major desert areas that make up the American Southwest:

The roughly 200,000-square-mile Chihuahuan Desert stretches from the southeastern corner of Arizona across southern New Mexico and west Texas to the Edwards Plateau. It runs deep into central Mexico,The Chihuahuan Desert is the most moderate of the three deserts, made up of low and high desert regions and grasslands. It sees the most rain on a regular basis throughout the year with anywhere between 8-12 inches, and areas in New Mexico receive up to 17 inches per year. Unfortunately, because of the Chihuahuan Desert’s higher altitude in southern New Mexico, and the rain patterns there, winter prospecting is a real challenge, especially dry washing. October - March averages 2 inches of rainfall per month, with an average daytime temperature of 55 degrees, making it hard for the ground to dry throughout the season. The pay layer in the Chihuahuan Desert is most likely going to be deeper and more evenly distributed and more highly concentrated than in the Sonoran Desert, but there will be a lot of effort needed to stay on track sampling to find the richest pay layer.

The Sonoran Desert occurs primarily in Mexico. In the USA, most of it can be found in the southern third of Arizona, with small areas in southeastern California.The Sonoran Desert region of Arizona receives between 3-20 inches per year, but these numbers are skewed for the actual low desert gold-bearing region of the state. The Sonoran Desert encompasses a large section of high desert area, ending a few miles south of Prescott, Arizona, following a higher elevation line to the east and west. The normal rainfall in the lower elevation gold-bearing areas of Arizona averages 6 inches annually, all of which falls in about 30 days and includes the monsoons. Yuma is considered the driest area of the state with only 3 inches of rain on average.

The Mojave Desert is primarily in southeastern California and southwestern Nevada, with small portions extending into Arizona and Utah. It has a large amount of high desert elevations and has skewed numbers for the majority of the gold-bearing areas. Lowland areas at less than 1,000 feet elevation average 3.7 inches per year of rain, while Granite Mountain at 4,200 feet above sea level averages 8.5 inches annually. Rich pay layers have been found northwest of Barstow, California by testing and eliminating low to no pay overburden. This area is known for seismic activity with several earthquakes and aftershocks occurring west of the 117 degree meridian, which helps in concentrating gold.


When prospecting in the desert, it’s a good idea to test larger areas in compass headings— testing every few feet north to south to find highest values, then east to west of that spot. Doing so provides you with a line in the desert for further testing. Because of the extended days of rainfall in the Chihuahuan and most of the Mojave compared to the Sonoran Desert, you’ll likely discover a shallow and slightly more compacted layer of good material that is worth processing. However, this “pocket gold” layer can be directly above the really good pay layer you want. Finding gold and digging straight down without continued testing and sampling is not taking advantage of the forces of nature, especially that of water following the path of least resistance and taking the heavies along for the ride. In other words, don’t settle for just any pay layer— follow and use the over burden to get to the BEST pay layer!

If you are planning a desert prospecting trip far in advance, it’s a good idea to start checking weather patterns in April, which is when desert prospecting begins to wind down. That way you will be very prepared when the following fall and winter rolls around. That also gives you time to form a Plan B if the weather is not conducive to your Plan A. If you are a member of Gold Prospectors Association of America (GPAA), there are hundreds of opportunities across the Southwestern states to get on the gold at a GPAA claim. Knowing a little about desert geology is a great start to understanding more about the “why” and “how” gold deposits are formed. And weather is a key factor in knowing “where” gold settles after it breaks from the lode and residuals. Get out there and get your share! Good luck getting the GOLD!

Posted by: Denise AT 07:03 pm   |  Permalink   |  Email
Friday, April 27 2018

A good rule of thumb that most prospectors agree on is to look for placer gold on bedrock and within crevices in the bedrock. This simple principle makes sense— placer gold is heavy and dense and therefore settles at the lowest point as it is pushed around by flowing water. However, gold isn’t always going to make it all the way down to true solid bedrock at the bottom of all gravels. Instead, in certain conditions, it will be found ABOVE bedrock. When these conditions exist, gold will collect on “false bedrock.” For example, a clay layer in streams can act like bedrock and yield more gold than the true bedrock below it. 

bedrock goldAnother situation where gold cannot make it to bedrock is where the streams and gullies have “caliche.” Caliche is a form of cemented gravel often found in desert areas. The gravel is deposited by water flows, just as it would be in any other stream. The difference is that the water contains dissolved calcium salts, and as the water dries up in the streambed, the calcium salts turn into calcium carbonate or calcite. This material gets deposited on the gravel a little at a time and eventually the calcite glues it all together into a solid mass. The solid mass then acts like false bedrock and any new gold flowing across it is stopped in its downward movement by the caliche.

Residual placer gold is formed near the source of the gold and doesn’t really have a chance to work its way downward. Hillside placers are residual placers that are sliding and making their way down the side of a hill into a stream drainage. Gold generally is distributed all through these types of gravels and is not concentrated in any one place. A hillside placer often will be located up above a stream, making it difficult to determine it from a bench placer. Old benches of river gravel can be good places to prospect because they are virgin ground, but because the river used to flow at this location, it’s highly likely that the best gold will be right on bedrock or in crevices of the bedrock. The best way to tell the difference between hillside and bench placers is the shape of the rocks in the gravel. If the gravels and rocks are well-rounded and smoothed, then it’s probably an old river bench. If the gravel is angular, pointy, and sharp, it’s probably a hillside placer that hasn’t yet made its way into a stream.

Another type of placer—the windblown placer— concentrates on the surface, just exactly the opposite of what you would find in a river or stream. The lightest materials such as sand and silt are blown away by the wind. Heavy materials like gold remain behind on the surface. These types of placers are marked by desert pavement, which is a concentration of small to medium-sized rocks that cover the surface and prevent continuing wind erosion. They occur in dry regions with flat terrain, and are often favorite locations of metal detectorists who find nice nuggets at shallow depths.

The next time you find yourself in an environment with well-washed river gravels, you know that the gold will most likely be on the bedrock. But if you find yourself in other types of environments, especially in the desert, consider the possibility that the best gold may actually collect ABOVE it.  Good luck!

Posted by: Denise AT 06:43 pm   |  Permalink   |  Email
Tuesday, February 06 2018

Historically, California has been known as the land of the big nuggets. After the Gold Rush began in 1849, gold nuggetsome of the biggest nuggets were discovered there because so many more people were out looking. For example, in 1854, miners working underground in the Morgan Mine at Carson Hill in Calaveras County pulled out a 195-pound mass of gold. It was 15 inches wide and four inches thick!  In 1859, a gigantic nugget was taken from ancient Tertiary river gravels on the slopes of Sawmill Peak near the West Branch of the Feather River and the small community of Dogtown. That nugget weighed 54 troy pounds. The spot where it was discovered was a hydraulic mine on the Willard claim that had a history of producing large nuggets in the past, including a 96-ounce nugget.

Plenty of stories abound from California, but plenty of big gold has come from other states as well. Colorado's biggest nugget weighed in at 156 ounces (13 troy pounds). It came from the Gold Flake mine located on Farmcomb Hill in Summit County, Colorado in 1877.  It's easy to see why Montana's nickname is the "Treasure State" since it has produced a few big nuggets, too. One weighed 53 ounces and was displayed at the Paris World Expoition of 1889. The largest in Montana was over 170 ounces and was dug at a depth of 12 feet in Snow Shoe Gulch on the Little Blackfoot River. Nevada's largest nugget was taken from the diggings of the Osceola District in 1878. It weighed 24 pounds (but eight pounds of that was quartz). The old Spanish miners found plenty of big gold in New Mexico, including one nugget in the late 1890s that weighed over 65 ounces.

buy gold nuggetsUnlike many Western states, the largest nugget in Alaska was found rather recently. In 1998, the Alaska Centennial Nugget, weighing 294 ounces, was mined along Swift Creek near the town of Ruby. This area is well known for its past production of large nuggets. A big nugget was also found in Anvil Creek near Nome which weighed 182 ounces.

North Carolina's claim to fame is the Reed Gold Mine located in Cabarrus County. It was the site of the first documented discovery of gold in 1799. For years, that 17 pound nugget was used as a doorstop because no one recognized what it was! At the time, it was worth roughly $4,000 (when the price of gold was $20.67 for an ounce). The Reed Mine actually produced a lot of big gold, including some weighing 28 pounds, 17 pounds, 16 pounds, and 13 pounds. Two different nuggets came from this area that weighed eight pounds each and another two nuggets were nine pounds each. Several more nuggets have been unearthed that weighed five pounds and less.

These examples of where large nuggets have been found are by no means exhaustive. A Google search will provide lots of fun stories about past and present finds across the United States. But no matter who has found what, the big question remains: Where do you hunt for big gold these days? Generally, big nuggets occur in places where rich gold-bearing fluids flow through the same pathways for a long period of time, allowing continued deposition of golgold nuggets for saled that lead to the formation of large pieces. These bigger pieces form where a change in geology allows a gold-bearing waterway to efficiently drop gold all in the same place. The same type of geology that produces rich pockets of ore with lots of visible gold are often the same areas where big nuggets are found. The really big nuggets are parts of pockets that have so much gold that they hold together as a single piece even after tumbling around in a stream.

The simple answer to where to hunt for big nuggets is to hunt where they have been found in the past. Past finds of big gold indicates these locations have the right geology for their formation. Big nuggets in a stream environment will work their way to bedrock very fast and stay put. They will often be lodged in deep crevices. Keep in mind that big nuggets are also worth more than their actual metal value. The fact they are so rare adds to their value. If you haven't found your big gold yet, keep looking! And if you can't wait to own your own shiny stuff, buy gold nuggets here.

Nugget of News Blog

Posted by: Denise AT 09:20 pm   |  Permalink   |  Email
Saturday, December 02 2017

You might have heard the term “flood plain gold” and are wondering what it really means. A very simple definition is “fine-sized gold flakes carried or redistributed by flood waters and deposited on gravel bars as the flood waters recede.” When this “redistribution” occurs, it is usually after heavy winter storms that churned up rivers enough to turn part of the bedload over and move the river bar gravels from one place to another. Within these gravels is fine gold that was previously deposited there.  When waterways flow way up and above their normal banks, they generally drop the heavier gold in the front of the bar, and as pressure decreases, the finer gold starts dropping into the mixed gravel. Over time, some of this finer gold will work its way down to bedrock, but generally it stays on the move.

flood plain gold deposits

How did the gold get there in the first place? There are many classifications of placer deposits, and their definitions can provide the answer. Among the most well-known is stream placers. Streams carry gold from eroded veins and concentrate them in various ways. Modern streams refer to present-day gold-bearing waterways that are the most common sources of gold for today’s prospectors. Tertiary and intervolcanic channels are rivers buried from mud and volcanic flows that existed prior to our modern-day waterways. High benches were created as rivers cut their way deeper into the bedrock and could be located hundreds of feet above today’s modern rivers. Desert placers are generally the result of torrential flash flooding and not a constant water flow. Glacial stream deposits are created by melting glaciers that can concentrate gold if the water flow is sufficient. Marine or beach deposits can come from wave action against cliffs, from off-shore currents bringing in gold-bearing material from under the ocean, or even from gold-bearing streams that flowed into the beach area eons ago.

Since there is a strong possibility that gold can get moved around during storms, it’s now important to know WHERE to find this “dropped out” gold. The secret is to find that drop point and to capitalize on its accumulation. Fine gold looks fantastic in a pan or box, but its weight can be deceivingly light. It takes a lot of fine gold to be equal to a larger piece and to have enough weight to make the recovery effort worthwhile. Some of the best areas to look for flood plain gold are where the stream or river widens out, or levels out, or changes direction. The inside of a bend is good. Rocks and weeds and small shrubs are also potentially good collection spots. When checking out collection spots, be extra careful. Calm water on the surface can hide swift currents underneath.

Keep in mind that the effects of heavy winter rains and snow will not be the same on all waterways. Redistribution might occur to a larger degree on larger rivers. Or it could be the opposite where you live and prospect. No one hopes for an especially “bad winter,” but if Mother Nature makes it so, this information could be the silver lining— a way to turn lemons into lemonade come spring when you can get out and take advantage of any gold redistribution that occurs. Good luck and be safe!

Nugget of News Blog

Posted by: Denise AT 06:09 pm   |  Permalink   |  Email
Wednesday, June 14 2017

Fun and exercise are two great reasons to go gold prospecting, but you might as well make some money while you're at it, right? The best way to do that is to increase production rates. Assuming you are mining on a known gold-bearing claim or waterway, volume is the key to your success!

gold panningGraduating from the basic gold pan to some other form of simple equipment is the best way to increase production rates. Just going from a pan to a sluice will increase production by at least 500%, depending on how it is used. A highbanker will work about the same amount of material as a well-run sluice, though it can move the water to you instead of you bringing the gravel to the water, thereby dramatically incsuction dredgereasing volume of production. A drywasher will produce similar results by allowing you to work without water.

A dredge or highbanker/suction dredge combo is the next step up. A dredge uses a gas motor to generate the suction that will load and transport the material to the sluice, which greatly increases volume, as well as allows you to reach gravel on the river bottom that would otherwise be inaccessible (unless the river is seasonal or there is a prolonged drought). The more material a dredger can push across the riffles, the more gold can be recovered. An additional benefit to dredging is that it also allows you to clean gold out of all the cracks and crevices in the bedrock. A shovel just cannot do that.

The size of the dredge intake nozzle is the most important factor in how much material a dredge can process, but it is not a direct one-to-one relationship. For example, a 5 inch dredge will not move twice the material that a 2.5 inch dredge can move. It actually can move much more. The surface of the hose is figured in square dredge nozzleinches, the area (and therefore the volume) goes up much faster than the diameter and the corresponding production rates go up proportionally. A larger hose size will also clog less because more sizes of rock and gravel will pass through. Having to stop and remove clogs can significantly reduce the time you get to spend actually moving dirt and finding gold. No matter the size, you're likely to have rocks jam up the hose from time to time, but generally, the larger the hose the less frequent the clogs that slow or stop production. In most areas of the country, a 2 inch dredge is considered a "recreational" size and may not require a permit to use, whereas much larger nozzle sizes would require a permit. Always know the laws where you intend to gold prospect and mine before you buy equipment.

Beyond dredges or highbanker/suction dredge combos, you can get into some professional mining set-ups that use trommels and jigs and shaker tables and earth moving equipment. Every deposit is different, varying in size and grade and structure. Environmental conditions and access will dictate mining methods and knowing the rock types and size of the gravel is critical in determining which equipment will work best for increasing your production. Finding a suitable deposit to mine and finding a way to work it economically— to justify your time and expense— is the first step.  Then choose the right equipment to increase your recovery rate and speed of recovery and make more money.  Good luck!

Posted by: Denise AT 04:00 pm   |  Permalink   |  Email
Wednesday, March 08 2017

You might think that glaciers are important to gold prospecting only in Alaska and the Yukon, but glaciers have also affected placer deposits in the Midwest and some western states, too. 

What is a glacier?

Glaciers are formed when a huge mass of ice is created by accumulated snow. The body of ice grows over the years when more snow falls during colder months than melts during warmer months. Glaciers shrink when the melting is greater than the snow accumulation. Once the weight of the glacier grows large enough, the weight of the snow and ice presses down anglacier goldd compacts. The body of ice will then slowly flow downhill. The power of the solid ice moving downhill rips loose rock and soil. Solid rock underneath the glacier that is firmly attached to the mountain will stay in place, but be polished and smoothed as the glacier slides over it. Scratch marks and gouges appear along the surface of these polished rocks and indicate the direction that the glacier was moving.

Eventually the body of the glacier reaches a warmer elevation where the ice melts more easily. Here, at the foot of the glacier, are gigantic piles of rocks and boulders and debris that have been bulldozed down by the moving massive glacier. These glacial gravels are known as “moraines.” However, finding gold in this unsorted jumble of glacial moraine material produced by a glacier’s bulldozing effect is like finding a needle in a haystack—not worth the time to process…. until the glacier’s natural melt waters or another water source washes through it, and does a bit of natural sorting.

Alluvial gold deposits

Normal alluvial placer deposits form by the power of flowing water washing away lighter materials and gravels and leaving behind heavier material such as gold— very similar to what happens in a sluice box when the flow of water washes away the lighter materials and the gold is deposited in the riffles.  When flowing streams and glacier melt water process and wash away the glacial moraine gravel, the gold works its way downward.  Gold will then be deposited on bedrock or false bedrock (such as clay or other packed material). As the glaciers themselves melt, the huge quantity of water creates an effective sluicing system that can sort the gold out of gravels. These flows can leave behind very profitable pay zones along the channels cut by the ice melt waters on bedrock benches, among packed false bedrock gravels, and on the downstream side of bedrock high spots.

Where to look for glacial placer gold deposits in the West

In California, glaciers still exist in the southern Sierra Nevada, small parts of the Cascade ranges and the Shasta-Trinity Alps. In the northern Sierra Nevada and higher parts of the Klamath and Trinity ranges, that area’s placer deposits were greatly affected by glaciers that existed thousands of years ago. Glacial derived placer gold is important in a number of other western states, too, including Idaho (Boise Basin and Mount Pisgah), Montana (Pioneer District, upper portions of Gold Creek near Deer Lodge) and in Colorado (Fairplay District, Arkansas River Valley in southern Lake County).

Where to look for glacial placer gold deposits in the Midwest

What you might be very surprised to know is that glaciers are the source of nearly all the placer gold found across the Midwest. During the past ice ages (which were repeated events, not just a one-time occurrence), great sheets of glacial ice leveled the middle parts of North America, acting like giant bulldozers by pushing enormous amounts of material southward from Canada. When the ice melted, the area was left with extensive glacial moraine (gravel) deposits. Although it’s spotty and sporadic, some of these glacial deposits have gold, depending on where the glacial gravels came from in Canada and if that region was gold-bearing. Glacial gold is found in several of the northeast states such as New York, Vermont, and Pennsylvania. Glacial gold is also found more extensively in Midwest states such as Indiana, Illinois, Ohio, Michigan, Wisconsin, Iowa, Minnesota, Kansas, Nebraska, Missouri and the Dakotas.

All things considered, while glaciers can destroy a placer deposit, the moraines they leave behind can produce some very worthwhile deposits of gold, and are worth prospecting if you live in or visit these areas.

Posted by: Denise AT 03:03 pm   |  Permalink   |  0 Comments  |  Email
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