For part 2 of this series I want to discuss how the strike and dip that you see on a geologic map can tell you if the streams that cross that formation should have that elusive bookshelf gold catching bedrock that we all dream of. Foliation symbols on a geologic map will generally provide the same info as well. Find the corresponding youtube video here (https://www.youtube.com/watch?v=PdiWviSjMuk)
I know we all dream about bedrock that looks like a sluice box, kinda like in the picture below:
So lets take a look at a geologic map and see how the strike and dip symbols as well as the foliation symbols can tell us if a creek we area interested in fill have that text book sluice box bedrock. On the below geologic map note the sections of stream highlighted in blue and in red. As you can see the blue section of the stream runs perpendicular to the strike and dip and foliation symbols on the map. This means that that section of stream should have bedrock that is running perpendicular to the stream flow and hence forms what looks like riffles in a sluice box. Please know that some rock types like granite do not form the classic sluice box bedrock unless it has been foliated.
The section of stream in red will be more prone to having bedrock that runs parallel with the flow of the stream and therefor will most likely not have as good of catch zones as the blue section of the stream .
This can be a useful tool to know, as it can let you target sections of streams that are more likely to have gold catches, and you will know this before you ever leave your house. It can also be very helpful if bedrock isn’t exposed anywhere within the creek.
I hope this little tip helps you guys and helps put a little more gold in your pan when you are out in the field prospecting.
Thanks!
Check out the corresponding YouTube video by clicking on the icon below.