and gas and oil, gold etc etc?

I assume nowadays we have special sonar dooberries and things but in the olden days, how did they find coal and gold and oil and things?

Even things like iron, aluminium and soap. it all comes out of the ground but there must be a way of knowing where to start digging.

Originally whereit was exposed to the surface then follow it then someone whill have twigged its under this type of rock, sowhere this rock is if i dig / drill i should find some.

I use Yellow Pages….
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IGMC

These days if we want to find coal its where we left it.

I wish it was as easy as sonar dobberies.

First you need to know the geology of a region. This is done by ground mapping and in this day and age with airborne gravity and magnetic surveys. Then you look for a combination of the right rock types, structures depending on the commodity etc. then you use airborne and ground electromagnetic surveys and soil sampling to locate any anomalies. You then drill test these to see if there is anything there. It’s an expensive game. A 500m diamond drill hole will cost you upwards of $100000. And you don’t always find anything.

Coal reserves still quantified by exploratory drilling. Tighter spacings allow geology to be more accurately determined. It is expensive though, so a balance has to be struck. I have seen drill records from NCB days. Holes really close together. The seams must have been like Swiss cheese.

Extensive geophysical surveys, exploratory drilling and similar offshore. Or you find someone who has already done this for you and buy the info