GeologyRocks

Most geological maps indicate faults and also have a little symbol like an arrow which indicates the angle of dip, so it's possible to approximately guess the configuration of a fault, although there are usually variations in the dip.

Geological maps are great for the early stages of investigation (desk study) but for most purposes you'll have to get on site and prove the location (or absence) of the fault in your zone of interest.

al8301 and gus,

can you help me locate a possible fault on this topograhic map..it will be helpful for me to assess the tunnel support...thanks

Hi, 

can you get hold of a geological map? They have the faults drawn onto them so are really easy to spot. I'm more a palaeontologist than a structural geologist but if I remember from my first year lectures, can you use geomorph skills to locate the best place to put in a tunnel and/or other features?

Leah

leah,

 thats my problem right know because they want us to prepare an assumed location of normal fault without going to site for preliminary assessment by using this map...

After speaking to a colleague he has suggetsed that you look for a really obviouse sharp topographic change, or say it is in a really linear valley.... But as I remember a first year lecturer saying " Just beacuse there's a valley it doesn't mean there is a fault"

Sorry I can't be of more help

Leah

If this is a commercial job then just go and buy a map of the area or have a good search on-line. I'm not sure what country the location is but the BGS have lots of useful data on-line, I suspect the USGS also have the same.

If this is an academic excercise then it seems a little pointless because:

1: In the real world you'd get the geological map

2: As Leah rightly says valleys often form along the lines of a fault (a plane of weakness) but also that the presence of a valley does not indicate the presence of a fault.

and

3: The presence / absence of a fault is unlikley to be the driving influence behind the tunnel location (economic factors are more likely)

Sorry I can't give a more useful answer!

Mount Damchak is in the Philippines. The most obvious feature I can see on your map is the large river valley on the far right, but as has been pointed out already, that doesn't mean a fault is present.

I saw the same linear alignment as Benault but, like him, there's no way I would say it's defininately a fault because I don't want to be held responsible if your tunnel support collapses.  I don't think anyone on this forum can give you an answer based on a topographic map and no other information.  There's got to be a geological map of the area, otherwise forget it.

thanks Gus and Benault for the advice

You might find these useful. The first is a link to the Baguio GQ:

http://mgb.gov.ph/Maps/Geological/Baguio.jpg

Links to other geologic maps of the Phillipines:

http://mgb.gov.ph/lgmp.aspx