Download Homework No. 1

EPSC 454 – Exploration and Environmental Geophysics
PROBLEM SET #1 (Gravity)
DUE: September 14, 2016
1. A large room in a cave has an approximate radius of 20 meters. The
surrounding rock has density of 2400 kg/m3. What would be the maximum
gravity anomaly if the depth of the room were 80 meters? If the gravimeter is
accurate to 0.01 mGal, theoretically, would the room be detectable at 150
meters depth? 300m? 600m? What is the half width of the anomaly at these
depths? What survey spacing would you use for each of these depths?
2. A flat lying iron formation has a density contrast of 200 kg/m3 with the
surrounding rock and covers an area of 1 km2. What is the thickness of the iron
formation if it produces an anomaly of 3.5 mGal? What is the total mass of the
formation? If the surrounding rock is density 2670 kg/m3, and the higher
density of the iron formation is attributable to the iron, what is the total mass of
the iron in the formation?
3. Do problem 6-4 in Burger. (note – these problem numbers are the same in both
editions of the book, at least for this chapter.)
4. Do problem 6-10 in Burger.