Page 317 - Whole Earth Geophysics An Introductory Textbook For Geologists And Geophysicists
P. 317
299 of the magnetic anomalies, with longer wavelength <j 20 to 30 km. Their thinner a regions. colder magnitude of mag-
Studies Basement depth the results in Gradient Paramagnetic rocks capable of ferromagnetic 20 km. resulting in to those in the magnitudes the remanent
Paleomagnetic Magnetic ect Earth's surface depend on rocks are shallow, short-wavelength sedimentary cover Geothermal depths of about may be considerably less than amplitude compared from subtracted of function the instances
Deep ss + 0 beneath High reach 600°C at thickness of basement lower in magnetization magnetization. is (AF) a is many In
b) (Vv) Afewouy Magnetic anomalics measured at basemeni deeply buried b) T J gradient geothermal of the great (high geothermal gradient) potentially to‘induced due remanent to due (F,,,,,) field ambient anomaly field fields. (F,,,;)
oneubayy
Basement E Ve basement. a) Where crystalline Basement stecp gradients. occur. b) gradients. Gradient oe 00 Low Induced * ginetiC Magnetization a normal Regions with amplitudes because high regions for hot anomalies are field magnetic field Magnetic the of magnitude total the (F), field remanent and (F;,)
Magnetic Surface Depth to magnetic basement. located within amplitudes and Geothermal hn Curie depth.a) Curie depth ferromagnetic behavior. Magnetic Fina F, ‘em = the After total the of induced the
Shallow 9.14 sources. commonly amplitudes and anomalies with smalle: Normal + i ° 1 9.15 magnetic anomalies may exhibit behavior. b) The
a) FIGURE high 8) Gv) Apeuouy FIGURE layer with
oneubey
salt
to
(V). leading to a (x). relative y magnetic susceptib result. b) A magnetic anomaly magnetic subdued leads to a and induced the of sum and induced the to due field
Salt Dome ‘a %, “ tre recognized as high-velocity material high and high-amplitude susceptibility o vector the material - material. fields local field: From magnetic total region
b) density (p) and small, negative is material the the ambient + Fina the in field
be the of + of
both high gravity maximum material of the of thus is the Foun magnetic
Interpretation s 9 § might dome gencrally has a gravity minimum. The a of magnetization magnetization magnetization location added to = F direction and ambient
Magnetic # igneous intrusion and salt intrusion A pronounced magnetization magnetizations: total induced Femanent given a at magnetizations, magnitude Earth’s
9 Intrusion x . x ‘ : igneous low density. resulting in total The = J j ind = J rem field fae Wout = em ‘amb
Chapter 7 An refraction. a) An surrounding sedimentary strata. remanent where: total The remanent where:
298 Igneous + f ° + f Ss 9.13 has
a) PIODOL UORIBYOL IILUSIOS (6y) Aswouy (49) Aewouy FIGURE critical dome anomaly.
AYABID oneubeyy