JOURNAL OF THE BALKAN GEOPHYSICAL SOCIETY, Vol. 2, No 1, February 1999, p. 15-29, 14 figs.

Possibility of deep gabbroic rocks, east of Tuz Lake, central Turkey,

interpreted from aeromagnetic data*

Abdullah Ates

A.Ü., Fen. Fak., Jeofizik Müh. Böl., Besevler 06100, Ankara, Turkey

E-mail: ates@science.ankara.edu.tr

(Received 17 September 1998; accepted 20 October 1998 )

Abstract: In the east of Tuz lake, gabbroic rocks are observed as small outcrops from the surface geology. Regional aeromagnetic data measured by the Canadian Aero Service (CAS) show strong anomalies in the region. Gabbroic rocks are the only magnetized rocks in the region. However, surface exposures of the gabbroic rocks do not seem to have adequate size and extension to explain such magnetic anomalies of high amplitudes.

High-and low-pass filtered aeromagnetic anomalies were calculated by using the cut-off wavenumbers obtained from the azimuthally-averaged power spectra. Two-dimensional models were constructed from the high and low-pass filtered anomalies with the control of the power spectrum depth estimates. The two-dimensional model produced from the low-pass filtered anomalies suggests the existence of a conical shaped, deeply buried, body. The bottom of the body extends down to deeper levels of the upper crust. Pseudogravity anomalies and maxima of the horizontal gradient of the low pass-pass filtered anomalies were produced. A three-dimensional model was also constructed by employing an automated method. This model resembles the two-dimensional model produced from the low-pass filtered anomalies.

Key Words: Gabbroic Rocks, Aeromagnetic Data, Central Turkey