By: Hamizah Hanim Hamzah, Helen Ellwood, and Zoltán Erdős.

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Presentation transcript:

By: Hamizah Hanim Hamzah, Helen Ellwood, and Zoltán Erdős

Contents Obtaining measurements Processing data Results Interpretation

Study Area Line B (4.5km) Line A (1km) Line C (4.2km) N

Measuring Gravity The Lacoste-Romberg Gravity Meter

Measuring Elevations Geodimeter

Processing Method Corrections needed for: 1.Tides 2.Instrument drift Due to elastic creep in springs 3.Differences in latitude g increases towards poles

Processing Method 4.Height of measurement above reference datum: Free-Air Correction = mGal/m 5.Extra mass between measurement and reference datum: Bouguer Correction = ρh Where ρ=density (gm/cm 3 ) and h = height above datum (m) 6.Effect of surrounding terrain

NNWSSE ρ = 2 gm/cm 3

SW NE ρ = 2 gm/cm 3

SW NE ρ = 2 gm/cm 3

Buoguer Anomaly Map with stations colour-coded according to measured anomaly

Comparison With Resistivity Results Line C anomaly has been filtered to remove long and very short wavelength variations, and compared with resistivity inversion result.

A Possible Model for Line B Basement, ρ=2.67g/cm 3

A Possible Model for Line C

Another Possibility for Line C Gravity interpretation is non-unique

Geological and Topographic Map of Region

Summary 3 lines: A – Oreg-Hegy, B&C – traversing Enying Ridge; Various corrections needed to produce relative Bouguer Anomaly map; Anomaly profiles each represent complex structures on many different scales; There is no evidence for a tectonic origin for the Enying Ridge formation. Acknowledgements: Res1 and Res2 for their results; Greg Houseman and Piroska Lorinczi for all their help.

Question Time Measuring gravity gets lonely