scholarly journals New gravity data for the Bathurst Mining Camp, northeastern New Brunswick: a colour-shaded map of the 1st vertical derivative of the Bouguer gravity anomaly with geological contacts and faults, and locations of selected volcanogenic massive sulphide deposits

2007 ◽  
Author(s):  
R Morris ◽  
D M Jobin ◽  
M D Thomas ◽  
N Rogers ◽  
S R McCutcheon
Keyword(s):  
New Brunswick ◽  
Gravity Anomaly ◽  
Gravity Data ◽  
Massive Sulphide ◽  
Bouguer Gravity ◽  
Vertical Derivative ◽  
Bouguer Gravity Anomaly ◽  
Massive Sulphide Deposits ◽  
Volcanogenic Massive Sulphide ◽  
Bathurst Mining Camp

Reprocessing legacy three-dimensional seismic data from the Halfmile Lake and Brunswick No. 6 volcanogenic massive sulphide deposits, New Brunswick, Canada

2019 ◽  
Vol 56 (5) ◽  
pp. 569-583 ◽  
Author(s):  
Gilles Bellefleur ◽  
Saeid Cheraghi ◽  
Alireza Malehmir
Keyword(s):  
New Brunswick ◽  
Seismic Data ◽  
Three Dimensional ◽  
Massive Sulphide ◽  
Seismic Survey ◽  
Deep Zone ◽  
3D Seismic ◽  
Massive Sulphide Deposits ◽  
Volcanogenic Massive Sulphide ◽  
Sulphide Deposits

We reprocessed legacy three-dimensional (3D) seismic data from the Halfmile Lake and Brunswick areas, both of which were acquired for mineral exploration in the Bathurst Mining Camp, New Brunswick. Each 3D seismic survey was acquired over known volcanogenic massive sulphide deposits and covered areas with strong mineral potential. Most improvements resulted from a reduction of coherent and random noise on prestack gathers and from an improved velocity model, combined with re-imaging with dip moveout corrections and poststack migration or prestack time migration. At Halfmile Lake, the new imaging results show the Deep zone and a possible extension of the sulphide mineralization at greater depth. True amplitude processing has shown that this anomaly has strong amplitudes and is offset from the Deep zone by a shallowly dipping fault (<15°). With the clearer geological context provided by our results, this anomaly, which appears as a stand-alone anomaly on an original image obtained by Noranda Exploration Ltd., becomes a defendable exploration target. Nonorthogonal acquisition geometry and receiver patches of the Brunswick No. 6 3D seismic survey generated artefacts after dip moveout processing that reduced the overall quality of the seismic volumes. By using a filtering approach based on the application of a weighted Laplacian-Gaussian filter in the Kx–Ky domain, we reduced the noise and improved the continuity of reflections. We also imaged the short and flat reflections observed previously only in the shallow part of prestack time migrated data. These short reflections appear as diffractions on the filtered stacked section with dip moveout corrections, indicating that they originate from small geological bodies or discontinuities in the subsurface.

Further Studies of Reflections from the Deep Crust in Southern Alberta

1975 ◽  
Vol 12 (4) ◽  
pp. 539-557 ◽  
Author(s):  
G. L. Cumming ◽  
N. N. Chandra
Keyword(s):  
Gravity Anomaly ◽  
Seismic Data ◽  
Gravity Data ◽  
Power Spectra ◽  
Reflection Coefficients ◽  
Bouguer Gravity ◽  
Model Calculations ◽  
Bouguer Gravity Anomaly ◽  
Deep Crust ◽  
Southern Alberta

The correlation between Bouguer gravity anomaly and depth to the 'Riel' reflecting horizon established in southern Alberta in the region around 113 °longitude and 51 °latitude is not substantiated on a smaller gravity anomaly further to the south. Only small variations in depth to the 'Riel' reflecting horizon occur and these do not correlate well with the gravity data. The reflecting horizons are continuous over distances of only a few kilometres. Model calculations of the reflecting zones based on an analysis of the variations in power spectra of the reflections indicate substantial changes in the layered reflecting zones over distances of the order of a few hundred metres. Some attempts at deconvolving the seismic data confirm that the prominent reflections are caused by rapid variations in reflection coefficients indicating finely layered zones a few hundred metres thick.

scholarly journals Gravity observations on Santorini island (Greece): Historical and recent campaigns

2021 ◽  
Vol 51 (1) ◽  
pp. 1-24
Author(s):  
Melissinos PARASKEVAS ◽  
Demitris PARADISSIS ◽  
Konstantinos RAPTAKIS ◽  
Paraskevi NOMIKOU ◽  
Emilie HOOFT ◽  
...  
Keyword(s):  
Gravity Anomaly ◽  
Bronze Age ◽  
Gravity Data ◽  
Absolute Gravity ◽  
Bouguer Gravity ◽  
Near Surface ◽  
Bouguer Gravity Anomaly ◽  
Minoan Eruption ◽  
Marine Gravity ◽  
Gravity Measurements

Santorini is located in the central part of the Hellenic Volcanic Arc (South Aegean Sea) and is well known for the Late-Bronze-Age “Minoan” eruption that may have been responsible for the decline of the great Minoan civilization on the island of Crete. To use gravity to probe the internal structure of the volcano and to determine whether there are temporal variations in gravity due to near surface changes, we construct two gravity maps. Dionysos Satellite Observatory (DSO) of the National Technical University of Athens (NTUA) carried out terrestrial gravity measurements in December 2012 and in September 2014 at selected locations on Thera, Nea Kameni, Palea Kameni, Therasia, Aspronisi and Christiana islands. Absolute gravity values were calculated using raw gravity data at every station for all datasets. The results were compared with gravity measurements performed in July 1976 by DSO/NTUA and absolute gravity values derived from the Hellenic Military Geographical Service (HMGS) and other sources. Marine gravity data that were collected during the PROTEUS project in November and December 2015 fill between the land gravity datasets. An appropriate Digital Elevation Model (DEM) with topographic and bathymetric data was also produced. Finally, based on the two combined datasets (one for 2012–2014 and one for the 1970s), Free air and complete Bouguer gravity anomaly maps were produced following the appropriate data corrections and reductions. The pattern of complete Bouguer gravity anomaly maps was consistent with seismological results within the caldera. Finally from the comparison of the measurements made at the same place, we found that, within the caldera, the inner process of the volcano is ongoing both before, and after, the unrest period of 2011–2012.

Sign in / Sign up

Export Citation Format

Share Document