Reflection seismic study of the Siljan Ring impact structure: Orsa - Stacked data

Two new reflection seismic profiles over the Paleozoic successions of the western part of the Siljan Ring impact structure were acquired during 2011, the Mora and the Orsa profile. This data set concerns the Orsa profile. The profile has length of c. 12 km and the processed data image the geological section to about 3 km depth (Silurian siliciclastic and Ordovician carbonate rocks to serveral hundred metres depth, below disturbed Paleoproterozoic crystalline basement). During the survey, 542 source points (VIBSIST 3000) were recorded by 320 receiver channels for 30 seconds. From this recording, the following data sets were generated and are published here: 1) decoded and quality controlled raw data; 2) pre-processed (shot geometry applied) data; 3) stacked data; 4) migrated data; 5) depth converted data and velocity field. Key acquisition parameters are: Number of channels: 320 (160–160) Near offset: 0m Geophone spacing: 10 m Geophone type: 28 Hz single Source spacing: 20 m Source type: VIBSIST 3000 Hit interval between hammer blows: 100–200 ms Sweeps per source point: 3–4 Nominal fold: 80 Recording instrument: SERCEL 428UL Sample rate: 1 ms Field low cut: Out Field high cut: 400 Hz Record length: 30 s Profile length: 12 km Source points: 542 Dates acquired: 10/6–15/6: 2011 This dataset contains processed data of the Orsa profile. Processing steps for this data set: 1: Read decoded VIBSIST data 2: Bulk static shift to zero time 3: Apply geometry 4: Pick first breaks 5: Spherical divergence correction 6: Trace editing 7: Trace balance: 0–3000 ms 8: Spectral equalization: 0–600 ms: 50–80–200–240 Hz; 700–1500 ms: 40–70–180–240 Hz 9: Time variant bandpass filter: 0–400 ms: 50–80–240–360 Hz; 450–600 ms: 45–70–210–300 Hz; 700–1000 ms: 40–60–180–270 Hz; 1100–3000 ms: 35–50–150–225 Hz 10: Refraction statics: datum 180 m, replacement velocity 3000 m/s 11: Residual statics 12: Median filter: 11 traces, 3 samples, 1600, 2000, 2400 m/s, subtract 13: AGC: 50 ms 14: No mute 15: Residual statics 16: Velocity analysis 17: NMO correction: 70% stretch mute 18: Trace balance 19: FX Decon: 19 trace window 20: Dip filter 1.5 ms/trace cutoff 21: Trace balance Processed seismic data stored as one file for the enitre seismic profile, according to SEG technical standard SEG-Y revision 1 (SEG-Y_r1.0, 2002); https://seg.org/Publications/SEG-Technical-StandardsOpens in a new tab