Constraints on Reelfoot Rift Evolution from a Reflection Seismic Profile in the Northern Rift

1992 ◽  
Vol 63 (3) ◽  
pp. 233-241 ◽  
Author(s):  
M.B. Goldhaber ◽  
C.J. Potter ◽  
C.D. Taylor
Keyword(s):  
Seismic Data ◽  
Seismic Reflection ◽  
Seismic Profile ◽  
Fault System ◽  
Seismic Reflection Profile ◽  
The South ◽  
Dome A ◽  
Reflection Seismic ◽  
The North ◽  
Northwestern Margin

Abstract An 82.8 km segment of a northwest-southeast trending seismic-reflection profile across the northernmost part of the Reelfoot rift shows that the Cambrian rift geometry there is quite distinct from that of the main part of Reelfoot rift to the south, and that of the Rough Creek graben to the east. The profile is within the area of intersection of the Reelfoot rift and Rough Creek graben and shows a systematic southeastward thickening of the Cambrian synrift clastic sequence with as much as 1940 meters of section present against the Pennyrile fault system as compared to 970 meters near the Lusk Creek and Shawneetown fault systems, towards the northwestern margin of the rift. This contrasts with the more symmetric rift pattern in the seismically active zone to the south, where the maximum thickness of synrift sediments is along the rift axis, and with an opposite sense of rift asymmetry in the Rough Creek graben, where the synrift sequence thickens to the north against the Rough Creek - Shawneetown fault. Reflection patterns in the vicinity of Hicks dome, a “cryptovolcano”, are consistent with the hypothesis that the dome originated by explosive release of mantle-derived gases associated with alkali volcanism. The seismic data also reveal that the fluorine mineralization in the area is associated with faults that offset basement; this is further evidence that deeply-derived fluids are significant in the geologic evolution of the area.

SEISMIC DATA PROBLEMS ON COASTAL LIMESTONE, W.A.

1969 ◽  
Vol 9 (1) ◽  
pp. 136
Author(s):  
D. D. Taylor
Keyword(s):  
Seismic Data ◽  
The South ◽  
Reflection Seismic ◽  
The North ◽  
Great Portion

The surface Coastal Limestone in the Perth basin extends from Cape Leeuwin in the South to Geraldton in the north forming a strip along the coast up to 15 miles wide. Over a great portion of this area the reflection seismic results are unreliable. Seismic studies on the limestone disclose some aspects of the problem and indicate ways to improve the quality of the data.

The discovery of a new sedimentary basin: offshore Raukumara, East Coast, North Island, New Zealand

2008 ◽  
Vol 48 (1) ◽  
pp. 53 ◽  
Author(s):  
Chris Uruski ◽  
Callum Kennedy ◽  
Rupert Sutherland ◽  
Vaughan Stagpoole ◽  
Stuart Henrys
Keyword(s):  
New Zealand ◽  
Oil And Gas ◽  
East Coast ◽  
Plate Boundary ◽  
Source Rocks ◽  
Fault System ◽  
Northern Coast ◽  
The South ◽  
Petroleum Potential ◽  
The North

The East Coast of North Island, New Zealand, is the site of subduction of the Pacific below the Australian plate, and, consequently, much of the basin is highly deformed. An exception is the Raukumara Sub-basin, which forms the northern end of the East Coast Basin and is relatively undeformed. It occupies a marine plain that extends to the north-northeast from the northern coast of the Raukumara Peninsula, reaching water depths of about 3,000 m, although much of the sub-basin lies within the 2,000 m isobath. The sub-basin is about 100 km across and has a roughly triangular plan, bounded by an east-west fault system in the south. It extends about 300 km to the northeast and is bounded to the east by the East Cape subduction ridge and to the west by the volcanic Kermadec Ridge. The northern seismic lines reveal a thickness of around 8 km increasing to 12–13 km in the south. Its stratigraphy consists of a fairly uniformly bedded basal section and an upper, more variable unit separated by a wedge of chaotically bedded material. In the absence of direct evidence from wells and samples, analogies are drawn with onshore geology, where older marine Cretaceous and Paleogene units are separated from a Neogene succession by an allochthonous series of thrust slices emplaced around the time of initiation of the modern plate boundary. The Raukumara Sub-basin is not easily classified. Its location is apparently that of a fore-arc basin along an ocean-to-ocean collision zone, although its sedimentary fill must have been derived chiefly from erosion of the New Zealand land mass. Its relative lack of deformation introduces questions about basin formation and petroleum potential. Although no commercial discoveries have been made in the East Coast Basin, known source rocks are of marine origin and are commonly oil prone, so there is good potential for oil as well as gas in the basin. New seismic data confirm the extent of the sub-basin and its considerable sedimentary thickness. The presence of potential trapping structures and direct hydrocarbon indicators suggest that the Raukumara Sub-basin may contain large volumes of oil and gas.

Multiscale seismic imaging of active fault zones for hazard assessment: A case study of the Santa Monica fault zone, Los Angeles, California

Geophysics ◽  
1998 ◽  
Vol 63 (2) ◽  
pp. 479-489 ◽  
Author(s):  
Thomas L. Pratt ◽  
James F. Dolan ◽  
Jackson K. Odum ◽  
William J. Stephenson ◽  
Robert A. Williams ◽  
...  
Keyword(s):  
High Resolution ◽  
Los Angeles ◽  
Hazard Assessment ◽  
Seismic Reflection ◽  
Seismic Profile ◽  
Strike Slip ◽  
Alluvial Fan ◽  
Depth Range ◽  
Seismic Reflection Profile ◽  
Santa Monica

High‐resolution seismic reflection profiles at two different scales were acquired across the transpressional Santa Monica Fault of north Los Angeles as part of an integrated hazard assessment of the fault. The seismic data confirm the location of the fault and related shallow faulting seen in a trench to deeper structures known from regional studies. The trench shows a series of near‐vertical strike‐slip faults beneath a topographic scarp inferred to be caused by thrusting on the Santa Monica fault. Analysis of the disruption of soil horizons in the trench indicates multiple earthquakes have occurred on these strike‐slip faults within the past 50 000 years, with the latest being 1000 to 3000 years ago. A 3.8-km-long, high‐resolution seismic reflection profile shows reflector truncations that constrain the shallow portion of the Santa Monica Fault (upper 300 m) to dip northward between 30° and 55°, most likely 30° to 35°, in contrast to the 60° to 70° dip interpreted for the deeper portion of the fault. Prominent, nearly continuous reflectors on the profile are interpreted to be the erosional unconformity between the 1.2 Ma and older Pico Formation and the base of alluvial fan deposits. The unconformity lies at depths of 30–60 m north of the fault and 110–130 m south of the fault, with about 100 m of vertical displacement (180 m of dip‐slip motion on a 30°–35° dipping fault) across the fault since deposition of the upper Pico Formation. The continuity of the uncomformity on the seismic profile constrains the fault to lie in a relatively narrow (50 m) zone, and to project to the surface beneath Ohio Avenue immediately south of the trench. A very high‐resolution seismic profile adjacent to the trench images reflectors in the 15 to 60 m depth range that are arched slightly by folding just north of the fault. A disrupted zone on the profile beneath the south end of the trench is interpreted as being caused by the deeper portions of the trenched strike‐slip faults where they merge with the thrust fault.

3-D structure below Ävrö Island from high‐resolution reflection seismic studies, southeastern Sweden

Geophysics ◽  
1999 ◽  
Vol 64 (3) ◽  
pp. 662-667 ◽  
Author(s):  
Christopher Juhlin ◽  
Hans Palm
Keyword(s):  
Seismic Reflection ◽  
Fracture Zones ◽  
The South ◽  
North West ◽  
Reflection Seismic ◽  
Site Investigations ◽  
Seismic Reflection Method ◽  
Shot Point ◽  
Crystalline Crust ◽  
A Charge

Two 1-km-long perpendicular seismic reflection lines were acquired on Ävrö Island, southeast Sweden, in October 1996 in order to (1) test the seismic reflection method for future site investigations, (2) map known fracture zones, and (3) add to the Swedish database of reflection seismic studies of the shallow crystalline crust. An east‐west line was shot with 5-m geophone and shot point spacing, and a north‐south line was shot with 10-m geophone and shotpoint spacing. An explosive source with a charge size of 100 g was used along both lines. The data clearly image three major dipping reflectors and one subhorizontal one in the upper 200 ms (600 m). The dipping reflectors (to the south, east, and north‐west) intersect or project to the surface at or close to where surface‐mapped fracture zones exist. The south‐dipping reflector correlates with the top of a heavily fractured interval observed in a borehole (KAV01) at about 400 m. The subhorizontal zone at about 100–200 m correlates with a known fracture zone in the same borehole (KAV01). 3-D effects are apparent in the data, and only where the profiles cross can the true orientation of the reflecting events be determined. To properly orient and locate all events observed on the lines requires acquisition of 3-D data.

scholarly journals Reflection seismic studies over the end-glacial Burträsk fault, Skellefteå, Sweden

2010 ◽  
Vol 2 (2) ◽  
pp. 307-329 ◽  
Author(s):  
C. Juhlin ◽  
B. Lund
Keyword(s):  
Fracture Zone ◽  
Seismic Data ◽  
Mafic Rock ◽  
Seismic Profile ◽  
Large Displacements ◽  
Fault Geometry ◽  
Seismic Section ◽  
Glacial Ice ◽  
Crustal Rocks ◽  
Reflection Seismic

Abstract. Reflection seismic data were acquired along a ca. 22 km long profile over the end-glacial Burträsk Fault with a nominal receiver and source spacing of 20 m. A steeply dipping reflection can be correlated to the Burträsk Fault, indicating that the fault dips at about 55° to the southeast near the surface. The reflection from the fault is rather poorly imaged, probably due to a jump in the fault and the crookedness of the seismic profile in the vicinity of the fault. A more pronounced steeply dipping reflection is observed about 4 km southeast of the Burträsk Fault. Based on its correlation with a topographic low at the surface this reflection is interpreted to originate from a fracture zone. There are no signs of large displacements along this fault as the glacial ice receded, but it may be active today. Other reflections on the processed seismic section may originate from changes in lithological variations in the supra-crustal rocks or from intrusions of more mafic rock. Constraints on the fault geometry provided by the reflection seismic data will help determine what stresses were required to activate the fault when the major rupture along it occurred.

scholarly journals Deep Structure of the North Natal Valley (Mozambique) Using Combined Wide‐Angle and Reflection Seismic Data

2021 ◽  
Vol 126 (4) ◽  
Author(s):  
A. Leprêtre ◽  
P. Schnürle ◽  
M. Evain ◽  
F. Verrier ◽  
D. Moorcroft ◽  
...  
Keyword(s):  
Seismic Data ◽  
Deep Structure ◽  
Wide Angle ◽  
Reflection Seismic ◽  
The North

scholarly journals Depositional History of Paleocene Sediments in the Offshore Canterbury Basin, New Zealand

2021 ◽  
Author(s):  
◽  
Sanjay Paul Samuel
Keyword(s):  
Seismic Data ◽  
The South ◽  
Depositional History ◽  
Reservoir Rocks ◽  
The North ◽  
Late Paleocene ◽  
Shelf Slope ◽  
History Of ◽  
Well Correlation ◽  
First Time

<p>The Paleocene interval within the Canterbury Basin has been relatively understudied with respect to the Neogene and Cretaceous intervals. Within the Paleocene interval is the Tartan Formation and the Charteris Bay Sandstone, which are potential source and reservoir rocks respectively. These two formations have not been previously mapped in the offshore Canterbury Basin and their limits have not been defined. This study utilises a database of nearly 12,000km of 2D seismic data together with data from four open–file wells and sidewall core samples from three wells and newly availiable biostratigraphic information to better constrain the chronostratigraphical interpretation of seismic data. Seismic mapping together with corroboration from well correlation and core lithofacies analysis revealed new insights into the development of the offshore Canterbury Basin through the Paleocene. These include the delineation of the lateral extents and thicknesses of the Tartan Formation and Charteris Bay Sandstone and location of the palaeo shelf–slope break and also the development of a new well correlation panel that incorporates the Tartan Formation for the first time.  This study presents four new paleogeographic maps for the offshore Canterbury Basin that significantly improves our understanding of the development of the basin during the Paleocene. These maps show that during the Earliest Paleocene, the mudstones of the Katiki Formation were being deposited in the south of the study area, with the siltier sediments of the Conway Formation being deposited in the north. The coarser grained Charteris Bay Sandstone was deposited from Early to possibly Middle Paleocene in the northeast. The mudstones of the Moeraki Formation were being deposited in the south at this time. From Middle to Late Paleocene, the mudstones of the Moeraki Formation were deposited in the south and these mudstones onlapped against the Charteris Bay Sandstone which remained as a high in the north. The Tartan Formation was deposited during the Late Paleocene in the central and southern areas of the offshore Canterbury Basin, during a relative fall in sea–level. Deposition had ceased in the north of the study area or erosion possibly removed Late Paleocene sediments from there. During the Latest Paleocene, the mudstones of the Moeraki Formation were deposited over the Tartan Formation in the central and southern parts of the offshore Canterbury Basin with the northern area undergoing erosion, sediment bypass or both.</p>

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