Seismic Structure and Tectonic Evolution of Borneo and Sulawesi

2021 ◽  
Author(s):  
Harry Telajan Linang ◽  
Amy Gilligan ◽  
Jennifer Jenkins ◽  
Tim Greenfield ◽  
Felix Tongkul ◽  
...  
Keyword(s):  
Subduction Zones ◽  
Receiver Function ◽  
Leading Edge ◽  
Sedimentary Basins ◽  
Crustal Thickness ◽  
The Philippines ◽  
Seismic Structure ◽  
Eurasian Plate ◽  
Seismic Stations ◽  
Preliminary Results

<div> <div> <div> <p>Borneo is located at the centre of Southeast Asia, which is one of the most active tectonic regions on Earth due to the subduction of the Indo-Australian plate in the south and the Philippines Sea plate in the east. Borneo resides on the leading edge of the Sundaland block of the Eurasian plate and exhibits lower rates of seismicity when compared to the surrounding regions due to its intraplate setting. Sulawesi, an island which lies just southeast of Borneo, is characterised by intense seismicity due to multiple subduction zones in its vicinity. The tectonic relationship between the two islands is poorly understood, including the provenance of their respective lithospheres, which may have Eurasian and/or East Gondwana origin.</p> <p>Here, we present recent receiver function (RF) results from temporary and permanent broadband seismic stations in the region, which can be used to help improve our understanding of the crust and mantle lithosphere beneath Borneo and Sulawesi. We applied H-K stacking, receiver function migration and inversion to obtain reliable estimates of the crustal thickness beneath the seismic stations. Our preliminary results indicate that the crust beneath Sabah (in northern Borneo), which is a post-subduction setting, appears to be much more complex and is overall thicker (more than 35 km) than the rest of the island. In addition, we find that crustal thickness varies between different tectonic blocks defined from previous surface mapping, with the thinnest crust (23 to 25 km) occurring beneath Sarawak in the west-northwest as well as in the east of Kalimantan.</p> <p>We also present preliminary results from Virtual Deep Seismic Sounding (VDSS) in northern Borneo, where from the RF results we know that there is thick and complex crust. VDSS is able to produce well constrained crustal thickness results in regions where the RF analysis has difficulty recovering the Moho, likely due to complexities such as thick sedimentary basins and obducted ophiolite sequences.</p> </div> </div> </div>

Seismic Structure and Tectonic Evolution of Borneo and Sulawesi

2020 ◽  
Author(s):  
Harry Telajan Linang ◽  
Amy Gilligan ◽  
Jennifer Jenkins ◽  
Tim Greenfield ◽  
Nick Rawlinson
Keyword(s):  
Subduction Zones ◽  
Receiver Function ◽  
Leading Edge ◽  
Crustal Thickness ◽  
The Philippines ◽  
Seismic Structure ◽  
Eurasian Plate ◽  
Surface Mapping ◽  
Indonesian Archipelago ◽  
Subduction Setting

<p>Southeast Asia (SEA) is one of the most active tectonic regions on the planet due to its convergent setting, which accommodates rapid northward motion of the Indo-Australian plate and westward motion of the Philippines Sea plate. This activity gives rise to intense seismicity along the convergent plate margins in and around SEA, including the Sunda Arc, which wraps its way around the southern margin of the Indonesian archipelago.</p><p>Borneo is located at the centre of SEA, on the leading edge of the Sundaland block of the Eurasian plate, and exhibits lower rates of seismicity when compared to the surrounding regions due to its intraplate setting. Sulawesi, an island which lies adjacent to Borneo in the east, is characterised by intense seismicity due to multiple subduction zones in its vicinity. The tectonic relationship between the two islands is poorly understood, as is the provenance of their lithosphere, which may have Eurasian or East Gondwana origin.</p><p>The aim of this presentation is to showcase recent receiver function results from temporary and permanent broadband seismic stations in the region, which can be used to help improve our understanding of the structure of the crust and the mantle lithosphere beneath Borneo and Sulawesi. H-K stacking, receiver function migration and inversion are all applied in an effort to determine robust crustal thickness estimates and variations in shear wavespeed with depth. Our preliminary results from Borneo indicate that the crust beneath Sabah (northern Borneo), which is a post-subduction setting, appears to be much more complex than the rest of the island. Furthermore, we find that crustal thickness varies between different tectonic blocks defined from surface mapping, with the thinnest crust (24 km thick) occurring beneath Sarawak in the northwest.</p>

Crustal seismic structure beneath the Garhwal Himalaya using regional and teleseismic waveform modelling

2020 ◽  
Vol 222 (3) ◽  
pp. 2040-2052
Author(s):  
Nagaraju Kanna ◽  
Sandeep Gupta
Keyword(s):  
Receiver Function ◽  
Garhwal Himalaya ◽  
Moho Depth ◽  
Seismic Structure ◽  
Uppermost Mantle ◽  
Seismic Stations ◽  
Wave Velocities ◽  
Function Modelling ◽  
Partial Melts ◽  
Lower Crustal

SUMMARY We investigate the crustal seismic structure of the Garhwal Himalayan region using regional and teleseismic earthquake waveforms, recorded over 19 closely spaced broad-band seismic stations along a linear profile that traverses from the Sub Himalayas to Higher Himalayas. The regional earthquake traveltime analysis provides uppermost mantle P- and S-wave velocities as 8.2 and 4.5 km s−1, respectively. The calculated receiver functions from the teleseismic P waveforms show apparent P-to-S conversions from the Moho as well as from intracrustal depths, at most of the seismic stations. These conversions also show significant azimuthal variations across the Himalayas, indicating complex crustal structure across the Garhwal Himalaya. We constrain the receiver function modelling using the calculated uppermost mantle (Pn and Sn) velocities. Common conversion point stacking image of P-to-S conversions as well as receiver function modelling results show a prominent intracrustal low shear velocity layer with a flat–ramp–flat geometry beneath the Main Central Thrust zone. This low velocity indicates the possible presence of partial melts/fluids in the intracrustal depths beneath the Garhwal Himalaya. We correlate the inferred intracrustal partial melts/fluids with the local seismicity and suggest that the intracrustal fluids are one of the possible reasons for the occurrence of upper-to-mid-crustal earthquakes in this area. The results further show that the Moho depth varies from ∼45 km beneath the Sub Himalayas to ∼58 km to the south of the Tethys Himalayas. The calculated lower crustal shear wave velocities of ∼3.9 and 4.3 km s−1 beneath the Lesser and Higher Himalayas suggest the presence of granulite and partially eclogite rocks in the lower crust below the Lesser and Higher Himalayas, respectively. We also suggest that the inferred lower crustal rocks are the possible reasons for the presence and absence of the lower crustal seismicity beneath the Lesser and Higher Himalayas, respectively.

Shallow seismic structure beneath the continental China revealed by P-wave polarization, Rayleigh wave ellipticity and receiver function

2021 ◽  
Vol 225 (2) ◽  
pp. 998-1019
Author(s):  
Xiao Xiao ◽  
Shihua Cheng ◽  
Jianping Wu ◽  
Weilai Wang ◽  
Li Sun ◽  
...  
Keyword(s):  
Rayleigh Wave ◽  
Reference Model ◽  
Receiver Function ◽  
Joint Inversion ◽  
Sedimentary Basins ◽  
P Wave ◽  
Seismic Structure ◽  
Seismic Model ◽  
Velocity Anomalies ◽  
Orogenic Belts

SUMMARY We construct a high-resolution shallow 3-D seismic model in the top 10 km of the upper crust in the continental China, with constraints of P polarization, Rayleigh wave ellipticity and receiver function obtained from records of 3848 seismic stations. Our 3-D seismic model has a spatial resolution of 0.6–1.2° in the north–south seismic belt and the trans-north China orogen, and 1–2° in the rest of the continental China (except the Tarim basin and the southwest Tibet). The seismic model exhibits low velocity anomalies of deposits in major sedimentary basins and high velocity anomalies of crustal bedrocks in young orogenic belts and old tectonic blocks. The inferred sediment thickness maps display thick deposits in major sedimentary basins, some compacted sediments in the intermontane basins in young orogenic belts and little sediments in old tectonic blocks. We also discuss compaction effects of the sediments and implications of tectonic history and geological evolution of the major basins in the continental China based on the inferred seismic models. This study provides an effective mean of seismic imaging through joint inversion of various seismic constraints and establishes a framework of seismic data sharing for future studies in the seismological community in a first step of developing a China Seismological Reference Model.

Crustal thickness and adakite occurrence in the Philippines: Is there a relationship?

Island Arc ◽  
2008 ◽  
Vol 17 (4) ◽  
pp. 421-431 ◽  
Author(s):  
Carla B. Dimalanta ◽  
Graciano P. Yumul, Jr
Keyword(s):  
Crustal Thickness ◽  
The Philippines

Deep seismic reflection profiling of sedimentary basins offshore Brazil: Geological objectives and preliminary results in the Sergipe Basin

1995 ◽  
Vol 20 (4) ◽  
pp. 515-539 ◽  
Author(s):  
Webster Ueipass Mohriak ◽  
JoséHenrique Lira Rabelo ◽  
Renato Darros De Matos ◽  
Mozart C. De Barros
Keyword(s):  
Seismic Reflection ◽  
Sedimentary Basins ◽  
Deep Seismic Reflection ◽  
Preliminary Results ◽  
Seismic Reflection Profiling

Striking differences in lithospheric structure between the north- and south-western Alps: insights from receiver functions along the Cifalps profiles and a new Vs model

2021 ◽  
Author(s):  
Anne Paul ◽  
Ahmed Nouibat ◽  
Liang Zhao ◽  
Stefano Solarino ◽  
Stéphane Schwartz ◽  
...  
Keyword(s):  
Receiver Function ◽  
Negative Polarity ◽  
Western Alps ◽  
Lithospheric Structure ◽  
Seismic Stations ◽  
Continental Subduction ◽  
The North ◽  
Ligurian Alps ◽  
The Alps ◽  
Converted Waves

<p>The CIFALPS receiver-function (RF) profile in the southwestern Alps provided the first seismological evidence of continental subduction in the Alps, with the detection of waves converted on the European Moho at 75-80 km depth beneath the western edge of the Po basin (Zhao et al., 2015). To complement the CIFALPS profile and enhance our knowledge of the lithospheric structure of the Western Alps, we installed CIFALPS2, a temporary network of 55 broadband seismic stations that operated for ~14 months (2018-2019) across the North-Western Alps (Zhao et al., 2018). The CIFALPS2 line runs from the Eastern Massif Central to the Ligurian coast, across the Mont-Blanc and Gran Paradiso massifs and the Ligurian Alps. Seismic stations were installed along a quasi-linear profile with a spacing of 7-10 km.</p><p>We will show 2 receiver-function CCP (common-conversion point) depth-migrated sections along the CIFALPS2 profile, the first one across the Alps, and the second one across the Ligurian Alps and the Po basin. The time-to-depth migration of RF data is based on the new 3-D Vs model of the Greater Alpine region derived by Nouibat et al. (2021) using transdimensional ambient noise tomography on a large dataset including the AlpArray seismic network. Depth sections across the Vs model are also useful for interpreting the RF CCP sections as they have striking similarities.</p><p>The images of the lithospheric structure of the NW Alps along CIFALPS2 are surprisingly different from those of the SW Alps along CIFALPS. The deepest P-to-S converted phases on the European Moho are detected at 60-65 km depth beneath the Ivrea-Verbano zone, that is 15 km less than on CIFALPS. The negative polarity converted phase interpreted as the base of the Ivrea body mantle flake on the CIFALPS section is still visible on CIFALPS2, but with a lower amplitude. The RF section confirms the existence of a jump of the European Moho of ~10 km amplitude in less than 10 km distance, which is located within a few km from the western boundary of the Mont Blanc external crystalline massif. All these observations are confirmed by the Vs model that also displays a less deep continental subduction than on CIFALPS, weaker S-wave velocities in the Ivrea body wedge, and the jump of the European Moho.</p><p>The Moho beneath the Ligurian Alps is detected at 25-30 km depth both on the RF and on the Vs depth sections. Moving northwards, this Ligurian Moho is separated from the Adriatic Moho by a puzzling S-dipping set of P-to-S converted waves with negative polarity. The crust of the Ligurian Alps is characterized by a set of north-dipping negative-polarity converted waves at 10 to 20 km depth beneath the Valosio massif, which is a small internal crystalline massif of (U)HP metamorphic rocks located north of Voltri. The similarity of this set of negative-polarity conversions to the one observed beneath the Dora Maira massif on the CIFALPS profile suggests that it may be a relic of the Alpine structure overprinted by the opening of the Ligurian sea.</p>

scholarly journals Melt equilibration depths as sensors of lithospheric thickness during Eurasia-Arabia collision and the uplift of the Anatolian Plateau

Geology ◽  
2019 ◽  
Vol 47 (10) ◽  
pp. 943-947 ◽  
Author(s):  
M.R. Reid ◽  
J.R. Delph ◽  
M.A. Cosca ◽  
W.K. Schleiffarth ◽  
G. Gençalioğlu Kuşcu
Keyword(s):  
Late Miocene ◽  
Large Scale ◽  
Middle Miocene ◽  
Volcanic Rocks ◽  
Suture Zone ◽  
Arabian Plate ◽  
Seismic Structure ◽  
Eurasian Plate ◽  
Lithospheric Thickness ◽  
Anatolian Plateau

Abstract A co-investigation of mantle melting conditions and seismic structure revealed an evolutionary record of mantle dynamics accompanying the transition from subduction to collision along the Africa-Eurasia margin and the >1 km uplift of the Anatolian Plateau. New 40Ar/39Ar dates of volcanic rocks from the Eastern Taurides (southeast Turkey) considerably expand the known spatial extent of Miocene-aged mafic volcanism following a magmatic lull over much of Anatolia that ended at ca. 20 Ma. Mantle equilibration depths for these chemically diverse basalts are interpreted to indicate that early to middle Miocene lithospheric thickness in the region varied from ∼50 km or less near the Bitlis suture zone to ∼80 km near the Inner Tauride suture zone. This southward-tapering lithospheric base could be a vestige of the former interface between the subducted (and now detached) portion of the Arabian plate and the overriding Eurasian plate, and/or a reflection of mantle weakening associated with greater mantle hydration trenchward prior to collision. Asthenospheric upwelling driven by slab tearing and foundering along this former interface, possibly accompanied by convective removal of the lithosphere, could have led to renewed volcanic activity after 20 Ma. Melt equilibration depths for late Miocene and Pliocene basalts together with seismic imaging of the present lithosphere indicate that relatively invariant lithospheric thicknesses of 60–70 km have persisted since the middle Miocene. Thus, no evidence is found for large-scale (tens of kilometers) Miocene delamination of the lower lithosphere from the overriding plate, which has been proposed elsewhere to account for late Miocene and younger uplift of Anatolia.

scholarly journals Structure of the Sediment and Crust in the Northeast North China Craton from Improved Sequential H-k Stacking Method

2019 ◽  
Vol 11 (1) ◽  
pp. 682-696
Author(s):  
Yi Zhang ◽  
Jinli Huang
Keyword(s):  
North China Craton ◽  
North China ◽  
Poisson Ratio ◽  
Receiver Function ◽  
Theoretical Calculations ◽  
Sedimentary Basins ◽  
Improved Method ◽  
Low Velocity ◽  
The North ◽  
Receiver Function Method

Abstract H-k stacking method is a standard receiver-function method to detect crustal thickness. But this method can not be applied in low-velocity sedimentary basins. To solve this problem, we propose an improved sequential H-k stacking method. The improved method needs two sequential stacks. Firstly, sediment structure is calculated using converted waves and multiples on the bottom boundary of sediments. Secondly, the sedimentary results are applied to calculate the crustal structure. Theoretical calculations and “recovery tests” indicate that the improved method can obtain accurate estimates in sedimentary basins. With the teleseismic data of North China Craton, the structure of sediments is thick in the depression and thin in the uplifted area, which is consistent with Deep Seismic Sounding results. The crust to the west of the North-South Gravity Lineament is relatively thick and has a low average Poisson ratio, whereas the east is relatively thin and has a high average Poisson ratio. This result and the structural feature from data regression imply that the eastern crust of the North China Craton has experienced wide extension, which reflect the crustal response to the severe destruction and deformation in that area compared to the western crust.

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