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1.
It is a common opinion that only crustal earthquakes can occur in the Crimea–Black Sea region. Since the existence of deep earthquakes in the Crimea–Black Sea region is extremely important for the construction of a geodynamic model for this region, an attempt is made to verify the validity of this widespread view. To do this, the coordinates of all earthquakes recorded by the stations of the Crimean seismological network are reinterpreted with an algorithm developed by one of the authors. The data published in the seismological catalogs and bulletins of the Crimea–Black Sea region for 1970–2012 are used for the analysis. To refine the coordinates of hypocenters of earthquakes in the Crimea–Black Sea region, in addition to the data from stations of the Crimean seismological network, information from seismic stations located around the Black Sea coast are used. In total, the data from 61 seismic stations were used to determine the hypocenter coordinates. The used earthquake catalogs for 1970–2012 contain information on ~2140 events with magnitudes from–1.5 to 5.5. The bulletins provide information on the arrival times of P- and S-waves at seismic stations for 1988 events recorded by three or more stations. The principal innovation of this study is the use of the original author’s hypocenter determination algorithm, which minimizes the functional of distances between the points (X, Y, H) and (x, y, h) corresponding to the theoretical and observed seismic wave travel times from the earthquake source to the recording stations. The determination of the coordinates of earthquake hypocenters is much more stable in this case than the usual minimization of the residual functional for the arrival time of an earthquake wave at a station (the difference between the theoretical and observed values). Since determination of the hypocenter coordinates can be influenced by the chosen velocity column beneath each station, special attention is focused on collecting information on velocity profiles. To evaluate the influence of the upper mantle on the results of calculating the velocity model, two different low-velocity and high-velocity models are used; the results are compared with each other. Both velocity models are set to a depth of 640 km, which is fundamentally important in determining hypocenters for deep earthquakes. Studies of the Crimea–Black Sea region have revealed more than 70 earthquakes with a source depth of more than 60 km. The adequacy of the obtained depth values is confirmed by the results of comparing the initial experimental data from the bulletins with the theoretical travel-time curves for earthquake sources with depths of 50 and 200 km. The sources of deep earthquakes found in the Crimea–Black Sea region significantly change our understanding of the structure and geotectonics of this region. 相似文献
2.
2008年5月12日四川龙门山断裂带发生了汶川8.0级地震,之后四川境内发生了两次7.0级地震(其中一个是芦山地震),为了研究汶川地震之后龙门山断裂带及周边区域的地震活动性,本研究收集了国家地震台网和四川区域地震台网2010年1月1日—2017年12月31日四川地区发生的17次M≥5.0地震以及120多次5.0>M≥4.0地震的波形资料,利用波形拟合法反演了震源机制解及区域应力场.反演结果显示,位于龙门山断裂带上的地震,震源机制以逆冲型为主,鲜水河断裂带地震震源机制以走滑型为主,而川滇块体西南部的理塘断裂、金沙江断裂附近,震源机制解以正断层为主.根据震源机制解反演得到的龙门山地区、鲜水河地区的主压应力场方向为WNW、近EW向.川滇块体的巴塘、理塘等地区,其主压应力轴方向为12°左右,接近SN向,且仰角接近40°左右.本研究利用面波振幅谱特征对震源深度进行了精确定位,定位结果与中国地震台网中心(CENC),美国地震调查局(USGS),国际地震中心(ISC)等机构地震目录进行了对比.结果显示,四川地区强震震源深度主要分布在20km以上的中上地壳.龙门山地区震源优势分布在10～20km,鲜水河断裂地震震源深度在10km左右,川滇块体西南部的理塘断裂,巴塘断裂,金沙江断裂等地区,震源深度一般在5～10km范围. 相似文献
3.
The problem of determining focal depths of earthquakes in the Crimea–Black Sea region is considered. Based on the results of interannual studies, it is found that the focal depths of Crimean earthquakes are mainly crustal, with maximum values of up to 60 km. Some recent publications, however, have described deep-focus earthquakes with depths of up to 300 km which were “revealed” in the Crimean region. In this respect, there arose the need to study such a large difference in estimated focal depths. Convincing examples show that the sensational “revelation” of deep earthquakes in Crimea was caused by incorrect processing of the experimental data, in particular, due to (1) a sharp distortion in the recorded arrival times of body waves, (2) exclusion of data from stations nearest to a source, (3) unreasonable arbitrary selection of data from seismic stations, and (4) dropping of data from the worldwide seismological network, including those on deep seismic phases. Thus, the conclusions about the presence of deep mantle earthquakes in Crimea are erroneous. We have redetermined the parameters of hypocenters and verified that the focal depths of earthquakes in the Crimea–Black Sea region are no more than 60 km. Based on these data, we analyze the features of the spatial distribution of focal depths to show that earthquake sources are grouped along conduits that dip southeastward, from the continental part of Crimea toward the Black Sea Basin, in the case of grouping of sources in the Alushta–Yalta and Sevastopol areas. The seismic focal layer of the Kerch–Anapa area dips northeastward, from the Black Sea beneath the North Caucasus. 相似文献
4.
Subduction zone seismicity and the thermo-mechanical evolution of downgoing lithosphere 总被引：1，自引：0，他引：1
In this paper we discuss characteristic features of subduction zone seismicity at depths between about 100 km and 700 km, with emphasis on the role of temperature and rheology in controlling the deformation of, and the seismic energy release in downgoing lithosphere. This is done in two steps. After a brief review of earlier developments, we first show that the depth distribution of hypocentres at depths between 100 km and 700 km in subducted lithosphere can be explained by a model in which seismic activity is confined to those parts of the slab which have temperatures below a depth-dependent critical valueT
cr.Second, the variation of seismic energy release (frequency of events, magnitude) with depth is addressed by inferring a rheological evolution from the slab's thermal evolution and by combining this with models for the system of forces acting on the subducting lithosphere. It is found that considerable stress concentration occurs in a reheating slab in the depth range of 400 to 650–700 km: the slab weakens, but the stress level strongly increases. On the basis of this stress concentration a model is formulated for earthquake generation within subducting slabs. The model predicts a maximum depth of seismic activity in the depth range of 635 to 760 km and, for deep earthquake zones, a relative maximum in seismic energy release near the maximum depth of earthquakes. From our modelling it follows that, whereas such a maximum is indeed likely to develop in deep earthquake zones, zones with a maximum depth around 300 km (such as the Aleutians) are expected to exhibit a smooth decay in seismic energy release with depth. This is in excellent agreement with observational data. In conclusion, the incoroporation of both depth-dependent forces and depth-dependent rheology provides new insight into the generation of intermediate and deep earthquakes and into the variation of seismic activity with depth.Our results imply that no barrier to slab penetration at a depth of 650–700 km is required to explain the maximum depth of seismic activity and the pattern of seismic energy release in deep earthquake zones. 相似文献
5.
2006年底,我们沿“张渤地震带”布设了一条从唐海—北京—商都的宽频带地震台阵剖面.本文利用台阵记录的远震波形资料,通过接收函数和面波联合反演对剖面下方100 km深度范围内地壳上地幔S波速度结构进行了研究.结果表明剖面东段莫霍面深度约30～34 km,西段深度约38～42 km,平原与山区的过渡地带地壳厚度变化较快.地壳内部10～20 km深度范围内存在多个低速体.在唐山7.8级地震震区附近Moho面出现小幅度隆起,中地壳存在明显的S波低速体.张家口以西,剖面下方10～20 km范围内存在两个S波低速体,张北6.2级地震发生在这两个低速体之间狭小的高速区. 在观测剖面附近,历史上发生的4个大震都与壳内低速体的分布有关. 张家口以东,上地幔普遍存在低速层,顶部埋深在60~80 km之间,并表现出明显的东部浅西部深的特点. 相似文献
6.
利用西藏自治区林芝地区的固定地震台站与南迦巴瓦流动测震台站在2017年11月18日至2017年11月24日记录到的430个余震的直达波走时数据反演得到了震源区的三维P波速度、S波速度结构,并利用三维速度结构对余震进行了重定位.成像结果显示,米林地震震源区在0~5km深度内存在低地震波速度异常;在5~15km深度内,存在高地震波速度异常,该高速异常致使震源区西南侧的地震波速度高于东北侧.重定位结果中,余震呈条带状以NW-SE走向展布,震源深度具有西南方向深、东北方向浅的特征.主震位于11km深度处、高地震波速异常体顶部,余震主要分布在高地震波速度与低地震波速度过渡的区域.对成像结果的分析表明,震源区浅部的低速异常具有低泊松比的特性,与富石英的沉积变质杂岩体-东久杂岩单元的岩性特征有关;深部的速度结构特征则可能反映了发震断层上盘地震波速度高,下盘地震波速度低的介质特性.余震重定位结果与成像结果联合表明:此次地震发震断层从11km深度处,东久杂岩体下方的高地震波速度异常顶部开始破裂,继而在5~15km深度内发生后续破裂,后续破裂的发生区域正处于喜马拉雅构造单元与冈底斯构造单元接触的形变区内.此外,根据地震波速度计算的泊松比反映了震源区持续的低泊松比特征,暗示此次地震与流体活动并无直接关系. 相似文献
7.
Siberian traps are the result of huge basalt eruptions which took place about 250 Ma ago over a vast territory of Siberia. The genesis of Siberian traps is attributed to a mantle plume with a center in the region of Iceland or beneath the central Urals in terms of their present coordinates. The eruption mechanism is associated with delamination—replacement of the mantle lithosphere by the deep magma material. The receiver function analysis of the records from the Norilsk seismic station (NRIL) allows comparing these hypotheses with the factual data on the depth structure of the region of Siberian traps. The S-wave velocity section place the seismic lithosphere/asthenosphere boundary (LAB) at a depth of 155–190 km, commensurate with the data for the other cratons. The mantle lithosphere has a high S-wave velocity characteristic of cratons (4.6–4.8 km/s instead of the typical value 4.5 km/s). The seismic boundary, which is located at a depth around 410 km beneath the continents is depressed by ~10 km in the region of the NRIL station. The phase diagram of olivine/wadsleyite transformation accounts for this depression by a 50–100°С increase in temperature. At the depths of 350–400 km, the S-wave velocity drops due to partial melting. A new reduction in the S-wave velocities is observed at a depth of 460 km. The similar anomalies (deepening of the 410-km seismic boundary and low shear wave velocity at depths of 350–400 and 460–500 km, respectively) were previously revealed in the other regions of the Meso-Cenozoic volcanism. In the case of a differently directed drift of the Siberian lithosphere and underlying mantle at depths down to 500 km, these anomalies are barely accountable. In particular, if the mantle at a depth ranging from 200 to 500 km is fixed, the anomalies should be observed at the original locations where they emerged 250 Ma ago, i.e. thousands of km from the Siberian traps. Our seismic data suggest that despite the low viscosity of the asthenosphere, the mantle drift at depths ranging from 200 to 500 km is correlated with the drift of the Siberian lithospheric plate. Furthermore, the position of the mantle plume beneath the Urals is easier to reconcile with the seismic data than its position beneath Iceland because of the Siberian traps being less remote from the Urals. 相似文献
8.
Haruhisa Nakamichi Satoru Tanaka Hiroyuki Hamaguchi 《Journal of Volcanology and Geothermal Research》2002,116(3-4)
A genetic algorithm inversion of receiver functions derived from a dense seismic network around Iwate volcano, northeastern Japan, provides the fine S wave velocity structure of the crust and uppermost mantle. Since receiver functions are insensitive to an absolute velocity, travel times of P and S waves propagating vertically from earthquakes in the subducting slab beneath the volcano are involved in the inversion. The distribution of velocity perturbations in relation to the hypocenters of the low-frequency (LF) earthquakes helps our understanding of deep magmatism beneath Iwate volcano. A high-velocity region (dVS/VS=10%) exists around the volcano at depths of 2–15 km, with the bottom depth decreasing to 11 km beneath the volcano’s summit. Just beneath the thinning high-velocity region, a low-velocity region (dVS/VS=−10%) exists at depths of 11–20 km. Intermediate-depth LF (ILF) events are distributed vertically in the high-velocity region down to the top of the low-velocity region. This distribution suggests that a magma reservoir situated in the low-velocity region supplies magma to a narrow conduit that is detectable by the hypocenters of LF earthquakes. Another broad low-velocity region (dVS/VS=−5 to −10%) occurs at depths of 17–35 km. Additional clusters of deep LF (DLF) events exist at depths of 32–37 km in the broad low-velocity zone. The DLF and ILF events are the manifestations of magma movement near the Moho discontinuity and in the conduit just beneath the volcano, respectively. 相似文献
9.
A major seismic swarm occurred near Parícutin volcano between the end of May and early July 2006. More than 700 earthquakes
with magnitude (M
L
) exceeding 2.4 were located. Parícutin, located in the Michoacán–Guanajuato volcanic field in western Mexico, is well known
as the site of the 1943 eruption in which a new 400 m cinder cone was constructed in what had been farmland. The 2006 swarm
exhibits all of the characteristics typically associated with swarms of volcanic origins. The earthquake rate showed the typical
ramp up and ramp down over the course of several days. Magnitudes were evenly distributed in time with a notably high b-value
of 2.45. The earthquake locations cluster around a northeast-striking trend extending approximately 6 km. Over the first two
weeks, hypocenters migrated steadily a few hundred meters per day, rising from 9 to 5 km depth and moving northeast about
5 km. On approximately June 7, the ascent of hypocenters stalled. For the next three weeks, hypocenters held their depth while
migrating laterally back to the southwest. Focal mechanisms during the first part of the swarm reflected the increased stress
caused by dike inflation. Following June 7, the stress orientation changed and became more consistent with the inflation of
horizontal sill-like structures. Though only limited information is available from the seismic swarm preceding the 1943 eruption,
several features, including the swarm duration and magnitude relationships, were comparable to those of the 2006 episode.
The strong indicators of a magmatic origin to the 2006 swarm suggest that at this location there are few, if any, traditional
seismic discriminants that could be used to distinguish which seismic swarms and dike emplacement events might culminate in
eruption. 相似文献
10.
本文使用双差定位法对2014年9月12日至12月30日浙江珊溪水库发生的4184次地震进行重定位,并采用CAP方法对11次ML≥3.0地震事件的震源机制解进行反演,讨论了震群序列的活动特征及其与断裂之间的关系,分析了水库水位与地震之间的关系.重新定位的结果显示,在空间分布上,2014年震群序列发生在2006年震群序列NW向延伸的方向上,两者形成一条线性条带,该条带平行分布于双溪—焦溪垟断裂南侧.重定位得到的震源主要在0.7—6 km深度范围内分层分布,垂直于地震条带走向的震源剖面刻画出的结构面以高角度倾向SW.震源机制解结果显示多数地震为走滑型,均存在一个与地震条带走向一致的NW向节面,呈右旋走滑错动性质.考虑到断裂的定位误差,线性分布的震群活动极有可能沿双溪—焦溪垟断裂的破裂面活动,精定位的震源位置和震源机制刻画出了该断裂的几何结构和活动性质.但由于多数地震的震源深度在6 km以上,因此震群活动不能归为双溪—焦溪垟断裂活动的结果,即双溪—焦溪垟断裂不是这两次震群的发震构造,而且仍然属于水库诱发地震,而水库地震存在激发该断裂发生构造地震的可能.水库水位上升或者下降与震群活动关系不大,震群活动有随时间进一步增强的趋势, 可能是库水沿库底断层破裂面长期渗透和扩散增加了孔隙压所致. 相似文献
11.
为提高北京遥测地震台网的地震参数测定能力,对北京地区（38°-41°N,114°-119°E）建立了一个新的地震波速度模型MDBJ81。这一模型有四个水平层置于均匀半空间之上,第一层分成三块,以反映该地区浅部结构的横向差异及地形起伏效应。在联合测定地震参数和速度结构过程中,其可调整速度模型参数包括:各层中的平均P波速度,各层层顶深度,第一层三块厚度以及平均P波S波速度比。通过分离参数,避免了求解大型方程组。 最后求解中使用了北京台网1979年记录的43个地震,共836个P波及S波震相到时。结果表明,北京周围地区的确存在速度结构的横向差异,第一层底深度自西北向东南逐块增加。得到的新震中位置一般比原台网测定位置更靠近表面断层线。 相似文献
12.
稀疏台网下的传统走时定位难以确定中小地震的震源深度,而地震波深度震相蕴含着震源深度信息,为确定地震震源深度提供了新的途径。近震深度震相sPL和直达Pg波到时差与震源深度呈线性关系,可用以约束地震震源深度。本文以珊溪水库2014年震群事件为例,利用单台sPL震相测定了地震震源深度。结果表明:震源深度的测定结果与基于水库台网高密度台站下Pg和Sg走时定位Hyposat方法和全波形拟合CAP方法测定的震源深度高度一致,为4—6 km,与区域活动断层探测结果相符。sPL震相的优势震中距为30—50 km,区域台网范围内sPL与Pg的到时差与震源深度的线性关系相对固定,因此利用单台sPL震相即可快速获取可靠的地震震源深度,适用于稀疏台网下的中小地震震源深度的确定,且误差可控制在1—2 km范围内。 相似文献
13.
We present the pattern of seismic activity in the period between 2001 and 2007 for the Novy Kostel focal zone, which is recently
the most active zone of the West-Bohemia/Vogtland earthquake swarm region. While the year 2001 was characterized by dying
out of the 2000-swarm activity in the form of a few microswarms, almost no seismicity occurred in the period between 2002
and 2003. Since 2004 an elevated seismic activity occurs in the form of repeating microearthquake swarms. We used a relative
location method to relate the hypocenter positions of the post-swarm activity to the geometry of the 2000-swarm cluster. We
found that the activity has concentrated in several clusters, which have been repeatedly activated. Some clusters coincide
with the position of the previous activity; the others have activated so far inactive deep segments at the southern edge of
the Novy Kostel fault. Besides the shift of the hypocenters to the edges of the previously active area we observe a southward
migration of the activity and an increase of maximum depths of earthquakes from 10 to 13 km. The waveform similarity analysis
disclosed that some fault patches consist of only a single, repeatedly activated fault plane, while the others consist of
multiple, differently oriented fault planes activated almost simultaneously. Most of the focal mechanisms are consistent with
the geometry of hypocenters showing NNW-SSE trending steep fault planes with left-lateral strike-slip mechanisms and varying
dip-slip component. 相似文献
14.
S. A. Kovachev I. P. Kuzin L. I. Lobkovskii 《Izvestiya Physics of the Solid Earth》2009,45(9):777-793
The results of detailed seismological observations with bottom seismographs in the Central Kurile segment in August-September,
2006 are discussed. The system of six bottom seismographs was placed on the island slope of the Kurile deep-sea trench southeast
of Urup Island and southwest of the Bussol Strait. Over 230 earthquakes with M
LH = 0.5–5.5 were registered in the area with a radius of 150 km around the center of the observation system at depths up to
300 km during 16 days. Records of 80 earthquakes with hypocenters in the earth crust (h = 0–30 km) beneath the island slope of the Kurile deep-sea trench were first obtained by bottom seismographs. These data
are inconsistent with previous concepts of aseismicity of this zone. The discovery of the unique morphological structure of
the Benioff zone beneath the central Kurile Arc represents the most important result of detailed seismological observations.
The zone consists of an inner seismoactive subzone, which is located beneath the island slope of the arc at depths of 15–210
km, being characterized by an angle of incline of 50° under the latter and crosses the ocean bottom approximately 80 km away
from the trench axis, and outer low-activity subzone. The latter is traceable beyond the trench almost parallel to the inner
zone beginning from a depth of 50 km below the sea bottom up to a depth of approximately 300 km. Due to the slightly lower
incline (∼45°) of the outer subzone, both subzones gradually converge downward. The integral thickness of the Benioff zone
varies from 150 km in its upper part to 125 km at depths of 210–260 km. The medium sandwiched between these subzones is practically
aseismic. The reality of this defined structure is confirmed by the distribution of aftershocks of the earthquake that occurred
on November 15, 2006 (M = 8.3). These seismic events served as foreshocks for the subsequent strong earthquake of January 13, 2007 (M = 8.1) with the hypocenter located beyond the trench under the ocean bottom. Such a structure of this zone within the central
Kurile Arc segment is unique, having no analogues either in the flanks of the Kurile-Kamchatka Arc or other arcs. The results
of detailed seismological observations obtained two months before the first of the catastrophic Central Kurile earthquakes
appeared to be typical for the period of foreshocks (the lower seismic activity of the Simushir block, which hosted the hypocenter
of the earthquake that occurred on November 15, 2006, particularly at depths of 0–50 km, the gentler incline of the recurrence
plot, and other features). 相似文献
15.
糯扎渡水库地区地震活动和震源参数研究 总被引：1，自引：0，他引：1
本文利用糯扎渡水库台网和景洪水库台网记录的地震波形反演震源谱, 计算了2011年1月至2014年3月糯扎渡水库附近143个1.0级以上地震的震源参数。 分析研究发现: ① 糯扎渡水库蓄水后, 库区内地震活动明显增强, 尤其是在水位上升3~4个月后; ② 水库开始蓄水后, 库区内地震震源深度变浅, 一段时间以后则与库区外的差别减小; ③ 地震拐角频率随地震矩增大而减小, 且蓄水以后, 库区内地震拐角频率的对数与地震矩的对数线性关系更明显; ④ 应力降、 视应力与地震矩存在正相关关系, 且相同地震矩时库区内的应力降与视应力低于蓄水前和库区外的地震应力降与视应力值; ⑤ 蓄水对库区内地震的影响可延伸至库底10 km深度处, 且在3~6 km深度内影响最大、 库区内外地震频度与视应力均值差异最显著。 相似文献
16.
The Buyuk Menderes Graben is a depression in the Menderes core complex of western Turkey. The region is one of the most rapidly
deforming regions of continental crust in the world and has exceptionally high seismic activity. In this study, shallow and
deep seismic studies were conducted at the Buyuk Menderes graben. These studies included surface geological mapping and two
seismic reflection sections. Detailed modelling was performed with the seismic study. In addition to these, a moving windows
power spectrum was applied to the Bouguer gravity profile data of the study area. Since no deep well is available in this
area, the geological interpretation of the seismic stratigraphy is based on the correlation with the surface geology, this
was combined with the major reflections and the seismic facies observed along the profiles, and, thus, four main seismic units
can be distinguished in the basin fill. Structural features of the basin is driven by a complex extensional faults system,
consisting of a low-angle, S-dipping Buyuk Menderes detachment and by its synthetic and antithetic splays, bordering the opposite
flanks of the basin. As a result of conventional deep seismic reflection sections and gravity data, three layers were defined
in the study area. The first layer occurs at a thickness of 6 km, and the second layer is between 13 and 18 km. The third
layer is at ~33 km and may also emphasize Moho depth. The Buyuk Menderes graben has three clear reflectors which are base
sediments, brittle-ductile transition, Moho and faults that show a half-graben floored by a detachment. The Moho depth is
comparable with previous estimates. According to the results obtained, Bouguer gravity and seismic results are very much consistent
with each other. It was observed that at the depths determined from seismic and gravity data, the distribution percentage
of earthquake focal depths also rises. 相似文献
17.
We useP andS times listed in the International Seismological Summary to relocate 23 historical earthquakes (1927–1963) reported as occurring at or below 670 km. In all cases, our relocated hypocenters are shallower than the starting depths; furthermore, all events converge to 691 km or less, with a precision estimated at ±10 km. This study upholds the results of Stark and Frohlich, who had usedpP–P times of post-WWSSN earthquakes to constrain reliable hypocentral depths to no greater than 684 km. In particular, we reject Rothé's claim that a 1963 event in the vicinity of New Guinea occurred at a depth of more than 780 km. 相似文献
18.
A. A. Lukk 《Izvestiya Physics of the Solid Earth》2011,47(4):299-316
The existence of a layer of unstable seismotectonic strain, which spatially coincides with the waveguide previously detected here at depths of 12–20 km, is established in the central part of the Tajik Depression [Lukk et al., 1970; Nersesov and Chepkunas, 1970; 1971]. This crustal layer is assumed to be weakened and saturated by fluid. The latter is supposedly achieved due to the supply of the liquid component from the bottom crust or upper mantle in the cracks and pores of the waveguide material. A near vertical pillar-like seismogenic body revealed in the work [Shevchenko et al., 2011], which penetrates the waveguide in the depth interval 0–40 km, is considered as one of the possible channels of such inflow. The detected loosened layer (the waveguide) is characterized by a signficant reduction in seismic activity. However, no such reduction is observed within the pillar-like seismogenic body at these depths. Moreover, compared to the nearest ambient environment, the upper 10–15 km of this body feature considerably increased seismic activity that manifested itself in a series of 13 strong earthquakes (with M ≥ 4.7) that occurred within the past approximately 100 years. 相似文献
19.
20.
本文研究塔里木盆地区域磁异常图的反演及磁源体结构.由于众多异常的叠加和反演固有的多解性,区域磁异常图的准确解释是非常困难的.三维欧拉反褶积是一种确定地质体位置和埋藏深度的自动定量反演方法,比较适用于计算区域磁异常源的埋藏深度.由于大型克拉通沉积盆地地层具有上新下老的规律性,将磁异常源分解为三个深度层次,圈定它们各自的分布区域,便可将它们与形成的地质作用及时代联系起来,为准确解释区域磁异常图提供可靠的依据.本文应用三维欧拉反褶积反演方法,计算出的塔里木盆地深度为2~5 km、5~10 km、10~20 km三个等级的磁异常源,它们与形成的地质作用及时代分别为: 中生代构造运动,海西期玄武岩侵位和太古代结晶基底的变质作用;圈定了它们各自的分布区域. 相似文献