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belt, East Tibet
Zhenhua Xue
To cite this version:
Zhenhua Xue. Mesozoic tectonic evolution of the Longmenshan thrust belt, East Tibet. Earth Sci- ences. Université d’Orléans, 2017. Chinese. �NNT : 2017ORLE2020�. �tel-01865843�
ÉCOLE DOCTORALE
ENERGIE, MATERIAUX, SCIENCES DE LA TERRE ET DE L’UNIVERS
Institut des Sciences de la Terre d’Orleans
THÈSE présentée par :
Xue Zhenhua
soutenue le 25 September, 2017
pour obtenir le grade de : Docteur de l’université d’Orléans Discipline/ Spécialité :
Sciences de la Terre et de l ’ Univers
THÈSE dirigée par :
Chen Yan Professeur, Université d’Orléans Faure Michel Professeur, Université d’Orléans
Lin Wei Professeur, Institute of Geology and Geophysics, CAS
RAPPORTEURS :
Li Haibing Professeur, China University of Geosciences Yan Danping Professeur, Institute of Geology, CAGS
____________________________________________________________________
JURY (y reporter tous les membres de jury présents à la soutenance) :
Chen Yan Professeur, Université d’Orléans Faure Michel Professeur, Université d’Orléans
Li Haibing Professeur, Institute of Geology, CAGS
Lin Wei Professeur, Institute of Geology and Geophysics, CAS Hu Jianmin Professeur, Insitute of Geomechanics, CAGS
Yan Danping Professeur, China University of Geosciences
Mesozoic tectonic evolution of the Longmenshan thrust belt, East Tibet
I
ABSTRACT
The Longmenshan Thrust Belt (LMTB) trending NE constitutes the northeastern boundary of the Tibetan Plateau, and separates the Songpan-Ganzi fold belt to the northwest and the Sichuan basin to the southeast, respectively. The LMTB is famous for its extremely steep topography, intensive activities as well as the abundant structures. As a typical composite orogen, the LMTB has had experienced intensive intracontinental deformation during the Mesozoic then is reactivated by the Cenozoic deformation, produced thin-skinned structures and basement-involved thin-skinned structures. The Mesozoic tectonic evolution of the LMTB is crucial to understand the intracontinental orogeny, uplifting of the Tibetan plateau and the alternation of the thin-skinned and thick-skinned structures.
The LMTB consists of three main thrusts, the Anxian-Guanxian thrust, the Beichuan-Yingxiu thrust and the Wenchuan-Maowen thrust distributed from SE to NW. A vertical cleavage belt has been delineated within the LMTB that divides the LMTB into a Western Zone and an Eastern Zone based on robust field structural analysis. The Eastern Zone characterized by NW-dipping foliation accommodated with NW-SE trending lineation, all shearing indicators show a top-to-the-SE shearing.
All the foliations within the Western Zone are exclusively dipping to the SE with NW- SE trending lineation, and reveal the top-to-the NW shearing. Combined structural geometry and kinematics, the LMTB is actually a flower-liking structure. There is no horizontal lineation observed in the LMTB, which contradicts to the ductile strike-slip structure.
According to the structural level, the Eastern Zone can be further divided into four subunits, from SE to NW, the autochthon, the para-autochthon, the allochthon and the meta-allochthon. The autochthon is located to the east of the Anxian-
Guanxian fault that is composed of Jurassic to Cretaceous rocks, weakly deformed as long wavelength fold. The para-autochthon bounded by the Anxian-Guanxian fault to the southeast and the Yingxiu-Beichuan fault to the northwest is mainly composed of Late Triassic rocks that is intensively folded and overturned to the southeast with the cleavage dipping to NW at local places. The allochthon includes the thrust belt between the Wenchuan-Maowen fault and the Yingxiu-Beichuan fault, the pervasive klippen distributes at the front of the LMTB. Extensive foliation and low greenschist
metamorphism assert its deeper structural level than the former two units. The meta- allochthon located between the vertical cleavage belt and the Wenchuan-Maowen fault, has had suffered the highest grade metamorphism from high greenschist to low amphibole facies. Detail structural level recorded in the meta-allochthon depicts a southeast-overturned antiform.
Combined redefined deformation, including the strata relationship based on pollen analysis, sedimentary characters of the Sichuan perpheral foreland basin and the zircon U-Pb age of the syntectonic granite, constrains this main deformation event in the Early Mesozoic around 219 Ma.
In the middle segment of the LMTB, there is a top-to-the-NW detachment fault developed along the western boundary of the Pengguan complex, which should be later stage superposition within the Eastern Zone. This detachment fault has been delineated along the southeastern boundary of the entire Songpan-Ganzi fold belt more 300 km in length by previous researchers. Integrated structural analysis, anisotropic of magnetic susceptibility study and gravity modeling suggest that the present architecture of the LMTB and its adjacent area is the result of basement slices extruding and stacking during the Late Mesozoic between 166-120 Ma.
The LMTB is far away from the contemporary plate boundary, devoid of ophiolite related material, could be an intracontinental orogen. On the basis of
regional tectonic background, the Longmenshan area as the northwestern boundary of the Yangtze block, has had suffered extensive pre-Mesozoic extension that
incidentally offer an ideal intracontinental weakzone. During the Early Mesozoic, the Yangtze basement underthrusts along the weakzone due to far-field effect of the Paleo-Tethys’ obliteration and exhumated the different structural level material to the surface, presented as the southeastward thrusting and contemporaneous
northwestward back thrusting. During the Late Mesozoic, the basement continues underthrusting due to the amalgamation of the Lhasa block to the Eurassia block, which lead to basement slices extrusion and stacking that resulted in couple developed detachment fault and thrust and crust thickening at the early stage. This process is a typical basement slice involved thin-skinned structure.
Keywords: Tibetan Plateau, intracontinental orogeny, thrust belt, thin-skinned structure
III
Contents
1. Introduction ... 1
1.1 Background and scientific issues ... 1
1) Intracontinental orogen ... 1
2) Thickening mechanism of the Tibetan Plateau ... 4
3) Thin-skined and thick-skined structures ... 6
1.2 Research methods ... 7
1) Research content ... 8
2) Research routine ... 9
1.3 Main achievements and innovations of the thesis... 10
1) Workload statistic ... 10
2εMain achievements ot the thesis ... 11
2. Geological settings of the Longmenshan and adjacent areas ... 13
2.1 Geomorphic location of the Longmenshan and brief introduction ... 13
2.2 Structural and geological history of the Longmenshan and adjacent areas ... 15
1) Proterozoic ... 15
2) Early Paleozoic ... 17
3) Late Paleozoic... 19
4) Mesozoic ... 20
5) Cenozoic ... 24
2.3 Previous evolutionary models of the Longmenshan thrust belt ... 25
1) Early Mesozoic ... 25
2) Late Mesozoic... 30
3) Cenozoic ... 32
2.4 Brief summary ... 35
3. Structural analysis of the Longmenshan thrust belt (LMTB) ... 37
3.1 The main tectonic boundaries of the LMTB ... 39
1) Anxian-Guanxian fault (F1) ... 39
2) Beichuan-Yingxiu fault (F2) ... 40
3) Wenchuan-Maoxian fault (F3) ... 41
4) Qingchuan fault (F4) ... 42
3.2 General zonation and structural geometry ... 42
1) Autochthon... 43
2) Para-autochthon ... 43
3) Allochthon ... 43
4) Meta-allochthon ... 44
5) Vertical cleavage belt (VCB) ... 45
6) Western zone ... 45
3.3 Kinematics analysis ... 46
1) Traditional method ... 46
2) Electron Backscatter Diffraction analysis (EBSD) ... 47
3.4 Detailed cross-section analysis ... 50
1) Qionglai-Baoxing corss section ... 51
2) Huaiyuan-sanjiang cross section ... 53
3) Yingxiu-Laofangzi cross section ... 58
4) Tonghua-Wenchuan-Tangbazi cross section ... 62
5) Hanwang-Qingping-Diexi cross section ... 67
6) Beichuan-Xuanping cross section ... 71
7) Jiangyou-Pingwu cross section ... 74
8) Tianjingshan-Qingchuan cross section ... 78
3.5 The involving domain of the vertical cleavage belt (VCB) ... 81
3.6 Timing of the main phase deformation ... 83
1) Relationship of strata involving deformation ... 83
2) Pollen analysis of the bricciated limestone at the leading edge of the Tangbazi klippe... 84
3) Geochronological constraints ... 98
3.7 Thermal structure of the meta-allochthon—Mica geothermometer measurements ... 102
1) Introduction of the Mica geothermometer ... 102
2) Sample description and results ... 102
3.8 The evolutionary scenario of the LMTB during the Early Mesozoic ... 104
4. Emplacement of the Pengguan complex—multiphase deformation .. 107
V
4.1 Introduction ... 107
4.2 Structural analysis of the Pengguan complex ... 112
1) Litho-tectonic units and bulk architecture ... 112
2) Kinematic analysis ... 114
4.3 Anisotropy of Magnetic Susceptibility (AMS) and petrofabric study ... 115
1) Methods of AMS analysis... 117
2) Magnetic mineralogy ... 119
3) AMS Results ... 120
4) Microstructural analysis ... 123
5) Interpretation of AMS and microstructures of the Pengguan granitic rocks . 125 4.4 Gravity modeling ... 126
1) Gravity map ... 126
2) 2D gravity modeling ... 128
3) Interpretation of the gravity model ... 129
4.5 Discussion ... 131
1) Summary of our new results ... 131
2) Lateral extent of the basement-slice-imbricated structure ... 132
3) Geochronological constraints ... 134
4) Evolution model of the LMTB and its tectonic implications ... 135
4.6 Brief summary ... 138
5. Mesozoic tectonic evolution of the Longmenshan and its implications ... 139
5.1 Multiphase deformation ... 139
5.2 Geological constraints of the multiphase deformation ... 141
5.3 Mesozoic tectonic evolution of the Longmenshan ... 143
5.4 Implications for the intraplate orogen ... 148
5.5 Implications for the thick-skinned and thin-skinned structure ... 149
6. Conclusions and unsettled issues ... 152
6.1 Conclusions ... 152
6.2 Unsettled issues ... 153
References ... 155
Appendix table 3.1 SEM data of mica geothermometer ... 172
Appendix table 3.2 Zircon SHRIMP U-Pb dating of the Mupi granite . 181
Appendix table 4.1 Measurements of anisotropy magnetic susceptibility
and microscopic observation ... 182
Appendix table 4.2 Micas
40Ar/
39Ar step heating results ... 184
Acknowlegement ... 186
1
1. Introduction
1.1 Background and scientific issues 1) Intracontinental orogen
“䙐ኡ⭘”ᴰᰙ⭡Gilbert (1890)ᨀࠪˈሶަᇊѹѪ⢩ᇊᰦᵏኡ䬮䲶ॷ
⭘DŽਠᆖ䈤ѝሶ䙐ኡᑖ䀓䟺Ѫ“䙐ኡഎѝ㓿ਇᕪ⛸㽦ⳡ⭘઼ަԆਈᖒⲴൠ ༣ѝⲴ⤝ゴ㓯ᙗൠᑖ”(Schuchert, 1925)DŽᶯඇᶴ䙐⨶䇪ᨀࠪਾˈ࣐བྷᆖ㘵 Wilson (1990)ሶ䙐ኡᑖᇊѹѪ“⤝䮯Ⲵ䲶䎧ൠᑖ”DŽ⧠൘ˈ䙐ኡ⭘ᤷᶯඇ؟ߢ
⻠ᫎ䗷〻ѝӗ⭏Ⲵа㌫ࡇዙ⸣ਈᖒǃਈ䍘⭘ǃዙ⍶⍫ࣘǃዙ⸣സ໎઼ൠ࣯
䲶ॷ䗷〻(Dewey and Bird, 1970; Sengör and Natal'in, 1996)ˈ䘉Ӌ⭘઼⧠䊑ԕ
ަ⢩↺Ⲵ㓴ਸᯩᔿ䇠ᖅҾዙ⸣സѝDŽᶯඇ⨶䇪ѝєњѫ㾱Ⲵ䀂㢢Ѫབྷ䱶ዙ⸣സ
઼བྷ⌻ዙ⸣സˈ∄Ҿབྷ䱶ዙ⸣സˈ䖳䟽Ⲵབྷ⌻ዙ⸣സ⋯⍫ࣘབྷ䱶䗩㕈؟ߢ
⋯⌻ѝ㜺ᯠ⭏ˈᆼᡀ༣ᒄ⢙䍘Ⲵᗚ⧟ˈᒦ൘⍫ࣘབྷ䱶䗩㕈໎⭏ᡆӗ⭏ᯠⲴዙ⍶
⢙䍘ᆼᡀབྷ䱶ൠ༣⭏䮯䗷〻 (Sutton and Watson, 1986)DŽ
Ր㔏䙐ኡᑖᇊѹተ䲀Ҿᶯඇ䗩㕈ˈ࠶Ѫ⻠ᫎර઼໎⭏ර(Figure 1.1 a઼b)DŽ
⻠ᫎර䙐ኡᑖᤷєњ“┲⎞”൘ዙ⸣സൠᒄкⲴࡊᙗབྷ䱶ඇփ൘؟ߢ⌻༣Ⲵᤆ
઼࣋⌻ѝ㜺ᢙᕐⲴ᧘ᥔ࣋лਁ⭏⻠ᫎˈᕅ䎧ዙ⸣സⲴ໎઼⻠ᫎඇփⲴᕪ⛸ਈ ᖒǃਈ䍘઼ዙ⍶⍫ࣘˈྲௌ傜䳵䙐ኡᑖ˗㘼໎⭏ර䙐ኡᑖᤷ൘⌻༣؟ߢ䗷〻 ѝ⎧ኡǃዋᕗㅹ⢙䍘䙀⑀ੁ⍫ࣘ䱶㕈䍤Ⲵˈդ䲿ᕪ⛸ᶴ䙐ਈᖒǃਈ䍘⭘ԕ
৺ൠ༣⭏䮯ˈєњ䱶ඇ䰤ࠐѾ⋑ᴹⴤ᧕⭘ˈྲ䱯ቄ⌠ኡ㜹(Brendan Murphy and Damian Nance, 1991; Windley, 1992, 1993; Windley and B.F, 1993; Nance and Murphy, 1994; Sengör and Natal'in, 1996; Sengor and Natalin, 1996; Cawood and Buchan, 2007)DŽԕкє⿽䙐ኡᑖਁ⭏൘⌻༣؟ߢᡆ䱶-䱶⻠ᫎབྷ䱶䗩㕈ˈ㘼䶎ᶯ ඇ䜘DŽ
ṩᦞ⌻ѝ㜺ǃ䖜ᦒᯝቲǃ؟ߢ⎸߿ᑖᶯඇ䗩⭼ࡂ࠶ᦞˈާᴹਔ㘱䱶ṨⲴ ࡊᙗབྷ䱶ᶯඇਸਾᖒᡀањᯠⲴᴤབྷⲴབྷ䱶ඇփˈਸӗ⭏Ⲵᯠ䱶ඇнਟ 䚯ݽⲴ؍⮉Ҷݸࡽᶴ䙐ⲴⰅ䘩ˈᡀѪᶴ䙐㮴ᕡᑖDŽഐ↔ˈࡊᙗᶯඇ⨶䇪㻛ᶯඇ
䜘ᒯ⌋؍⮉Ⲵਔ㘱䙐ኡᑖᴹޣⲴൠ༣ਈᖒᡰᢃ(Molnar and Tapponnier, 1975)ˈ⭡↔ᨀࠪㅜй⿽䙐ኡ㊫ර--䱶䙐ኡⲴ⹄ウDŽ
Figure 1.1 Classification of the orogens (Chuˈ2011) (a) Collisional orogen˗(b) Accretional orogen
䱶䙐ኡ⭘ᴰᰙ⭡ᗧഭᆖ㘵൘⹄ウই䶎Damara䙐ኡᑖ઼⅗⍢ॾ࣋㾯䙐 ኡᑖᰦԕ “䱶㽦ⳡᑖ”Ⲵᾲᘥᨀࠪ(Intracontinental fold belt)ᾲᘥᰦᕅࠪ(Martin, 1983)DŽᶯ䙐ኡ⭘н਼Ҿᶯ㕈䙐ኡˈнᱟᶯ㕈䙐ኡᑖ㔗㔝ਁኅⲴӗ⢙ᡆᶯ㕈 䙐ኡᑖ╄ॆⲴḀа䱦⇥ˈᆳᴹަ⤜⢩Ⲵབྷൠᶴ䙐ս㖞ǃᖒᡀ╄ॆশਢ৺ᖒᡀᵪ ࡦ(ᕐ䮯઼↓᮷, 2002)DŽоᶯ㕈䙐ኡᑖ㊫լˈ䱶䙐ኡᑖҏᆈ൘བྷ㿴⁑Ⲵᶴ 䙐ਈᖒǃਈ䍘⭘઼ዙ⍶⍫ࣘDŽഐ↔ˈᆖ㘵ਟԕ䙊䗷ᓄ⭘൘ᶯ㕈䙐ኡᑖѝⲴ
ൠ䍘ǃൠ⨳⢙⨶ᯩ⌅઼ᯩᔿᶕࢆ᷀䱶䙐ኡᑖDŽն䱶䙐ኡᑖⲴࣘ࣋ᆖᵪࡦа ⴤᆈ൘ҹ䇞DŽц⭼кިරⲴ䱶䙐ኡᑖྲই䶎Damara䙐ኡᑖǃ⅗⍢Ⲵ∄࡙⢋
ᯟኡǃ◣བྷ࡙ӊⲴPetermann䙐ኡᑖ઼Alice Spring䙐ኡᑖǃѝഭᯠ⭏ԓⲴཙ ኡǃॾेⲴ䱤ኡ-⠅ኡ㽦ⳡߢᯝᑖ઼ॾইⲴ䴚ጠኡǃे㖾⍢ⲴLaramide䙐ኡᑖ ԕ৺㾯ӊⲴZagrosㅹ(Dickinson and Snyder, 1978; Martin, 1983; Choukroune, 1992; Allen et al., 1999; Hand and Sandiford, 1999; Sandiford et al., 2001; English and Johnston, 2004; McQuarrie, 2004; Raimondo et al., 2010; Chu et al., 2012a, c)DŽ
3
䘉Ӌ䙐ኡᑖսҾ䘌ᶯඇ䗩⭼ࠐⲮ⭊㠣кॳޜ䟼Ⲵ䱶ൠ४ˈՐ㔏Ⲵᶯඇ؟ߢ
⁑ᔿᰐ⌅䀓䟺䘉Ӌ䙐ኡᑖⲴᖒᡀDŽൠᒄḡ⍫ࣘǃᒣᶯ؟ߢ઼ᶯ㕈⍫ࣘ䘌〻᭸ᓄ ᡀѪ䖳Ѫᑨ⭘Ⲵй⿽䀓䟺ᵪࡦ(Molnar and Tapponnier, 1975; Dickinson and Snyder, 1978; Tapponnier and Molnar, 1979; Hendrix et al., 1992; Avouac et al., 1993; English and Johnston, 2004)ˈ਼ᰦݸࡽᆈ൘Ⲵ㮴ᕡᶴ䙐ᑖҏᱟӗ⭏䱶ਈ ᖒⲴ䟽㾱ഐѻа(Choukroune, 1992; M. Hand and M. Sandiford, 1999)DŽ
ֻྲ䴚ጠኡ䙐ኡᑖսҾᡁഭॾইᶯඇṨ䜘ˈ䘌ᶯඇ䗩⭼ˈަᰙѝ⭏ԓਈ ᖒ㻛䀓䟺ᡀ䱶䙐ኡ⭘(Chu et al., 2012a, b, c)DŽ䴚ጠኡൠ४ԕ䜤ᐎ-Ѥ↖ᯝ㻲 ᑖѪ⭼ˈь䜘४ฏѫ㾱؍ᆈᰙਔ⭏ԓᶴ䙐ਈᖒ˗㘼㾯䜘४ฏࡉ؍⮉ᰙѝ⭏ԓⲴ ᶴ䙐⢩ᖱDŽ䜤ᐎ-Ѥ↖ᯝ㻲ᑖѪањݸᵏᆈ൘Ⲵ䱶㮴ᕡᑖˈ൘ਔཚᒣ⌻؟ߢ Ⲵ䘌〻᭸ᓄлˈॾই㾯䜘Ⲵสᓅ⋯䜤ᐎ-Ѥ↖㮴ᕡᑖੁьই؟ߢ⎸߿ˈ㘼ⴆቲ⋯
⵰ᯠݳਔԓᰙᵏ⊹〟Ⲵ⌕ዙǃ㊹⸲ዙㅹ䖟ᕡዙቲ㓴ᡀⲴ━㝡ᑖਁ⭏ǃ㽦ⳡ 㕙⸝ˈᆼᡀ䱶䙐ኡ䗷〻ˈ਼ᰦդ䲿ᒯ⌋Ⲵ䙐ኡਾዙ⍶⍫ࣘ (Figure 1.2)DŽ
Figure 1.2 Structural cross section of the Early Paleozoic Xuefengshan orogen (Chu, 2011)
Alice spring䙐ኡᑖᱟսҾ◣བྷ࡙ӊѝ䜘䘁ь㾯䎠ੁ㓿ިⲴ䱶䙐ኡᑖˈᆳ
俆ݸ㓿শҶѝݳਔԓѻࡽⲴ㔃Ღสᓅᖒᡀ઼ᯠݳਔԓ-⌕㓚ᰦᵏっᇊⴆቲਁ㛢 䗷〻DŽݳਔԓ㔃Ღสᓅᖒᡀ䗷〻ѝ؍⮉Ⲵ㮴ᕡ४ฏˈ㓿শਔ⭏ԓᐘⲴ⊹〟
֯ᗇл䜘ዙ⸣സॷ䖟ॆˈ⌕㓚㠣⸣⛝㓚ਁ⭏ਈᖒᡆ䟽ᯠ⍫ॆҶݸᆈᯝ㻲ˈ ᖒᡀҶ࠷ࢢዙ⸣സⲴ䘶ߢᯝ㻲ᑖˈ࠶䳄ই䜘ⲴAmadeusൠ઼े䜘ⲴAruntal 㔃Ღสᓅൠඇˈєњඇփ൘ᶯӂ⭘ਁ⭏䙐ኡ⭘(Figure 1.2 a; Goleby et al., 1989; Martin Hand and Mike Sandiford, 1999; Sandiford et al., 2001)DŽᶴ䙐ਈᖒ ѫ㾱ਁ㛢ҾAmadeusൠे䜘ˈ㘼ݳਔԓ䙐ኡӗ⭏Ⲵᶴ䙐൘䘉ᵏ䱶䙐ኡ䗷 〻ѝ਼ṧ㓿শҶ⍫ॆ᭩䙐(Figure 1.3 b)DŽ
Figure 1.3 Alice Springs intracontinental orogen
(a) Geological map of Alice Springs orogen (Hand and Sandiford, 1999)˗(b) Cross section of the Alice Springs (Hand and Sandiford, 1999; Sandiford et al., 2001)
⭡Ҿ䱶䙐ኡᑖབྷൠᶴ䙐ս㖞Ⲵ⢩↺ᙗˈަ⹄ウ〻ᓖ઼ޣ⌘ᓖаⴤнྲᶯ 㕈䙐ኡᑖˈަࣘ࣋ᆖᵪࡦ઼䙐ኡ⢩ᖱҏᴹᖵ䘋а↕᧒䇘DŽնᱟ䱶䙐ኡҏᱟᶯ ඇᶴ䙐Ⲵ䟽㾱㓴ᡀ䜘࠶ˈҏᱟ⹄ウᶯ㕈ᶴ䙐ሩᶯඇ䜘ᖡ૽Ⲵ䟽㾱䖭փѻаˈ ഐ↔ᆳⲴᖒᡀǃᶴ䙐Ṭᷦԕ৺ࣘ࣋ᆖᵪࡦ䎺ᶕ䎺ਇࡠൠ䍘ᆖᇦԜⲴ䟽㿶ˈ⿽
⹄ウ⇥䈨ྲᶴ䙐ൠ䍘ᆖǃൠ⨳ॆᆖǃൠ⨳⢙⨶ㅹᯩ⌅䜭㻛ᓄ⭘Ҿ࠶᷀䱶䙐 ኡᑖⲴᖒᡀ઼╄ॆ䗷〻DŽоᶯ㕈䙐ኡᑖн਼ˈ䱶䙐ኡᑖᒦнᱟᶯඇ䰤؟ߢǃ
໎⭏ᡆ⻠ᫎⲴⴤ᧕㔃᷌ˈնᱟҶ䀓䱶䙐ኡ䗷〻ሩҾ⹄ウᶯඇ䜘ᶴ䙐ਈᖒǃ ४ฏᓄ࣋ⲴՐԕ৺ᶯᶴ䙐ሩᶯ㕈ਈᖒⲴ૽ᓄ䗷〻ˈ䜭ާᴹ䟽㾱Ⲵ、ᆖ
ѹDŽ
2) Thickening mechanism of the Tibetan Plateau
嗉䰘ኡѪ䶂㯿儈ь㕈ˈഐަ䲑ጝⲴൠ઼࣯ᕪ⛸Ⲵൠ䴷⍫ࣘᡀѪഭ䱵✝
⛩⹄ウൠ४DŽⴤ嗉䰘䎠ੁⲴൠ࣯ࢆ䶒㺘᰾ˈӾഋᐍൠࡠ䶂㯿儈ˈ൘нࡠ
100 kmⲴ≤ᒣ䐍ˈ⎧ᤄ⭡500 mᐖਣⴤ᧕ᬰॷ㠣5000 mԕк(Figure 1.4)DŽ
5
վᒤԓᆖᮠᦞ઼⋣⍱ץ㲰䙏⦷㺘᰾嗉䰘ኡൠ४൘ᯠ⭏ԓԕᶕ㓿শҶᕪ⛸㘼ᘛ 䙏Ⲵ䲶ॷ(Harrison, 1992; Tapponnier et al., 2001; Clark et al., 2005, 2010; Wang et al., 2012; Cook et al., 2013; Tian et al., 2013, 2014)DŽ⿽ቪᓖⲴൠ⨳⢙⨶ࢆ䶒൷ 㺘᰾ˈൠ༣ᓖ⭡ഋᐍൠⲴ45 kmᐖਣੁNWⴤ᧕໎㠣60 kmᐖਣ(Robert et al., 2010b; Zhang et al., 2013; Guo et al., 2014)DŽն䰞仈൘Ҿˈ嗉䰘ኡኡࡽ㕪ѿ ᯠ⭏ԓሩᓄⲴࡽ䱶ൠ(Burchfiel et al., 1995, 2008)ˈGPSⴁ⍻ҏ㺘᰾䶐䘁嗉䰘 ኡൠ㺘䘀〫⢙䍘䘀〫ᖸធ(Zhang et al., 2002, 2004)ˈ䘉⿽ᔲᑨ儈Ⲵൠ࣯о⢙䍘䘀
〫⢩ᖱ઼ᶴ䙐㺘⧠Ⲵн㙖ਸᕅࠪ嗉䰘ኡᯠ⭏ԓ䲶ॷ઼ൠ༣Ⲵ໎ᵪࡦⲴє⿽ㄟ ݳ⁑ර˖1). ൠ༣㜶ᙗ㻲ˈ⋯␡ޕ㠣ዙ⸣സቪᓖⲴ䎠━-䘶ߢᯝ㻲⍫ࣘˈ䱦⇥
ᙗ䘶ߢ-໎䮯ሬ㠤ൠ࣯Ⲵ䲶ॷ઼ൠ༣໎(Figure 1.5 a; Tapponnier et al., 2001;
Hubbard and Shaw, 2009)˗2). лൠ༣䙊䚃⍱⁑ᔿ(channel flow)ˈণлൠ༣䜘࠶
⟄㶽Ѫվ㋈┎㌫ᮠⲴ⢙䍘൘䟽࣋⭘઼ൠ㺘㲰ޡ਼⭘лੁཆ⍱ࣘˈ䚝䙷ࡊ ᙗǃߧⲴഋᐍൠਾ䖜ਈѪⴤੁкⲴ⍱ࣘˈӾ㘼ሬ㠤ൠ࣯䲶ॷ઼ൠ༣໎
(Figure 1.5 a; Royden et al., 1997, 2008; Burchfiel et al., 2008)DŽ
ࡽӪབྷཊᢺ嗉䰘ኡൠ࣯䲶ॷᰦ䰤ᇊ൘ᯠ⭏ԓˈᖸቁᴹӪ৫᧒䇘ѝ⭏ԓ嗉䰘 ኡൠ४Ⲵᶴ䙐ሩൠ࣯䲶ॷ઼ൠ༣໎Ⲵᖡ૽DŽࡽӪሩ嗉䰘ኡѝ⇥઼ই⇥Ⲵݳਔ ԓᵲዙփ䘋㹼ᶴ䙐࠶઼਼᷀ս㍐ᒤԓᆖ࠶᷀䇔Ѫˈ嗉䰘ኡ൘ⲭෙ㓚-ᰙㅜй㓚䙊 䗷ൠ༣ቪᓖⲴᾄᖒᥔࠪᡆৼ䟽䘶ߢ᧘㾶䙐ᡀ嗉䰘ኡൠ४ᰙᵏⲴൠ༣໎(Xu et al., 2008; Tian et al., 2016)DŽᮠ٬⁑ᤏ㔃᷌䘋а↕㺘᰾ˈ嗉䰘ኡѫᒢ䗩⭼ᯝቲк 䲑л㕃Ⲵ䬢රᯝ䶒ᖒᘱн䴰㾱ཚཊⲴ≤ᒣ㕙⸝ቡ㜭ӗ⭏ᱮ㪇Ⲵൠ࣯䲶ॷ઼ൠ༣
໎(Feng et al., 2015)DŽⴞࡽਚᗇࡠ嗉䰘ኡൠ४ൠ㺘Ⲵዙ⡷ᥔࠪ䇱ᦞˈ㘼Ҷ䀓䘉
⿽ᶴ䙐⢩ᖱ઼⢱⣦Ⲵࠐօᖒᘱੁൠ༣␡䜘ᔦըᯩᔿˈԕ৺൘ᶮ█-⭈ᆌ㽦ⳡᑖл 䜘ࠐօᖒᘱѪᡁԜ᧒ራᯠ⭏ԓԕࡽ嗉䰘ኡൠ༣໎ᨀ䟽བྷ⨶䇪ᦞˈ਼ᰦѪ 䶂㯿儈ᡀഐ⹄ウᨀᦞDŽ
Figure 1.4 Topographic cross section of the Longmen mountain (Clark et al., 2005)
Figure 1.5 Two end-members model of the uplifting of the Tibetan Plateau (a) Deep rooted thrust-slip fault piled up that lead to crustal thickening (Tapponnier et al., 2001); (b) Channel flow (Royden et al., 2008)
3) Thin-skined and thick-skined structure
㮴Ⳟᶴ䙐ᴰᰙ⭡Rogers (1849)൘䀓䟺⅗⍢ֿ㖇ኡᔿ㽦ⳡᑖᰦᨀࠪDŽ䙐ኡᑖ
ࡽ䱶ިර㮴Ⳟᶴ䙐ᤷˈ⊹〟ⴆቲоสᓅѻ䰤䙊䗷⸣㞿ǃ⌕ዙǃ亥ዙㅹ䖟ᕡዙቲ
7
㓴ᡀⲴ䶒оสᓅਁ⭏ˈ⊹〟ⴆቲਁ⭏ᕪ⛸Ⲵ㕙⸝ǃ䘶ߢˈ㓗䘶ߢᯝ 㻲ੁл≷ޕѫᯝቲѻкˈᒦ㺘⧠Ѫਾㄟࡽㄟ㮴Ⲵᾄᖒ˗㘼Ⳟᶴ䙐ᤷ൘ 䙐ኡ䗷〻ѝˈสᓅ⢙䍘ҏধޕҶ䘶ߢ᧘㾶ਈᖒDŽᴰѪިරⲴቡᱟˈ൘䱯ቄঁᯟ 䙐ኡᑖˈᕪ⛸䘶ߢ᧘㾶Ⲵ㮴Ⳟᶴ䙐઼สᓅধޕਈᖒⲴⳞᶴ䙐䜭ᒯ⌋ਁ㛢 (Bellahsen et al., 2014; Pfiffner, 2016)DŽ
嗉䰘ኡ䘶ߢ᧘㾶ᑖࡽ䱶࠶ᐳа㌫ࡇⲴ᧘㾶փ઼伎ᶕጠˈ᧘㾶䐍ਟ䗮ࠐॱ ޜ䟼ˈ㺘⧠ѪިරⲴ㮴Ⳟᶴ䙐⢩ᖱ˗ն⋯嗉䰘ኡ਼ṧ࠶ᐳ⵰䇨ཊᯠݳਔԓสᓅ ᵲዙˈ㻛ѝ⭏ԓⲴ㮴Ⳟᶴ䙐ᡰത䲀DŽBurchfiel et al. (1995)൘䈖㓶ᶴ䙐䀓᷀Ⲵส
кˈሶ䘉ӋสᓅᵲዙփᖂѪᕪ⛸䘶ߢ᧘㾶ᑖⲴൠ㌫㔏ˈণሶ嗉䰘ኡѝ⭏ԓ ਈᖒᇊѹѪสᓅᵚধޕਈᖒⲴ㮴Ⳟᶴ䙐DŽ䈖㓶Ⲵൠ䴷৽ሴࢆ䶒઼ࡽ䱶⊹〟ൠ
⢩ᖱ㺘᰾ˈ嗉䰘ኡই⇥ˈѪสᓅⲴᇍޤᵲዙধޕਈᖒˈҾިරⲴⳞᶴ䙐 (Figure 1.6 a)˗㘼嗉䰘ኡे⇥ˈࡉӵ㺘⧠Ѫⴆቲᕪ⛸䘶ߢ᧘㾶Ⲵ㮴Ⳟᶴ䙐(Figure 1.6 b; Jia et al., 2006)DŽ嗉䰘ኡे⇥Ⲵ㮴Ⳟᶴ䙐઼ই⇥ⲴⳞᶴ䙐൘ᰦ䰤кҏᴹ ᐞᔲˈे⇥㮴Ⳟᶴ䙐ਁ⭏൘ᰙѝ⭏ԓˈই⇥ⲴⳞᶴ䙐ਁ⭏൘ⲭෙц-ᰙㅜй 㓚(Jia et al., 2006)DŽRobert et al. (2010a, b)ṩᦞ൘嗉䰘ኡൠ४儈㋮ᓖൠ䴷৽ሴࢆ
䶒઼ިරࢆ䶒ᴬݹ䉡⍻㔃᷌ᨀࠪ嗉䰘ኡൠ४ঠ᭟ᵏԕ㮴Ⳟᶴ䙐Ⲵ䘶ߢዙ⡷
Ѫѫˈᯠ⭏ԓԕⳞᶴ䙐Ѫѫˈ਼ᰦդ䲿ᶮ█-⭈ᆌൠ༣໎DŽ嗉䰘ኡⲴ㮴Ⳟᶴ 䙐оⳞᶴ䙐ᴤ䘝ᵪࡦԕ৺ᰦ䰤ݸਾޣ㌫Ⲵৈᇊሩ⨶䀓䙐ኡᑖ㮴Ⳟᶴ䙐઼Ⳟ ᶴ䙐ӗ⭏ᵪࡦ৺Ҷ䀓嗉䰘ኡᖒᡀ઼╄ॆ䗷〻ᴹ䟽བྷѹDŽ
1.2 Research methods
ᵜ䇪᮷ԕ“嗉䰘ኡѝ⭏ԓᶴ䙐╄ॆ”Ѫѫ仈ˈ䘹ਆഋᐍ嗉䰘ኡ䘶ߢ᧘㾶ᑖѪ
⹄ウ४ˈ䙊䗷ѝሿቪᓖᶴ䙐䀓᷀ৈᇊ⹄ウ४Ⲵᶴ䙐Ṭᷦǃ࠶४⢩⛩ǃѫᵏᶴ䙐 һԦⲴ㺘⧠ṧᔿ˗䘋㘼䙊䗷ሩᖝ♼ᵲዙ⻱㓴ᶴੁᔲᙗ(AMS)ǃዙ⸣ᱮᗞ㓴ᶴ
࠶᷀৺䟽࣋⁑ᤏˈৈᇊࠪ嗉䰘ኡ䘶ߢ᧘㾶ᑖཊᵏᶴ䙐ਈᖒDŽṩᦞধޕਈᖒൠቲ ਐ࣐ޣ㌫ǃᆒ㊹ᒤԓᆖǃ਼ᶴ䙐ዙփ䬶⸣U-Pbᇊᒤ઼丗ᙗਈᖒᑖᯠ⭏ⸯ⢙
40Ar/39Arᇊᒤ⺞ᇊ嗉䰘ኡѫਈᖒᵏ઼ཊᵏਈᖒⲴᰦ䰤DŽ䘋а↕ৈᇊᰙѝ⭏ԓ嗉 䰘ኡ䘶ߢ᧘㾶ᑖṬᷦ৺ѝ⭏ԓสᓅዙ⡷ᥔࠪ-䘶ߢ᭩䙐ᰙѝ⭏ԓṬᷦ䗷〻DŽ
Figure 1.6 Cross section of the Longmenshan displaying thick-skinned and thin-skinned structures (Jia et al., 2006)
(a) Basement involved thick skinned structure of the south Longmenshan; (b) Thin-skinned structure of the north Longmenshan
1) Research content
a. Constructe the bulk architecture of the Early Mesozoic Longmenshan thrust belt
൘བྷ䟿䈳⹄ࡽӪ⹄ウᡀ᷌Ⲵสкˈ䙊䗷ሩ嗉䰘ኡ䘶ߢ᧘㾶ᑖ৺ઘ䗩ൠ४ བྷ㤳തǃ䈖㓶Ⲵ䟾ཆ㘳ሏˈ⺞ᇊަᶴ䙐ࠐօᆖ઼䘀ࣘᆖ⢩ᖱ˗ṩᦞሩн਼অݳ 㓴ᡀዙ⸣Ⲵⸯ⢙㓴ਸ઼ਈᖒ㺘⧠ˈ⺞ᇊ嗉䰘ኡⲴњᶴ䙐অݳ৺ަਐ㖞ޣ㌫DŽ
਼ᰦ㔃ਸൠ䴷৽ሴࢆ䶒ǃࡽ䱶ൠ⊹〟⢩ᖱㅹˈᆼழሩ嗉䰘ኡ䘶ߢ᧘㾶ᑖⲴᶴ 䙐╄ॆ䇔䇶DŽ
b. Distinguish multiphase deformation of the Longmenshan thrust belt focusing on the emplacement mechanism of the Pengguan massif
ᖝ♼ᵲዙѪ⹄ウ४Ⲵݳਔԓสᓅˈަ䗩⭼བྷཊоਔ⭏ԓൠቲǃѝ⭏ԓൠ ቲᶴ䙐᧕䀖ޣ㌫ˈ䏣ԕ㺘᰾ዙփ൘ᯠݳਔԓץսѻਾ㓿শҶਾᵏⲴᕪ⛸᭩䙐
⭘DŽԕ⻱ॆ⦷ੁᔲᙗ㋮⺞ৈᇊᖝ♼ᵲዙᶴ䙐ࠐօᖒᘱˈዙ⸣ᱮᗞ㓴ᶴ⺞ᇊ ዙփਈᖒ㓗࡛˗䟽࣋⁑ᤏ⽪ᵲዙփ৺തዙⲴᶴ䙐ࠐօᖒᘱˈ䙊䗷ཊ⇥㔬ਸ 䀓᷀ཊᵏᶴ䙐ਈᖒሩ䇔䇶嗉䰘ኡᶴ䙐╄ॆ䗷〻Ⲵ␡ॆᴹ䟽བྷѹDŽ
c. The geochronological constraints of the Longmenshan thrust belt
9
൘䟾ཆᶴ䙐⹄ウสк⺞ᇊধޕਈᖒൠቲޣ㌫ˈ⺞ᇊѫਈᖒᵏሩᒤ喴DŽ ሩᰦԓᆈ൘ҹ䇞Ⲵ䟽㾱ൠቲঅݳˈ䙊䗷ᆒ㊹䢤ᇊᐕ䟽ᯠ⺞ᇊൠቲⲴᰦԓˈ֯
ਈᖒⲴሩᒤ喴ᴤ㋮⺞˗ሩ䙐ኡᑖ਼ᶴ䙐㣡ዙ䘋㹼䬶⸣SHRIMP U-Pbᇊᒤ
઼ᕪᓄਈᑖ਼ਈᖒⸯ⢙40Ar/39Arᇊᒤ㔉ࠪ䖳Ѫਸ⨶Ⲵ㔍ሩᒤ喴DŽ
d. Early Mesozoic intracontinental orogeny and Late Mesozoic modification of the Longmenshan thrust belt.
൘ሩ嗉䰘ኡ䈖㓶ᶴ䙐ࠐօᆖǃ䘀ࣘᆖ઼ᒤԓᆖ䇔䇶สкˈ㔃ਸ⹄ウ४ᱮ
⭏ᇉԕᶕᶴ䙐╄ॆ⢩ᖱ઼਼ᵏ४ฏᶴ䙐㛼Ჟˈ࠶᷀嗉䰘ኡ䘶ߢ᧘㾶ᑖᰙѝ⭏ԓ
╄ॆ䗷〻˗ԕ↔Ѫ࠷ޕ⛩ˈৈᇊѝ⭏ԓԕᶕ嗉䰘ኡཊᵏਈᖒሩᰙѝ⭏ԓṬᷦ
Ⲵ᭩䙐ˈӾ㘼Ѫ⨶䀓ਔ⢩ᨀᯟ⌻䰝ਸᰦ൘ᢜᆀᶯඇ䗩㕈Ⲵᶴ䙐૽ᓄᨀᑞࣙ˗
ѝ⭏ԓⲴཊᵏਈᖒˈሩ嗉䰘ኡਾᵏѪ䶂㯿儈ь㕈ൠ༣໎ҏᴹаᇊⲴ䍑
⥞DŽ
2) Research routine
a. 䍴ᯉᩌ䳶˖ޘ䶒᭦䳶઼䇴ՠо䇪᮷ޣⲴൠ䍘ǃൠ⨳ॆᆖǃൠ⨳⢙⨶䍴 ᯉ; ൘৺ᰦҶ䀓઼ᦼᨑ⹄ウ亶ฏⲴഭཆࡽ⋯ࣘᘱ઼⹄ウ४⹄ウ䘋ኅⲴสк, ᙫ㔃ᖂ㓣, Ѫ䟾ཆᐕ઼ᇔ࠶᷀ᨀᤷሬ઼ᦞDŽ
b. 䟾ཆൠ䍘䈳ḕ઼ᶴ䙐ൠ䍘⹄ウ˖ԕ1: 20з४ฏൠ䍘䍴ᯉѪสˈ਼ᰦ
㔃ਸተ䜘ൠ४1: 5з४ฏൠ䍘䍴ᯉˈԕޣ䭞ࢆ䶒䟽⛩ᔰኅ䈖㓶Ⲵ䟾ཆൠ䍘䈳ḕ, ࡂ࠶ዙ⸣ᶴ䙐অݳˈৈᇊࠐօᆖǃᶴ䙐ᆖṶᷦ, ᒦ㌫㔏䟷䳶ዙ⸣ᆖ઼ᶴ䙐ᇊ
ੁǃᇊᒤṧ૱DŽሶ䟾ཆ䵢ཤ-ḷᵜ-㮴⡷н਼ቪᓖⲴᶴ䙐ਈᖒ⢩ᖱᴹᵪൠ㔃ਸ
൘а䎧ˈ䘋а↕⺞ᇊн਼ᶴ䙐অݳⲴࠐօᆖ઼䘀ࣘᆖ˗ᚒ༽н਼ቲ⅑ਈᖒਁ㛢 Ⲵオ䰤ኅᐳ⢩ᖱ৺ަᶴ䙐㺘⧠઼ਐ࣐ޣ㌫, 䘋㘼䘋㹼ਈᖒᵏ⅑Ⲵࡂ࠶; ᧒䇘н਼
ᵏ⅑ᶴ䙐һԦਁ⭏Ⲵ४ฏᶴ䙐㛼Ჟˈ᧘ࠪਟ㜭Ⲵࣘ࣋ᆖ⁑රDŽ
c. ⻱ॆ⦷ੁᔲᙗ(AMS)઼ⸯ⢙ᱮᗞ⢩ᖱ⹄ウ˖ሩ⹄ウ४䟽⛩ዙփ-ᖝ♼ᵲ ዙ䘋㹼Ҷ⻱㓴ᶴ⹄ウDŽᖝ♼ᵲዙ䟾ཆ㺘⧠Ѫඇ⣦Ⲵ㣡ዙˈ䵢ཤቪᓖкн㜭䇶
࡛ࠪ᰾ᱮⲴ丗ᙗਈᖒˈᖸ䳮ᔰኅՐ㔏Ⲵᶴ䙐䀓᷀DŽᖝ♼ᵲዙൠ࣯䲙ጫˈӵᴹє ᶑ␡࠷⋣⋏㓥⁚ަѝˈӔ䙊ᖸнׯ࡙DŽѪҶ֯AMS䟷ṧ࠶ᐳ㤳തᴤᒯˈਚ㜭 㛼䍏ᐕާᗂ↕ク䎺ዙփⲴߢ⋏ˈ❦ਾ֯⭘䫫ᵪ൘䟾ཆ㌫㔏䟷䳶ᇊੁṧ૱DŽ
AMS㜭㋮⺞㔉ࠪዙ⸣Ⲵ⻱䶒⨶઼⻱㓯⨶ˈ㔉ࠪዙփࠐօᆖ⢩ᖱDŽ䙊䗷ⸯ⢙ᱮᗞ
⢩ᖱ࠶᷀ˈ⺞ᇊዙփ㓿শਈᖒ㓗࡛ˈӾAMSᡰᗇࠪⲴࠐօṶᷦѝ४࠶ࠪᶴ䙐 ᡀഐ઼ዙ⍶ᡀഐˈ㔃ਸ४ฏࠐօᆖǃ䘀ࣘᆖ⢩ᖱˈᆼᡀዙփⲴᶴ䙐䀓᷀DŽ
d. 䟽࣋⁑ᤏ˖ԕ४ฏሿ㤳തབྷ∄ֻቪᐳṬ䟽࣋ᔲᑨമѪสˈ㔃ਸᴤབྷ㤳 തሿ∄ֻቪᐳṬ䟽࣋ᔲᑨᮠᦞˈ৽╄⹄ウ४ѝкൠ༣⢙䍘Ⲵ䟽࣋ؑ˗䙊䗷䈖 㓶⍻䟿ዙ⸣њቲսⲴᇶᓖˈ㔃ਸࡽӪሩ४ฏкњൠቲᇶᓖⲴ⍻䈅㔃᷌ˈԕ ൠ⨳⢙⨶䍴ᯉ৽᱐Ⲵ␡䜘ᖒᘱѪ䗩⭼(ᯝቲ␡䜘ᔦը⣦ᘱǃൠ䗩⭼ㅹ)ᆼᡀ䟽
࣋৽╄ˈ㧧ᗇᴤ㋮㓶Ⲵ␡䜘ࠐօᆖᖒᘱDŽ
e. ᒤԓᆖ⹄ウ˖ṩᦞൠቲѝᡰਜ਼ᆒ㊹Ⲵˈ䟽ᯠৈᇊޣዙ⸣ൠቲঅݳⲴᰦ
ԓ˗࡙⭘䬶⸣U-Pbᇊᒤ⺞ᇊ਼ᶴ䙐㣡ዙⲴᒤ喴ˈӾ㘼ḷᇊᶴ䙐һԦਁ⭏Ⲵᰦ
䰤DŽ൘ᶴ䙐䀓઼᷀ⸯ⢙ਈᖒ⢩ᖱ㿲ሏⲴสкˈ䘹ᤙ⹄ウ४Ⲵ丗ᙗ࢚࠷ᑖᡆ ᕪᓄਈᑖ਼ਈᖒⸯ⢙(䀂䰚⸣ǃⲭӁ⇽ǃ唁Ӂ⇽ǃ䫮䮯⸣ㅹ)ᔰኅ40Ar/39Arᒤ ԓᆖ࠶᷀ˈ㔃ਸ丗ᙗਈᖒⲴᶑԦˈ⺞ᇊཊᵏ⅑丗ᙗਈᖒਁ⭏Ⲵᰦ䰤DŽ
1.3 Main achievements and innovations of the thesis 1) Workload statistic
ᒿਧ ᐕᇩ ᮠ䟿 অս ѫ㾱ᆼᡀӪ 1 䟾ཆൠ䍘㘳ሏ 3.5 ᴸ 㯋ᥟॾǃ᷇Տ 2 䟾ཆ㿲⍻⛩ 714 њ 㯋ᥟॾǃ᷇Տ 3 ᇎ⍻ࢆ䶒 20 ᶑ 㯋ᥟॾǃ᷇Տ 4 ṧ૱䟷䳶 130 ඇ 㯋ᥟॾǃ᷇Տ 5 䟾ཆ➗⡷ 825 ᕐ 㯋ᥟॾ 6 ዙ⸣ᆖ㮴⡷䢤ᇊ 305 ⡷ 㯋ᥟॾ 7 ᶴ䙐ᇊੁ㮴⡷㿲ሏ 280 ⡷ 㯋ᥟॾ 8 㔈ࡦൠ䍘മ 10 ᕐ 㯋ᥟॾǃ᷇Տ 9 㔈ࡦࢆ䶒 12 ᶑ 㯋ᥟॾǃ᷇Տ 10 䬶⸣䱤ᶱਁݹᇎ傼 6 Ԧ 㯋ᥟॾǃ哾Ҁ
11 䬶⸣SHRIMP U-Pbᇊᒤ 1 Ԧ 㯋ᥟॾ
11
12 䬶⸣LA-ICP-MS⍻䈅 5 Ԧ 㯋ᥟॾǃ哾Ҁ
13 䟽࣋⁑ᤏࢆ䶒 2 ᶑ 㯋ᥟॾ
14 AMS䟷ṧ 36 ⛩ 㯋ᥟॾ
15 AMS⍻䈅 339 њ 㯋ᥟॾ
16 EBSD⍻䈅 12 Ԧ 㯋ᥟॾ
17 অⸯ⢙Ӂ⇽ᓖ䇑 7 Ԧ 㯋ᥟॾ 2εMain achievements of the thesis
1). A vertical cleavage belt (VCB) has been delineated along the Longmenshan thrust belt (LMTB), which divides the LMTB into an Eastern zone and a Western zone. The Eastern zone featured by the NW-dipping foliation and exclusively top-to- the-SE shearing along NW-SE trending lineation, while the Western zone display all the foliation dip to SE and display top-to-the-NW shearing along the NW-SE trending lineation. There is no imprint relationship between these two opposite kinematics and could happened contemporaneously. No ductile strike-slip structures have been found along the LMTB.
2). The Eastern zone can be further divided into four subunits based on roboust field observations and inner door anaysis, from SE to NW, autochthon, para-
autochthon, allochthon and meta-allochthon, which are bounded by three main thrust of the LMTB and the VCB. These four subunits are characterized by enhancing deformation and deepening structural level from SE to NW. The highest
metamorphism record in the meta-allochthon attained to low amphibole metamorphic grade, as a core of a SE-vergening anticline.
3). The LMTB suffered intensive shortening could be the result of the basement subduction. Both geophysical and geological evidences suggest a pre-T2 rifting along the Longmenshan, the subsequent closure of the rift offers a potential soften zone where the basement subducted during the Early Mesozoic.
4). Pollen analysis of the brecciated limestone at the leading edge of the
Tangbazi klippe, one of the klippen has a narrow tail covering concordantly deformed Jurassic-Cenozoic rocks, overthrough the strata evidence for Cenozoic thrusting of the klippen belt.
5). The Pengguan massif, one of the orogen-paralle proterozoic basement, could be the surface expression of the basement slice extrusion along the LMTB during the Late Mesozoic. The basement slices extruded southeastwards accommendated with the top-to-the-SE shearing at the foreland and the top-to-the-NW detachment at the hinterland, and the basement slices backstopped, piled up could lead to the crustal thickening.
6). Integrating previous research and new findings of the thesis, a Mesozoic evolutionary model of the LMTB has been proposed.
13
2. Geological settings of the Longmenshan and adjacent areas
2.1 Geomorphic location of the Longmenshan and brief introduction
嗉䰘ኡѫփսҾҾᡁഭഋᐍⴱ㾯䜘ൠ४ˈьे䎧㠚ഋᐍⲴᒯݳˈо㊣ԃኡ
䘎ˈ㾯ইᔦը㠣ཙޘˈ㻛勌≤⋣ᯝ㻲ᯌᡚˈޘ䮯㓖500 kmˈᇭ㓖35-50 km(Figure 2.1)DŽ嗉䰘ኡ䲑ጝⲴൠ࣯֯ᗇ嗉䰘ኡь㾯䜘≄ىਁ⭏ᐞᔲˈь䜘䗾仾 එ䴘≤ݵ䏣ˈᱟഋᐍ㪇Ⲵ᳤䴘४ᡰ൘ൠ˗㾯䜘㛼仾එ䴘≤〰ቁˈ≄ىॱ࠶ᒢ
⠕DŽབྷൠ⭥⻱⍻䟿ࢆ䶒઼ൠ䴷৽ሴࢆ䶒㺘᰾ᶮ█-⭈ᆌ㽦ⳡᑖ઼ഋᐍൠⲴ␡䜘 ൠ༣㔃ᶴާᴹᱮ㪇ⲴᐞᔲˈӾഋᐍൠࡠᶮ█-⭈ᆌ㽦ⳡᑖˈൠ༣ᓖӾ44 km ケਈ㠣60 kmˈ㺘⧠Ѫᡚ❦н਼Ⲵєњঅݳ(䇨ᘇ⩤ , 1992; Robert et al., 2010a, b; Guo et al., 2013)ˈ䴷ѝཆⲴ⊦ᐍൠ䴷(2008)઼㣖ኡൠ䴷(2013)ׯਁ⭏Ҿ↔
(Figure 2.1)DŽ
Figure 2.1 Simplified geological map of the Longmenshan thrust belt (Modified after Harrowfield et al., 2005)
嗉䰘ኡ䘶ߢ᧘㾶ᑖ४ฏк⭡йᶑٮੁNWⲴ䘶ߢᯝ㻲ᑖ㓴ᡀˈ䈖㓶Ⲵᶴ䙐 䀓᷀㺘᰾ˈ嗉䰘ኡ䘶ߢᯝ㻲ᑖ⭡NWੁSEӾ丗ᙗਈᖒ䙀⑀䗷Ѫ㜶ᙗˈѪި
රⲴࡽኅᔿՐᯩᔿ(䱸⽮ਁㅹ, 1994a; Chen and Wilson, 1996)ˈൠ䴷৽ሴࢆ䶒઼
ൠ䴷։䴷䴷Ⓚ␡ᓖս㖞൷㺘᰾嗉䰘ኡйᶑѫᒢᯝ㻲ੁNW᭦ᮋҾ15-20 km␡Ⲵ
━㝡䶒ᒦੁ嗉䰘ኡ㞩䱶ᔦը(Li et al., 2010; Guo et al., 2013; Feng et al., 2015)DŽ嗉
䰘ኡ䘶ߢ᧘㾶ᑖѪިරⲴ༽ਸර䙐ኡᑖˈࡽѝ⭏ԓᤱ㔝Ⲵըኅ㛼Ჟлˈ嗉䰘ኡ սҾᢜᆀᶯඇっᇊ䱶ඇNW㕈(嗉ᆖ᰾, 1991; ᵾᴸ, 2008; ᵾր㠓, 2009)ˈ൘㓿 শᰙѝ⭏ԓਔ⢩ᨀᯟ⌻䰝ਸᶴ䙐ฏлਁ⭏ᒯ⌋Ⲵ䱶䙐ኡһԦਾ(䇨ᘇ⩤ㅹ, 1992; Burchfiel et al., 1995; Chen and Wilson, 1996; Liu et al., 2013)ˈᯠ⭏ԓᯠ⢩
ᨀᯟ⌻䰝ਸ⻠ᫎл㓿শᕪ⛸⍫ॆ(Clark et al., 2000; Kirby et al., 2002; Hubbard et
al., 2009)ˈ֯嗉䰘ኡ䘶ߢ᧘㾶ᑖнӵ൘NW-SEᯩੁкਈᖒቲ⅑㺘⧠н൷а
(Luo, 1991; Burchfiel et al., 1995; Chen et al., 1995; Worley and Wilson, 1996;
Burchfiel et al., 2008)ˈ⋯嗉䰘ኡNE-SW䎠ੁкҏ㺘⧠ࠪ࠶⇥⢩ᖱ(Jia et al., 2006; Jin et al., 2009; Xu et al., 2009; Jin et al., 2010)DŽ
嗉䰘ኡ㾯े䜘Ⲵᶮ█-⭈ᆌ㽦ⳡᑖѪаь㾯ੁᔦըǃьᇭ㾯ゴǃᒣ䶒к㺘⧠
Ѫقй䀂ᖒⲴ༽⨶⸣ൠ(Yin and Nie, 1993; Chang, 2000)DŽेחԕ䱯ቬ⧋য-ь
ᰶԁ㕍ਸᑖѪ⭼ˈ㾯ইחԕ⭈ᆌ-⨶ຈ㕍ਸᑖѪ⭼ˈSE䗩⭼ࡉѪ嗉䰘ኡ䘶ߢ᧘ 㾶ᑖ(Figure 2.1)DŽᶮ█-⭈ᆌ㽦ⳡᑖ࠶ᐳ䗮10 kmⲴйਐ㓚㾯ᓧ㗔༽⨶⸣
(Figure 2.2)ˈѪॾই-ॾे⻠ᫎᰦᢜᆀᶯඇ䗩㕈Ⲵ㻛ࣘ⊹〟⌻ᰦᵏˈᒯ⌋⊹〟
ᶕ㠚ॾইǃॾेǃ㾯ᰶԁԕ৺⭈ᆌ-⨶ຈ㕍ਸᑖ⺾ኁ⢙䍘(Bruguier et al., 1997;
Weislogel et al., 2006; Zhang et al., 2008; Weislogel et al., 2010)DŽ⋯ᶮ█-⭈ᆌ㽦ⳡ ᑖཊቲ⅑━㝡ቲ(䴷ᰖ-ሂ↖⌕䍘ዙ⡷ዙǃᘇ⮉㓚⌕⚠ዙǃᰙйਐ⸣㞿ቲ)ਁ⭏
ᒯ⌋ⲴੁইⲴ࢚࠷⭘ˈ䙐ᡀҶ㾯ᓧ㗔ᕪ⛸㽦ⳡਈᖒ઼བྷҾ50%Ⲵ㕙⸝(䇨ᘇ⩤
ㅹ, 1992; Calassou, 1994; ⦻ᇇ⿰ㅹ, 1997; Roger et al., 2004; Harrowfield and Wilson, 2005)DŽ
ᕪ⛸㽦ⳡⲴ㾯ᓧ㗔༽⨶⸣ᑖᒯ⌋ץޕ਼䙐ኡᡆ䙐ኡਾ226-205 MaⲴෳ䗮 ݻ䍘ǃAරᡆ䫉⻡ᙗ㣡ዙˈ䈖㓶Ⲵൠ⨳ॆᆖ࠶᷀㺘᰾ዙ⍶ѫ㾱ᶕⓀҾ࣐ൠ ༣⟄㶽ˈդᴹਔ㘱สᓅ⟄㶽⢙䍘ԕ৺ቁ䟿ᒄⓀ⢙䍘࣐ޕˈዙփᒯ⌋䇠ᖅާᴹ ਔ㘱䬶⸣Ṩ䜘Ⲵ⢙䍘DŽቭ㇑ᴰࡍ⹄ウ䇔Ѫᶮ█-⭈ᆌѪॾই-ॾेᶯඇ⻠ᫎᰦ↻
⮉Ⲵਔ⢩ᨀᯟሿ⌻ˈާᴹ⌻༣สᓅ(Yin and Nie, 1993)ˈնᴤཊ⹄ウ㘵ṩᦞ㽦 ⳡᑖዙփⲴൠ⨳ॆᆖ⢩ᖱ઼儈㋮ᓖൠ䴷৽ሴࢆ䶒㔃᷌䇔Ѫᶮ█-⭈ᆌ㽦ⳡᑖл 䜘Ѫᢜᆀสᓅ(Roger et al., 2004; 㜑ڕ≁ㅹ, 2005; Zhang et al., 2006; 儈䭀ㅹ, 2006; Xiao et al., 2007b; Zhang et al., 2007; Yuan et al., 2010; Guo et al., 2013;
Sigoyer et al., 2014; Guo et al., 2014, 2015)DŽ
15
ഋᐍൠѪᢜᆀᶯඇⲴ䟽㾱㓴ᡀ䜘࠶ˈ⭡ਔݳਔԓ-ᯠݳਔԓ㔃Ღสᓅ઼
к㾶Ⲵ䴷ᰖ-ᯠ⭏ԓⴆቲ㓴ᡀ˗䴷ᰖ㓚-ྕ䲦㓚⺾ኁዙ઼⸣⚠ዙѻкᒯ⌋㕪ཡᘇ
⮉㌫ˈ䲿ਾ㻛⸣⛝㓚-ѝйਐ⻣䞨ⴀዙо⚛ኡዙнᮤਸ㾶ⴆ(ഋᐍⴱൠ䍘ⸯӗተ, 1991)DŽഋᐍൠ㾯े㕈൘嗉䰘ኡѝ⭏ᑖԕᶕᤱ㔝Ⲵ䘶ߢ䖭㦧⭘лˈᖒᡀઘ㕈
ࡽ䱶ൠˈ㋮⺞䇠ᖅҶኡ㙖ਸ䗷〻ѝˈࡽ䱶ൠ⊹〟ѝᗳ৺⊹〟⢙㿴ᖻᙗ䗱
〫ਈॆ䗷〻(ፄ⿹㥳઼嗉ᆖ᰾, 1991; Chen et al., 1994a; Li et al., 2003; Meng et al., 2005)DŽഋᐍൠሂ↖㓚⌕亥ዙǃᘇ⮉㓚亥ዙǃйਐц㫨ਁዙݵᖃཊቲ⅑━
㝡ቲˈॿ䈳嗉䰘ኡੁഋᐍൠՐਈᖒ(Yan et al., 2003b; Wang et al., 2014)ˈ 䈕྇ཊቲ⅑━㝡փ㌫о儈㋮ᓖൠ䴷৽ሴࢆ䶒㔃᷌н䈻㘼ਸ(Hubbard and Shaw, 2009; Hubbard et al., 2010; Feng et al., 2015)DŽ
2.2 Structural and geological history of the Longmenshan and adjacent areas 1) Proterozoic
嗉䰘ኡ⋯ᢜᆀᶯඇNW㕈ˈ⭡ेੁই࠶ᐳݳਔԓᵲዙवᤜ≹ইᵲዙǃޣਓ
ෝǃᒣཤኡǃࡈᇦකォワǃ䖯ᆀ亦ǃ䴚䲶वǃ⢏ᢈǃᖝ♼ǃѩᐤォワǃᇍޤᵲ ዙǃᓧᇊᵲዙㅹ(Figure 2.2)DŽ㋮⺞ᒤԓᆖᇊᒤᐕ㺘᰾䘉ӋᵲዙփቡսҾ840- 750 Maѻ䰤(Li et al., 1999; ᵾ⥞ॾㅹ, 2001; Zhou and Michael, 2002; Yan et al., 2003a; Zhou et al., 2006; ᵾր㠓, 2006; Xiao et al., 2007a; Zhao and Zhou, 2007;
Yan et al., 2008b; Pei et al., 2009; ᵾր㠓ㅹ, 2009)DŽᵲዙփ࠶ᐳаӋสᙗ-䎵ส ᙗץޕփˈ㻛䀓䟺Ѫоൠᒄḡޣ䱶㻲䉧лⲴӗ⢙ˈᒦо◣བྷ࡙ӊൠ४ݳਔ ԓสᙗዙ⍶ሩ∄(Li et al., 1999; ᵾ⥞ॾㅹ, 2001)˗ᴤཊᆖ㘵䙊䗷ൠ⨳ॆᆖ⢩ᖱሩ
∄࠶᷀䇔ѪᢜᆀᶯඇNW㕈䘉Ӌᯠݳਔԓᵲዙփ(䖯ᆀ亦ᵲዙ䲔ཆ)ѪRodiniaབྷ 䱶ਸᰦ⋯ᢜᆀᶯඇ⍫ࣘ䗩㕈؟ߢ㛼Ჟлӗ⭏Ⲵዋᕗ⚛ኡዙ(ഋᐍⴱൠ䍘ⸯӗተ, 1991; 嗉ᆖ᰾, 1991; Zhou and Michael, 2002; Yan et al., 2003a; Zhou et al., 2006;
ᵾր㠓, 2006; ᮷哾ㅹ, 2006; Xiao et al., 2007a; Zhao and Zhou, 2007; Yan et al., 2008b; Pei et al., 2009; ᵾր㠓ㅹ, 2009)DŽ
սҾ嗉䰘ኡे⇥㾯े㕈Ⲵ⻗ਓൠඇˈ࠶࡛ԕࣹ⮕㕍ਸᑖǃ䶂ᐍ-䱣ᒣޣᯝ 㻲ǃ㱾⢉ᯝ㻲Ѫ⭼ˈо嗉䰘ኡ䘶ߢ᧘㾶ᑖ઼ᶮ█-⭈ᆌ㽦ⳡᑖ᧕༔DŽዙᙗ㓴ᡀк Ӿेੁই࠶࡛Ѫ㪓ᇦ⋣ਈ䍘Ⲵ㳷㔯ዙ྇(䎆㓽㚚ㅹ, 2007)ǃ⁚অ㗔⍺〟ዙǃ⻗ਓ
㗔⚛ኡዙǃ⚛ኡ⺾ኁ⊹〟ዙ(䰛ޘӪㅹ, 2003, 2004)ˈ㻛䀓䟺Ѫݳਔԓᰦᵏ
Rodinia䎵བྷ䱶ਸᰦˈਔᶯඇ⭡ेੁইੁ؟ߢⲴаᮤ྇ዋᕗޣዙ྇DŽ
Fgiure 2.2 Proterozoic complex distributed along western boundary of the Yangtze bolock HZ˖Hanzhong complex; HN˖Hannan complex; GKY˖Guankouya complex; LJP˖
Liujiaping complex; PTS˖Pingtoushan complex; JZD˖Jiaoziding complex; MT˖Moutuo complex; PG˖Pengguan complex; XLB˖Xuelongbao complex; DB˖Danba dome; BX˖
Baoxing complex; KD˖Kanding complex.
䘉Ӌݳਔԓ㣡䍘ዙ⸣оᯠݳਔԓਈ⊹〟ዙޡ਼ᶴᡀ嗉䰘ኡൠ४⋯㓯࠶ᐳ ⲴสᓅᵲዙDŽ䖯ᆀ亦ォワṨ䜘⭡ݳਔԓ㣡䍘ዙ⸣઼䙊ᵘằ㗔⚛ኡዙ㓴ᡀDŽ䙊 ᵘằ㗔л⇥ѫ㾱ԕ⚛ኡ⟄ዙѪѫˈѪа྇⦴↖ዙ-ᆹኡዙ-㤡ᆹዙ-⍱㓩ዙ㓴ਸDŽ
ަѝ؍ᆈⲴѝ䞨ᙗ⚛ኡዙⲴዙ⍶䬶⸣LA-ICP-MSᒤ喴ӻҾ829±6 Ma~1000±7 Maˈൠ⨳ॆᆖᮠᦞᣅമ൷㩭Ҿӊ⻡ᙗ㌫ࡇˈൠॆ⢩ᖱሩᓄҾᶯඇ؟ߢ⧟ຳѝዋ ᕗ⚛ኡዙ(Pei et al., 2009; ᵾր㠓ㅹ, 2009, 2011)DŽ㘼⻗ਓ㗔ዙ⸣ⸯ⢙㓴ਸоⸯ
⢙㓴ਸ৽᱐Ⲵ㬍⡷ዙਈ䍘⭘਼ṧ৽᱐Ҷ⌻䰝ਸᰦᡰդ䲿Ⲵ䱶༣࣐ᡆᶯඇ
؟ߢⲴ㔃᷌(兿᱕Ჟ, 1994)DŽ
17
810 Maѻਾ䘋ޕRodinia䎵བྷ䱶㻲䀓䱦⇥ˈൠ㺘ӗࠪԕࡈᇦකォワṨ䜘ࡈ
ᇦක㗔Ѫԓ㺘Ⲵ䞨ᙗ⚛ኡዙ㌫DŽࡈᇦක㗔⚛ኡዙዙ⍶䬶⸣LA-ICP-MSᒤ喴䰤
Ҿ809±11 Maˈ〰൏ݳ㍐ǃᗞ䟿ݳ㍐䝽࠶ᴢ㓯਼ṧ㺘᰾ࡈᇦක㗔оިරⲴབྷ䱶
㻲䉧⍱㓩ዙ⢩ᖱ㊫լˈᖒᡀҾབྷ䱶䗩㕈Ӿᥔࡠըኅ䖜ਈⲴ㻲䉧ᶴ䙐㛼Ჟ(ᵾր 㠓ㅹ, 2009, 2011)DŽ㘼793 MaᐖਣⲴ䖯ᆀ亦䗷䬍䍘ਾ⻠ᫎර㣡ዙˈԕ৺≹ই ᵲዙѝٚ䵎ዙ-⻡ᙗवփ਼ṧ৽᱐བྷ䱶㻲䉧⧟ຳлⲴዙ⍶⍫ࣘ(傜⏖ࡉㅹ, 1997;
Pei et al., 2009)DŽ
ഐ↔ˈ嗉䰘ኡൠ४ᯠݳਔԓᰙᵏਟ㜭ѪRodiniaབྷ䱶㚊ਸӗ⭏а㌫ࡇ⋯ᢜ ᆀᶯඇNW㕈࠶ᐳⲴዋᕗዙ⍶ዙ઼⚛ኡዙˈ䲿ਾ䘋ޕࡠRodiniaབྷ䱶㻲䀓䱦
⇥ˈ४ฏк䘋ޕըኅᶴ䙐㛼ᲟDŽ
䴷ᰖ㓚⻣䞨ⴀዙнᮤਸⴆ൘ࡽ䴷ᰖⲴ㣡ዙ઼ᗞᕡਈ䍘Ⲵ⚛ኡዙǃ⊹〟ዙ кˈ⊹〟⢙⢩ᖱ৺࠶ᐳ㤳ത㺘᰾䴷ᰖ㓚ᰦᵏ㔗ҶRodinia㻲䉧オ䰤ˈᒦф㻲 䉧ተ䲀࠶ᐳˈᮤփк䇠ᖅҶっᇊ⊹〟䗷〻DŽ嗉䰘ኡই⇥䛋ጳԕ㾯ˈйਐц⸲
ዙ⭊㠣ⴤ᧕нᮤњⴆ൘สᓅᵲዙѻкˈ㺘᰾㠣ቁ൘嗉䰘ኡই⇥ˈݳਔԓᵲዙփ
൘ᰙѝ⭏ԓѪਔ䱶ඇᆈ൘ˈާᴹっᇊᔦըⲴṩ䜘(Figure 3.1)DŽ
2) Early Paleozoic
ഋᐍൠ䜘ˈሂ↖㌫઼ྕ䲦㌫ѫ㾱Ѫ⎧ᡆ㓶㋂䱶Ⓚ⺾ኁ⊹〟ዙˈкሂ
↖㔏ተ䜘ൠ४ࠪ⧠㫨ਁዙDŽሂ↖㌫ተ䜘ᮤਸⴆ൘䴷ᰖ㓚⻣䞨ⴀዙкˈᖒᡀа྇
⑀ਈ䗷⊹〟փ㌫DŽሂ↖-ྕ䲦㓚ൠቲа㡜䖳㮴ˈተ䜘ൠ४⭊㠣㕪ཡˈնሂ↖-
ྕ䲦㌫ѝ䰤ᒦнᆈ൘᰾ᱮⲴ䀂ᓖнᮤਸDŽ䱸Ცằ(1987)䇔Ѫᢜᆀᶯඇ㾯㕈൘ሂ
↖㓚ᰦᵏѪっᇊབྷ䱶䗩㕈㻲䉧⧟ຳDŽ䖯ᆀ亦ᵲዙьחࠪ䵢Ⲵ∋ຄᆀ⚛ኡዙˈൠ
ॆ⢩ᖱ઼SHRIMP䬶⸣U-Pbᇊᒤ਼ṧ䀓䟺Ѫ473.6 MaⲴ䱶㻲䉧⚛ኡዙ(ᵾր
㠓, 2009)ˈ䱀䘠Ҷ嗉䰘ኡൠ४ྕ䲦㓚ըኅ㻲䲧⧟ຳDŽ
嗉䰘ኡ䘶ߢ᧘㾶ᑖሂ↖-ྕ䲦㌫ѫ㾱ਁ㛢൘ᖝ♼ᵲዙNEԕ৺嗉䰘ኡे⇥䖯 ᆀ亦ൠ४(Figure 2.3)DŽ⭡Ҿሂ↖-ྕ䲦㌫ਁ⭏ᕪ⛸Ⲵ㽦ⳡਈᖒˈഐ↔ަ⊹〟ᓖ
ާᴹн⺞ᇊᙗDŽሂ↖㌫ԕ㋇㋂⺾ኁዙѪѫˈྕ䲦㌫⭡ቲབྷ⨶ዙ઼ቁ䟿䱶Ⓚ⺾
ኁዙ㓴ᡀˈ൘嗉䰘ኡे⇥㺘⧠Ѫሂ↖-ྕ䲦㓚ок㾶ቲᘇ⮉㌫䘶ߢ㠣ਈ䍘Ⲵᘇ
⮉㌫ѻк(Figure 3.1)ˈ㘼嗉䰘ኡই⇥ྕ䲦㓚ൠቲѫ㾱Ѫа྇㓟߰Ⲵབྷ⨶ዙˈ䇠 ᖅҶ᰾ᱮⲴ丗ᙗਈᖒDŽ
Figure 2.3 Lithostratigraphy of the Sichuan foreland basin and adjacent regions ᘇ⮉㓚ԕᶕˈ嗉䰘ኡൠ४൘っᇊᯌඑкਁ⭏ᤱ㔝ᕐ㻲䲧ˈᒦ᧕ਇᐘⲴ ᘇ⮉㌫⊹〟(Figure 2.3)DŽ嗉䰘ኡ䘶ߢ᧘㾶ᑖᒯ⌋ࠪ䵢Ⲵᘇ⮉㌫㤲৯㗔ˈѫ㾱࠶
ᐳ൘ेᐍ-᱐⿰ᯝ㻲㾯ेחˈᱟа྇ਈ䍘〻ᓖн਼Ⲵ⌕⸲ዙǃॳ᷊ዙǃ⌕䍘⡷ዙ
઼㔒Ӂ⇽⡷ዙˈڦቄཀྵ䘿䮌⣦⚠ዙˈᓖӾ1000-4000 mнㅹˈྲ᷌䘉྇⊹〟
ᓖ߶⺞ˈ㺘᰾ᘇ⮉㓚ᰦᵏᢜᆀᶯඇNW㕈ਁ⭏Ҷᕪ⛸ᘛ䙏⊹䱽ˈᖸਟ㜭ሩᓄ 嗉䰘ኡൠ४ᤱ㔝Ⲵըኅ㻲䲧ˈӗ⭏ᒣ㹼ᢜᆀᶯඇNW㕈࠶ᐳⲴᐘབྷⲴ⊹〟オ 䰤ˈᒦфࡍᖒᡀⲴेᐍ-᱐⿰ᯝ㻲ᖸਟ㜭᧗ࡦ⵰ᘇ⮉㌫ᐘⲴ⊹〟DŽ൘嗉䰘ኡ 䘶ߢ᧘㾶ᑖ㞩䱶䖯ᆀ亦ǃ䴚䲶वǃ⢏ᢈㅹൠˈᘇ⮉㓚олԿሂ↖-ྕ䲦ൠቲᯝ
19
ቲᡆ䀂ᓖнᮤਸ᧕䀖(Figure 3.1)ˈᤷ⽪᰾ᱮⲴਾᵏᶴ䙐ਐ࣐᭩䙐⭘DŽᮤ྇ᘇ
⮉㌫㤲৯㗔㓿শҶվ㔯⡷ዙਈ䍘⭘ˈተ䜘ൠ४䗮ࡠվ䀂䰚ዙਈ䍘
⭘ˈᒦ䇠ᖅҶᆼᮤⲴᐤ㖇රਈ䍘ᑖ(Worley et al., 1995; Arne et al., 1997)DŽ
ᙫփᶕⴻˈሂ↖-ᘇ⮉㓚ൠቲ൘嗉䰘ኡൠ४࠶ᐳާᴹተ䲀ᙗˈ൘ᢜᆀᶯඇे
㕈㕪ཡᰙሂ↖ц⊹〟ˈ൘䖯ᆀ亦ൠ४㕪ཡѝሂ↖ц-ྕ䲦㓚⊹〟ˈ㘼ᘇ⮉㌫৸ᱟ а྇ᐘ⊹〟ˈ䘉⿽ᓖǃዙ৺ൠቲ㕪ཡⲴь㾯ᯩੁਈॆˈ৽᱐嗉䰘ኡൠ४
൘ᰙਔ⭏ԓ㓿শҶ㻲䀓-ᣜॷ-ተ䜘㻲䀓Ⲵ৽༽䗷〻ˈնަ⊹〟⧟ຳᙫփѪըኅ 㻲䲧⧟ຳ(嗉ᆖ᰾, 1991; ᵾր㠓ㅹ, 2009, 2011)DŽ
3) Late Paleozoic
ਔ⭏ԓᰦᵏˈᢜᆀᶯඇ㻛ࣘབྷ䱶䗩㕈嗉䰘ኡൠ४ਁ⭏ཊᵏᕐᙗһԦ(丙ݻ
⥧, 1984; 㖇ᘇ・, 1984; 嗉ᆖ᰾, 1991)ˈᖒᡀа㌫ࡇNE-SW䎠ੁⲴ਼⊹〟↓ᯝ ቲˈ᧗ࡦ⌕㓚䘁6000 mⲴ⊹〟DŽ嗉䰘ኡ䘶ߢ᧘㾶ᑖл⌕㔏Ѫа྇⍵⎧
⸲ዙǃ㊹⸲ዙǃ⌕ዙ઼⌕⚠ዙˈ⊹〟ᓖ䗮ࡠ3000 mԕкDŽѝк⌕㔏ѫ㾱Ѫ а྇⻣䞨ⴀዙˈᓖӾ300 mࡠ2000 mнㅹˈѫ㾱࠶ᐳ൘嗉䰘ኡे⇥Ⲵୀ⦻መ
ੁᯌ઼嗉䰘ኡই⇥ᡀ䜭㾯䜘ൠ४(Figure 3.1)ˈо⸣⛝-лйਐ㔏ޡ਼ᶴᡀ嗉䰘ኡ ኡࡽⲴ伎ᶕጠ઼䘶ߢ᧘㾶ᑖˈᒦ㓿শҶᒯ⌋ਈ䍘઼ᕪ⛸ⲴਈᖒDŽ൘ᶮ█-⭈ᆌ㽦 ⳡᑖь䜘䗩㕈࠶ᐳⲴл⌕㔏ᓖ䗮1000 mᐖਣˈ⊹〟⢩ᖱᱮ⽪Ѫབྷ䱶ᷦᯌඑ 㠣␡≤⊹〟⧟ຳˈተ䜘ൠ४⭊㠣㺘⧠ࠪ༽⨶⸣⊹〟严ᖻDŽ
⹄ウ४བྷ䜘࠶४ฏ㕪ཡ⸣⛝㓚ൠቲˈӵ൘嗉䰘ኡ䘶ߢ᧘㾶ᑖ઼ᶮ█-⭈ᆌ㽦 ⳡᑖь䜘䗩㕈ᴹ䲀ӗࠪDŽ嗉䰘ኡ䘶ߢ᧘㾶ᑖ⸣⛝㓚ൠቲཊѪ⍵≤⧟ຳл⚠ዙ
઼ⲭӁዙˈཀྵቁ䟿⸲䍘⚠ዙ઼亥ዙˈо⌕㓚ൠቲа䎧ԕ伎ᶕጠ઼᧘㾶փᖒᔿ ӗࠪDŽᶮ█-⭈ᆌ㽦ⳡᑖь㕈ˈ⸣⛝㌫བྷཊѪ⚠ዙǃ㊹⸲ዙ৺␡≤⧟ຳⲴ亥ዙˈ
ᓖӵᴹࠐⲮ㊣DŽ⌕-⸣⛝㓚ൠቲ⊹〟⢩ᖱ㺘᰾嗉䰘ኡൠ४⊹〟⧟ຳӾᘇ⮉㓚 ԕᶕаⴤ؍ᤱ⵰ըኅ㛼ᲟлⲴ␡≤⧟ຳDŽ
ഋᐍൠ㾯䜘лҼਐ㔏ѫ㾱⭡⍵≤⚠ዙ઼ⲭӁዙ㓴ᡀˈਜ਼⸲䍘ᓅዙˈ 㓿শᕪ⛸㽦ⳡਈᖒ⭘DŽҼਐцᰦᵏˈ嗉䰘ኡ㾯ই䜘ǃӁইൠ४ᒯ⌋ץޕ⦴
↖ዙ(ጘⴹኡ⦴↖ዙ)ˈተ䜘ൠ४ᓖ䗮2000-4000 m(ഋᐍⴱൠ䍘ⸯӗተ, 1991)ˈ ᒦ൘嗉䰘ኡ䘶ߢ᧘㾶ᑖਁ⧠оጘⴹኡൠ४ޣⲴ⦴↖ዙ(ࡈṁṩㅹ, 1991)DŽҼ
ਐц嗉䰘ኡൠ४Ⲵըኅ⭘䗮ࡠ亦ጠ䱦⇥ˈᒦ⋯ᢜᆀᶯඇNW䗩㕈ᒯ⌋⊹〟⻣
䞨ⴀ䟽࣋⍱ǃ⍺〟ዙǃ␡≤䍘ዙㅹըኅ⧟ຳлⲴ⢩ᖱ⊹〟⢙(㖇ᘇ・, 1984, 1991, 1994; Chen, 1985; 㖇ᘇ・઼嗉ᆖ᰾, 1992; ᵡ਼ޤ઼㫢ᗳ㓟, 1994)DŽ
ᶮ█-⭈ᆌ㽦ⳡᑖь㕈ⲴлҼਐ㔏ᓖ䖳㮴ˈ䙊ᑨ൘100 mᐖਣˈ⭡␡≤亥 ዙǃ⸲ዙ઼⚠ዙ㓴ᡀˈ䙊ᑨਜ਼ᴹཆᶕ⚠ዙ⸣ഒඇDŽаӋ⺾ኁዙ㺘⧠ࠪ⍺〟ዙ
⢩ᖱˈਟ㜭⊹〟Ҿབྷ䱶઼ᷦ␡≤ᒣˈൠቲቲᒿѝዙቲо⚠ዙথ⸣ቲӂቲ㺘
᰾४ฏкᕪ⛸Ⲵըኅ⍫ࣘ(Chen, 1985; ᵡ਼ޤ઼㫢ᗳ㓟, 1994)DŽ൘ᶮ█-⭈ᆌ㽦 ⳡᑖই䜘ˈӗࠪ⎧᷅⣦⟄ዙDŽᰐ䇪ᱟ൘ᢜᆀᶯඇ㾯े㕈䘈ᱟᶮ█-⭈ᆌьই 㕈ˈоըኅ਼ᵏⲴสᙗዙ㜹઼ሿරץޕփ࠷ࢢҼਐԕࡽⲴൠቲঅݳDŽ嗉䰘ኡ 䱴䘁ዙ⸣സ儈ᇶᓖǃ儈⭥䱫⦷Ⲵสᙗǃ䎵สᙗᔲᑨ⢙䍘Ⲵᆈ൘ˈҏ㺘᰾䈕४ ᴮਁ⭏䗷ዙ⸣സⲴᕐ㻲৺⟄㶽ൠᒄ⢙䍘Ⲵབྷ䟿к⎼(ᵾ・઼䠁ഭݳ, 1987)DŽ ൠ䴷৽ሴࢆ䶒ҏ⽪ࠪഋᐍઘ㕈ࡽ䱶ൠҼਐ㓚ⴆቲл↻ᆈਔ⭏ԓ㻲䉧ൠ(Jia et al., 2006)DŽ
4) Mesozoic
л-ѝйਐ㔏൘ᶮ█-⭈ᆌ㽦ⳡᑖࠪ䵢ᴹ䲀ˈоഋᐍൠ㾯े㕈਼ቲսዙᙗ
լˈ൷Ѫа྇⍵⎧⻣䞨ⴀዙ઼䍘⺾ኁዙDŽ⻣䞨ⴀዙˈཊѪቲ⚠ዙǃާᴹ Ӕ䭉ቲ⨶Ⲵ勅㋂⚠ዙ˗䍘⺾ኁዙ䙊ᑨо㊹⸲ዙǃ亥ዙо⻣䞨ⴀӂቲ㓴ᡀ (Figure 2.4)DŽлйਐ㔏ᴰᓅ䜘Ⲵ伎ԉޣ㓴⭡ᴤ␡⎧Ⲵ㮴ቲ⚠ዙо⍺〟ዙර⸲
ዙ㓴ᡀDŽᒯ⌋࠶ᐳⲴቲ⍵㢢Ⲵ⻣䞨ⴀዙᤷ⽪བྷ䱶ᷦ⊹〟⧟ຳˈ㘼࠶ᐳⲴӔ䭉 ቲ⨶Ⲵ⚠ዙ઼勅㋂⣦⚠ዙ㺘᰾䙀⑀ੁ⍵≤⧟ຳ䖜ਈDŽлйਐ㔏伎ԉޣ㓴Ⲵ␡⎧
ዙ⸣䀓䟺ᡀ␡≤㻲䉧⊹〟ˈਟ㜭Ѫ嗉䰘ኡൠ४Ҽਐ㓚㻲䉧ԕᶕᤱ㔝Ⲵ⊹〟⢙
(㖇ᘇ・઼嗉ᆖ᰾, 1992)DŽ䢤Ҿ൘ᮤњഋᐍൠઘ䗩ѝ-лйਐ㔏ᒦᵚ㿲ሏࡠབྷ䱶
ᷦޣⲴ⧺⪊⼱ᡆ⍵⎧⧺⪊⺾ኁˈԕ৺⌕ዙǃ亥ዙǃ⌕⚠ዙ৽᱐Ⲵ⊹〟ˈ ਟԕ䇔Ѫѝ-лйਐ㔏ഋᐍൠ㾯े㕈ൠ४䙀⑀䖜ਈѪっᇊൠ⊹〟䱦⇥㘼䶎⧺
⪊⼱⧟ዋ(Read, 1985; Meng et al., 2005)DŽ
ᰐ䇪൘ഋᐍઘ㕈ࡽ䱶ൠ䘈ᱟᶮ█-⭈ᆌ㽦ⳡᑖˈєњঅݳкйਐ㔏⊹〟
⧟ຳ൷ਁ⭏ᱮ㪇ਈॆ˖൘ഋᐍࡽ䱶ൠˈкйਐ㔏⭡ᴰл䜘⍵⎧傜䶽ຈ㓴
ੁкнᮤਸ䗷ࡠ䱶Ⓚ⺾ኁ⊹〟Ⲵ享ᇦ⋣㓴(Figure 2.4)ˈф䈕нᮤਸ⭼䶒ӵ൘ ઘ㕈ࡽ䱶ൠਁ㛢ˈ㺘᰾ѕṬਇ嗉䰘ኡ䘶ߢ᧘㾶ᑖ⍫ࣘ᧗ࡦˈഋᐍൠᔰ⭡
21
っᇊⲴ㻛ࣘ䱶㕈ᔰੁࡽ䱶ൠ⍫ࣘ䱶㕈䖜ਈDŽ䱶享ᇦ⋣㓴ѫ㾱⭡⚠㢢⸲
ዙǃቁ䟿亥ዙ৺➔ቲԕ৺н਼ቲսⲴᓅዙ㓴ᡀˈަ⊹〟઼⊹〟ᓖ൘⁚ੁ
кਁ⭏ᐞᔲᙗਈॆˈᮤփᓖ䘌བྷҾަл䜘⎧Ⲵ⻣䞨ⴀዙ⊹〟(Chen et al., 1994a; Chen et al., 1995; Meng et al., 2005; Li et al., 2013; Luo et al., 2014; Zhang et al., 2015)DŽ䶐䘁嗉䰘ኡ䘶ߢ᧘㾶ᑖˈ享ᇦ⋣㓴ѫ㾱⭡㋇㋂⊹〟⢙ǃߢ〟ዙ㓴 ᡀˈ䲿⵰ੁഋᐍൠ䗱〫ˈ䙀⑀䖜ਈѪ⒆⋺㓶㋂⊹〟DŽ享ᇦ⋣㓴ᮤփкѪ аⴤ嗉䰘ኡⲴᾄᖒ⊹〟փˈᓖੁഋᐍൠ䜘䙀⑀ቆ⚝DŽ䘉⿽⊹〟⭡⍵
⎧ੁ䱶䖜ਈԕ৺ᾄᖒⲴൠቲᓖˈ㻛䀓䟺Ѫ嗉䰘ኡ䘶ߢ᧘㾶ᑖሩഋᐍൠ 䘶ߢ࣐䖭ӗ⭏Ⲵࡽ䱶ൠ⊹〟(ፄ⿹㥳઼嗉ᆖ᰾, 1991; Chen et al., 1994a; ᴮݱᆊ
઼ᵾࣷ, 1995; ࡈṁṩㅹ, 1995; Li et al., 2003; 䍮ьㅹ, 2003)DŽൠ⨳⢙⨶ᮠ٬⁑ᤏ ҏ㺘᰾ഋᐍઘ㕈ࡽ䱶ൠ൘嗉䰘ኡйਐц䘶ߢ᧘㾶࣐䖭лᖒᡀ(Li et al., 2003;
Meng et al., 2005; He, 2014)DŽ嗉䰘ኡे⇥ˈᕪ⛸㽦ⳡⲴкйਐ㔏享ᇦ⋣㓴㻛лֿ
㖇㔏ⲭ⭠ඍ㓴нᮤਸ㾶ⴆˈੁ嗉䰘ኡই⇥䙀⑀䗷Ѫ享ᇦ⋣㓴ഋ⇥о享ᇦ⋣㓴 й⇥Ⲵнᮤਸ᧕䀖ޣ㌫(Figure 2.4)ˈ㺘᰾嗉䰘ኡ䘶ߢ᧘㾶ᑖ൘ੁഋᐍൠՐ
䗷〻ѝⲴᰦオ䗱〫ᙗDŽࡽ䱶ൠ⊦ᐍаਧ䫫ᆄ䍴ᯉᱮ⽪ˈ᱐⿰-ेᐍᯝ㻲ԕ㾯ˈ ᖝ♼ᵲዙо享ᇦ⋣㓴⸲ዙԕᶴ䙐ዙ⡷ਐ㖞Ⲵᯩᔿӗࠪˈф享ᇦ⋣ᰙᵏ⊹〟⢙ҏ ধޕ䘉ᵏ䘶ߢਈᖒˈ䈤᰾ेᐍ-᱐⿰ᯝ㻲Ⲵ䘶ߢ⍫ࣘˈ֯ࡽ䱶ൠੁഋᐍൠ
䗱〫DŽкйਐ㔏享ᇦ⋣㓴Ҽ⇥⸲ዙѝࠪ⧠ᖝ♼ᵲዙสᓅᵲዙǃ䴷ᰖ㓚⚛ኡዙ઼
ѝ-лйਐ㔏⸲ዙ⸣ˈᤷ⽪嗉䰘ኡൠ४ݳਔԓสᓅ൘йਐцᰦ㠣ቁ䜘࠶᳤䵢
൘ൠ㺘(ፄ⿹㥳઼嗉ᆖ᰾, 1991; Li et al., 2014)DŽ
嗉䰘ኡই⇥ᘰ䘌㾯䜘ˈ享ᇦ⋣㓴⸲ዙⴤ᧕нᮤਸ㾶ⴆ൘ݳਔԓᵲዙѻкˈ фݳਔԓਈ䍘ⴆቲ઼䲿ਾⲴሂ↖-Ҽਐൠቲ൘ᇍޤൠ४䘎㔝ӗࠪˈ䈤᰾൘嗉䰘ኡ ই⇥ݳਔԓสᓅ൘йਐцᰦᵏԕਔ䱶ᖒᔿᆈ൘(Figure 3.1)DŽ
Figure 2.4 Mesozoic lithostratigraphy of the northwest Sichuan basin and adjacent regions (Meng et al., 2005)
23
ᶮ█-⭈ᆌ㽦ⳡᑖˈкйਐ㔏ѪᐘⲴ༽⨶⸣⊹〟ˈ㓿শᕪ⛸㽦ⳡਈᖒˈ ተ䜘ൠ४ᓖਟ䗮10 kmˈަѝধޕਈᖒᴰᒤ䖫ⲴൠቲѪ䈪࡙ᵏ䳵⊏㓴ˈ䲿ਾ
㻛йਐцᵛ⪎ᴯᵏޛᇍኡ㓴нᮤਸ㾶ⴆ(Figure 2.4)ˈḷᘇ⵰㽦ⳡᑖ⍫ࣘⲴ㓸 㔃DŽ㽦ⳡᑖᒯ⌋NW-SE䎠ੁⲴ㽦ⳡᖒ䘩㺘᰾ਈᖒᰙᵏNE-SWੁᥔ㕙⸝ˈ
ੁSE䶐䘁嗉䰘ኡ䘶ߢ᧘㾶ᑖˈ㽦ⳡ䖤䘩ᕗᖒੁইᕟᴢˈ䲿ਾਈѪNE-SW䎠
ੁⲴ㽦ⳡᖒ䘩(Figure 2.1)DŽ㽦ⳡᖒ䘩Ⲵਈॆˈ㻛䀓䟺Ѫйਐ嗉䰘ኡਁ⭏ᐖ㹼
ᢝᙗ䎠━Ⲵ㔃᷌(Dirks et al., 1994; 䱸⽮ਁㅹ, 1994a, b; Chen et al., 1995; Arne et al., 1997; Meng et al., 2005)DŽᶮ█-⭈ᆌ㽦ⳡᑖץޕབྷ䟿ѝ⭏ԓAරǃIරǃ 䫉⻡ᙗ઼ෳ䗮ݻ䍘㣡ዙˈᒤ喴൘226-205 Maѻ䰤(Roger et al., 2004; 㜑ڕ≁
ㅹ, 2005; Zhang et al., 2006; Xiao et al., 2007b; Zhang et al., 2007; Yuan et al., 2010;
Sigoyer et al., 2014)DŽབྷཊᮠዙփ࠷ク㽦ⳡᖒ䘩ᒦਁ㛢⧟⣦᧕䀖ਈ䍘ᑖˈሶᶮ█-
⭈ᆌᕪ⛸Ⲵ㽦ⳡਈᖒ䘋а↕䲀ᇊ൘йਐѻࡽDŽ❦㘼ˈ㠚⭏Ժ࡙⸣K-Arᒤ喴
৸㺘᰾ᮤњ㽦ⳡᑖ㓿শᒯ⌋190-150 MaⲴਈ䍘⭘(༿ᇇᇎ, 1993)DŽ
ֿ㖇㌫ⲭ⭠ඍ㓴Ѫа྇অᡀ࠶ዙ઼ਁ㛢ᶯ⣦Ӕ䭉ቲ⨶Ⲵ⸲ዙˈੁഋᐍ
ൠ䜘䙀⑀ਈѪ㓶㋂⸲ዙ(Figure 2.4)ˈѪа྇䱶⋣⍱ǃ⒆⋺⊹〟ˈѫ㾱࠶ᐳ
൘嗉䰘ኡे⇥㊣ԃኡই䜘ԕ৺嗉䰘ኡই⇥䛋ጳԕ㾯(Figure 3.1)DŽокйਐ㔏享 ᇦ⋣㓴∄ˈлֿ㖇㔏ᱮ㪇⢩ᖱᱟ൘ᮤњഋᐍൠަᓖ䜭∄䖳൷аˈᓅዙ ҏнˈᖸཊൠᯩн䎵䗷100 mˈ⸣ѫ㾱⭡㜭ᒢᙗ䖳ᕪⲴਔ⭏ԓ⸣㤡ዙǃ⚠
ዙ઼བྷ⨶ዙˈަ㢟ྭⲴ⼘ശᓖ㺘᰾㓿শ䖳䮯䐍Ⲵᩜ䘀DŽᮤ྇⸣ѝᒦᵚ㿱ݳ ਔԓสᓅᵲዙᡆѝ⭏ԓ㣡ዙ⢙䍘DŽлֿ㖇㔏ᓖ൷аˈᒯ⌋ਁ㛢Ⲵ㮴Ⲵᓅ
ዙˈ⸣㢟ྭⲴ⼘ശ㺘᰾ᰙֿ㖇ц嗉䰘ኡ༴Ҿ䙐ኡਾⲴᆱ䶉ᵏDŽѝкֿ㖇㔏ॳ
ዙ㓴઼⋉ⓚᓉ㓴Ѫа྇ቲ⸲ዙǃ㊹⸲ዙ઼亥ዙˈൠԕߢ〟ᡷ⊹〟ǃ⋣
⌋⒆⋺⊹〟Ѫѫˈѫ㾱䳶ѝ൘嗉䰘ኡे⇥㊣ԃኡই䜘઼嗉䰘ኡই⇥䛋ጳԕ㾯ˈ
⺾ኁ䬶⸣઼ਔ≤⍱ᯩੁ㺘᰾嗉䰘ኡे⇥Ⲵѝкֿ㖇㔏⊹〟⢙Ⓚѫ㾱ᶕ㠚嗉䰘ኡ 㾯े⇥ǃ㊣ԃኡ઼བྷᐤኡˈ㘼ই⇥⢙Ⓚѫ㾱ᶕ㠚嗉䰘ኡ䘶ߢ᧘㾶ᑖ(ፄ⿹㥳઼嗉 ᆖ᰾, 1991; 㖇ᘇ・઼嗉ᆖ᰾, 1992; Luo et al., 2014)DŽ䘉⿽ቲ⋣⌋⊹〟઼ߢ〟
ᡷ⊹〟㺘᰾ࡽ䱶ᥐᴢൠ䖭㦧㛼Ჟ(Heller et al., 1988; Jordan, 1995)ˈ䈤᰾ֿ㖇 цᔰˈ嗉䰘ኡ䘶ߢ᧘㾶ᑖᔰᯠа䖞ੁSE䘶ߢ᧘㾶ᒦሩഋᐍࡽ䱶ൠ࣐
䖭DŽ䘉аᵏⲴ䘶ߢ᧘㾶ਟ㜭ሬ㠤嗉䰘ኡ⋯㓯лֿ㖇㔏ൠቲਁ⭏㽦ⳡਈᖒ(Figure
3.1)DŽഋᐍൠֿ㖇㓚ൠቲˈ൘ᒣ㺑ࢆ䶒࠶᷀ѝѪ䟽㾱Ⲵḷᘇቲ䇱᰾嗉䰘ኡ ኡࡽᕪ⛸Ⲵ㽦ⳡǃ䘶ߢՊӗ⭏ᱮ㪇Ⲵൠ࣯ᣜॷ(䱸ㄩᯠㅹ, 2005; Hubbard and Shaw, 2009; Hubbard et al., 2010)DŽ
ⲭෙ㓚ൠቲ൘ഋᐍൠ㾯䜘ᒯ⌋࠶ᐳˈ൘嗉䰘ኡই⇥㻛ᒯ⌋Ⲵㅜഋ㓚㾶ⴆ (Figure 3.1)DŽ⋯嗉䰘ኡ䘶ߢ᧘㾶ᑖˈьे⇥ⲭෙ㓚ൠቲབྷཊԕঅᯌᖒᔿੁഋᐍ
ൠᔦըˈ㘼㾯ই⇥ⲭෙ㓚ൠቲ਼ṧধޕ㽦ⳡ઼䘶ߢ᧘㾶ਈᖒˈфкⲭෙ㔏 олⲭෙ㔏ԕ䀂ᓖнᮤਸޣ㌫ӗࠪˈлⲭෙ㔏ѻਾ嗉䰘ኡઘ㕈ࡽ䱶ൠ⅑࣐
䖭⊹〟ˈ嗉䰘ኡ㾯ই⇥ⲭෙ㓚-ᰙㅜй㓚ᰦᵏⲴࡽ䱶ൠ᰾ᱮਐ࣐൘йਐц ઘ㕈ࡽ䱶ൠѻкˈ㺘⧠᰾ᱮⲴ⭏ࡽ䱶ൠ⢩ᖱˈ⭏ࡽ䱶ൠㅹമᤷ⽪
⊹〟ѝᗳ䳶ѝ൘嗉䰘ኡ㾯ই⇥ˈ㺘᰾㠣ቁ൘嗉䰘ኡ㾯ই⇥ⲭෙц㠣ᰙㅜй㓚 䟽ᯠ㓿শ䘶ߢ᧘㾶⍫ࣘ(䍮ьㅹ, 2003; 䇨ᘇ⩤ㅹ, 2007; Xu et al., 2008; Tian et al., 2016)DŽ㋮㓶ൠ䴷ࢆ䶒㺘᰾ˈ嗉䰘ኡই⇥⭏ࡽ䱶ൠˈⲭෙ㓚ൠቲ㺘⧠ࠪި
රⲴ⭏䮯ൠቲ⢩ᖱˈ㔃ਸᇍޤᵲዙ㾯䜘㌌ἡዙᑖⲭෙц-ᰙㅜй㓚40Ar/39Arᒤ ԓᆖ㔃᷌ˈ䘋а↕㺘᰾嗉䰘ኡ㾯ই⇥ཊᵏ⅑ਐ࣐⍫ࣘ(Jia et al., 2006; Tian et al., 2016)DŽ
5) Cenozoic
⭡Ҿ嗉䰘ኡൠ४ᯠ⭏ԓൠቲнਁ㛢ˈᯠ⭏ԓᶴ䙐㺘⧠ᒦнᱮ㪇DŽվᒤԓ ᆖᮠᦞǃ⋣⍱ץ㲰䙏⦷㺘᰾嗉䰘ኡѪ䶂㯿儈ь㕈ˈਇᯠ⭏ԓঠᓖ-⅗ӊབྷ䱶
⻠ᫎᖡ૽ˈൠ࣯ਁ⭏ᱮ㪇䲶ॷˈᶮ█-⭈ᆌ㽦ⳡᑖ㣡ዙоᖝ♼ᵲዙⲴ⼧⚠⸣
㻲ਈᖴ䘩㔃᷌㺘᰾⊦ᐍ-㤲⊦ᯝ㻲єחㅜй㓚ਁ⭏Ҷᱮ㪇Ⲵᐞᔲ䲶ॷˈ㘼᱐⿰-
ेᐍᯝ㻲єח⢙䍘ѝᯠцԕᶕҏਁ⭏Ҷᐞᔲᙗ䲶ॷ(Arne et al., 1997; Kirby et al., 2002; Clark et al., 2005; Godard et al., 2009; Wang et al., 2012; Cook et al., 2013;
Furlong and Kirby, 2013; Tian et al., 2013)DŽᯠ⭏ԓᕪ⛸Ⲵ䲶ॷ֯嗉䰘ኡ⋯㓯Ⲵݳ ਔԓสᓅᵲዙབྷ㿴⁑㲰ˈԕᒯ⌋⸣⊹〟൘ㅜй㓚བྷ䛁ዙѝ(Chen et al., 1994b; Chen and Wilson, 1996)DŽ൘嗉䰘ኡൠ४ˈᯠ⭏ԓᶴ䙐㺘⧠ԕ㜶ᙗ㻲Ѫ ѫˈᖸ䳮ৈᇊᯠ⭏ԓ丗ᙗਈᖒDŽ⭡Ҿঠᓖᶯඇᤱ㔝ੁेⲴᥔˈሬ㠤䶂㯿儈
⢙䍘ੁьই䘳䙨(Tapponnier et al., 2001)ˈ50-21 Maᵏ䰤ݸ⋯૰⢒ኡ-㓒⋣ᐖ㹼䎠
━ᯝ㻲חੁ䘳䙨(Tapponnier et al., 1990; Harrison et al., 1992; Leloup and Kienast,
25
1993)ˈ䲿ਾ⋯NW-SE䎠ੁⲴᐖ㹼䎠━勌≤⋣ᯝ㻲ਁ⭏חੁ䘳䙨ˈᒦդᴹ12
Maᕪ⛸Ⲵዙ⍶⍫ࣘ(Roger et al., 1995)DŽ
2.3 Previous evolutionary models of the Longmenshan thrust belt
嗉䰘ኡ䘶ߢ᧘㾶ᑖѪ䟽㾱Ⲵൠ䍘⭼㓯ˈ਼ᰦѪањѝ⭏ԓ-ᯠ⭏ԓཊᵏ ਈᖒⲴ༽ਸර䙐ኡᑖˈަᴰިරⲴ⢩ᖱнӵ㺘⧠Ѫᶱ儈Ⲵൠ࣯ǃ࣐Ⲵൠ༣ˈ 䘈㺘⧠ࠪᶱབྷ㿴⁑Ⲵ䘶ߢ᧘㾶⭘઼оѻդ⭏Ⲵઘ㕈ࡽ䱶ൠDŽ㓿䗷ࠐॱᒤⲴ
⹄ウˈབྷᇦᲞ䙽䇔ਟⲴᱟ嗉䰘ኡѪањ༽ਸර䙐ኡᑖˈ㠣ቁ㓿শҶѝ⭏ԓ઼
ᯠ⭏ԓєᵏᶴ䙐ਈᖒˈᒦфᯠ⭏ԓⲴਈᖒሩᰙᵏⲴ䎧ࡠᶴ䙐⍫ॆ⭘(Burchfiel et al., 2008; Roger et al., 2010; Liu et al., 2013)DŽࡽӪ䙊䗷ሩ嗉䰘ኡ઼ᶮ█-⭈ᆌ㽦 ⳡᑖᶴ䙐ᆖǃ਼ս㍐ᒤԓᆖᐕˈ㔃ਸൠ⨳⢙⨶৽ሴࢆ䶒ԕ৺ഋᐍઘ㕈ࡽ䱶
ൠⲴ╄ॆশਢˈሩ嗉䰘ኡ䘶ߢ᧘㾶ᑖⲴᖒᡀᨀࠪҶн਼Ⲵ㿲⛩ˈሩ嗉䰘ኡ䘶ߢ ᧘㾶ᑖѫ㾱ࣘ࣋ᆖ⁑රѫ㾱䳶ѝ൘ᰙѝ⭏ԓǃѝ⭏ԓ઼ᯠ⭏ԓйњᰦ䰤⇥DŽ
1) Early Mesozoic
嗉䰘ኡ䘶ߢ᧘㾶ᑖᰙѝ⭏ԓ䙐ኡ⁑ᔿᴰᰙ⭡㖇ᘇ・(1984)ᨀࠪⲴCර؟ߢ
⁑ᔿˈн਼ҾՐ㔏Ⲵ⌻༣ੁ䱶༣؟ߢ⁑ᔿDŽ䈕⁑ᔿᤷࠪˈ嗉䰘ኡսҾっᇊབྷ䱶
ൠ䗩㕈ˈ⭡Ҿ↓ᯝቲ⍫ࣘˈ֯␡䜘ዙ⸣സ߿㮴㻲ˈᡀѪ▌൘Ⲵ㻲䶒˗
㓿শਔ⭏ԓ-ᰙѝ⭏ԓっᇊ⊹〟⭘ˈ൘ᮠॳࡠᮠз㊣Ⲵ䱶⊹〟⢙࣐䖭ǃ
ᇎлˈᖒᡀⲴ⊹〟⢙ᓖབྷҾ䘁ԓ⎧⌻⊹〟⢙ⲴᇶᓖˈᐘབྷⲴ䟽࣯࣋㜭֯⊹
〟ⴆቲⲴสᓅ⭊㠣㧛䴽䶒ਁ⭏䭉ᯝǃ⊹䱽ˈሬ㠤ዙ⸣സਁ⭏䭉ࣘˈᖒᡀੁ嗉䰘 кٮᯌⲴ⭼䶒(Figure 2.5)DŽঠ᭟ᰙᵏˈ嗉䰘ኡൠ४Ⲵሂ↖㓚-ᘇ⮉㓚ᒯ⌋⊹〟
Ⲵ⌕䍘ዙѪ━㝡ቲˈᐘ⊹〟⢙⋯⵰━㝡ቲˈ൘ᕪབྷ䟽࣋䖭㦧⭘лˈੁ
嗉䰘ኡᯩੁ▌〫ˈ֯ᰙᵏⲴ↓ᯝቲ৽䖜Ѫ䘶ᯝቲˈ䈕䱦⇥ᕪ䈳⢙䍘㠚䓛䟽࣯࣋
㜭Ⲵ⭘ሬ㠤䙐ኡ˗ঠ᭟ᵏˈ⭡Ҿᶮ█-⭈ᆌᐢ㓿പ㔃ˈь䜘ਔཚᒣ⌻ᶯඇ؟
ߢⲴ䘌〻᭸ᓄˈ֯嗉䰘ኡൠ४สᓅ䘋а↕⎸߿઼䘶ߢDŽᶮ█-⭈ᆌ㽦ⳡᑖⲴዙ
⍶ዙᡀ࠶⭡ьੁ㾯ਁ⭏㿴ᖻᙗਈॆˈਟ㜭ਇᢜᆀൠ༣઼ൠᒄੁ㾯ٮᯌ؟ߢ䗷〻 ѝሬ㠤Ⲵዙ⍶࠶ᔲDŽൠ䴷⍻␡ࢆ䶒઼བྷൠ⭥⻱㔉ࠪⲴㅹᓖ㔃ᶴമ㺘᰾⊦ᐍ-㤲
⊦ᑖԕлˈዙ⸣സㅹ㓯ᡀ㠼⣦ੁ㾯䜘лᨂˈ䘈ᵚࡠ䗮✝൷㺑Ⲵ⣦ᘱDŽഐ↔ˈ Cර؟ߢⲴᵜ䍘ᱟݸ㻲䉧䗩㕈൘ᐘ⊹〟⢙㾶ⴆॷ઼㠚䓛䟽࣋⭘лˈਔ
ཚᒣ⌻ᶯඇ؟ߢⲴ䘌〻᭸ᓄˈ֯ᢜᆀᶯඇੁ㾯ਁ⭏Ҷ䱶⎸߿؟ߢ⭘ˈᒦ൘ 嗉䰘ኡൠ㺘㺘⧠Ѫа㌫ࡇ䘶ߢ᧘㾶ᶴ䙐(Figure 2.5; 㖇ᘇ・, 1984, 1991, 1994; 㖇 ᘇ・઼઼嗉ᆖ᰾, 1992)DŽ
Figure 2.5 C-type subdcution model proposed by Luo 1984
䇨ᘇ⩤䙊䗷ሩᶮ█-⭈ᆌ䈖㓶Ⲵᶴ䙐ປമᨀࠪйඇփ˖ণे䜘Ⲵࣣӊ䱶ඇ (ᰶԁඇփ)ǃь䜘Ⲵᢜᆀᶯඇ৺㾯䜘Ⲵ᰼䜭-㖼ຈᗞᶯඇӂ⭘ˈሬ㠤ᢜᆀᶯ ඇे䜘ǃ㾯ই䜘ਔ⢩ᨀᯟ⌻є᭟؟ߢ⻠ᫎ৺䱶≷㚊ˈӗ⭏ԕᶮ█-⭈ᆌ㽦ⳡᑖ ѪѫփⲴ━㝡රኡ䬮(Figure 2.6; 䇨ᘇ⩤ㅹ, 1991; 䇨ᘇ⩤ㅹ, 1992; ⦻ᇇ⿰ㅹ, 1997)DŽ俆ݸˈᶮ█-⭈ᆌˈ⭡Ҿਔ⢩ᨀᯟ⌻㓿⭡䱯ቬ⧋য㕍ਸᑖੁे؟ߢˈ ӗ⭏ᕪ⛸Ⲵ⭡ेੁইⲴᥔਈᖒˈᶴᡀ䘁ь㾯ੁੁইࠨࠪⲴᕗᖒ━㝡ᑖ˗䲿ਾ
ਔ⢩ᨀᯟ⌻ই᭟⋯⭈ᆌ-⨶ຈ㕍ਸᑖੁSWੁѹᮖዋᕗл䶒؟ߢ䰝ਸˈ൘ᶮ█-
⭈ᆌӗ⭏⭡㾯ੁьⲴᥔ࣋ˈ⭡↔ӗ⭏ⲴS-N䎠ੁⲴ㽦ⳡᖒ䘩ਐ࣐൘ᰙᵏੁ
SࠨࠪⲴᕗᖒᶴ䙐кDŽ൘䘉⿽ৼੁ؟ߢ᭦㕙ᵪࡦлˈ⋯⵰ᶮ█-⭈ᆌ䜘ཊቲ⅑
27
━㝡ᑖˈӗ⭏ԕ⌻༣Ѫ━㝡ᓅ䶒Ⲵ㖼ຈ-᰼䜭ѫࣘབྷ䱶䗩㕈йਐц༽⨶⸣໎⭏ᾄ
઼ԕ䱶༣━㝡ᑖѪᓅⲴᢜᆀ㻛ࣘ䱶Ⓚйਐ㌫༽⨶⸣ᾄˈ嗉䰘ኡ䘶ߢ᧘㾶ᑖণѪ ᢜᆀ㻛ࣘ䱶㕈໎⭏ᾄⲴࡽ䱶㽦ⳡᑖDŽ
Figrue 2.6 Bivergent subduction and thrusting along Yangtz passive margin of the Early Mesozoic Longmen Shan (Xu et al., 1992)
ᖸཊᆖ㘵䇔Ѫᰙѝ⭏ԓॾইॾेᶯඇ⻠ᫎᰦˈᶮ█-⭈ᆌे⭼䱯ቬ⧋য⌻ੁ
N؟ߢˈ൘ᶮ█-⭈ᆌӗ⭏а㌫ࡇੁSⲴ࢚࠷ˈ㘼嗉䰘ኡѪᢜᆀᶯඇ઼ᶮ█
-⭈ᆌ䗩⭼ˈ㓿শᐖ㹼䎠━ᢝᒦ൘嗉䰘ኡൠ४ӗ⭏ᒯ⌋ੁSEⲴ䘶ߢ᧘㾶
⭘ˈণᶮ█-⭈ᆌᑖ⧠ᴹNE-SWੁᥔӗ⭏а㌫ࡇNW-SE䎠ੁⲴ㽦ⳡˈ㠣 嗉䰘ኡൠ४ˈ㊫լ“䱶䖜ᦒᯝቲ”ˈ㺘⧠Ѫᐖ㹼䎠━ˈ֯NW-SE䎠ੁⲴ㽦ⳡᖒ 䘩ੁ嗉䰘ኡൠ४䖜ਈѪNE-SW䎠ੁⲴ㽦ⳡ˗ੁഋᐍൠᯩੁˈ嗉䰘ኡᢝ ᙗ䎠━Ր䙂ѪੁSE䘶ߢ᧘㾶ˈᖒᡀ嗉䰘ኡᒯ⌋Ⲵ䘶ߢ᧘㾶ᶴ䙐(Figure 2.7;
Chen et al., 1994b; Chen et al., 1994a; Dirks et al., 1994; Chen et al., 1995; Worley et al., 1995; Worley and Wilson, 1996; Arne et al., 1997; Harrowfield and Wilson,
2005)DŽMattauer (1992)ᨀࠪᶮ█-⭈ᆌ㽦ⳡᑖᐘⴆቲ⋯⵰ᓅ䜘━㝡ᑖੁS࢚
࠷ˈ䙐ᡀ㽦ⳡᖒ䘩ੁSࠨࠪᒦ൘㽦ⳡᑖই㕈ᖒᡀа㌫ࡇ䘶ߢ᧘㾶ᑖDŽWorley et al. (1996)ሩ⊦ᐍ-㤲⊦࢚࠷ᑖⲴ⸣ῤᆀ⸣व㼩փᖴ䘩й㔤࠷⡷⹄ウ㺘᰾ˈ⸣ῤ ᆀ؍ᆈⲴव㼩փᖴ䘩փ⧠Ҷ≤ᒣᯩੁⲴᐖ㹼࢚࠷ˈ䲿ਾ・ণਁ⭏ੁSEⲴ䘶ߢ
᧘㾶⭘ˈⸯ⢙ޡ⭏ޣ㌫㺘᰾嗉䰘ኡൠ४Ⲵጠᵏਈ䍘ᰦ䰤ਁ⭏൘䎠━ੁ䘶ߢ䖜 ਈᵏ䰤ˈⸯ⢙ޡ⭏ޣ㌫ҏ㺘᰾嗉䰘ኡൠ४ጠᵏਈ䍘⭘ਁ⭏൘ᐖ㹼䎠━ੁSE
ᯩੁ䘶ߢ䗷〻ѝਁ⭏DŽBurchfiel et al. (1995)ሩ嗉䰘ኡ৺ઘ䗩ൠ४䈖㓶ᶴ䙐࠶᷀
䇔Ѫˈਔ⢩ᨀᯟ⌻нӵੁे䜘Ⲵ䱯ቬ⧋য؟ߢˈ਼ᰦ⋯⭈ᆌ-⨶ຈ㕍ਸᑖੁSW
؟ߢˈєᶑ؟ߢᑖޡ਼⭘֯ᶮ█-⭈ᆌ⌻ੁᢜᆀᶯඇᯌੁᥔࠪӗ⭏嗉䰘ኡᒯ
⌋Ⲵ䘶ߢ᧘㾶ˈ਼ᰦ㺘⧠ࠪቁ䟿Ⲵᐖ㹼䎠━࠶䟿ˈԆ䘈䇔Ѫॾইॾे⻠ᫎᰦॾ ইᶯඇⲴ亪ᰦ䪸䖜ਟ㜭䙐ᡀ嗉䰘ኡൠ४Ⲵ䎠━(Figure 2.7)DŽ
Figure 2.7 Interpretation of the Longmen Shan allochthon as part of a transpressive boundary along the major zone of early Mesozoic N-S convergence in central China
(Burchfiel et al., 1995)
Chen et al. (1996)ሩ嗉䰘ኡᰙѝ⭏ԓ䎠━䗷〻ѝӗ⭏ੁSE䘶ߢӗ⭏Ⲵ᧘㾶
փ઼伎ᶕጠኅᔰҶ䶎ᑨ䈖㓶Ⲵᶴ䙐ࠐօᆖ⹄ウˈᨀࠪйਐцԕࡽᢜᆀᶯඇ NW㕈ᤱ㔝Ⲵըኅ㻲䲧ᖒᡀа㌫ࡇNE䎠ੁⲴ਼⊹〟↓ᯝ(Figure 2.8 a)˗ঠ᭟ᵏ
⭡Ҿᶮ█-⭈ᆌ㽦ⳡᑖਈᖒ൘嗉䰘ኡൠ४ӗ⭏ੁSEⲴ䘶ߢ᧘㾶⭘ˈ֯ᰙᵏⲴ
↓ᯝቲӗ⭏৽䖜ˈᖒᡀ⊦ᐍ-㤲⊦ᯝ㻲ᑖ઼ेᐍ-᱐⿰ᯝ㻲ᑖˈᰙᵏ↓ᯝ䗷〻ѝ
਼⊹〟Ⲵᐘ⊹〟⢙ԕ俉≤ᯝ㻲Ѫᓅᯝቲ㻛᧘㾶㠣ഋᐍൠˈᖒᡀ嗉䰘ኡኡࡽ
ᒯ⌋Ⲵ᧘㾶փ઼伎ᶕጠˈᒦդ䲿ӗ⭏ഋᐍઘ㕈ࡽ䱶ൠᰙᵏ╄ॆ(Figure 2.8 b)˗
йਐ㠣ᰙⲭෙц䱦⇥Ѫ䱦⇥ᔿ䘶ߢ᧘㾶䗷〻ˈҏᱟ嗉䰘ኡ䘶ߢ᧘㾶ᑖ⭡㞩䱶
ੁࡽ䱶䙀⑀Ր䙂Ⲵ䗷〻ˈᖒᡀ♼৯-ᆹ৯ㅹਾᵏⲴ䘶ߢᯝ㻲ˈཊᵏ⅑Ⲵ䘶ߢ᧘㾶
⍫ࣘоᶮ█-⭈ᆌⲴዙ⍶⍫ࣘᖸྭൠሩᓄ(Figure 2.8 c)DŽ
29
Figure 2.8 A simplified geological model illustrating the evolution of the Longmen Shan Thrust-Nappe Belt and relationship to the development of the Western Sichuan Foreland
Basm.(Chen and Wilson, 1996)
Figure 2.9 Northward subduction of the Yangtz Block (Yan et al., 2011)
Yan et al. (2011)ṩᦞᶴ䙐㾱㍐ᐞᔲ઼㽦ⳡᖒᘱਐ࣐ˈ൘嗉䰘ኡ䘶ߢ᧘㾶ᑖ 䇶࡛ࠪᰙѝ⭏ԓаᵏѫ㾱ਈᖒਁ⭏൘237-208 Maѻ䰤ˈ൘嗉䰘ኡे⇥㺘⧠Ѫк 䜘ੁWSWⲴ䘶ߢ᧘㾶ˈᒦ൘嗉䰘ኡѝ⇥դᴹᐖ㹼䎠━ˈ䘉ᵏᰦ䰤ሬ㠤ᶮ█-⭈
ᆌൠ༣ᒯ⌋໎ˈк䜘ੁWSWⲴ䘀ࣘᆖѪॾইᶯඇੁॾेᶯඇ⻠ᫎᰦˈ؟ߢ ᶯ⡷к䜘ൠᒄ䀂⍱⍫ࣘ൘嗉䰘ኡൠ㺘Ⲵ૽ᓄ(Figure 2.9)DŽZheng et al.(2016)䙊䗷 ሩेᐍ-᱐⿰ᯝ㻲Ⲵٷ⦴↖⧫⪳઼㠚⭏Ժ࡙⸣K/Arᇊᒤˈ俆⅑ⴤ㿲㔉ࠪ嗉䰘 ኡѫᒢᯝ㻲ᰙѝ⭏ԓ⍫ࣘⲴᒤԓᆖ䇱ᦞDŽ
2) Late Mesozoic
䈖㓶Ⲵᶴ䙐䀓᷀㺘᰾ᢜᆀ㻛ࣘ䱶㕈໎⭏ᾄ嗉䰘ኡൠ४ˈнӵ㺘⧠Ѫᒯ⌋ੁ
SEⲴ䘶ߢ᧘㾶ˈ൘嗉䰘ኡ⋯㓯ⲴݳਔԓᵲዙփNW䗩⭼ս㖞䘈ਁ㛢⵰нॿ䈳Ⲵ к䜘ੁNW࢚࠷Ⲵ㌌ἡዙᑖDŽ㌌ἡዙᑖᯠ⭏Ӂ⇽≙≙ᒤԓᆖ઼ഋᐍൠ㾯䜘 ⲭෙ㓚⭏ࡽ䱶ൠ࠶࡛䲀ᇊݳਔԓᵲዙփNW䗩⭼↓ᯝ࢚࠷઼ੁSE䘶ߢሩ ഋᐍൠⲴ࣐䖭⭘൘ⲭෙ㓚ˈഐ㘼ੁNWⲴ↓ᯝ઼ੁSEⲴ䘶ߢާᴹ਼ᰦ
ᙗDŽഐ↔ᨀࠪ⭡Ҿ⅗ӊབྷ䱶ই䜘ՇཊᗞᕡඇփⲴ䍤⭘൘ᕪ⛸Ⲵᥔᓄ࣋
лˈሬ㠤ᢜᆀᶯඇੁᶮ█-⭈ᆌਁ⭏䱶؟ߢˈ䘋㘼ᶮ█-⭈ᆌл䜘⢙䍘⋯嗉 䰘ኡ䘶ߢ᧘㾶ᑖੁSEᯩੁਁ⭏ᾄᖒᥔࠪ(Figure 2.10; 䇨ᘇ⩤ㅹ, 1999)DŽᥔࠪ䗷 〻ѝӗ⭏嗉䰘ኡࡽ䱶Ⲵ䘶ߢ᧘㾶ԕ৺㞩䱶਼ᰦᵏ↓ᯝˈ㊫լௌ傜䳵䙐ኡᑖⲴ ѫѝཞ䘶ߢᯝቲ઼㯿ই㌫ˈ֯嗉䰘ኡ䘶ߢ᧘㾶ᑖਁ⭏ᰙᵏ䲶ॷ(䇨ᘇ⩤ㅹ, 2007; Xu et al., 2008)DŽ
Figure 2.10 Crustal wedge extrusion of the Late Mesozoic Longmen Shan (Xu et al., 2007) Tian et al.(2016)䙊䗷ᓄ࣋൪࠶᷀ˈ䇔Ѫ䇨ᘇ⩤ㅹ(2007)ⲭෙ㓚ൠ༣ᾄᖒᥔࠪ
⁑ᔿՊ൘嗉䰘ኡ㞩䱶ൠ४ࠪ⧠ተ䜘Ⲵըኅᓄ࣋൪ˈ䟾ཆᓄᖃ㺘⧠ࠪኡ䰤ըኅ
ൠㅹˈ䘉о䟾ཆⲴ㿲ሏнㅖਸDŽTian et al.(2016)ഐ㘼ᨀࠪ嗉䰘ኡൠ४ѝ⭏
ԓӽ❦ᤱ㔝㺘⧠Ѫᥔ㛼ᲟˈੁSEⲴ䘶ߢ᧘㾶ᥔ䗷〻ѝᖒᡀൠ༣ቪᓖⲴ
Duplexᶴ䙐ˈᒦᤷࠪ൘DuplexⲴ亦⭼ᯝቲ਼ṧՊᖒᡀݳਔԓᵲዙփNW⭼ੁ
NWⲴ↓ᯝ⭘DŽ
Yan et al.(2008)൘嗉䰘ኡ䘶ߢ᧘㾶ᑖݳਔԓᵲዙ亦䜘઼ਔ⭏ԓоѝ⭏ԓⴆቲ ѻ䰤࠶࡛䇶࡛ࠪєᶑк䜘ੁSEⲴ↓ᯝቲˈ䘉єᶑ↓ᯝቲѝ䰤ᖒᡀа њĀൠ༣䙊䚃⍱āˈ䀓䟺Ѫ䙐ኡᑖෞਾⲴᕐᙗ⧟ຳˈսҾᶮ█-⭈ᆌ㽦ⳡᑖл 䜘໎ǃ␡ਈ䍘Ⲵ⢙䍘൘嗉䰘ኡൠ४ԕ“ൠ༣⍱”ⲴᖒᔿੁSEEᯩੁᥔࠪ㘼ෞ
31
(2.11)ˈ䘉ᵏⲴըኅෞሬ㠤ݳਔԓᵲዙѻкᘇ⮉㌫-ྕ䲦㌫ⲴᲞ䙽㕪ཡˈᒦф
൘ᮤњᢜᆀᶯඇ㾯㕈ݳਔԓォワ䜭ᴹᖸа㠤Ⲵ㺘⧠DŽሩ⻗ਓൠඇǃ嗉䰘ኡѝ⇥
ᖝ♼ᵲዙൠ४ǃѩᐤൠ४Ⲵਈ䍘ᶑԦ⍻䈅㔉ࠪ亪ᰦ䪸ⲴP-T-t䖘䘩⢩ᖱˈ ሩᓄ⵰ॾই-ॾेᶯඇ⻠ᫎ໎-ෞⲴ䗷〻(Huang et al., 2003; Yan et al., 2003a, 2008a, b, Yan et al., 2008a, 2011, 2012; Zhou et al., 2008; ࡈ咔ㅹ, 2008)˗
Figure 2.11 The Early and Middle Jurassic extensional in the Longmen Shan thrust belt indicates SE-ward retrograde migration of the South China Block (Yan et al., 2011)
൘嗉䰘ኡൠ४ˈ䟽࣋൷㺑എᕩሩ嗉䰘䙐ኡᑖⲴᶴ䙐╄ॆҏ䎧⵰䶎ᑨޣ䭞Ⲵ
⭘(ᵾࣷㅹ, 2005; ḟሿᒣㅹ, 2009; Li et al., 2013, 2014)DŽ䟽࣋䍴ᯉ㺘᰾ˈᶮ█-
⭈ᆌ㽦ⳡᑖ઼ഋᐍൠ൷㺘⧠ࠪ䍏൷㺑䟽࣋ᔲᑨˈ㘼սҾѝ䰤Ⲵ嗉䰘ኡൠ४ࡉ 㺘⧠Ѫᱮ㪇Ⲵ↓൷㺑䟽࣋ᔲᑨˈṩᦞ㢮࡙൷㺑⁑රˈ嗉䰘ኡൠ४൘䈳ᮤ䗷〻ѝ Պӗ⭏ੁк䲶ॷⲴ࣋(ᵾࣷㅹ, 2005)DŽ䟽࣋൷㺑എᕩ૽ᓄ൘ൠ㺘ˈ䖜ॆѪ㲰Ⲵ
⊹〟⢙䇠ᖅ൘ഋᐍઘ㕈ࡽ䱶ൠѝDŽ䈖㓶Ⲵൠ⊹〟⢩ᖱ࠶᷀ሶࡽ䱶ൠⲴ⊹
〟⢙࠶Ѫє⿽㊫රഋቲṧᔿ˖1)ᾄᖒᶴ䙐⊹〟ᒿࡇˈࡽ䱶ൠⲴ⊹〟༴Ҿ侕侯
⣦ᘱˈ⊹〟オ䰤བྷҾ⢙ⓀⲴ㔉ˈᮤ྇⊹〟ᒿࡇੁк㋂ᖴ䙀⑀ਈ㋇ˈ⊹〟⢙Ⓚ
Ⓚнᯝੁࡽ䱶ൠ䜘㔉ˈਟ㜭ሩᓄ嗉䰘ኡᕪ⛸䘶ߢ᧘㾶ሩࡽ䱶ൠⲴ࣐䖭 䗷〻˗2)བྷරᶯ⣦䘁ㅹⲴᶴ䙐⊹〟ᒿࡇˈ㺘᰾ൠ༴Ҿ䗷価઼⣦ᘱˈ⊹〟オ 䰤⋑ᴹᓄᢙབྷˈሩᓄ⊹〟⧟ຳሩっᇊˈਟ㜭ሩᓄᶴ䙐࣐䖭䰤ⅷᵏ嗉䰘ኡൠ ४䟽࣋൷㺑എᕩˈഐ㘼ਚᨀ⢙Ⓚ㘼нӗ⭏⊹〟オ䰤ˈє⿽㊫රⲴ⊹〟ᒿࡇӔ ᴯӗࠪˈҏփ⧠Ҷঠ᭟ᵏ嗉䰘ኡੁSEⲴ䘶ߢ᧘㾶оᆱ䶉ᰦᵏ䶉ᘱഎᕩӂӔ ᴯ⭘(Li et al., 2013, 2014)DŽ
3) Cenozoic
ᖸཊᆖ㘵䇔Ѫ嗉䰘ኡ⧠Ӻᶴ䙐Ṭᷦѫ㾱ᖒᡀҾᯠ⭏ԓˈवᤜൠ࣯䲶ॷǃൠ ༣໎ԕ৺嗉䰘ኡᒯ⌋ਁ㛢Ⲵ伎ᶕጠ઼᧘㾶փᶴ䙐(Meng et al., 2006; Royden et al., 2008; Burchfiel et al., 2008)DŽ਼ṧᱟ嗉䰘ኡ⋯㓯ݳਔԓᵲዙփNW䗩⭼ੁ
NWⲴ↓ᯝ࢚࠷ˈRoyden et al.(2008)䀓䟺Ѫchannel flow൘ൠ㺘Ⲵ૽ᓄ(Figure
2.12)DŽ䈕⁑ᔿሶᖝ♼ᵲዙ䀓䟺ᡀchannel flowⲴⴆቲ䜘࠶ˈަл䜘ൠ༣⍱ੁཆ
⍱ࠪˈሶᖝ♼ᵲዙㅹݳਔԓสᓅᵲዙ亦ࠪˈ൘ަNW㕈ᖒᡀੁNWⲴ↓ᯝԕ৺
SE㕈ੁSEⲴ䘶ߢˈ㊫լ䶂㯿儈Ⲵѫѝཞ䘶ߢᯝ㻲઼㯿ই㌫DŽ
Figure 2.12 Geological structure along a profile through the Pengguan massif indicating the massif as the crest of the channel flow (Royden et al., 2008)
Meng et al. (2006)ṩᦞ嗉伎ᶕጠⲴオ䰤ࠐօᆖᖒᘱǃ䜘ᓄਈ࠶᷀ǃ࠶ᐳオ 䰤ս㖞о嗉䰘ൠ࣯Ⲵ㙖ਸޣ㌫ㅹ䇔Ѫ伎ᶕጠⲴቡսоᯠ⭏ԓԕᶕⲴ䟽࣋━㾶
ޣDŽ↓ᱟ⭡Ҿᯠ⭏ԓchannel flowⲴ⭘൘嗉䰘ኡൠ४ӗ⭏ᕪ⛸Ⲵൠ࣯ᐞˈᖒ
ᡀ൘нࡠ100 kmⲴ≤ᒣ䐍ˈ儈〻⭡ഋᐍൠࠐⲮ㊣ੁNWᬰॷ㠣5000 m
ԕкᶱ䲑Ⲵൠ࣯ˈᒦሬ㠤䟽࣯࣋㜭Ⲵ㍟〟(Richardson et al., 2008; Godard et al., 2009; Wang et al., 2012)DŽ࠶ᐳ൘嗉䰘ኡѝ⇥Ⲵབྷර伎ᶕጠˈަቮ䜘઼ѝ䜘㺘⧠
Ѫа㌫ࡇ↓ᯝˈ㘼൘伎ᶕጠࡽ㕈㺘⧠ѪੁьইⲴ䘶ߢ᧘㾶ˈ䘉⿽䟾ཆ㿲ሏⲴ伎 ᶕጠ䜘“ࡽਾ”Ⲵᶴ䙐㺘⧠ˈоⴤ伎ᶕጠࢆ䶒Ⲵᓄ࣋࠶᷀㔃᷌а㠤˗൘ 嗉䰘ኡই⇥伎ᶕጠк䜘Ѫ㘱ൠቲˈл䜘ᯠൠቲˈфᶴᡀ伎ᶕጠⲴњቲսԕᶴ 䙐ޣ㌫᧕䀖˗伎ᶕጠⲴਁ㛢઼࠶ᐳ㤳തо嗉䰘ኡNE-SW䎠ੁкൠ࣯ᐞᔲᇶ࠷
ޣˈൠ࣯儈Ⲵᖝ♼ᵲዙǃᇍޤᵲዙㅹьই㕈ˈ࠶ᐳ䇨ཊⲴ伎ᶕጠˈ㘼൘嗉䰘 ኡे⇥伎ᶕጠ勌ᴹਁ㛢˗嗉䰘ኡѝ⇥Ⲵ伎ᶕጠⴆ൘㽦ⳡਈᖒⲴֿ㖇-ⲭෙ㓚-ᯠ
