Cấu trúc địa chất sâu khu vực trũng sâu biển đông và lân cận theo tài liệu địa vật lý

Ca chn a v Tr i hc Khoa hc T  LuVa cu: 60 44 15 ng dn: TS.  o v: 2012 Deep geological structure of the deep basin of the East Sea and adjacent based on geophysics data 59 tr. Abstract. Ta cht - a va cht kin to khu vt s  c c s d            n; Gii vi vt th hai chi d liu  u s d t s kt qu      s i gi   ng trng l  i quy gi  tht gnh theo kt qu  a d ng trng lc; M nh d t ct ca chu trng lc - a ch   m b dy tr Keywords. Va ca cht hc; Bia vu a cht Content   Câ ́ u tru ́ c đi ̣ a châ ́ t sâu khu vư ̣ c tru ̃ ng sâu Biê ̉ n Đông va ̀ lân câ ̣ n theo ta ̀ i liê ̣ u đi ̣ a vâ ̣ t ly ́ ng n PHƢƠNG PHÁP NGHIÊN CỨU u ca ch c   a v      0 N,  0     nghim mt s  - i: gi  ta chn, d ng trng l u vi m di quy tuy - nh d c  cu (theo tuyn). -  Gradient ngang ci vi mnh h tht g din theo s liu trng lc. - n theo tuy  nh nhc bit. 2 21 1 2121 2 2 2 2 1 xx r xx r yx r yx r yx r yx r R    - ng l nh c th c a chn. 2.1. Phƣơng pháp phân tích tƣơng quan a. Liên hệ tƣơng quan và phƣơng pháp phân tích tƣơng quan M m biu hi u m  ca hing t   H s nh bc sau: 2.2. Phƣơng pháp nâng trƣờng Tip tc ging th c t mng th  mt b mt,     suy yu mp t t ng dng rt to ln trong thc t  cp tc gii ng thc th ba ca Green. Theo ng th  ca U tm P nc cho b (2.2)  n   c m 2.2. (2.3)  (2.4) Vic tip tc gi   ti n c min tn s lu dng vic tip tc gii   . Nng th t z = z 0 trong ph rng so vc ca ngun ti bii Fourier F [U] cu din trong min tn s c / / / / / / 00 U(x,y,z ) ( , , ) ( , , ) u z U x y z x x y y z dx dy             2 2 2 3/2 1 ( , , ) 2 ( ) u z x y z x y z        c bi c hai v c.3) qua min tn s  p: (2.5) Vi F [U u i Fourier cp t u cn thi u din gia F[ u ng: (2.6) t rng: (2.7) y, vic tip tng th  mt m thc hic bi s h (2.7) ry bi vc. T y rp tiu dn tt c   |k|  u     i vc tip t. 2.3. Phƣơng pháp Gradient ngang cực đại  xut b  ca ngu ng thc hi  H[(, )]=      2 +     2 (2.8)  nh Gradient ngang ci: t   tr Gradient ngang cng ta s  H m xung quanh theo bng thc: H    1, < H    ,  > H    + 1,  H    , 1 < H    ,  > H    , + 1 H    1, 1 < H    , > H    + 1, + 1 H    + 1, 1 < H    , > H    1, + 1 H    ,  2 H    ,          :   =  2  = 1 2  H    1, 2H    , + H    + 1,   b= 1 2  H    + 1, H    1,   11 ( , , ) 2 u x y z zr        / 0 () / 0 1 2 , , 0 k z z e F z z k rk              uu F U F U F                  .            : H     =   2 +   + H    ,  (2.9)                          ,          ,                     .  -nh 2.4. Phƣơng pha ́ p tính đa ̣ o ha ̀ m chuâ ̉ n ho ́ a toa ̀ n phâ ̀ n        gi      a cht c   c tng: G H = (2.10)  xz  zz ng cng trng l  t ti :       ,          (2.11) (2.12)                         H   H   H    2.5. Giải bài toán ngƣợc đối với vật thể hai chiều. c  s t b m i, s  m gia li c     1 0 22 22 1 M zzxz zzxz VV M VV (p) (p) 2 Z (x)=Z (ξ)=b +t ξ+t ξ p 1p 2p n 2 (h) qs i lt i i=1 F= Δg (x )-Δg (x ,h)    i dc theo tuyc ox ly x=d j  d j c ly sao cho [d p d p+1 ] ca b mt ti c xp x b c t: (2.13)  b, t 1 , t 2    u l s t v mt m kh k ng d k t chui c nh B mt ti  ng trng lc  i tt c  m  m s c: (2.14)  u ng trng lc t  hi th j,   c: (2.15) Nu m khc: (2.16) Np x=d j c ly vi m   c: (2.17) ng ht cnh ct k  c. ( 2.18) c s c gii khi cc ti CƠ SỞ DỮ LIỆU VÀ TƢ LIỆU SỬ DỤNG 1. Cơ sơ ̉ sô ́ liê ̣ u sƣ ̉ du ̣ ng  lic t kha cha chn s liu ta i c bii m cp    tic hin c ni ngou chnh nhng mt b ranh git d j    Δg (x) i Δg (x) j m-1 j m 0 m j=1 Δg(x)= Δg (x)+Δg(d ,h ,h ,x)  1 0 j 2 2 2 2 () g ( ) 2 2 ( ) ( ) j j d h j j s d z d dx ds x k k xx                      1 22 0 22 () () ( ) ln () j j d jj d xh g x k d xz          (p) z(ξ)=b +t ξ p 1 j+1 j 22 d j j j 0 j 22 d 0 0 j (x-ξ) +h (x-ξ) (x-ξ) Δg (x)=kσ (x-ξ)ln -2h arctg +2h arctg (x-ξ) +h h h      cc Kainozoi, Conrad, Moho, h tht ct tng ha cht-a vu. Ngun s liu trng lc trong khu vu r ng bn gc t n kh  o n s liu kh c s t b n s liu kh v tinh v   liu v ng d ng tn d liu trng lc v   ng nhng b cao, th hia cht trong khu v d ng trng l  chnh  t l  -09-02) v i chi tit tho u ca   liu trng lc ch yc s d    Nguô ̀ n sô ́ liê ̣ u sƣ ̉ du ̣ ng trong luâ ̣ n văn na ̀ y : -      (   )  (The General Bathymetric Chart of the Oceans) 1:200.000 -    l 1:1000.000 : (http://www.ngdc.noaa.gov/mgg/sedthick/sedthick.html) -             1 :200.000 ta ch: http://topex.ucsd.edu/cgi-bin/get_data.cgi -        (                   internet) ta ch: http://maps.ngdc.noaa.gov/viewers/geophysics -                         /V cruise, 1987, Gagarynsky R/V cruises, 1990-1992        1:200.000 -     -  7-10     2007-2008     c đnh ranh gii ngoi thm lc đa Vit Nam        1:100.000      :   1:1000.000 (                  ), (                  ) 1:1000.000. MỘT SỐ KẾT LUẬN VÀ KIẾN NGHỊ Một số kiến ngh            i v ca ch    t s kt lu +        :          (  3.2g/cm 3 )  (     2.85g/cm 3 ),               1016km.          i b        11 13km,       Moho n     + :        1828                (     2.9g/cm 3 ),        28         . + Ranh gii gi    :  ( 2.9g/cm 3 )     (      2.7g/cm 3 )                             ,                    . + :          (    2.7g/cm 3 )  (         3 ).            .   0  0 N, 108 0  0 E)  49km.             ,  24km.                           2          +                  0.53km,  3km.                  . +                 3  110km,     2-7km,            2-6km,  (6 0  0 , 108 0  0 )  3-9km. +                :                 ,  (26)           mt Moho 14         n 3.8   n ,             14  ?. Một số kiến ngh: - Cn tic s lia v   a v ca chn - C v c s     la ho -  ca tr  ng lc, s  trin cc bi References 1.  (2003),    2.  (2000),                      ,         , PetroVietnam 3.   , 24(1), tr. 67 - 80. 4. ng, ,  5.  (2006),  ,                , NXB         ,  6.  am,  7.   H  8, tr. 59-63. 8. ,   3, tr. 23-26. 9.             frommagnetic or gravity Geophysics, 51, 1494 -1498. 10. Grauch V. J. S., L. Cordell (1987), Limitations of determining density or magnetic      Geophysics, 52, 118-121. 11. Parker, R. L. (1972)       Jeophys. J. Royal Astr. Soc, 31, pp.447-455. 12. Richard J. Blakely (1995), Potential theory in Gravity and Magnetic Applications, Cambrige University press, United States of America 13. Wolfgang Jacoby, Peter L. Smilde (2009), Gravity interpretation fundamentals and application of gravity inversion and geological interpretation, Springer, Verlag Berlin Heidelberg. 14.     Techtonophysics, 338, pp. 1-21. . Content   Câ ́ u tru ́ c đi ̣ a châ ́ t sâu khu vư ̣ c tru ̃ ng sâu Biê ̉ n Đông va ̀ lân câ ̣ n theo ta ̀ i liê ̣ u đi ̣ a vâ ̣ t ly ́ ng. c s c gii khi cc ti CƠ SỞ DỮ LIỆU VÀ TƢ LIỆU SỬ DỤNG 1. Cơ sơ ̉ sô ́ liê ̣ u sƣ ̉ du ̣ ng  lic