GRAVITY STUDIES IN THE MARGALLA AND HAZARA RANGES

Abstract

Gravity and ll1agnetic studies were ca rried out on til t> weste rn limb of Hazara Syntaxis for investigat io n of structll l al ft>;t tures. The bascment trend revealed by regio nal gra vit y efk cts is in co ntrad ict ion to th e surfi cial geo logica l strll ctures whi ch stri ke ge nna ll y NE - SW and is simila r to th e 111 0lk l lkvl'- loped o n the ba:,is or ea rthqu ake se isill o logy. It ~ env isage d tllat tilcrL' c" ists :1 ddac illl1L'l1 t 1.0 Ill' \WI1L';ltil till' il1\"l'sli t!;IiL'd area. The ba sement seems to be dippin g towards no rth '~;ls l at an angle or 2 degrees. The residual it y e ffc c ls aSSO L' j:I' ted wi th the ove rly ing formatio ns indi cate that till;' 1v1 :lin Boundary Thrust ex te nds from M:n galla Pa ss to Ghnra gali a nd Kuldana (MulTee). A buried ort'shoo t of the :v'lain Bou ll da ry Thrust (MBT) is inferrcd to bc passing nca r Mohnl ~d Khanp ur, and is ex posed nea r Langrial a nd Nat hi aga li N,'<I r Haripur. the maximum thickness of Holoccne deposits over Hazara Slatcs is 400 mctres.