Objective The Emeishan large igneous province (ELIP) in SW China is the only one large igneous province in China recognized by international geologists. Previous studies of ELIP over past two decades indicate that ...Objective The Emeishan large igneous province (ELIP) in SW China is the only one large igneous province in China recognized by international geologists. Previous studies of ELIP over past two decades indicate that the ELIP age, duration, scale and generation mechanism are still controversial. Among those scientific topics, some scholars suggest that ELIP is an example of up-doming prior to LIP formation, which was evidenced by: (1) The thickness of the Yangxin Formation (P^v) limestone unit, which lies directly beneath ELIP, reduces from the center of erosional area to the outer edge. (2) Paleo-karst surfaces are present. (3) The clastic rocks of alluvial fan deposits, from the eroded materials in the maximum uplifted area, developed surrounding the inner zone. However, other scholars urge that those so-called "alluvial fan" deposits are "hydromagmatic deposits", erupted or emplaced at or near sea level, and conclude that there was no pre-emptive uplift in ELIP. In order to constrain the above-mentioned scientific issue, we conducted detailed field geological investigations and systematically measured geological sections to provide new evidence by using sedimentary data.展开更多
基金supported by the China Geological Survey project(grant No.1212011120623)
文摘Objective The Emeishan large igneous province (ELIP) in SW China is the only one large igneous province in China recognized by international geologists. Previous studies of ELIP over past two decades indicate that the ELIP age, duration, scale and generation mechanism are still controversial. Among those scientific topics, some scholars suggest that ELIP is an example of up-doming prior to LIP formation, which was evidenced by: (1) The thickness of the Yangxin Formation (P^v) limestone unit, which lies directly beneath ELIP, reduces from the center of erosional area to the outer edge. (2) Paleo-karst surfaces are present. (3) The clastic rocks of alluvial fan deposits, from the eroded materials in the maximum uplifted area, developed surrounding the inner zone. However, other scholars urge that those so-called "alluvial fan" deposits are "hydromagmatic deposits", erupted or emplaced at or near sea level, and conclude that there was no pre-emptive uplift in ELIP. In order to constrain the above-mentioned scientific issue, we conducted detailed field geological investigations and systematically measured geological sections to provide new evidence by using sedimentary data.