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
It is the first time that the fossil footprints of a group of Middle Eocene elephant ancestors have been discovered in the Gonjo Basin,East Tibet Plateau.The Gonjo Formation is attributed to the Middle Eocene Epoch(U-...It is the first time that the fossil footprints of a group of Middle Eocene elephant ancestors have been discovered in the Gonjo Basin,East Tibet Plateau.The Gonjo Formation is attributed to the Middle Eocene Epoch(U-Pb age=44.7±1.2 Ma)and consists mainly of purplish-red,medium-to coarse-grained sandstones,siltstones interbedded with mudstones,and conglomerates with sedimentary structures like ripple marks,rip-up clasts,and trough-cross bedding,suggesting fluvial-lacustrine systems.The group of fossil footprints has a characteristic oval-concave shape,and the toe impressions are absent.Some fossil footprints are overstepped with a pockmarked texture resembling Proboscipeda enigmatica.More than 165 fossil footprints of the group are relatively well-preserved with different diameters,which is evidence of highly social behavior and trackmakers of different ages,including calves,juveniles,adolescents,and adults.The size frequency of the fossil footprints enabled us to deduce the body mass,shoulder height,and hip-height distribution of the trackmakers that crossed the East Tibet Plateau 44.7 Ma ago.The trackmakers comprised an estimated average hip-height of 111.8 cm,an average shoulder height of 172.8 cm for males/155.9 cm for females,and an average body mass of approximately 1218.1 kg for males/907.8 kg for females.The abundance of fossil footprints reveals that in the Middle Eocene Epoch,the environment was extraordinarily conducive for the elephant ancestors to live in the East Xizang region.展开更多
The Pleistocene Fluvial-lacustrine of Ait Hajji Formation is located in South East of Tiddas, and in the Qua-ternary deposits of the Moroccan Central Plateau. These outcrops represent on a geomorphosite of great im-po...The Pleistocene Fluvial-lacustrine of Ait Hajji Formation is located in South East of Tiddas, and in the Qua-ternary deposits of the Moroccan Central Plateau. These outcrops represent on a geomorphosite of great im-portance for the study of geological heritage, and for a natural eco-tourism valorization in Morocco. For to aim a natural tourism promotion, for indigenous peoples, this geomorphosite in question has an fluorescent and dense flora with a diversified fauna in the heart of one Ordovician quartzite bar and Devonian limestone ridges. In Oued Boulahmayel geomorphosite contains a memory geological Formation of a Pleistocene epi-sode, beginning firstly by a dynamic fluviatil land synchronous with a local volcanic activity (Phonolite ne-phelinc) replaced by a lake sedimentation related to the formation of a dam natural, created a few hundred meters downstream from Boulahmayel. For valorizing of the hinterland of the plains towns, it is necessary to develop a geo-eco-tourism integrated who provide its harvest and will argue the benefits resources of rural people of high-mountains in their own environment. It is proposed in the perspective to initiate a sustainable development approach, while ensuring the conservation and ensure the continued natural existence of the surroundings environments and to appreciate the potential of the region. Thus that beauty hidden in the hin-terland upstream to a tourist eager for discoveries, to encourage them to practice their stay as short as it is, in a safe space and very quiet. In order to materialize the concept of geo-eco-tourism, we must deploy the ef-forts of local people, policy makers and scientists in order to produce tourist maps with different interesting routes, to implant signal panels, to develop tracks campsites and trails within the forests, creating shelters and rest houses in private homes, as well as provide training for specialized guide’s rescuers.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.
基金supported by the National Natural Science Foundation of China(No.92055212)the State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan(No.GPMR202105).
文摘It is the first time that the fossil footprints of a group of Middle Eocene elephant ancestors have been discovered in the Gonjo Basin,East Tibet Plateau.The Gonjo Formation is attributed to the Middle Eocene Epoch(U-Pb age=44.7±1.2 Ma)and consists mainly of purplish-red,medium-to coarse-grained sandstones,siltstones interbedded with mudstones,and conglomerates with sedimentary structures like ripple marks,rip-up clasts,and trough-cross bedding,suggesting fluvial-lacustrine systems.The group of fossil footprints has a characteristic oval-concave shape,and the toe impressions are absent.Some fossil footprints are overstepped with a pockmarked texture resembling Proboscipeda enigmatica.More than 165 fossil footprints of the group are relatively well-preserved with different diameters,which is evidence of highly social behavior and trackmakers of different ages,including calves,juveniles,adolescents,and adults.The size frequency of the fossil footprints enabled us to deduce the body mass,shoulder height,and hip-height distribution of the trackmakers that crossed the East Tibet Plateau 44.7 Ma ago.The trackmakers comprised an estimated average hip-height of 111.8 cm,an average shoulder height of 172.8 cm for males/155.9 cm for females,and an average body mass of approximately 1218.1 kg for males/907.8 kg for females.The abundance of fossil footprints reveals that in the Middle Eocene Epoch,the environment was extraordinarily conducive for the elephant ancestors to live in the East Xizang region.
文摘The Pleistocene Fluvial-lacustrine of Ait Hajji Formation is located in South East of Tiddas, and in the Qua-ternary deposits of the Moroccan Central Plateau. These outcrops represent on a geomorphosite of great im-portance for the study of geological heritage, and for a natural eco-tourism valorization in Morocco. For to aim a natural tourism promotion, for indigenous peoples, this geomorphosite in question has an fluorescent and dense flora with a diversified fauna in the heart of one Ordovician quartzite bar and Devonian limestone ridges. In Oued Boulahmayel geomorphosite contains a memory geological Formation of a Pleistocene epi-sode, beginning firstly by a dynamic fluviatil land synchronous with a local volcanic activity (Phonolite ne-phelinc) replaced by a lake sedimentation related to the formation of a dam natural, created a few hundred meters downstream from Boulahmayel. For valorizing of the hinterland of the plains towns, it is necessary to develop a geo-eco-tourism integrated who provide its harvest and will argue the benefits resources of rural people of high-mountains in their own environment. It is proposed in the perspective to initiate a sustainable development approach, while ensuring the conservation and ensure the continued natural existence of the surroundings environments and to appreciate the potential of the region. Thus that beauty hidden in the hin-terland upstream to a tourist eager for discoveries, to encourage them to practice their stay as short as it is, in a safe space and very quiet. In order to materialize the concept of geo-eco-tourism, we must deploy the ef-forts of local people, policy makers and scientists in order to produce tourist maps with different interesting routes, to implant signal panels, to develop tracks campsites and trails within the forests, creating shelters and rest houses in private homes, as well as provide training for specialized guide’s rescuers.
