英国《自然通讯》杂志2015年1月刊登了张钧翔、海部阳介等人的题为"台湾第一个古老型人属"的论文,报道了从澎湖海沟60~120 m深处打捞上来的1件人类下颌骨(以下简称澎湖下颌)和11种哺乳动物化石,认为澎湖下颌的时代为晚于450 k...英国《自然通讯》杂志2015年1月刊登了张钧翔、海部阳介等人的题为"台湾第一个古老型人属"的论文,报道了从澎湖海沟60~120 m深处打捞上来的1件人类下颌骨(以下简称澎湖下颌)和11种哺乳动物化石,认为澎湖下颌的时代为晚于450 ka BP,最可能为190 ka^10 ka BP。张文没有确定它属于人属的哪个物种,并认为难以确定性别。笔者就张文提供的比较详细的丰富资料作进一步的分析和讨论后认为,澎湖下颌的整体特征指示它属于中更新世,最可能属于中更新世中后期,可能在450 ka和130 ka BP之间;它有不少特征指示其与东亚化石人类有比较密切的亲缘关系,但不大可能属于直立人,还有个别特征提示其先辈可能接受过来自西方基因流的影响;参照中国中更新世人的相关数据,澎湖下颌可能属于女性。展开更多
This paper deals with deformation textures and fabrics of mantle-derived xenoliths and dislocation microstructures of olivine in the upper mantle in the Penghu Islands, Taiwan. According to the calculation of the chem...This paper deals with deformation textures and fabrics of mantle-derived xenoliths and dislocation microstructures of olivine in the upper mantle in the Penghu Islands, Taiwan. According to the calculation of the chemical composition of xenolith minerals (pyroxene), the equilibrium temperatures and pressures were 986-1116@ and 1.50-2.60 GPa, respectively. Deformation events in the upper mantle may fall into three sequences' (1) uniform steady-state flow deformation with high temperatures and low stresses, (2) shear flow deformation with high temperatures and relatively high stresses on diapiric margins of the upper mantle, and (3) extraction deformation of {110} glide bands with low temperatures and high strain rates. Deformation events and thermal structure of the upper mantle in the study area show that eastern Fujian and the Penghu Islands are characterized by very similar rheological properties of the upper mantle. Volcanism of basalts in the Penghu Islands is related to hot spots of the upper mantle under neath the Taiwan Strait, and diapirism and upwelling of the upper mantle are the dominant factors responsible for rifting of the continental margins in eastern China.展开更多
The Taiwan Strait tunnel, as a great project, has been studied for a long time and met many challenges from the beginning of the feasibility study that has attracted attention among scientists and engineers on both si...The Taiwan Strait tunnel, as a great project, has been studied for a long time and met many challenges from the beginning of the feasibility study that has attracted attention among scientists and engineers on both sides of the Taiwan Strait and around the world as well. The key question is whether this undersea tunnel can be constructed with present technologies under such complex geologic and seismologic conditions. Results of current researches indicate that the sea floor of the Strait is covered with a horizontal layer composed of both the Pleistocene and the Holocene sandstone and shale with a thickness of about 200～300 m, without any large fault belt or fold.This can serve as a good bearing and impermeable layer for constructing such an undersea tunnel. The Penghu Islands and Penghu terrace, which are composed of hard basaltic rock over a wide area of 70 km (NS)×40 km (EW), might be connected each othar by a bridge instead of an undersea tunnel, and serve as a construction site. Although there are several geologic units separated by faults under the upper horizontal layer, these faults do not cut through the upper layer. Only the NE offshore fault along the Fujian coast and that along the west coast of Taiwan should be noticed, between which a suspension tunnel instead of an undersea tunnel can be constructed. Therefore it is judged that the tunnel beginning from Amoy, through the Jinmen Island and the Penghu Islands to the Peigang harbour is worth recommendation.展开更多
文摘英国《自然通讯》杂志2015年1月刊登了张钧翔、海部阳介等人的题为"台湾第一个古老型人属"的论文,报道了从澎湖海沟60~120 m深处打捞上来的1件人类下颌骨(以下简称澎湖下颌)和11种哺乳动物化石,认为澎湖下颌的时代为晚于450 ka BP,最可能为190 ka^10 ka BP。张文没有确定它属于人属的哪个物种,并认为难以确定性别。笔者就张文提供的比较详细的丰富资料作进一步的分析和讨论后认为,澎湖下颌的整体特征指示它属于中更新世,最可能属于中更新世中后期,可能在450 ka和130 ka BP之间;它有不少特征指示其与东亚化石人类有比较密切的亲缘关系,但不大可能属于直立人,还有个别特征提示其先辈可能接受过来自西方基因流的影响;参照中国中更新世人的相关数据,澎湖下颌可能属于女性。
基金This study was supported mainly by China National Natural Science Foundation Grant No.4880126partly by U.S. National Science Foundation Grant INT-8612713
文摘This paper deals with deformation textures and fabrics of mantle-derived xenoliths and dislocation microstructures of olivine in the upper mantle in the Penghu Islands, Taiwan. According to the calculation of the chemical composition of xenolith minerals (pyroxene), the equilibrium temperatures and pressures were 986-1116@ and 1.50-2.60 GPa, respectively. Deformation events in the upper mantle may fall into three sequences' (1) uniform steady-state flow deformation with high temperatures and low stresses, (2) shear flow deformation with high temperatures and relatively high stresses on diapiric margins of the upper mantle, and (3) extraction deformation of {110} glide bands with low temperatures and high strain rates. Deformation events and thermal structure of the upper mantle in the study area show that eastern Fujian and the Penghu Islands are characterized by very similar rheological properties of the upper mantle. Volcanism of basalts in the Penghu Islands is related to hot spots of the upper mantle under neath the Taiwan Strait, and diapirism and upwelling of the upper mantle are the dominant factors responsible for rifting of the continental margins in eastern China.
文摘The Taiwan Strait tunnel, as a great project, has been studied for a long time and met many challenges from the beginning of the feasibility study that has attracted attention among scientists and engineers on both sides of the Taiwan Strait and around the world as well. The key question is whether this undersea tunnel can be constructed with present technologies under such complex geologic and seismologic conditions. Results of current researches indicate that the sea floor of the Strait is covered with a horizontal layer composed of both the Pleistocene and the Holocene sandstone and shale with a thickness of about 200～300 m, without any large fault belt or fold.This can serve as a good bearing and impermeable layer for constructing such an undersea tunnel. The Penghu Islands and Penghu terrace, which are composed of hard basaltic rock over a wide area of 70 km (NS)×40 km (EW), might be connected each othar by a bridge instead of an undersea tunnel, and serve as a construction site. Although there are several geologic units separated by faults under the upper horizontal layer, these faults do not cut through the upper layer. Only the NE offshore fault along the Fujian coast and that along the west coast of Taiwan should be noticed, between which a suspension tunnel instead of an undersea tunnel can be constructed. Therefore it is judged that the tunnel beginning from Amoy, through the Jinmen Island and the Penghu Islands to the Peigang harbour is worth recommendation.
