Collaborative Research: Neotectonic Structure of Terror Rift, Western Ross Sea

合作研究：西罗斯海恐怖裂谷的新构造结构

• 批准号: 0125624
• 负责人: Terry Wilson
• 金额: --
• 依托单位: Ohio State University Research Foundation -DO NOT USE
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0125624&HistoricalAwards=false
• 关键词: Collaborative; Research; Neotectonic; Structure; Terror

This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for a study to investigate the tectonic development of the southwestern Ross Sea region. Displacements between East and West Antarctica have long been proposed based on global plate circuits, apparent hot spot motions, interpretations of seafloor magnetic anomalies, paleomagnetism, and on geologic grounds. Such motions require plate boundaries crossing Antarctica, yet these boundaries have never been explicitly defined. This project will attempt to delineate the late Cenozoic - active boundary between East and West Antarctica along the Terror Rift in the western Ross Sea, where young structures have been identified, continuity between active extension and intracontinental structures can be established, and where accessibility via ship will allow new key data sets to be acquired. We will use multi-source marine and airborne geophysical data to map the fault patterns and volcanic structure along the eastern margin of the Terror Rift. The orientations of volcanic fissures and seamount alignments on the seafloor will be mapped using multibeam bathymetry. The volcanic alignments will show the regional extension or shear directions across the Terror Rift and the orientations of associated crustal stresses. Swath bathymetry and single channel seismic data will be used to document neotectonic fault patterns and the eastern limit of recent faulting. Delineation of neotectonic fault patterns will demonstrate whether the eastern margin of the Terror Rift forms a continuous boundary and whether the rift itself can be linked with postulated strike-slip faults in the northwestern Ross Sea. Seafloor findings from this project will be combined with fault kinematic and stress field determinations from the surrounding volcanic islands and the Transantarctic Mountains. The integrated results will test the propositions that the eastern boundary of the Terror Rift forms the limit of the major, late Cenozoic -active structures through the Ross Sea and that Terror Rift kinematics involve dextral transtension linked to the right-lateral strike-slip faulting to the north. These results will help constrain the kinematic and dynamic links between the West Antarctic rift system and Southern Ocean structures and any related motions between East and West Antarctica. In the first year, a collaborative structural analysis of existing multichannel and single channel seismic profiles and aeromagnetic data over the Terror Rift will be conducted. The location of volcanic vents or fissures and any fault scarps on the sea floor will be identified and a preliminary interpretation of the age and kinematics of deformation in the Terror Rift will be produced. Late in the second year, a one-month cruise on RVIB N.B. Palmer will carry out multibeam bathymetric and sidescan sonar mapping of selected portions of the seafloor of Terror Rift. Gravity, magnetics, seismic reflection and Bathy2000 3.5 kHz sub-bottom profile data will also be collected across the rift. In the third year, we will use these multisource data to map the orientations and forms of volcanic bodies and the extent and geometry of neotectonic faulting associated with the Terror Rift. The project will: 1) complete a map of neotectonic faults and volcanic structures in the Terror Rift; 2) interpret the structural pattern to derive the motions and stresses associated with development of the rift; 3) compare Terror Rift structures with faults and lineaments mapped in the Transantarctic Mountains to improve age constraints on the structures; and 4) integrate the late Cenozoic structural interpretations from the western Ross Sea with Southern Ocean plate boundary kinematics.

该奖项由极地计划办公室的南极地质和地球物理学计划提供，为研究提供了一项研究的资金，以调查西南罗斯海地区的构造发展。长期以来，基于全球板电路，明显的热点运动，海底磁异常的解释，古磁性，古磁性和地质理由，东南极之间的位移长期以来一直提出。这种运动需要越过南极洲的板边界，但是这些边界从未明确定义。该项目将试图描述西南极洲东部和西部的恐怖裂谷之间的活跃边界，在西罗斯海，已经确定了年轻的结构，可以建立主动扩展与室内结构之间的连续性，并且可以通过船舶获得可访问的船舶，可以获取新的关键数据集。我们将使用多源海洋和空中地球物理数据来绘制恐怖裂谷东部边缘的断层模式和火山结构。海底的火山裂缝和海拔对齐的方向将使用多微光测深。火山对齐将显示恐怖裂谷的区域延伸或剪切方向以及相关的地壳压力的方向。施加的测深和单个通道地震数据将用于记录新骨架断层模式和最近断层的东部限制。 Neotectonic断层模式的描述将证明恐怖裂谷的东边缘是否形成连续的边界，以及裂谷本身是否可以与西北罗斯海中假定的滑雪断层联系在一起。该项目的海底调查结果将与周围火山岛和跨境山脉的运动运动和应力场的确定结合使用。综合结果将测试恐怖裂谷的东部边界通过罗斯海形成的恐怖裂谷的东部边界，这是较晚的，杜鹃的活性结构的极限，而恐怖裂谷运动学涉及与右侧滑环相关的右旋transention。这些结果将有助于限制南极裂谷系统与南方海洋结构以及东南极洲之间的任何相关运动之间的运动学和动态联系。 在第一年，将对现有的多通道和单渠道地震概况以及对恐怖裂痕的航空磁数据进行协作结构分析。将确定火山通风口或裂缝的位置以及任何断层陡峭的疤痕，并将产生对恐怖裂谷变形的年龄和运动学的初步解释。第二年末，在RVIB N.B.进行了为期一个月的巡游。帕尔默（Palmer）将在恐怖裂谷的一部分部分进行多束测深和侧扫形映射。重力，磁性，地震反射和BATHY2000 3.5 kHz子底部轮廓数据也将在整个裂谷中收集。在第三年，我们将使用这些多源数据来绘制火山机构的取向和形式以及与恐怖裂痕相关的新骨架断层的程度和几何形状。该项目将：1）在恐怖裂谷中完成新的神经断层和火山结构的地图； 2）解释结构模式，以得出与裂谷发展相关的运动和压力； 3）将恐怖裂谷的结构与跨二十个山脉映射的断层和谱系进行比较，以改善结构的年龄限制； 4）将西罗斯海的新生代结构解释与南部海洋板边界运动学相结合。