Table 1: Station data for the entire survey, including coordinates and description of BPBASE

During GANOVEX VI new gravity data were collected along an east-west profile in North Victoria Land south of the Drygalski Ice Tongue, extending 150 km across the Transantarctic Mountains, and comprising 21 data points. Thirty five additional data points were collected over a small area near Brimstone Peak, near the western end of the regional profile. The survey south of the Drygalski has been connected to northern gravity data (GANOVEX V) by a survey line of 12 points. All data have been terrain corrected, and are further constrained by satellite elevation (GPS) and radar ice-thickness measurements. A pronounced regional Bouguer gravity gradient decreasing to the west by approximately 3 mgal/km is superimposed over a coast-parallel belt of granitoid basement rock. West of this belt the local gravity fields become mote variable. Over Beta Peak (Ferrar dolerite) a 50 mgal spike is obser- ved. Within this area, the Ferrar sills are exposed at the surface. West of Brimstone Peak (Ferrar/Kirk patrick sequences), a smooth regional gradient appears to reassert itself. We interpret the initial gradient east (oceanward) of the break-in-slope to be representative of the crust/mantle boundary within the study area. We interpret the initial break-in-slope and the apparent flattening of the regional gradient to be an effect of the N-S trending zone of dense Ferrar sills and associated deep crusttil fractionate replacing less dense basement. We attribute the variability of the local field to be the product of sub-glacial density contrasts that cannot be removed. The regional gravity gradient of the profile is steeper than that observed to the north (Mt. Melbourne quadrangle) and shallower than that reported to the south (McMurdo Sound). The absolute values of the coastal points of origin south of the Drygalski and within the Mt. Melbourne quadrangle differ by 60 to 100 mgal. In addition, topographic relief within the regional transect area is subdued relative to the Transantarctic Mountains to the north and south. We speculate that the root structure of the Transantarctic Mountains undergoes a change somewhere between the Mt. Melbourne quadrangle and the region south of the Drygalski Ice Tongue.

在南极重力勘探第六次科考（GANOVEX VI）期间，科研人员于德格尔斯基冰舌（Drygalski Ice Tongue）以南的北维多利亚地（North Victoria Land）沿东西向剖面采集了新的重力数据，该剖面横跨横贯南极山脉（Transantarctic Mountains），延伸150 km，共包含21个数据测点。此外，在区域剖面西端附近的硫磺峰（Brimstone Peak）周边小区域内，额外采集了35个数据测点。本次德格尔斯基冰舌以南的测量工作，通过一条含12个测点的测线，与南极重力勘探第五次科考（GANOVEX V）获取的北部重力数据实现了衔接。所有数据均已完成地形校正，并辅以卫星高程（GPS）与雷达冰厚测量数据进行约束。一条显著的区域布格重力梯度（Bouguer gravity gradient）以约3毫伽（mgal）每千米的速率向西递减，该梯度叠加于一条与海岸平行的花岗岩质基底岩带之上。该岩带以西的局部重力场变得更为复杂多变。在贝塔峰（Beta Peak，出露费拉辉绿岩（Ferrar dolerite））区域，观测到了幅值达50毫伽的重力异常尖峰。该区域内，费拉岩床（Ferrar sills）裸露于地表。硫磺峰以西（对应费拉/柯克帕特里克地层序列），平滑的区域重力梯度似乎重新显现。我们认为，坡折带（break-in-slope）以东（朝向海洋方向）的初始重力梯度，代表了研究区域内的壳幔边界。我们将坡折带与区域梯度的明显平缓现象，归因于近南北向展布的高密度费拉岩床及相关深部地壳分异体替换了低密度基底的结果。我们将局部重力场的变化性，归因于无法移除的冰下密度差异所致。本次剖面的区域重力梯度比北部墨尔本山图幅（Mt. Melbourne quadrangle）观测到的更陡，却比南部麦克默多湾（McMurdo Sound）区域报道的更平缓。德格尔斯基冰舌以南与墨尔本山图幅内的海岸原点测点的绝对重力值相差60至100毫伽。此外，相较于南北两侧的横贯南极山脉，本次区域剖面区域内的地形起伏较为平缓。我们推测，横贯南极山脉的山根结构，在墨尔本山图幅与德格尔斯基冰舌以南区域之间存在变化。