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Abstract The Dras 1 Volcanic Formation of the Ladakh Himalaya, India, represents the eastern, upper crustal equivalent of the lower crustal gabbros and mantle peridotites of the Kohistan Arc exposed in Pakistan. Together these form a Cretaceous intraoceanic arc now located within the Indus Suture zone between India and Eurasia. During the Late Cretaceous, the Dras–Kohistan Arc, which was located above a north-dipping subduction zone, collided with the south-facing active margin of Eurasia, resulting in a switch from oceanic to continental arc volcanism. In the present study we analyzed samples from the pre-collisional Dras 1 Volcanic Formation and the postcollisional Kardung Volcanic Formation for a suite of trace elements and Nd isotopes. The Kardung Volcanic Formation shows more pronounced light rare earth element enrichment, higher Th/La and lower ɛNd values compared with the Dras 1 Volcanic Formation. These differences are consistent with an increase in the reworking of the continental crust by sediment subduction through the arc after collision. As little as 20% of the Nd in the Dras 1 Volcanic Formation might be provided by sources such as the Karakoram, while approximately 45% of the Nd in the Kardung Volcanic Formation is from this source. However, even before collision, the Dras–Kohistan Arc shows geochemical evidence for more continental sediment contamination than is seen in modern western Pacific arcs, implying its relative proximity to the Eurasian landmass. Comparison of the lava chemistry in the Dras–Kohistan Arc with that in the forearc turbidites suggests that these sediments are partially postcollisional, Jurutze Formation and not all pre-collisional Nindam Formation. Thus, the Dras–Eurasia collision can be dated as Turonian–Santonian (83.5–93.5 Ma), older than it was previously considered to be, but consistent with radiometric ages from Kohistan. 相似文献
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ROBYN LONGHURST 《New Zealand geographer》1995,51(1):13-15
I discuss the discursive constraints on the participation in sport of 22 Hamilton women who are pregnant for the first time. Most women tended to withdraw from sport especially as they became more visibly pregnant. Their withdrawal can be partly explained using Julia Kristeva's notion of abjection. Pregnant bodies are often considered to be fragile, fearful and ‘inactive’-they are containers for unborn children and are best confined to places and activities where protection for the unborn child can, supposedly, be maximised. 相似文献
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R. LONGHURST 《New Zealand geographer》1994,50(1):14-19
Feminist approaches to geography have become increasingly sophisticated. Reflections on and a vision for feminist geography at the University of Waikato offers an avenue for other geographers to begin thinking through development in their own personal teaching and research agendas and initiatives in their own departments. 相似文献
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ROBYN LONGHURST 《New Zealand geographer》1997,53(2):34-39
This paper is based mainly on the stories of 31 women who were living in Hamilton, Aotearoa/New Zealand between 1992 and 1994 and were pregnant for the first time. The majority of these women claimed that they tended to withdraw from public places (for example, night clubs, bars, pubs, restaurants, cafes) and from public activities (for example, sport, leisure, and paid employment) as their pregnancy progressed. 1 argue that this withdrawal can, at least in part, be linked to a discourse that suggests pregnant women are ‘poverly’ emotional, irrational and frequently forget things. Their bodily and mental ‘difference’ is naturalised through discourse and used to disqualify them from stepping ‘objectively’ and ‘dispassionately’ into the public sphere and engaging in ‘public affairs’. 相似文献
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