It must have been difficult for the bride and groom to recognize each other in the dim light of the church. The milky light of late summer could only enter the turf-roofed church through an arched window on the east side and a few openings resembling arrow slits. After the ceremony, the guests fortified themselves with seal meat.
The marriage of the Icelander and the girl from Greenland was one of the last raucous festivals in the far northern Viking colony. It all ended soon afterwards, when the last oil lamps went out in the Nordic settlements in Greenland.
Here’s the key paragraph, IMO:
Although the descendants of the Vikings had adjusted to life in the north, there were limits to their assimilation. “They would have had to live more and more like the Inuit, distancing themselves from their cultural roots,” says Arneborg. “This growing contradiction between identity and reality was apparently what led to their decline.”
Jared Diamond used this in his analysis of failures, although he argued that they refused to take up the Inuit lifestyle when this suggests that they had done so to a large extent. That doesn’t really count as a ‘failure’ in my book, more of a fairly conscious decision to retain their cultural heritage.