Gasland:
What is the occasion in the movie Gasland?

When Josh Fox receives a $100,000 offer from a natural gas company interested in exploring in his land in Pennsylvania's Delaware River Basin, he decides to do his own research on drilling and the process known as fracking. Josh sets out to interview those who live near drilling sites, and his findings are frightening -- their wells contaminated, residents can actually set their tap water on fire. Visits to sites in Colorado, Wyoming and Texas yield similar horrific findings.

Explanation:

the purpose of the heading in the passage is to identify who is telling the story.

this excerpt is part of the book sugar changed the world (2010) written by marc aronson and marina budhos. as the book has been written by two people, the heading "marc" indicates that this specific excerpt is being narrated by aronson. in the fragment, marc describes his grandfather's story after hearing it from his cousin. however, there are other excerpts where budhos is the one that tells the story of her family.

aronson and budhos, who are husband and wife in real life, decided to write sugar changed the world when they found out how sugar, which had an important role in slavery and economy, changed their ancestors' lives.