July 29, 2013

Monday Geology Picture(s): Giant Fossil Clams on Chumbe Island, Zanzibar

Posted by Evelyn Mervine


My husband Jackie, our tour guide, and a giant clam fossil!

Back in June my husband and I went on a week-long vacation to Zanzibar, an archipelago in the Indian Ocean just off the coast of Tanzania. When I told my American friends that I was going on vacation to Zanzibar, they mostly responded, “Wow! That sounds so exotic! Where is that, exactly?” However, when I told my South African friends that I was going on vacation in Zanzibar, many of them responded something along the lines of, “Oh, that’s great! I was there last year.” ┬áThat’s because Zanzibar– along with the Seychelles and Mauritius— is a popular vacation spot for South Africans. These Indian Ocean islands are to South Africans what, perhaps, the Caribbean islands are to Americans; they are tourist hotspots, and many travel companies offer package deals that include flights, hotel, food, tours, and so on. Today, much of Zanzibar’s economy is based on tourism. For our vacation, my husband and I booked a package deal and stayed at the beautiful Azanzi Beach Hotel on the northern side of Ugunja, the largest and most populous island of Zanzibar. We had a fantastic vacation! Our vacation was a great mixture of relaxing on the beach, outdoor activities, and exploring Zanzibar’s rich history and culture.

Over the next few weeks, I’d like to share some of my Zanzibar pictures for my “Monday Geology Picture” posts. I have many great pictures to share– mostly tropical pictures of coral and beaches and such. I’ll start by sharing some pictures from Chumbe Island, a small island located a 45 minute boat ride from Stone Town, which is the main city on Ugunja. Chumbe Island is a privately-owned nature reserve that funds itself largely through eco-tourism. You can stay on the island in one of the eco-friendly huts or you can take a day trip out to the island. My husband and I took a day trip to the island. Our trip included the beautiful boat ride, snorkelling amongst some of the most impressive coral reef I have ever seen, a delicious gourmet lunch, a walk through a forest, and a climb to the top of a lighthouse. We went to Chumbe Island largely because we were hoping to catch sight of the impressive coconut crab, a large, land-based crab that climbs trees and is known to eat coconuts! However, coconut crabs are nocturnal, so we didn’t catch sight of one during our visit. However, we did see plenty of other interesting things on Chumbe Island.

In this post I am sharing some pictures of some giant clam fossils which we saw on Chumbe Island. These fossils are quite impressive! I tried to find a scientific paper that would tell me more about them, but I wasn’t able to find anything with a quick search. If anyone knows of any papers on these fossils or can tell me more about them, please leave a comment below. The Chumbe Island website states that the fossil clams are 15,000 years old.

If you’re ever in Zanzibar, I highly recommend a visit to beautiful Chumbe Island. Staying overnight at the island is a little expensive, but remember that the money goes towards conservation. The day trip also provides a more affordable option. However, next time my husband and I travel to Zanzibar, we plan to spend at least a night on Chumbe Island. Hopefully then we’ll finally see a coconut crab!


Clam fossil with flip-flop for scale.


Clam fossil with lens cap for scale.


A closer view of a clam fossil with lens cap for scale.


Yours truly posing next to one of the clam fossils.


Clam fossil with lens cap for scale.