Abstract

Whether or not lignite can be formed in a marine environment is the basis of controversy. Four examples suggesting that lignite can be so formed, not only as an admixture to terrigenous sediment, but also as separate thin beds, at least under special conditions, are as follows: 1. Nodales Channel, British Columbia. Poorly sorted mixtures of gravel, sand, silt, and clay contain echinoderm and mollusk remains and terrigenous plant material in water of weak salinity and tidal currents. Burial is rapid. Deposition in this type environment could result in sedimentary rocks interbedded with impure lignites. 2. Chukchi Sea, Alaska. Coal fragments, probably representing resedimentation of detritus from eroded coal beds, and remains of Recent terrigenous plants are found in cores as well as in surface seafloor samples in southeast Chukchi Sea. 3. San Diego region, California. Lignite is common in the lower Eocene Delmar formation and is frequently found in limestone composed principally of pelecypod shells, indicating transportation to final depositional site in water that was at least brackish, 4. La Jolla and Point Loma, California. Cretaceous marine sedimentary rocks contain lignitiferous mudstone. It is not clear whether the lignite was transported to the depositional site as such, or arrived as plant remains which were buried and subsequently lignitized.

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