Coal Petrologic Investigation of Tropical and Subtropical Peats

本研究的目的是研究位于加勒比海/南太平洋的几种对比性热带和亚热带泥炭矿床的岩石学和孢粉学特征、地表形成过程和早期煤化阶段。佛罗里达地区。本研究是美国国家科学基金会先前支持的工作的延续，重点是在某些地点进行新的和/或后续研究，以及在先前工作过程中开发的某些有前途的新分析技术（如人工煤化实验）。选择了3个热带和1个亚热带成煤环境进行研究：1)哥斯达黎加的Moin沿海棕榈沼泽；2)巴拿马的Changuinola沼泽-沼泽复合体；3)波多黎各的阿雷西博锯草红树林沼泽；4)佛罗里达的大沼泽地-红树林沼泽-沼泽复合体。虽然所有这些环境都有相似之处，但每一种环境都表现出一个或多个显著的不同之处，之所以选择这些环境，是因为它们有望产生新的和重要的信息，用于解释和预测文献中报道的在热带海岸线相关环境中形成的许多古代煤炭的成分和几何形状。由于前一笔赠款的重点是巴拿马和哥斯达黎加的矿藏，因此这项提议更加强调阿雷西博和埃弗格莱兹的矿藏。本研究将采用的方法包括：1)实地测量pH值、盐度和其他地表条件；2)泥炭序列的野外描述；3)地表凋落物和地表样品的收集；4)导向活塞芯集合；5)切片机薄片的透射、反射和荧光显微镜；6)低温灰化和x射线衍射评价矿物学含量；7)结合放射性碳测年对地表和地下样品进行花粉分析，以解释矿床的古生态和发育历史。

The purpose of this research is to investigate the petrographic and palynologic characteristics, surficial processes of formation, and early stages of coalification of several contrasting tropical and subtropical peat deposits located in the Caribbean/S. Florida region. This research represents a continuation of work previously supported by NSF, with emphasis on new and/or follow-up studies of certain sites and on certain promising new analytical techniques developed during the course of the previous work (such as, artificial coalification experiments). Three tropical and one subtropical coal-forming settings have been selected for study :1) the Moin coastal, palm swamp of Costa Rica; 2) the Changuinola swamp-marsh complex of Panama; 3) the Arecibo sawgrass-mangrove swamp of Puerto Rico; and 4) the Everglades-mangrove swamp-marsh complex of Florida. Although all of these settings have similarities, each exhibits one or more significant differences from the others and was selected because it is expected to yield new and essential information with which to interpret and predict the composition and geometry of the many ancient coals that have been reported in the literature to have formed in tropical shoreline-related settings. Since the focus of the previous grant was on the deposits in Panama and Costa Rica, this proposal puts more emphasis on the Arecibo and Everglades deposits. The methodology to be employed in this study will include: 1) field measurements of pH, salinity and other surface conditions; 2) field descriptions of peat sequences: 3) collection of surface litter and surface samples; 4) collection of oriented piston cores; 5) transmitted, reflected, and fluorescent light microscopy from microtome thin sections; 6) low temperature ashing and x-ray diffraction for assessment of mineralogic content; and 7) pollen analysis of surface and subsurface samples combined with radiocarbon dating, for interpreting the paleoecological and developmental history of the deposits.