faqs.org » Abstracts Index » Abstracts » Earth sciences

Penetrative calcretes and their stratigraphic implications: comment and reply

Article Abstract:

The results of outcrop mapping at Cooper Jack Point in the Turks and Caicos Islands negate earlier reports on the modern calcretes which form at the surface of subaerially exposed calcretes. Furthermore, the proposed 'penetrative calcretes' or calcified root mats are not found at multiple horizons but are instead restricted to a single lithostratigraphic unit and located to a maximum of 2 meters below the surficial calcrete. The Reply confirms the earlier conclusions on the calcretes and indicate that the arguments presented are based from inaccurate field observations.

Methods, Natural history, Composition, Geology, Stratigraphic, Stratigraphy, Rocks, Carbonate, Carbonate rocks, Turks and Caicos Islands

---

Stratigraphic classification of ancient lakes: balancing tectonic and climatic controls

Article Abstract:

Lakes and lake deposits are significant sources of biodiversity since studies about them help geologists gain a better understanding of the local terrain Tectonic movements and climate change coequally affect facies associations of lakes, which may be fluvial-lacustrine, fluctuating profundal or evaporative facies. Reseach findings indicate that the balance rates of potential accommodations, which are mostly tectonic, and sediment with water fill, which is mostly a function of climate, predominantly control lake occurrences, distribution and character.

Lakes, Lake sediments

---

Effects of climate and landscape development on the terrestrial phosphorous cycle

Article Abstract:

Landscape developments caused by the changes in the rate of phosphorous weathering during glacial cycles is not fully understood. Phosphorus is a biolimiting agent. Its presence in lake sediment cores suggests possible terrestrial movements during the late Pleistocene period. Phosphorus crystallizes into its mineral form during increased soil and landscape developments. Landscape stabilizations account for the rapid release of solid-phase phosphorus into the earth.

Soil chemistry, Phosphorus, Phosphorus (Chemical element)

Some parts © 2012 Advameg, Inc.