La zona lacustre de Banyoles (Girona, España)

Descripció de la zona lacustre de Banyoles des del punt de vista geològic i hidrogeologic

Apatite fission track analytical data for samples from ODP Leg 152

We test a new approach to understanding the tectonic evolution of passive margins by using fission-track analysis on detrital apatites from sediments deposited offshore East Greenland. These apatites have not undergone postdepositional track annealing and therefore reflect provenance. The apatites preserve a component of the source rocks' thermal history that otherwise may not be retained within the present-day outcrop. Fission-track derived denudational histories from samples at Ocean Drilling Program drill sites offshore East Greenland at lat 63°N are compared with data from the onshore Singertat Complex. Previous apatite fission-track studies and geomorphic mapping of the East Greenland coast have shown that locally up to 6 km of denudation may have occurred, implying significant tectonic or magmatic activity starting as much as 30 m.y. after breakup at 56 Ma. In contrast, apatite fission-track data presented here record <2 km of Cenozoic denudation in southeast Greenland, probably driven by magmatic underplating at the time of breakup. Large-magnitude, postrift denudation of East Greenland is restricted to the area around Kangerdlugssuaq (68°N). The timing (<40-50 Ma) and magnitude are in accord with revised plume track models suggesting that the Iceland plume crossed the margin here during the late Eocene.

(Table 1) Average aluminium accumulation rate at 40 DSDP Sites for the time interval 0-10 Ma and relative rates for other time intervals

A six-fold increase in the rate of accumulation of Al in north and central Atlantic and Pacific Ocean sediments indicates vastly increased denudation of the continents during the past 15 Ma. The increase is more apparent in hemipelagic than pelagic sites, demonstrating widely distributed local controls. Similarities in the rate of increase in the Atlantic and Pacific show that tectonic elevation is not responsible for the difference in sedimentation rate. Also, similarities in the difference at sites of low and high latitude suggest that glaciation is not the most significant source. A lack of correspondence between sedimentation rates and Vail's sea-level curve similarly rule out that effect. The conclusion drawn here is that worldwide climatic deterioration during the late Tertiary is the explanation for the striking increase in detrital sedimentation in the World ocean.

Sand resources on the Inner Continental Shelf of the Cape Fear region, North Carolina /

"November 1977."

Beach erosion and accretion at Virginia Beach, Virginia, and vicinity /

"December 1977."

Sand resources on the inner continental shelf of the Cape May region, New Jersey /

"July 1980."

An inexpensive, portable vibracoring system for shallow-water and land application /

"July 1981."

Shoaling rates and related data from Knik Arm near Anchorage, Alaska /

"March 1976."

Sedimentation in the Stony Brook Basin, New Jersey, 1956-59.

"Open-file report."

Water-quality and fluvial-sediment characteristics of selected streams in northeast Kansas /

Mode of access: Internet.

Apparatus for testing the permeability of samples of unconsolidated sediment in the field /

Mode of access: Internet.

Permeability tests by the Thiem method /

Mode of access: Internet.

Update : New Jersey Zinc/Mobil Chemical Superfund Site, DePue, Illinois = U ltimos acontecimientos : Sitio Superfund New Jersey Zinc/Mobil Chemical, Depue, Illinois.

The potentially responsible parties (PRPs) have removed the beaver dams and have collected the sediment samples they need for treatability studies. The treatability studies will establish the correct silt fence to minimize releases of sediment during the actual dredging to occur this fall. The studies will also determine the types and amounts of materials (lime, kiln dust, fly ash, etc.) required to stabilize the sediment, chemically tie up the metals and insure the sediment mixture will bear the weight of the cap on the Interim Storage Cell where the sediment will be placed. The Illinois Environmental Protection Agency (Illinois EPA) anticipates work to be completed by late fall or early winter 2004, if lake and river levels that affect the South Ditch are at their normal seasonal levels.

A Review of surface-water sediment fractions and their interactions with presistent manmade organic compounds /

Mode of access: Internet.

Sedimentation survey of Lago Dos Bocas, Puerto Rico, August 1994 /

Mode of access: Internet.