How long did it take to form 30cm of chalk on the South Downs?

Question

We need the answer asap

Answer 1

Subdivision of the Maastrichtian chalk from the Danish North Sea has proven difficult because of its homogenous composition, which is caused by a fairly stable depositional environment; nevertheless, the chalk petrophysical properties show cyclic behavior that potentially can be used for subdivision. Petrophysical properties of a 23 m-long succession of Maastrichtian chalk from the Dan field were examined for cyclicity by spectral analysis. Magnetic susceptibility values measured on plug samples, together with the neutron porosity and natural gamma radiation well-log data, were analyzed both as complete data sets and in subsets to survey the general existence of cycles in the chalk. All three properties contain consistent cycles at approximately 2 m wavelength, as well as additional frequencies where the relative dominance of the different frequencies differs. Cross-spectral analyses of subsets of the petrophysical parameters provide substantial evidence for the coexistence of the approximately 2 m cycles in the Maastrichtian chalk. Furthermore, the magnetic susceptibility carries spectral evidence for a higher frequency because most power spectra of the subsets from the magnetic susceptibility have a spectral peak in the 1.8-2.0 cycles/m interval (i.e., approximately 0.5 m cycle). The cycles can be interpreted as resulting from the eccentricity (94.5 k.y.) and the precession (22.5 k.y.) of the Milankovitch cycles, assuming a SEDIMENTATION RATE OF 2.6 cm/k.y The existence and the understanding of cycles at a submeter scale yield possibilities for an advantageously precise subdivision of chalk reservoirs and correlation between wells.

Answer 2

Between 22,200 to 25,800 years.

It is on the deep ocean floor, well away from land, that the purest calcareous ooze has accumulated which would be regarded as the present-day forerunner to a chalk bed, and reported accumulation rates there range from 1–8cm per 1,000 years for calcareous ooze dominated by foraminifera and 2–10 cm per 1,000 years for oozes dominated by coccoliths.

The chalk beds of southern England are estimated to be around 405 metres (about 1,329 feet) thick and are said to span the complete duration of the so-called Late Cretaceous geological period, estimated by evolutionists to account for between 30 and 35 million years of evolutionary time. A simple calculation reveals that the average rate of chalk accumulation therefore over this time period is between 1.16 and 1.35cm per l,000 years, right at the lower end of today’s accumulation rates quoted above.

Answer 3

Hardly any time at all.
But the answer you get depends on your assumptions

http://www.creationontheweb.com/content/view/1765

Answer 4

Creationist assumptions are almost always incorrect.