Maastrichtian Depositional Systems in the Sacramento and San Joaquin Basins
Victor B. Cherven, 1984. "Maastrichtian Depositional Systems in the Sacramento and San Joaquin Basins", 1984 Midyear Meeting San Jose, California, Ralph E. Hunter, H. Edward Clifton, N. Timothy Hall, John L. Chin
Download citation file:
The continuous southern Sacramento-northern San Joaquin Basin shoaled from minus 1000 m to sea level during deposition of 2 km of deltaic, slope, and submarine fan deposits during the Maastrichtian Epoch of theLate Cretaceous Period. Basin filling was accomplished by a combination of 1) progradation of sandy deltas and muddy slopes, and 2) aggradation of mostly sandy submarine fans. The basin filled from north to south as fluvial systems flowing southwest out of the Sierra Nevada built a deltaic complex that prograded more rapidly in the Sacramento Basin, filling it before more stable deltas to the south could fill the San Joaquin Basin. As the Sacramento Basin became filled, the fluvial-deltaic systems turned more southerly and prograded into the San Joaquin Basin.
Deltaic systems consist of 1) prodelta shale, 2) upward-coarsening delta-fron sandstone, 3) delta-plain carbonaceous shale and lignite and upward-fining distributary-channel sandstone, and 4) very fine-grained (transgressive) shelf shale. Slope systems consist of 1) hemipelagic shale, 2) massive to upward-fining slope-channel sandstone, and 3) slump deposits. Submarinefan systams consist of 1) thick-bedded, upward-fining upper-fan-channel sandstone, 2) medium-to thick-bedded, massive- to upward-fining middle-fan sandstone and shale in discrete packets separated bby thin shale beds, and 3) thin- to medium-bedded, lower-fan fine-grained sandstone and shale in discrete packets separated by shale.