The variation in paleoclimate during the last deglaciation and Holocene were evaluated based on physical and biological variation in the bottom water oxygen level on the Baja margin in Soledad Basin. Sediment from core OXMZ MV99-PC14 raised from a depth of 540m off the Magdalena Margin of Baja California, Mexico was analyzed for the presence of benthic foraminifera, which are presumed to respond to marine productivity and change in bottom water oxygen. This location is an ideal location to study paleoclimate oscillation and ocean and atmospheric interactions due to its shallow sill depth (290m), high sediment rate (~110cm/kr), sensitivity to El Niño Southern Oscillation (ENSO) and ENSO-like variations. Computed Benthic Foraminiferal Oxygen Index (BFOI) and productivity (DSR-Factor3) variations down core showed enhanced productivity and low oxygen during the Mid Holocene. ENSO-like signals were recorded during the Mid Holocene (4-10 cal BP) when the climate witnessed a cold La Niña-like state. A changing pattern of ocean circulation, depth of thermocline and fluctuations in productivity occurred throughout Holocene in Soledad Basin. This was mainly due to the changing budget of oxygen, created primarily by variations in productivity which had an inverse relationship with oxygen levels. Similar variability was found in low and high latitude paleoclimate records from Chukchi shelf, Cariaco Basin, Santa Barbara basin, Point Conception, and Baja California.

A multiproxy analyses of sediment from a 4.3 m core extracted from 25 m water depth on the shelf of the northern Gulf of Aqaba suggest shifts in depositional environments over the past 4000 yrs. Foraminifera assemblages, grain-size distribution, sediment characterization, and radiocarbon age dating indicate several eco-stratigraphic zones including two periods of aridity from ~3900 to 2900 yr BP and ~1130 yr BP to present, a transitional period from ~2900 to 2500 yr BP, and an abrupt shift to wetter conditions between ~2500 to 1130 yr BP. Furthermore, this study records two foraminifera-barren horizons at 170 and 190 cm that correlate to grain size anomalies at that depth. A tsunami wave generated sometime during 2200-1800 yr BP is one possible explanation for this occurrence. Seismic stratigraphy indicates a reflector at approximately 3 m below the seafloor that delineates the boundary between a relict, coral fringing reef horizon, U8, and the overlying U9 strata. Sedimentation rates that adjust for sediment compaction suggest the sequence lies near the foraminifera-barren horizons at ~200 cm in the core. These data signify a dramatic environmental event possibly corresponding to reef termination on the Northern Gulf of Aqaba shelf.

The last glacial maximum, ca. 21,000 years ago, caused a fall in eustatic sea level of ca. 120 m below present. The low-gradient, shallow Sunda Shelf, Southeast Asia was subaerially exposed during this sea-level lowstand and experienced rising sea level thereafter. Sea level rose to a +1.3––5 m highstand ca. 6,500 cal yr BP, and then fell to modern sea level. The objective of this research is to characterize environmental change on the Sunda Shelf in response to the post-glacial rising eustatic sea level. To address this objective, six gravity cores were collected along a transect crossing the paleo-Chao Phraya incised river valley complex between peninsular Malaysia and southern Vietnam. Thirteen AMS radiocarbon samples, 130 bulk sediment magnetic susceptibility samples (BMS), 66 X-ray fluorescence spectrometry (XRF) samples, and 54 samples for the analysis of foraminiferal assemblages were used to characterize change in the depositional environments of the cored sediments. BMS, XRF, and foraminiferal analysis distinguish two main units. Unit 1 is found in the lower part of the cores and typically contains more terrestrial material than sediments further up-core as shown by higher BMS values, higher % Ti, % Al, % Fe, and lower indicators of marine influence, for example, lower % Ca, % planktonic foraminifera, and percentages of deeper water benthic foraminifera such as Heterolepa dutemplei. Unit 2 is characterized by a significant increase in % Ca, % Heterolepa dutemplei and % planktonic foraminifera ca. 6,500 cal yr BP. Unit 1 is consistent with shallower water depths and is part of a transgressive systems tract (TST, ca. 1 m thick) that terminates ca. 6,500 cal yr BP. Unit 2 represents the overlying highstand systems tract (HST, ca. 1 m thick) and is characterized by an increase in % planktonics, % Ca, and shifts in benthic foraminiferal assemblages, indicating deeper water conditions than the sediments below. This shift from a TST to a HST ca. 6500 cal yr BP is consistent with the Sunda Shelf sea-level record.

This is an important and authoritative review of foraminiferal ecology, the first for over a decade. Professor Murray relates ecological data on living forms of foraminifera to the palaeoecology of fossil species, and defines in detail areas of global distribution.