Seventy seven surface sediment samples and core samples from the outer Sunda Shelf were analyzed and a number of seismic profiles of the shelf were interpreted. The bottom sediments could be divided into six types: te...Seventy seven surface sediment samples and core samples from the outer Sunda Shelf were analyzed and a number of seismic profiles of the shelf were interpreted. The bottom sediments could be divided into six types: terrigenous sand, biogenic sand, silt sand, clay silt sand, clayey silt and coral reef detritus. Our seismic data showed a thick, prograding Pleistocene deltaic sequence near the shelfbreak and a thin Holocene sedimentary layer on the outer shelf. Eleven thermoluminescence (TL) ages were determined. The oldest relict sediments were derived from Late Pleistocene deposits. Based on sediment types, ages, and origins, five sedimentary areas were identified: area of modern Mekong sediments; insular shelf area receiving modern sediments from small Borneo rivers; shelf area near the Natuna Anambas islands in the southeastern Gulf of Thailand Basin off the Malay Peninsula; area of relict sediments on the outer shelf north of the Natuna Islands, and typical coral reefs and detritus sediments.展开更多
The typical glacial-marine sedimentation has been recorded from core NP93-2 in the Prydz Bay, Antarctica. The sedimentation processes, sedimentary environment and paleoclimate variations since 12937 a B. P. have been ...The typical glacial-marine sedimentation has been recorded from core NP93-2 in the Prydz Bay, Antarctica. The sedimentation processes, sedimentary environment and paleoclimate variations since 12937 a B. P. have been discussed, based on grain size, mineral composition and micropaleontological data, etc.. The climate variation occurred at 10 ha, which expressed that there were increased inputs of terrigenous clastics. The climate change once again but temporarily took place at late Holocene.展开更多
In this paper, authors report some results obtained from systematic rock magnetic measurements on Core NP95 1 and Core NG93 1 , which were collected from the Prydz Bay, Eastern Antarctica and Great Wall Bay (Maxwell...In this paper, authors report some results obtained from systematic rock magnetic measurements on Core NP95 1 and Core NG93 1 , which were collected from the Prydz Bay, Eastern Antarctica and Great Wall Bay (Maxwell Bay), Western Antarctica respectively during the 11th and 9th CHINARE and a sequence of paleoclimate variations is well established based on sediment rock magnetic properties. In Antarctica, the magnetic properties show a close linkage to paleoenvironmental variations. The Core NP95 1 well recorded several paleoclimatic events, such as Heinrich event 1, Bolling Allerod warm period and Younger Dryas cold event. The Heinrich event 1 occurred at about 14 2 ka B.P., Younger Dryas cold event occurred between 11 7 ka B.P. and 10 3 ka B.P., and the boundary of Pleistocene and Holocene in Antarctica is 10 3 ka B.P.. In Holocene, two warm periods were recorded at about 10 0 ka B.P. and 6 0 ka B.P. with a little cold period between them. After 6 0 ka B.P. , two cores both recorded a cold climatic oscillation. Paleoclimate described by two cores rock magnetic measurements was simultaneously changed in Eastern and Western Antarctica during the same period two cores commonly covered.展开更多
文摘Seventy seven surface sediment samples and core samples from the outer Sunda Shelf were analyzed and a number of seismic profiles of the shelf were interpreted. The bottom sediments could be divided into six types: terrigenous sand, biogenic sand, silt sand, clay silt sand, clayey silt and coral reef detritus. Our seismic data showed a thick, prograding Pleistocene deltaic sequence near the shelfbreak and a thin Holocene sedimentary layer on the outer shelf. Eleven thermoluminescence (TL) ages were determined. The oldest relict sediments were derived from Late Pleistocene deposits. Based on sediment types, ages, and origins, five sedimentary areas were identified: area of modern Mekong sediments; insular shelf area receiving modern sediments from small Borneo rivers; shelf area near the Natuna Anambas islands in the southeastern Gulf of Thailand Basin off the Malay Peninsula; area of relict sediments on the outer shelf north of the Natuna Islands, and typical coral reefs and detritus sediments.
文摘The typical glacial-marine sedimentation has been recorded from core NP93-2 in the Prydz Bay, Antarctica. The sedimentation processes, sedimentary environment and paleoclimate variations since 12937 a B. P. have been discussed, based on grain size, mineral composition and micropaleontological data, etc.. The climate variation occurred at 10 ha, which expressed that there were increased inputs of terrigenous clastics. The climate change once again but temporarily took place at late Holocene.
文摘In this paper, authors report some results obtained from systematic rock magnetic measurements on Core NP95 1 and Core NG93 1 , which were collected from the Prydz Bay, Eastern Antarctica and Great Wall Bay (Maxwell Bay), Western Antarctica respectively during the 11th and 9th CHINARE and a sequence of paleoclimate variations is well established based on sediment rock magnetic properties. In Antarctica, the magnetic properties show a close linkage to paleoenvironmental variations. The Core NP95 1 well recorded several paleoclimatic events, such as Heinrich event 1, Bolling Allerod warm period and Younger Dryas cold event. The Heinrich event 1 occurred at about 14 2 ka B.P., Younger Dryas cold event occurred between 11 7 ka B.P. and 10 3 ka B.P., and the boundary of Pleistocene and Holocene in Antarctica is 10 3 ka B.P.. In Holocene, two warm periods were recorded at about 10 0 ka B.P. and 6 0 ka B.P. with a little cold period between them. After 6 0 ka B.P. , two cores both recorded a cold climatic oscillation. Paleoclimate described by two cores rock magnetic measurements was simultaneously changed in Eastern and Western Antarctica during the same period two cores commonly covered.