الفجوة الزرقاء
Sawmill Sink
A fossil-rich inland blue hole on Abaco with a toxic hydrogen sulfide layer and oxygen-free deep water. It is a research site: underwater activity is reported to need a special permit.
Sawmill Sink is a near-circular shaft about 15.5 m across in the pine forest of south-central Great Abaco. Below a fresh-water cap lies a cloudy, hydrogen sulfide-rich mixing layer that blocks daylight, and beneath that is salt water with no oxygen, which is why bones and plants on its rubble cone have survived for thousands of years.
The site is known through scientific diving rather than tourism. Fossil recovery there produced extinct tortoises, dozens of Cuban crocodiles, birds, bats and human remains, studied by a team of Bahamian and US researchers. Because of these finds, published accounts report that any underwater activity requires a special permit, and the sink is inside the South Abaco Blue Holes Conservation Area.
البيئة
Fresh water to about 9.5 m, a hydrogen sulfide-bearing halocline to about 27 m, and anoxic salt water below; a talus cone from about 9 m to 34 m; cave passage continuing south to 54 m.
الظروف
The hydrogen sulfide layer blocks light and is poisonous; National Geographic reported a bacterial layer colouring the water at roughly 9 to 11 m.
نطاقات اعتيادية من مصادر منشورة، لا ظروف آنية.
كل حقيقة في هذه الصفحة مع مصدرها (7)
| حقيقة | الحالة | المصدر |
|---|---|---|
| The opening is nearly circular and up to 15.5 m in diameter. | موثق | [1] |
| Fresh water extends to 9.5 m, a hydrogen sulfide-bearing halocline and mixed zone to 27 m, and anoxic salt water below; a talus cone lies from 9 to 34 m. | موثق | [1] |
| The cave associated with the sink extends more than 600 m south to depths of 54 m.As published in 2007. | موثق | [1] |
| Bacteria colour the water at about 30 to 36 ft (9 to 11 m), and poisonous hydrogen sulfide is present in that layer and the one below.2010 magazine account. | تم الإبلاغ | [3] |
| Any underwater activity at Sawmill Sink requires a special permit because of archaeological discoveries.2019 report; authority not named. | تم الإبلاغ | [2] |
| A special permit is required for any underwater activity.2019 report. | تم الإبلاغ | [2] |
| The sink is in the pinelands of south-central Great Abaco Island.Numeric coordinates withheld: permit-only research site. | موثق | [1] |
موثق: مُصرَّح به من مصدر رسمي أو أولي فتحناه. مُبلَّغ عنه: من مصدر ثانوي فقط. المصادر متضاربة: تتضمن الملاحظة النسختين. قد يكون قديماً: أحدث مصدر وجدناه قديم.
مكتوب بأسلوبنا الخاص من المصادر أعلاه. الإبلاغ عن تصحيح